The View Up Here

Random scribblings about kites, photography, machining, and anything else

Archive for February, 2015

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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Know Where Your Filters Are

Posted by Tom Benedict on 13/02/2015

In an earlier post I described some of what we did at work to fix the damage to the optics on one of our instruments. This instrument has been a constant source of fun and excitement. Prior to the lens damage it had another catastrophic failure in which one of its filters fell out of the filter jukebox and destroyed part of the filter change mechanism. That prompted an immediate instrument change so we could take it apart and fix the damage. But it also prompted a longer-term investigation into how the fault occurred so we could make sure it never happened again.

Something Wrong

As near as we could tell, one of the latches that keep the filters in the jukebox failed, which allowed the filter to slip out and into the space the guide rails occupy. When the jukebox came down, it smashed the tips off the guide rails. We held a brainstorming session to come up with ideas to stop this from happening and to detect if it ever does. The preventative measures were relatively straightforward. The sensing took more work. Some of the approaches were relatively easy to implement, but didn’t give us the level of sensing we were after. One of the more difficult and invasive approaches gave us all of the information we wanted, but would take the most time to implement. Needless to say that’s the option we ran with.

The filter jukebox has eight slots, so the instrument can hold eight filters. We added proximity switches to each slot so we can tell if it’s occupied by a filter. We also added sense lines to each of the latches that act on the filters so we can tell what state they’re in. Finally, we added a ninth proximity switch in the in-beam position so we can tell if a filter is in the beam. This lets us detect filters falling out of the jukebox, like the one that caused the earlier failure. It also lets us sense if the filter change mechanism had a mechanical failure and let go of a filter before it was either fully deployed in-beam or fully stowed in the jukebox. Basically, it lets us know if the mechanism does anything it’s  not supposed to do.

Installing Electronics

The electronics were designed and built by one of my co-workers. I did most of the mechanical work – the proximity switch plate, the light baffle, the modifications to the bulkheads to pass the latch sense signals through, etc. My boss and my co-worker did all  of the cabling and came up with the test plan.

New Filter Sensing Instrumentation

It took almost a week to install the electronics. Some of that was spent building and testing cables. Most of it was spent dealing with what we call “summit issues”: things that go wrong simply because they go wrong. My one contribution to the electronics was to build a ribbon cable. Seems simple enough. I’ve never messed up a ribbon cable. I mean, how hard can it be, right?

When I plugged in my new cable one of the proximity switches self destructed in a most spectacular way. Hissing, a bit of flame, and gouts of brown smoke gushing out from under the proximity switch plate. We took the entire system back to headquarters to replace the damaged parts and figure out what went wrong.

Back at HQ I took the ribbon cable apart, expecting to see a bent pin, a flawed ribbon cable, or any of the other likely causes for such a failure. What I found was an aluminum shaving wedged between two of the pins. Apparently when the mounting holes for the new electronics were being drilled, some metal chips fell into the box of spare parts and one of them wedge inside the IDC connector I used to build the cable. Including the drive to and from HQ and the time I spent cleaning the smoke damage off of all of the filters, total time lost was close to a day… for a metal chip. “Summit issue.”

Happiness is a Working Instrument

We finally finished all the work yesterday. We tested it thoroughly, then tested it again. Then tested it again. My boss was kind enough to pose for me at the end of what for him has been seven straight weeks of work on this instrument. (So if he looks a little stressed, cut the guy some slack.)

Back on the Telescope

With all new rails, jukebox rails, filter frames, and a wonderful new sensing system, it was finally time to put it back on the telescope.

– 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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