The View Up Here

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Archive for the ‘Photography’ Category

Friggin’ Cable Releases

Posted by Tom Benedict on 24/03/2015

A year or so ago I bought a remote cable release for my camera. I wanted something that would do time lapse, long exposures, delayed exposures, you name it. Turns out there are scads of these things out there. They all seem to use the same basic electronics. The difference mostly lay in the packaging and form factor. So I picked one, used it, and got a lot of good use out of it.

In my post about batteries I mentioned that I managed to kill my cable release by letting the alkaline batteries I’d put in it go stale. And leaky. And corrosive. And… >deep breath< Whew! Let the past be the past.

Wireless Timer Release

Anyway, while shopping for a new one I saw that Yongnuo had a wireless version for not too much money. I picked one up off of Ebay, tested it, verified that it worked, and… promptly had it fail when I took it out in the field. It would focus on a half-press, but wouldn’t trip the shutter on a full-press. The weird thing is the display said “Release”, so I knew the switch was good. But it wouldn’t actually do anything.

The wireless release comes as two components: a handheld transmitter with a display, button pad, shutter button, etc., and a receiver that you stick on the camera. The receiver doubles as a cable release, complete with a shutter button of its own. When I tested it it worked perfectly! So I wasn’t entirely dead in the water. Just mostly.

The Yongnuo MC-36R also allows for a cable to be used instead of the wireless connection. Today I made a cable using some spare 1/8″ stereo headphone plugs and some spare wire I’d salvaged from a dead sensor at work. I built the cable, plugged it in, and… had the same exact behavior! Half-press would focus the camera, but the full-press did nothing!

Digital devices are usually pretty self-contained. Except for witnessing the battery-driven demise of electronics, there’s typically very little you can do to salvage something that has stopped working. But this was sounding a lot less like a logic fault in some chip and a lot more like a failed connection. So I opened the unit up.

The MC-36R has two circuit boards inside. One houses the LCD, buttons, and processor. The other houses the 2.4GHz transmitter, the channel-selecting DIP switch bank, and the 1/8″ stereo jack for the optional cable. I expected the connection between the two to be some sort of three-wire UART. Instead I found Vcc, Gnd, 1, and 2, and the #2 wire had popped out of the connector. ??! Each state of the switch had its own discrete wire! I shoved the wire back in and everything worked perfectly!

When I put the thing back together I saw what the underlying problem was. There’s almost no room inside the thing. The connector for the 2.4GHz board bumps up against the big honking half/full press switch for the shutter. So if one of the wires is even slightly out of place when the unit is assembled it’ll get pulled out of the connector. In my case the #2 wire was the one who lost. A little care during re-assembly and I avoided the problem.

I have to wonder how many of these things fail during QC testing. I wonder how many more are eventually returned when they quit working. In the event mine dies again I can replace the connector with a new one. It’s a 4-conductor micro-JST. I have a bag of them. Meanwhile I’m back up and running. And now I have a cable I can use, too.

– Tom

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Posted in Electronics, Engineering, Photography | Tagged: , , , , , , , , | Leave a Comment »

Bend a Little and Have Fun

Posted by Tom Benedict on 14/03/2015

Years ago I joined a group called Utata – a group of photographers, writers, and like-minded folks who enjoy lively discussion and creating and promoting art. Utata has several ongoing projects as well as two big annual projects. At the time I joined I was almost exclusively doing aerial photography from a kite, so I found myself unable – or to be truthful, unwilling – to participate in many of the projects. One in particular, the Iron Photographer, routinely kicked my butt.

The Iron Photographer project is modeled along the same lines as Iron Chef: All of the participants are given the same three elements to work with – two compositional and one artistic or calling for a specific technique – and are asked to create new, original works. On the face of it it’s a welcome challenge for any photographer. But if you’re limiting yourself to creating only aerial landscapes it’s less of a challenge and more of an impossibility. Take, for example Iron Photographer 211. The elements were: 1 – a bowl; 2 – something broken; 3 – photographed simply. You can make an aerial photograph that would qualify, but it would be a mighty tall order. I quickly became frustrated and stopped participating.

The lesson I didn’t learn back then was this: bend a little. The whole idea of Iron Photographer is to knock people out of their comfort zone and get them to put their thinking caps on. I staunchly refused and missed out on a lot of opportunities to have fun with a camera.

After a three year dry-ish spell I’m finally starting to get back into photography. This time not all of it is aerial. I figured I’d give Iron Photographer another try. I started with IP 212. The elements are: 1 – the photographer’s hand resting on a flat surface; 2 – an object resting in the palm of the hand; 3 – holga-fied. The only element I needed clarification on was that third one. The idea is to make it look as if the photograph came out of a Holga camera. I don’t own one, so I downloaded Holgarizer – a Photoshop action that would produce a similar result.

The Iron Photographer projects make you think. Yeah, I could’ve done a set of photos of my hand on a table with various objects in it. But where’s the fun in that? Better to ask why my hand is lying on a flat surface. Which flat surface is it lying on? What is sitting in my palm? And who chose to make the photograph? Of course for the requirements of the project it must be the owner of the hand. But from the standpoint of the narrative all of these are open-ended questions.

The first idea that sprang to mind felt cliché even before I made the photograph, but I made it anyway.

As Found

It’s not a happy picture. I wanted it to look like a crime scene: a dingy floor, the weak greenish glow of fluorescent lights, a pallid cast to the skin, and stark shadows outlining someone’s final act. In fact I’d just scrubbed the floor clean so I wouldn’t contaminate my prescription medication. The lighting was all provided by daylight-balanced strobes. And I’m actually pretty tan at the moment. But who’s keeping tabs? The only really stressful moment came when I started to clean up and realized I’d misplaced one of my pills. As tiny as these things are, they’d be lethal to my cats. I spent the time to track down every single one.

Then, of course, I saw that another participant in IP212 had come up with the same idea. Darn!

That’s when I started to wonder: Did the owner of the hand have to be the one who put the object in it? When I figured out the answer was “no” the idea for the next photograph came to mind. I opened the door to my daughter’s room and said, “Wanna be a totalitarian? Grab your boots!”

Of all of the events that mark the passing from childhood to adulthood, one my daughter celebrated with no small amount of gusto was the successful completion of her last high school PE class. She proudly announced that her only reason for wearing tennis shoes to school was null and void, and that she wanted combat boots. She and Rydra picked out a pair that would make any real princess proud.

