The View Up Here

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Posts Tagged ‘Camera’

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

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

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 »

KAP in the Golden Hour

Posted by Tom Benedict on 30/08/2010

One of the things to look for in a photo club is honesty.  There are clubs where it’s all about the kudos and patting each other on the back.  In my mind these really don’t do a a photographer much good.  But then there are the ones where you get honest critique, whether it hurts or not.  If you’re really looking to improve, it shouldn’t hurt at all.  Honest critique, after all, is one of the best helping hands an artist can have extended to them.

At a recent photo club meeting, one of the members I respect highly, both for his artistry and for his honesty, gave me a critique on a set of images I showed.  It boiled down to this:  Great vantage point, rotten light.  Ouch?  Not really.  He’s right.

Until recently most of my KAP work has been done under the bright midday sun.  In the back of my mind I knew this.  Heck, all the work I put into finding the best way to make a panorama revolved around the notion of working in sunny-16 conditions.  And despite having most of John Shaw’s and Galen Rowell’s books on my shelves, I just didn’t manage to put two and two together and see that this was the wrong time to do photography of any sort, KAP or no KAP.  So the critique I got was a much-needed kick in the seat of the pants.  Want to improve my kite aerial photography?  Work in better light.

That “better light” happens during the half hour before and after sunrise or sunset.  It’s known as the “golden hour”, not just because of the color of the light but because of the quality that light brings to a photograph.  They simply look better.

Of course the “hour” part of the golden “hour” is subjective, and depends a great deal on location.  In far northern or southern latitudes, that “hour” can stretch on for hours and hours as the sun slowly sinks toward the horizon.  Here close to the equator it’s about fifteen minutes on either side of sunrise or sunset.  But the “golden half-hour” just doesn’t have that magical ring to it.  So “golden hour” it is.

On the ground, doing photography in the golden hour is only slightly different from doing it at any other time of the day.  Exposures are a little longer, or a lot longer, depending on how late you’re out.  But a tripod fixes that.  If the wind is blowing and you need a faster shutter speed, you can open up your aperture or bump up your ISO.  In the days of film, you loaded a faster film and had done with it.

In the air things are a little more difficult.  The kite is your tripod, and even the most stable kite will still move around.  I fought camera motion during the day by using a 1/1000 or faster exposure speed.  With my camera, that’s simply not available in the golden hour.  With a DSLR, it’s possible to bump the ISO to 200 or 400 without suffering much of a penalty with noise.  With my compact camera, ISO 100 is as fast as I can go and still get acceptable noise.  And unfortunately, during sunrise and sunset is when the wind is at its squirreliest.  On the West Side of Hawaii, the wind is largely thermal in origin.  Thermals collapse as the sun sets, so everything is in flux during the golden hour.

One other significant difference is that on the ground the photographer can make rational choices about metering in order to render a subject the way they intend.  In the air you have to set and forget.  In broad daylight, I came to the conclusion that using the sunny-16 rule was the right way to go: manual exposure mode, fixed aperture, and a fixed shutter speed based on a 1/ISO f/16 starting point.  Toward sunset the light is changing constantly, so a manual meter setting simply isn’t the right approach.  I had to come up with something else.

All of this makes life hard.  Hard, but not impossible.  I started off re-learning how to photograph during the golden hour from the ground.  I skipped the tripod, not wanting to lure myself into a false sense of security.  Several evenings of exposure tests toward sunset at Hapuna State Park got me going in the right direction.

The first thing I found was that metering toward the sun gave shutter speeds close to what I was using for sunny-16 conditions.  This meant doing foreground silhouette panoramas with a setting sun in the background could be done almost the same way I make broad-daylight panoramas.  Great no-brainer:

KAP Sunset

Next, I found that when photographing 180 degrees from the sun, I got the best results from metering 50/50 sky and horizon, and then re-composing the photograph:

180 Degrees from Sunset

The shutter times were longer, unfortunately, so my tried and true way of doing panoramas was out.  During the day, I’ll typically make a panorama by tripping the shutter and rotating the rig slowly around the pan axis as the camera continues to take pictures.  At 1/1250 second per exposure, this works fine.  At 1/100 second, this results in a bunch of blurred pictures.  So I used a different approach:  Set the camera to horizontal, meter, and compose each camera location individually while holding down the shutter.  The images that are made as the camera is moving will be blurred, but the ones where the camera is settled in a given orientation will mostly be sharp.

One problem I ran into was the balance between sky and foreground as the sun set.  As the light is falling, the sky actually stays quite bright.  It’s the ground that loses light first.  So the difference between illumination in the sky and on the ground eventually becomes so great the camera can’t capture both.  There are a number of fixes for this, including bracketing and HDR.  But from a strict photographic standpoint the best fix would be a graduated neutral density filter.  I grabbed my graduated ND filter set out of my DSLR bag and headed back out to the beach.

Graduated ND Test 1

The image on the left was done without the graduated ND filter, and the one on the right was with the filter.  The filter I used was an ND 0.6 (two-stop) hard-transition graduated filter from Hitec.  These are large, fragile, and expensive.  But I opted to test it in the air anyway, when I felt I was ready for it.

With all the results from metering, learning to fly in the shifty sunset wind, and the results of the ND filter test, I finally charged all my batteries, packed up all my gear, and put this to the test.

Hapuna + Graduated ND Filter

Compositionally this is quite weak, but it served to demonstrate the metering and filtering I came up with for doing golden hour kite aerial photography.  This panorama consists of nine images made with the camera held vertically.  It’s not without flaws: the rightmost pair of images is too bright, and needs to be brought into line.  But the sky isn’t blown and the shadows aren’t muddied.  All in all it’s a very workable image.

The only catch with all this is that I don’t want to fly my Hitec graduated ND filter again.  As I said, the filter is large, fragile, and expensive.  The filter holder is also quite heavy.  This serves to make my rig heavier, raise the minimum wind speed in which I can fly, and utterly unbalances the rig.  My tilt servo was working overtime to hold the camera in position, which increased battery draw.  No matter what I did, the filter got sand on it, and since it is made of acrylic, there is no easy way to clean the sand back off without scratching the filter.

But the results are compelling enough that I’m motivated to buy a screw-on graduated ND filter strictly for KAP.  I’m pleased with the results I’ve had so far.

The next step is to try all of this with a more photogenic subject with a little more altitude.  Worldwide KAP Week happens in less than two weeks, and is the perfect opportunity to really take all this out for a spin and see how it works out.

– Tom

Posted in Kite Aerial Photography, Photography | Tagged: , , , , , , , , , , , , , , | Leave a Comment »