Thursday, March 14, 2024

Flora: a minor revision of The Populist

The internal assembly of the Populist is made from a long strip of cardboard which is folded into a rectangular shape to form the image chamber and the film bays of the camera. It works OK but the template has to be assembled from two parts because it's too big for one adhesive label. It requires a long piece of card and careful assembly to make sure it's truly rectangular with parallel sides when it's glued inside the box. While making some medium format sized boxes for single-shot photo paper cameras recently, I realized they are exactly the same size as the image chamber of the Populist. A properly folded box inherently has parallel sides and would provide a little more glue surface for a stronger camera. This new box needs a hole to be cut for the pinhole. A goal of my original 2007 design was that it could be made by children with rounded tip school scissors which is probably why the internal assembly was designed that way. I gave up on that with the current 2017 design but never changed that part. The new scheme also requires a smaller piece of card.

After verifying the accuracy of the revised templates, I'll update the directions for making a Populist eventually. If you're thinking of making a Populist, the current design on-line is just fine, just make sure that internal assembly has parallel sides. Oh, darn. Now I'll have to make a bunch of cameras.

Local business Kimberly-Clark comes through again with attractive materials.


This camera really didn't need to be tested. There was really no doubt that it would work but I can faintly hear Mr. Natural whispering to me that it's not very Zen to make a camera and not take some pictures with it.

When we need our supply of Oaks Chocolate refilled, I send them an email with our list. Last Monday, they responded right away, telling me it would be ready on Wednesday the 6th. I read that as tomorrow. When I got there, they pointed out my inattention to the actual text of the message but since the place was completely empty they'd get it done if I wished to wait. Hmmm. What to do in an empty candy store to occupy my time? The hand-lettered signs on the corner of the display case asks customers to please not touch the century-old glass, which is neatly illustrated by the wavy reflection of the fluorescent fixture which stretches the length of the store and can't be avoided.



Fresh roasted nuts. I wonder if they ever make chocolate acorns?



The side of the Grand Opera House, with shadows.



Just to the right, the emergency exit from the ground floor seats with more of that tree on the corner.



The theme for the Fox Valley Photography Group this month is Self-Portraiture. I'm a very convenient and willing model so my face shows up in my photographs fairly often. Almost all photography classes require this as an assignment. It requires previsualization and it's impossible not to have some emotional attachment to the subject. Taking my hair out of a pony tail is probably about as revealing of my true self as I'm likely to get.



Thought there'd be more glowing locks with the backlighting. Looks a little like Gandalf with a good rendition of a unhandyman injury on my thumb. I gotta go to the optometrist and get my glasses straightened out.



There's no place to put a tripod at the Rooms of Blooms biennial flower show at The Paine Art Center but stone columns are a very stable support. No one seemed to think it odd there was a man holding an orange floral box against the wall for a minute and half.



Despite our regular consumption of Oaks Chocolate, we do keep alternatives around.



The base of the acrylic pepper grinder broke after over a decade of heavy use. It still contains the peppercorns and grinds all right but a cylindrical object isn't very convenient to have rolling around on it's side where you're cooking. We replaced it with one of Peugot's early products in stainless steel that included this charming little operator's manual.



We have a weekly video call with Andy and Kristin. Modern broadband service is amazing. We get to see Greyson freak out live at "The Black Dog" from the next block.



That evening was developing night at Photo Opp. I had two frames left but could probably find something to photograph if I went up there. It looks a lot better now with the new light fixtures and the vault painted.



That circular window on the west wall projects a spotlight into the space in the late afternoon. During the previous exposure I was chatting with Instax photographer Joy Laczny with whom I shared a wall at Photo Opp's Range of Photography exhibition last year. We both noticed the beam falling on the comfy white chair and she agreed to sit for me with her Photo Opp hoodie and a new-to-her Polaroid.
 

I ended up not developing the film there. I wanted to experiment with minimizing film curl. I read that commercial labs have humidity controlled drying closets to actually slow the drying process, so I left the tempering bath on while the film was drying. I checked it frequently and as soon as it wasn't sticky, cut the negatives, put them in envelopes and under a very heavy pile of oversized art books overnight. It worked sort of. Most of the sideways curl of the film was controlled but it still rolled up the long way. It was much easier to get it to stay in the film holder. I still got a few Newton Rings, but much better than recent rolls of color film.