“Ok,” I told her. “I’m gonna lie down on the ground outside, and you’re going to stand on me.”

Stunned silence. “What?!”

Even I had to admit she had a point. But once I described the photo to her she got into the swing of things.

The Regime

It took a while to work out the balance of the lights. Then it took a while to work out the best angle for my arm. Then it took a while for us to work out how she had to stand so it looked like she was bringing all her weight to bear on me without actually crushing my hand under her heel. In the end she wound up with one boot on and one boot off, standing en pointe on one sock-covered foot while squishing my hand with her booted heel. Early on she was tripping the shutter, but the contortions she was having to go through were more painful than what she was doing to my hand. We switched to a self-timer for the final few frames.

Though the Iron Photographer project lets you tag up to six photos for submission, you’re only really supposed to post one to the discussion forum. I chose this one. This becomes important later.

I had a couple of other ideas I wanted to try, but by this time I realized my first two photos were real downers. Despite the smiles and the laughter and the fun my daughter and I had making The Regime, I knew that no one looking at it would feel anywhere near as upbeat as we did. So I set morbid aside and went after something different.

The challenge called for something to be in the palm of the hand. It didn’t say that it had to be a physical object, just that something had to be there. I thought it would be neat to put something less tangible than a physical object in my hand. “I know!” I thought, “Light!”

I went through a couple of iterations on this one: I could have a beam of light coming out of my hand. (I might still try that one at some point, but not as part of this IP.) I could make the palm of my hand glow. The idea I finally settled on was to have an object in my hand influence light rather than generate it: a prism.

Years ago I worked in a lab that etched diffraction gratings into silicon using MEMS techniques. It was kind of a one man show, so I was responsible for the photolithography, the anisotropic etching setup, maintaining the safety and materials in the lab, characterizing the gratings we were making, etc. I also photographed the bejeebers out of everything we did on color transparency film. To see how much power went into each order of the gratings we were making we aimed lasers at them and measured the power in each of the return beams. It was an important step in characterizing the gratings. But it made for an even better photograph.

Each photograph was done as a single long-exposure frame. I’d turn off all the lights in the room, open the shutter, “paint” out the beams using a business card or some other flat white object (my hand stood in a couple of times), then turn on the lights for the prescribed amount of time and close the shutter. As painstaking as it sounds, once you got into a routine it went pretty quickly.

I used the same technique with the prism.

Can We Get There By Laser Light?

Even having used the technique, it took awhile to work out the details for this photo. Initially I illuminated the prism from the side. But the human palm isn’t all that flat. The prism kept rolling toward my fingers, directing the outgoing beam into the table or some other part of my hand. And painting a beam that’s going toward the camera is tough if you’re using a business card. The camera’s looking at the back side of the card! Eventually I figured out I should place the laser under the camera, and aim it back toward my hand. This gave me a way to see how well aligned the prism was to the beam: put the reflected light back into the laser’s aperture. It also made painting the foreground beam a lot easier since the camera could see the illuminated side of the card.

The difficulty was the outgoing beam. No matter what I did, the prism moved around in time with my heartbeat. You can see it as tiny wiggles in the painted beam. I could’ve Photoshopped that out, but where’s the fun in that?

Since that’s my own hand there on the table, I really didn’t have the option of turning on the room lights at the requisite time. Instead I set up a single strobe and a shoot-through umbrella up and to camera right. I kept the wireless transmitter handy on the table. Once I’d painted the beam I triggered the strobe and closed the shutter. It worked like a charm.

For my last IP212 photo I wanted to make something of a visual pun. The two compositional elements were a hand resting on a flat surface and an object resting in the hand. What if the object in the hand was a flat surface? In keeping with the whole optics theme I considered using a mirror, but honestly that’s kind of a boring photo. Besides, I’d already touched on the optics side of what I do for a living. I wanted to touch on the mechanical side, too. What if the flat object in the hand was being made into a flat object? Milling machine!

Hand Work

Before getting into the hows and whys of this I need to point out that I take shop safety very seriously. At no point did I do anything that put my hand or my tooling at risk. The only way to pull that off was to do this as two separate frames – one with the spindle moving and one with it stopped – and combine them.

I milled five of the six sides of this block using the 1″ cutter shown chucked in the mill. I milled the last side halfway, then stopped. Lighting was pretty straightforward: an umbrella in front and to the right, and a stofen bounced off the white wall behind the mill to provide speculars on the block and vise. I brought the spindle down until it was pressing the block into my hand, and made the first exposure. I wanted some motion blur out of the cutter, so I made a second exposure using ambient light, rotating the spindle by hand from above. Once I’d balanced the light between the two in Lightroom, I brought both frames into Photoshop for layering.

While going through the lighting for this a number of other photographs came to mind that didn’t fit into the IP212 requirements, but that nonetheless would make for pleasing photographs of machine work in progress. And that, to me, is the real benefit of taking on Utata projects like the Iron Photographer: The final result isn’t the photographs made for the project. It’s the ideas that the process of thinking through those photographs leaves you with. That’s what I missed out when I joined Utata years ago. I don’t plan on missing out on it again.

To my utter delight, Greg, the moderator who sets up the Iron Photographer challenges, favorited The Regime and wrote a really thoughtful comment on it. This is the first time one of the Utata moderators commented on one of my photos. Even more delightful, Debra Broughton wrote a short piece about it for the front page of the Utata web site and wrote a comment of her own. I admit I banged my forehead on my desk a little at my obtuseness for taking this long to jump into Utata projects with both feet. But thanks to Greg and Debra I did it with a smile.

– Tom

Posted in Machining, Photography | Tagged: , , , , , , , , , , , , , | 2 Comments »

Batteries for Photography

Posted by Tom Benedict on 14/03/2015

I’ve been told by more than one photographer over the years that for gear that uses AA or AAA batteries, alkalines are best. “Put a fresh set in at the beginning of the day and you’re good to go.” I swear if I hear this from one more person, I’m going to throw up.

I… Hate… Alkalines…

Alkaline batteries have an inherent shelf life. When they reach the end of that shelf life they like to do violent, nasty things. If they’re still installed in a piece of equipment when that time comes, it’s usually the piece of equipment that pays the ultimate price. I’ll give you three examples:

About a year ago I needed to use a light meter. (Yeah, an honest to goodness light meter!) We have a really nice Minolta meter at work, so I borrowed it. I got to where I was planning to do the photography only to find out it didn’t work. So I opened up the battery tray. UGH! You guessed it: battery innards were everywhere. I took it home, pulled it apart, and found that the acid hadn’t attacked the electronics, but it had gotten inside the wires from the battery tray, and had eaten down inside the insulation. I cleaned it out, bead blasted the battery terminals, and soldered in new battery wires. The meter was back in business, but my frustration with alkalines only grew.

Back in December I used the Canon 5D at work to photograph the damage to some of the optics in one of our instruments. (Our current working suspicion is that battery acid played a role in the damage to the optics. Hmmmm!) I grabbed the ring flash that’s stored in the case with the 5D only to find it wouldn’t power up. No problem, I thought, I’ll replace the batteries! I opened the battery compartment to find battery goo had oozed all over the place. I cleaned it out as best I could, but didn’t even bother to take it apart. I gave up on the idea of using the ring flash and used my own Speedlites instead.

A couple of weeks ago I went down to the beach to do some long duration sunset photos. I pulled out my timer release, tried to set it up to do some five minute exposures, but couldn’t get half the buttons on the thing to work. I set the timer release aside until I could take a better look at it and did what I could with 30 second exposures, but none of the frames I exposed really looked right. Earlier today I opened it up only to find the batteries had blown their goo all over the inside, and had eaten the ground plane out of the circuit board, taking half the buttons along with it. I chucked it in the can and ordered another one.

So what’s a photographer to use if not alkalines? My favorite so far are nickel metal hydrides – NiMH. They’re rechargeable, they’re durable, they hold charge well, and when they finally die they die quietly. They don’t take stuff with them the way alkalines do. When I get home after a day out with my cameras, I pop out all the batteries, stick them in chargers, and load my pictures onto the computer. By the time I’m done editing, the batteries are done charging. Back in they go, ready for the next day. In all the years I’ve been using NiMH batteries, I’ve never seen one destroy a piece of equipment. Not once.

When my new timer release shows up I’m replacing whatever batteries that come with it with a nice pair of Eneloop NiMH batteries. No more alkalines in my camera bag! EVER!

– Tom

Posted in Photography | Tagged: , , , , | 1 Comment »

A Tale of Three Portraits (and Two Lights)

Posted by Tom Benedict on 23/02/2015

When you have a hammer, everything starts to look like a nail. Then when you add a screwdriver, you want to add a hacksaw, too, so you can cut slots in the tops of all your nails and use the screwdriver instead. Adding photography gear to the bag is a lot like getting another tool for the shop. Yeah, there’s always another way to do it, but you want to play with the new tool!

A couple of weeks ago the outreach coordinator at the place where I work mentioned an astronomy fashion blog she had run across. That put her in mind of a shirt I own, so she contacted the writers of the blog and asked if she could send them a picture. One thing led to another, and I wound up with my first portrait assignment: a fancy selfie of me and my shirt.

I wanted to wait for my backdrops to arrive before tackling the t-shirt shot, but I also didn’t want to waste anyone’s time once they arrived. So I went into work one weekend to try out a couple of lighting setups. I found one I figured would work for the t-shirt shot, but I also played with some more dramatic lighting.

The Forbes Shot

This was a cross between the classic Peter Norton crossed-arms and rolled-up shirtsleeves and any of a number of financial magazine covers I’ve seen over the years. Even as I was setting up the lighting I thought, “This is the Forbes shot!” It’s a 42″ shoot-through umbrella directly above my head and slightly forward, just out of frame, with a second light behind me with a stofen to provide hair light. The toughest part of this was figuring out how to attach a flash to the magazine rack at my back. Once that problem was solved, though, the whole thing came together well.

Later that day when I picked my kids up from the park my son said, “We’re using shadow magic and fire magic to make warriors in our game!” I replied, “I’m using light magic to make myself look cooler than I am in real life!” Neither of them believed me until I showed them this frame. “You’re right! That looks a lot cooler than you are in real life!” Which just goes to show that sometimes it’s better to keep your trap shut around your kids.

About a week later backdrops arrived, and I set up the t-shirt shot the following week. Our outreach coordinator wanted one of the posters from our wide field imager in the background, so I suspended a framed print from the ceiling with my black muslin backdrop behind it. The black frame on the poster and the black Dacron kite line I used to suspend it from the ceiling all made the later editing a snap.

Wallace and Gromit Teeth

The setup for this one is a little more straightforward. It’s a 42″ shoot-through 45 degrees camera left, aiming down, with a 42″ silver umbrella 45 degrees camera right, aiming down, to provide fill. I wish I’d had a second shoot-through for the fill, and a third light for hair light, but you use what you have. I’m not 100% happy with the lighting on my face, but the background worked out really well. Unfortunately I did this about twenty minutes before an all-staff meeting, so things were a little rushed. I  wish I’d taken more time to work out the lighting, but c’est la vie.

When I posted this to Flickr it occurred to me that my teeth look like the teeth in a Wallace & Gromit film. I’ve since been assured by a fellow photographer and KAPer that this really is what I look like.

A couple of days later I remembered I had a third portrait I needed to do. This time it wasn’t one of me (yay!) Rydra had been wanting a new avatar photo to use online. I’ve done a couple of them for her in the past, most using selective color on some part of the image. She wanted another selective color photo, this time showing off a piece of jewelry she made: an ear cuff. We talked through how she wanted the photo to look, then pulled out the gear.

Initially I set things up with a main and a hair light, but the ear cuff looked too muted. Since that was one of the major elements in the shot, it had to be better lit. With some misgivings I pulled the hair light and re-positioned it next to the camera with a stofen to pick up catch lights in the metal of the ear cuff without providing too much fill. That worked, and gave Rydra the shot she wanted. But I found myself wishing I had a third light to separate her hair from the background the way I did in the Forbes shot.

Rydra 2015-02-22
Post-processing was pretty straightforward. I pulled the red channel to use as the base B&W image. That washed out her mouth a little too much, so I used the green channel for just that part of the photo. Both of these layers were masked to let the color of the stone on the ear cuff show through. I had to bump the saturation a little to let the color of the stone really show, but it didn’t take much.