Flora has a .25mm hand-drilled pinhole, 30mm from a 6x6cm frame. The film is Lomography 400 developed in Cinestill's liquid C-41 kit.

Friday, March 1, 2024

Monovision

After all the complexity of the last post with building multiple cameras, two angles of view, three ways of simulating binocular vision and five rolls of curly color film, I recovered with a dose of black and white film in just a single camera. The only black and white film I had was Kentmere 100 so I didn't even have to decide what film to use. The Toucan 45 had only seen one roll of film.

It was a mild sunny day, perfect for defining planes and rectangles.



It cracks me up how much this looks like an extremely curved film plane. In this case, it's the building that's curved.



It was quite a surprise to see that Miller's Bay was still full of ice. I knew I was flirting with flare pointing the camera toward the sun to get the textures of the ice highlighted by the solar reflection. The capture of the ice was only moderately successful and it looks like a pretty big meteorite just hit the eastern shore of the lake.



There were still a few brave ice fishers. As I carefully set up the tripod on the rocky shoreline, as close to them as I was willing to get, the more distant one told his companion that he was getting his picture taken. When the wind is coming off the lake, it's surprising how well you can hear conversations from out on the ice.



A cluster of trees on Monkey Island across the mushy looking ice of the southern inlet . 



The lake itself has only a few large chunks left bobbing near the shore which is completely lined by this brilliant border.



A planter between the columns in the front of the Wisconsin National Life Building. Interesting how the wide angle of view records a distinctly different shadow angle on the adjacent columns. The left is on a line with the sun and the camera and nearly shadowless, the right one 60 degrees away from that line.



Shadows on the side of the Masonic Temple.



A little too close to an Amarylis blossom,



An anatomically correct vase remaining from Valoween.




Sarah's corner of the sun room.



My corner.



The Toucan 45 has a .27mm pinhole 45mm from a 6x6cm frame. The Kentmere 100, which dries wonderfully flat, was semistand developed in Rodinal 1:100.


Wednesday, February 21, 2024

Extended baseline stereo cameras at two angles of view

 


For a future project I needed to practice processing stereo views. There were a few other things I was curious about. The stereo effect is based on parallax which gets smaller with distance. With a wide angle camera, which makes everything seem farther away, you have to be very close to get the 3D to really pop. I'm interested in stereo views of buildings, which you have to be kind of far away from to include the whole structure in the picture. A way to get around this is with a narrower angle of view that has a compressed perspective so depth isn't as obvious and you have to get farther away to get the whole building in the picture as well. The solution is to have an extended baseline between the images in your stereo pairs.

This can be done with two cameras very carefully placed so they're at exactly the same height, or by taking one picture after another, moving a single camera between exposures, again being very careful about being at the same level. I wondered if I could a make a stereo camera with an extended baseline. The most common baseline for medium format stereo cameras is 6cm, which matches the distance between our human eyes and is conveniently accomplished by placing two 6x6cm chambers right next to each other. 

By spacing those chambers separated by exactly one frame, you can make pairs on every other negative and get a 120mm baseline. For example, frames 1 and 3, then 2 and 4. Then you have to advance to frame 5 for a pair with frame 7 and so on. This is how it's often done with 35mm stereo cameras to achieve the normal 60mm baseline. I made two cameras - at superwide 90 degree 30mm, and "normal" 36 degree 90mm.


You only need one counter shutter. I accidentally put the counters on opposite sides, but it doesn't make any difference as long as you advance to the right number.


In order to get it loaded you have to extend the paper out a little longer than the arrow on the backing paper indicates.


 
Theres still about 15 cm of backing paper until you get to the film and I'm pretty sure I've gotten away with this with the Evil Cube and the Variable Cuboid with their longer bent film paths. Those cameras stretch the paper more tightly over the divider and hold the supply reel in a more protected chamber. With these loose-loading Populists, I'm pretty sure there was "fat roll" fogging when I loaded the camera. It caused lots of what looked like randomly spaced light leaks on different places on the tops of the images.