Rydra loved the new avatar picture, and put it into service the minute she got it. She’s usually super critical of any photos I make of her, so I took this as a win.

The more I use my new lighting gear, the more I like it. And no, not everything is a nail with a screwdriver slot cut in the head. But I think I need to add a third light so I can have a dedicated hair light when I need it. And maybe a fourth so I can gel a white background next time. Dammit! Where’s that hacksaw?!

– Tom

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What Does “Group f.64” Mean Today?

Posted by Tom Benedict on 18/02/2015

Group f.64 was a group of seven San Francisco photographers who shared a similar approach to photography: well-framed photos with tack-sharp focus and lots of depth of field. Their style of photography was a distinct break from that of the Pictorialists, the dominant style in the late 1800’s and early 1900’s  that favored a more painterly look of soft focus, darkroom manipulation, and toned prints. Ansel Adams, one of the founders of Group f.64, referred to the Pictorialists as the “fuzzy wuzzies” because of their deliberate choice of soft lenses and relaxed approach to the technical aspects of their photography. His starkly beautiful black and white photography of the American Southwest was a strong departure from the work of the Pictorialists, and typifies the work done by Group f.64.

When I got into large format photography years ago, I read several of Ansel Adams’s books and read his take on the whole Pictorialist vs. Group f.64 debate. I was a fan of Ansel Adams’s photography long before getting into it myself, so I set myself on the path blazed by Group f.64. The only problem was that none of my 35mm lenses went to f/64. So I spent more and more time with my 4×5 view camera, and marveled more and more at the negatives coming out of the trays in the darkroom.

Which was great until I made the switch to digital. Oh I still have all my 4×5 gear, including several boxes of film I hope I can replenish when they run out. But 99.999% of my photography is now made using digital cameras. That takes me back to the question about my 35mm lenses. Why didn’t any of them go to f/64?

Setting aside the aesthetics of the debate of Pictorialist vs. Group f.64 (which was really the whole point, if you think about it), I wanted to see what it would take to make a photograph that, from a technical aspect at least, fit in with the Group f.64 manifesto. (That’s just a fancy way of saying I spent the better part of the afternoon playing around with an online depth of field calculator.)

To do this exercise it’s important to note a couple of things: First, I’m comparing cameras of different sizes. To make this comparison I assumed each would use the appropriate “normal” lens for that camera (typically a lens with a focal length about the diagonal size of the film / detector being used). Second, depth of field depends on the actual focal length of the lens, not what the 35mm equivalent of that lens is. This is important to remember when comparing cameras smaller than an APS-C DSLR. Finally, I’m taking the DOF calculator at face value. I personally disagree that the extents of what most DOF calculators call “sharp” are actually sharp by modern standards, but that’s a discussion for another time.

Let’s play!

The members of Group f.64 all used large format view cameras. Most typical at the time was the 8×10 glass plate camera. A normal lens for an 8×10 is generally accepted to have a focal length around 300mm. When focused to about 10′ at f/64 this gives a range of usable focus between 7.2′ and 16.4′, or about 9.2′ of DOF.

Despite the diagonal of a 35mm negative being about 43mm, the accepted normal lens for a 35mm camera is the tried and true 50mm lens. To get a depth of field comparable to that of a 300mm lens at f/64, a 35mm camera with a 50mm lens focused to about 10′ would need to be stopped down to f/11 to achieve a similar DOF (7.1′ to 16.9′, or about 9.8′ DOF). So that answers my question about why my 35mm lenses didn’t go down to f/64. To achieve the same depth of field as Ansel Adams or Imogen Cunningham I only needed to stop my lenses down to f/11!

My APS-C DSLR has a detector that’s 0.625 times the size of a full-frame detector (or to put it another way, a full-frame detector is 1.6 times the size of my APS-C detector). Going through the math, a lens with about the same field of view as that 50mm on the 35mm camera used above would have a 35mm focal length. Focused to 10′ I would need to use an aperture of f/9.0 to get a DOF similar to the 300mm at f/64 on the glass plate camera (7.0′ to 17.2′, or about 10.2′ DOF). This is interesting to note because the 18-55mm kit lens that came with this camera has a sweet spot around f/8.0 at which it delivers remarkably sharp images. Not too far off from that f/9.0 figure!

Just for grins I decided to run the numbers for my Canon Powershot A650 IS. Rather than run the numbers for a “normal” lens (10.3mm in this case) I ran the numbers for the widest focal length available: 7.2mm (35mm equivalent of a 35mm lens). Since the apertures on the A650 IS are limited, I ran the numbers with the lens wide open at f/2.8. Focused at 10′ I got a usable DOF of 5.15′ to 173.3′ or about 168.2′ total DOF (aka “a crapload”). And that’s wide open!

The moral to this story? Want to do photography in the Pictorialist style? Don’t use a compact camera! (Ansel would be so proud of me.)

Of course there’s more to the story than this. Group f.64 took a stance against soft lenses and soft focus. But more than that they took a stance against photomanipulation in favor of what they considered straight photography. (And you thought that debate started with Photoshop!) I hope photography has matured enough as an art form that we can have both in the same room without anyone coming to blows.

– Tom

P.S. Naaaaaah!

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Life with an Amputee Cat

Posted by Tom Benedict on 17/02/2015

Ember Sleeping - Close-Up

Several years ago one of my cats, Ember, lost a leg to a car. It was a long, drawn-out process during which we and his vet tried to save his leg and give him back the life he had before the accident. In the end Ember persuaded us all that he’d be better off without it. Rydra and I took him in, and his vet performed the amputation. His road to recovery was lightning fast compared to the hell we’d already put him through. Within days he was running, jumping, meowing…

Ember Sleeping - Low Angle View

And sleeping… just like a cat.

The weekend before the amputation Rydra had me scouring the web for stories from people whose cats had also had legs amputated. We both knew what we had to do, but she wanted me to be comfortable with the decision. I found some Youtube videos and a couple of forum posts, but not much more than that. Now I’m doing my part so that other pet owners who find themselves in the situation I was in will have a little more information to draw from.

Ember’s case is complicated because the accident caused nerve damage and damage to his urinary tract as well as the shattered femur. His bladder and urethra were both ruptured. His vet was able to stitch his bladder closed, but she couldn’t reach his urethra, buried down inside his pelvis. Instead she inserted a catheter and used it as a mandrel over which he could rebuild his urethra on his own. When she removed the catheter a week later we all breathed a huge sigh of relief that the operation had worked. If his urethra hadn’t healed, he would’ve died.

The combination of the injury to his urinary tract and the nerve damage he suffered has some longer-term implications. He refuses to drink water, so we have him on a special diet of wet food that provides the water he needs. The nerve damage makes it hard for him to have bowel movements, so that, combined with his tendency to under-consume water is a recipe for constipation – a life-threatening situation if not treated. His vet prescribed him a laxative and a combination laxative and stool-softener, which we give to him twice a day. Even with the diet and the medication he sometimes needs enemas to reset the works, so to speak, and get him moving again. (No, no pictures to share for that particular operation!)

Setting those complications aside, life as a three-legged cat isn’t bad. Walking is awkward, but he manages. It hasn’t slowed down his ability to run, though, which makes sense if you look at a cat’s running gait: their back legs move as one. He can’t jump as high as he used to, and climbing trees is out of the question. But otherwise he gets around just as well as he did before the accident.

Ember Cleaning His Leg

The biggest impact has been with grooming. Cats scratch their head, neck, and shoulders using their back legs. He can still reach all those spots on the left side of his body, but not on the right. Within a couple of days of the amputation we’d worked out a kind of sign language so he can tell us he needs help: he arches his head and pops his leg nub as if he’s scratching. That’s the sign for one of us to reach out and lend a hand.

Ember - Surrogate Right Leg

These scratching sessions are distinctly different from normal petting, which he still enjoys thoroughly. He wants fingernails, and he wants them kicking as if he was scratching himself. He’s pretty good about giving us directions for where to scratch, how hard, etc. The only thing he likes better than a good scratching is the cat brush. At the urging of his vet we got a “slicker” brush we use to brush him all over every day or so. Just as he does when he asks us to scratch him with our fingers, he directs the brush sessions to hit all the spots he can’t normally reach. He’s a good teacher, and I’m a well-trained surrogate rear leg.

We’ve been careful not to take that too far, though. It’s one thing to be a surrogate leg so he can scratch places he can’t reach on his own. It’s another for us to carry him around and help him with tasks he’s perfectly capable of doing himself. We’ll pick him up to groom him or to pet him, but we always let him get down on his own or place him back where he was when we picked him up. He doesn’t rely on us for getting around.

All of our cats are indoor/outdoor animals, and all of them hunt. Ember is no exception, and is still just as avid a hunter as he was before he lost his leg. From the reading I did before taking Ember in for the amputation, I gathered that weight gain and lethargy are major concerns for amputee cats. Maybe it’s because he likes getting around on his own. Maybe it’s because he’s still such an active hunter. I can’t say for sure, but this hasn’t been a problem for him so far.

One surprising change is that he’s far more comfortable around cameras now. The first time I pointed a lens at Ember he freaked and ran as if a one-eyed monster was chasing him. (Which, in a way, one was.) I did photography at various stages of his treatment, so I guess he just got used to having a lens pointed at him. These days he’s completely laid-back about the whole thing, and even has patience for lighting.

Lighting Setup

As much as the pictures in this article might indicate that Ember is a complete slacker, I should probably point out that they’re all from one photo session that came after a full night of running around carousing outside. Eventually he had enough of me and my camera, and sent us packing.

Ember - Done

– Tom

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Hooked

Posted by Tom Benedict on 10/02/2015

I should’ve broadened my photographic horizons ages ago.

I’ve been in an artistic slump for the last three years. One bit of advice I got from fellow photographers was to step away from what I was doing and try something new. Portraiture, abstract, street, something. Just not whatever I was doing already. I chose to get into artificial lighting for portrait and product photography. Weird as it sounds coming from a landscape and aerial photographer, I love the idea of lighting a photograph myself rather than relying on the ambient light around me. Even more strange, I think this stemmed from a painter who’s known for his landscapes.

Years ago when I first dove into photography, my father urged me to study the works of artists other than photographers. He introduced me to the Dutch Masters and took me to the National Gallery in Washington DC to show me paintings by Vermeer and Rembrandt. I remember being blown away by the way Vermeer used what seemed like identical brush strokes to create velvets and satins in his portraits. Up close I couldn’t tell the two apart. But from a comfortable viewing distance one was clearly velvet and the other clearly satin. It blew my mind! (It also got me in trouble with more than one guard, standing eye-to-the-canvas with a Vermeer!)

But what really took my breath away were Rembrandt’s portraits. His light was phenomenal.

I had the opportunity to visit Rembrandt’s studio several years ago. I made a couple of photographs, including one in his portrait studio. I only had one lens with me, so I handheld a multi-shot panorama to go a little wider. But because of the crowd of visitors I didn’t get to go as wide as I would’ve liked. Still, it does a good job of illustrating his lighting setup. And that was really what I was trying to capture.

Rembrandt Studio

What’s not shown is the building outside the window. It’s taller than the window of Rembrandt’s studio, and faces south. More important, it’s painted white. This catches the sunlight and reflects it back toward the windows of the studio like a giant softbox. Inside the studio lie even more light modifiers: windows, window shades, and a white drape he could place to control the spread of light across his subject.

I would love to light a home studio the way Rembrandt lit his. Unfortunately my house doesn’t have good north-facing windows, and certainly doesn’t have buildings next door to diffuse the sunlight falling on them. So I’m stuck creating my own light.

One strobe and one umbrella are a start, but it’s not enough to give me the flexibility I’m after. The additional lighting equipment I ordered earlier in the year arrived, and I’ve been playing with it ever since. It’s helped out on a number of photo session at work and at home. I really only have one major stumbling block to overcome: I have no blank walls in my house to use as a background! I need a backdrop.

As I was shopping around for backdrop kits and muslins, I realized I have one more pressing need: a new camera bag. Right now I have two bags. The first is the one I do KAP with. It’s big enough to hold a single camera and lens, a charger, and a couple of filters. I cram everything else into The Other Bag. It’s an old Lowepro backpack Rydra and I used when we were using film. It’s a good solid bag, but it has one major drawback: it’s a backpack.

These days I find that whenever I go out to do photography, I’m already carrying something on my back. With KAP it’s my KAP bag. At work it’s my laptop bag. At home it’s more or less irrelevant, except that I have to have enough space in whatever bag I have to make everything fit, which is stretching it with the Lowepro backpack we have. I realized that what I really want is a shoulder bag.

I found a couple of bags, one of which is a perfect fit for my needs. But once I threw in the backdrop kit and muslins, the total came out way higher than my budget. Rather than compromise on gear I went on a house cleaning rampage and started listing stuff on Ebay. I had an old Yashica TLR with a jammed shutter, some 35mm gear, and a bunch of other non-photography stuff I realized I’d never use again. Selling off old gear is obviously not a sustainable way to support a habit… er… hobby like photography, but a thorough closet cleaning was long overdue, and cleaning out the garage earned me some brownie points with Rydra. Even better, I’ve already got enough for the backdrop kit and muslins, and should be able to get the new bag in the next couple of weeks.

In the process I’m learning that product photography is going to be a lot more fun once I have that backdrop! In order to create my listings on Ebay I’ve been improvising, using everything from bed sheets to place mats to butcher paper to create macro scoops for photographing all the stuff I’m trying to sell. But invariably I keep running up against some limitation in my setup – backdrop size, insufficient room for good camera-to-subject distance, etc. I spent an afternoon scoping out my house to find places I can set up and work without driving myself up the wall. I think I’ve finally got it sorted out. Even better, the muslin setup I’m planning to order should fit just fine.

The toughest part is waiting for Ebay to release the funds. For new sellers like me they hold onto all funds for three weeks before releasing them. It’s agony! But at least it’s agony with an end in sight.

Yeah, I really should’ve branched out a loooong time ago. >sigh<

– Tom

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Still Sick

Posted by Tom Benedict on 23/01/2015

The day after I posted Sick Lizzid I went back to work to put our wide field imager back together. (While I was out sick it had yet another failure. Grrr!) We got a lot done, but working in the cold at altitude is a recipe for relapse. I was out sick again yesterday and today.

So I spent my lucid reading time going through The Strobist. I finished Lighting 101 and started on Lighting 102. The second course goes into a lot more detail than the first, and includes student exercises (yaaay!) I had a little more energy this morning, so I went though the first several. These are more to familiarize the photographer with how light behaves than anything else, so I won’t post any of the pictures I made. I do, however, urge everyone going through the L101 and L102 classes to do every exercise. As pedantic as some of them may seem, nothing beats time in the saddle when it comes to learning a thing.

One of the things I like about The Strobist is that it’s very nonlinear in nature. Lessons do follow one another, but if something is relevant to the discussion there’s a link you can follow. Lighting 102 2.2 – Specular Discussion had a link to an article called Stainless Steel and Cookies, which in turn had a link to an article called Pretty, Shiny Things that discussed a technique called double diffusion. I’ve used this at work to get a relatively flat diffuse source. The flat field source I made for characterizing the linearity of our infrared wide field imager used double diffusion to minimize roll-off at the edge of the field.

The exercise for L102 2.2 was to play with specular reflections. I took a cue from the Pretty, Shiny Things article, in which the author was photographing wheat beers. I’m fresh out of decent beer, and too sick to drink anything, anyway. So I grabbed a bottle of Grand Marnier out of the cabinet and started playing.

Grand Marnier

I tried bare flash (eeks!), a shoot-through umbrella (better), and this, a double-diffused setup using the same umbrella with a Fotodiox shoot-through diffuser between the umbrella and the bottle. I didn’t think to try it without the umbrella until I’d already taken the setup apart, but by then I’d sapped what energy I had, and had to quit.

I’m really enjoying going through the lessons and exercises on The Strobist. It sounds weird, considering I’ve spent close to twenty years doing landscape photography. But I’m getting a real kick out of learning new ways to control light.

– Tom

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Sick Lizzid

Posted by Tom Benedict on 20/01/2015

There’s some kind of flu going around. I should’ve known when I saw the papers the other day at work. The headline read something like, “There’s Some Kind Of Flu Going Around!”. (Actually I think it said something derogatory about how the flu shot should’ve stopped this and didn’t. Hey, mutation’s the name of the game.) I tried to press on and not catch it until we’d finished all the work on that lens, but it finally caught up with me Saturday evening. I’ve been getting worse ever since.

I spent most of Sunday flopping around the house like a semi-fevered jellyfish. When I didn’t have the energy to flop around I read The Strobist. I know it’s been said a zillion times, but that’s hands-down the best site I’ve found for learning how to light photographs. But there was only so much reading I could take. I finally reached critical idea mass and just had to set up and play. No one was willing to model for me, so I set out to do a self-portrait.

I wanted to do basic corner lighting. It’s a straightforward single-light setup that lets you balance main and fill light on the subject as well as background light just by varying the distance between light and subject, and light and background. All you need is a corner with two light colored walls to work with.

That’s when I figured out I don’t have a corner with two light colored walls to work with. All the corners in my house either have furniture in them or one of the walls is actually a window. In desperation I finally wedged all my gear into the entryway to my house – a tiny 4’x4′ area. The only way it constituted a “corner” was if I called my front door a wall. Good working distance? Nope! Room for lighting? Not really. Desperate? You bet!

I didn’t really have room to do any balancing since I couldn’t move away from my background and I couldn’t get the light any closer to me than the edge of the entryway. I probably should’ve been frustrated, but the bigger problem was that no matter what I did, all the pictures I made looked like a sick guy who’d crammed himself in the entryway to his house and wedged himself in with camera gear. I’d have cried if it wasn’t so funny.

So instead I stuck a 100mm macro lens on my camera and took pictures of my eye. But what with the puffies, the redness, and everything else, it was just as bad as the self portraits. Come to think of it, it was probably worse.

When life hands you lemons, make margaritas.

I decided to do some creative editing instead. I like selective color eye photos, so that’s where I started. I left the iris alone, but desaturated the rest of the frame. It was kinda blah. So on a whim I started going through individual channels instead. The red channel smoothed everything out, but looked even more blah. Green was more interesting. But the blue channel was COOL. I looked like an alien. Or a lycan/vampire hybrid or something. Now we’re cooking!

My iris needed some work. So I bumped the saturation and vibrance, and toyed with the clarity a little. (MAN the new terms Photoshop CS6 has made me learn…) Then I tried rotating hue. A little fine-tuning and…

Lizzid EyeLizzid Eye!

Well… A sick lizzid, anyway. But hey, I’ll take it.

– Tom

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Heavens and (Optical) Hell

Posted by Tom Benedict on 19/01/2015

In an earlier post I mentioned we were in the middle of a big investigation into the degradation of one of our instruments. My active role in the investigation finished up Friday, so I’m breathing a big sigh of relief. Meanwhile I started processing all the photographs I made in the course of the investigation to document the work done. I ran a couple of time lapse cameras, so the photos number in the thousands. I only used a couple of the time lapse photos, though, so the number of “keepers” was a lot smaller.

I picked a subset of the keepers to narrarate the story thus far:

CFHT with Megacam

A couple of months back one of our astronomers analyzed the images coming off of our wide field imager to measure the zero point of each filter. A zero point is the measurement of the transmission of the instrument is in a given band. Because of dirt and grime building up on our primary mirror, we expect some drop in the zero point over time. What we didn’t expect was what he saw: a 20% drop in performance in g’ band with slightly less extreme drops in all the other bands. What made this worse was that we had just re-coated the mirror. We expected to get a marginal gain, not a dramatic loss. Clearly something was wrong. When the instrument came off the telescope we went up to take a look.

First Look - Something Wrong

I’ve done plenty of sunset photography at the beach. Most days I get away with some good frames and a camera that needs a damp wipe. Other times I get stuck in an onshore and my gear winds up covered in salt spray. But even at the worst of times, I’d never seen a lens that bad.

One of my co-workers spent an entire day trying to clean the lens. Stuff seemed to move around, but he found it almost impossible to actually take stuff off. By the end of the day the lens looked cleaner, but it was still bad. We all took bets on what the performance would be the next time it went on sky. I thought we’d see at least some of the performance restored from his cleaning efforts. None of us expected what happened, though. That 20% increased to a 50% loss of light. We’d made things worse. We pulled the instrument off the telescope and went up the next day to take another look at that lens.

Winter on the Mountain

We’d just had the worst ice storm of the season. The roads were still closed to the public while the road crews took the snow blowers up to clear the roads. When we finally got to the observatory and took a look at the instrument, what we saw wasn’t promising. After a very brief hands-off investigation, we started taking things apart.

Removing L1

Our first thought was that we were dealing with a contaminant, so that’s how we proceeded. We tried every solvent we could think of to take the “stuff” off the lens: DI water, methanol, isopropanol, acetone (I cringed at this one), toluene… None of it seemed to do a thing.

Early Testing

We did eventually find some chemicals that had an effect, but the amount of scrubbing necessary to make them do anything at all was really discouraging. Eventually we found that weak acids had a stronger effect, and required less scrubbing.

Finding what Cuts the Goo

We used two techniques to image the glass throughout the process: reflected light photography and dark field photography. Reflected light photography highlights differences in thickness in thin film layers through color change. Dark field illumination highlights contaminants like dust and other particulates. We used reflected light to show the spot of “clean” we were able to make with a weak acid.

Dark Field Illumination Technique

As splotchy as the reflected light photos were, it wasn’t until we used dark field illumination that the true extent of the “contamination” became apparent.

Dark Field Image

We made a comprehensive dark field survey of the lens to see what we were dealing with. A couple of features stood out: The center of the lens appeared to be cleaner than the rest of the surface. This is likely because of the cleaning technique used earlier – radial strokes from the center to the edge. The center was the starting point of each pass across the glass, so it got the most cleaning.

Another feature we saw was the dark ring about 1/3 of the way out from the center. Our optical engineer said this is the mark left by the vacuum fixture the lens manufacturer used to manipulate the glass during final polishing and coating.

The rest of the glass appeared to be covered by a blotchy layer of… something. We took samples and sent them off to a company so they could perform an assay to tell us what the heck was going on.

Using the Microscope

Meanwhile we borrowed a digital microscope from one of the other observatories on the mountain and set it up to take a closer look at what this contaminant was. Under that much magnification we were running into issues with vibration, so we put everything on the table and tried not to breathe when we were taking exposures.

(As a quick side note, that’s my Bogen 3021 legs and 3047 head I got for doing large format photography work back in ’95! It’s the most solid tripod I’ve ever owned. Despite having one of its feet burned off in lava in 2001, it’s still going strong. I love good gear!)

Microscopy - The Problem

What we saw under the microscope wasn’t encouraging. Either the entire lens was covered in bumps of… something… or we had a bigger problem. Were those craters?

We tried illuminating the patch under the microscope from various angles to see if we could figure out what was tall and what was short. But it wasn’t until we moved the microscope to the edge of the glass that we knew for sure.

Microscopy - Even the Edge is Bad

We were looking at pits in the coating. Something had killed the anti-reflection coating on our lens.

This is when the investigation divided forces. One side of the investigation pursued the question of what had caused the damage. The other side pursued the question of how we were going to recover and get the instrument back on the sky. We collected a new set of samples to send out for assay and moved the lens to another lab to begin the next stage: fixing whatever had gone wrong.

Test Swabbing

After an understandable amount of deliberation and debate, the powers that be decided the best course of action was to remove the coating from the lens. At its very best, an anti-reflection coating cuts the reflectivity of an air-glass interface by about 4%. Typical coatings recover more like 2% of the light that is normally reflected. We were looking at a 50% loss due to scattering from the damaged coating. Removing the coating would get us back in the 2-4% range. It was an irrevocable step to take, but it was clearly a win.

So we went back to the weak acids that had worked earlier, and began to experiment with concentration. The trick was to strike a balance between an acid that was strong enough to remove the coating in no more than a handful of applications, but not so strong it would attack the underlying glass. Our optical engineer identified a handful of acids that would be reasonably safe to use on the glass, and maximum exposure times we could use without damage. Hydrochloric seemed to be the best match, so we went back to testing.

Test Swab Technique

At 4% concentration, HCl was clearly removing the coating after only ten seconds of light scrubbing with a swab. The only problem was that even at 4% it was stronger than the concentration used by the glass manufacturer during their own testing.

Reflected Light Image - HCl Concentrations

We switched to a weaker solution: 50:1. At the same time we also wanted to minimize mechanical abrasion of the glass, so rather than going for a more aggressive swabbing action with the weaker acid, we tried a prolonged soak using a lens tissue saturated with acid.

Reflected Light Image - First Successful Soak Removal

After five minutes with an approximately pH 1.0 solution, we finally had something we could turn into a real procedure for stripping the lens.

At these concentrations the acid was about as strong as the white vinegar we’d tried earlier, and vapor concentrations were low enough not to require respirators. Respirators can be uncomfortable at the best of times, but at 14,000′ of altitude the restricted breathing is more than just a matter of comfort. It can mean having to break up work shifts to give people the chance to breathe. Working with just gloves as PPEs made life a lot easier.

Highway to Hell - Putting Acid on a Lens

There is something incredibly wrong about deliberately pouring acid onto a coated optic. Even knowing that the coating was shot, and that we couldn’t operate with that coating in place, I felt dirty when we loaded the first of several “patches”. Some part of me whispered, “You’re going to optical hell for this, boy.” With my heart in my throat I poured spoonful after spoonful of acid onto the patch.

Making of - The Work Begins

All of this was complicated by the fact that I was still doing photography of the procedure as we went. (Now you understand why I used time lapse cameras!) At times the cameras got in the way and slowed things down, but we all agreed that having a good documented record of the work was more important in case we missed something and had to re-establish what we’d done at some later date.

Dark Field Image - The Work Begins

It certainly helped that the technique worked. It wasn’t perfect, but it worked. We set up the next patch and began working in earnest.

Staying the Course - The Work Continues

There were a couple of features on the glass we weren’t certain of. One was the dark ring a third of the way out from the center – a ring left by the vacuum fixture the manufacturer had used to handle the glass. Would the acid work on that area? When we looked at it under the microscope the coating appeared to be less damaged than in other areas. Would that make it tougher to remove? Or easier?

Reflected Light Image - The Ring

The answer, as we learned, was tougher. The coating at the ring was less damaged than in other areas, but it was still damaged. It still needed to be removed. We only hoped that longer exposure to acid would eventually take it off.

Dark Field Image - End of Day 1

By the end of the first day we’d made some real progress. We were clear out to the dark ring, and had started on another potential problem area of the glass. After doing a DI water wipe to remove any remaining acid we made a dark field image to see how we were doing. The prognosis? GOOD!

For the record, the apparent scratches in the center of the lens are actually on the lens cover we bolted to the bottom of the lens. The glass itself is scratch-free.

Finishing Touches - Pipette Works Better

Day two was more of the same. We worked our way out toward the edge of the lens and continued to work on problem areas like the dark ring and a couple of other spots. As the problem areas got smaller, our patches also got smaller. At one point someone remarked that it looked like the lens had had a massive shaving accident. By then we knew the technique was clearly working, so the joke wasn’t as forced as it might’ve been earlier in the week. We could actually laugh without wincing.

As we neared the outer edge of the lens, the slope of the glass made it more likely that acid would run off our patches and down to the RTV that held the lens in its cell. Rather than spooning it on as I had the previous day, I switched to a pipette. Over the course of the day I put about a third of a liter of acid on our lens 0.09ml at a time. By the end of it my thumb was tired.

The lens has a 20mm wide baffle that fits around the outside diameter of the glass. This shadows the transition onto the AR coated surface, and covers the first 10mm of coating. We decided to leave the coating on the glass in this area. It wouldn’t affect the lens’s performance on sky, and it meant we had something of the old coating left in case we decided to get more chemical assays done in the future.

Edge Effects - Something Still there

In the areas we did remove, though, we saw a curious thing: We could still tell where the AR coating had been. Something was still there. Whether it was an undamaged underlying coating or just a chemical stain on the glass we couldn’t tell. It didn’t seem to scatter light the way the damaged coating had, though, so we left it alone.

Reflected Light Image - Coating Gone Lens Back

At the end of the second day the lens looked like… well… like a lens again. We did a final rinse with DI water and a final clean with methanol, then reinstalled the baffle and called it good.

Last Dustoff

The next day we blew it off with our version of canned air: high purity nitrogen and a regulator. In volume it’s cheaper than canned air, runs no risk of depositing stuff on the glass by accident, and lets us cover a lens this size in a matter of minutes. It’s a heckuvalot faster than the little Rocket Blower I use on my camera gear!

Last Look - Something Right

With the lens back on the instrument and the baffle back in place, we took one last look before putting it on the telescope. This is almost the same lighting that we used the first time we looked at the lens several weeks prior. The difference is striking. Before, I couldn’t even get my camera to focus on the bolt heads inside the optical tube assembly. This time? Not only could I focus on each of the bolts in the OTA, I could see all the way up to the pickoff mirrors for the guide cameras, and focus on the optics of the guide cameras themselves. Now that’s what a lens is supposed to look like!

Of course the day ran late. We were all getting used to leaving the mountain later than normal. With the instrument reassembled, we all sighed a big sigh of relief. And I finally got back to doing the kind of photography I prefer: landscapes.

Winter Ice

A little less snow and ice than when we started, but I couldn’t pass up the light.

We went up the next day to put the instrument back on the telescope. Everyone was eager to hear the news: Did we get the light back? A couple of people stuck around headquarters after the exchange to watch the first images come off at the beginning of the night. I opted to go home and spend the evening with my family. About 7:30pm I got a call from the remote observing room: The images looked great! The light was back! It was the best news I’d heard in weeks.

At 8:30pm I got a second call, this time from my boss. The filter mechanism had jammed. “When do we go up?” I asked. I knew the answer. It was bound to be some version of “Right now!” We drove back up and cleared the filter jam. While we were working on it the glycol chiller system stopped working, so we purged that. Then our all-sky infrared camera stopped working, so we worked on that. It was almost 2am by the time we finally headed home for the second time.

“Hey, is that the volcano?” my boss asked. Off in the distance we could see the Halemaumau vent lighting up its cloud of volcanic gases. “Sure is!” I replied. “Pull over and take a picture,” he said.

This is the thing I love about the people I work with. My boss had been up the night before doing on-sky engineering. We’d just been through weeks of hell trying to get this instrument back on sky. Its first night back, two more systems on it fail. By the time we finish it’s two in the morning and we’re zonked. But people still take the time to appreciate the beauty of the place we live, work in, and call home. I pulled over and set my camera down on a rock so I could take a picture of the volcano at night.

Volcano and Stars

It was a good day.

– Tom

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