I also had lots of other irritating problems with flare, sticky shutters and bumping the camera trying to open and close the shutter. Almost all of the pairs had some kind of issue.

I'm going to display them here in two formats, arranged for crosseyed viewing and as anaglyphs.

My favorite format is crosseyed viewing. Crossing your eyes makes a double image. When the left and right images meet in the middle, you refocus on some element in the image and see the depth. Because your eye muscles can adjust the overlap of the images, it's very forgiving of images that aren't perfectly matched and kind of tricks your brain into seeing depth even where the images don't overlap. It's also in full color, which if the images don't exactly color match is blended together by your brain. Here's a lesson with simplified graphics to learn how to do crosseyed viewing. 

The second method is color analglyphs where the left image is rendered in red and the right in cyan. By wearing spectacles filtered to allow just one eye to see each side of the pair you can see the depth. I was curious how this would deal with color images. Turns out not very well, you get at best a very faded version of the color image. I eventually learned to improve color by increasing contrast of the anaglyph generated by Anaglyph Workshop. With a lot of experimentation I could probably learn to edit the original for better color. Anaglyphs are also very exacting about alignment. It doesn't take much misplacement of the pinhole from the exact same position in front of the film so the two images aren't exactly the same. This was difficult especially for the extreme wide-angle camera where everything is a little exaggerated. I also made the chambers on that camera a little too wide and they overlapped with the image next them which gave the scanning software fits. This all required a lot of cropping and aligning to get a decent anaglyph.

If you've got some kind of 3D headset, you can do parallel viewing or if you want to print them for classic stereocards, here's a PDF of a slide show of the pictures in parallel format.

First the 30mm camera.

Leon's Frozen Custard. I thought it might be interesting to see the depth in the reflections on the windows.




A corner I've photographed before when it was white.


 

The sunken courtyard of The Public Library.






Behind the 400 block of Main. The minimum distance for the stereo effect to work is supposed to be 30 times the baseline which in this case is 3.6 meters, but the wide angle exaggerates depth so I should be able to get closer. I was only about 2m from the pillars. Really makes the 3D pop when you have objects this far in front of the others.




I  had worse luck with the 90mm camera. I thought this rather subtle arrangement of planes would be a good test for the extended baseline.





I had to race to catch the light on the railroad bridge, which I won, but it might be too far away to perceive much depth even with the extended baseline.








After some surgery to correct a blocking shutter on the rising pinhole of the wide camera, tightening the supply film bays a little and adding a little extra lightproofing inside, I reloaded them in total darkness.
Then I taped the floppy tops of these extra wide cameras closed and doubled the number of rubber bands. I still had some unexplained anamolies, but a much better success ratio.

From the wide camera.

The bushes in front of the convention center should pop out nicely. This and the next are done with the rising pinhole.







I think I can see some depth in the fluting of the columns and Greek keys in front of the Northwestern Building.




Plenty of depth in my picture but not much in the ice. This view would normally be filled with trucks and ice fishing huts at this time of year.





Lots of depth to work with in the canoe racks. Again, lots closer than 3.6 meters.




The trees in the foreground are the most common kind of stereo trick, but would there be depth in the stonework? The rising pinhole for these next two as well.




There was a nasty bit of flare on the right frame which I very clumsily retouched but it doesn't seem to affect the stereo much.






How about the long camera? More fluted columns at the Yacht Club with the rising pinhole.




More of that sketchy ice. Pushing my luck this close to those foreground wheels, but I think it works. The tripod was on a rather steep slope and somehow it was almost 5 degrees off level. Some identical cropping and rotation on both sides and realigning the distant horizon restored the stereo effect.




They had to cancel the Battle on Bago ice fishing contest but they kept up the party tent all weekend and raffled off the prizes.




It might be interesting to see how the stereo effect separates the trees from their shadows on the wall behind them. Upper pinhole again for this and the next.





The substation at Bowen and Murdock is the kind of large structure made of lots of planes that I was interested in using the extended baseline for.





On my last frame I thought I'd really push the limits of closeup. As luck would have it the left frame got cropped by running off the end of the film. Again, judicious cropping and alignment preserves the stereo effect but it might take a little concentration to get it to fuse.



I think the extended baseline enhances the stereo effect a bit, but for most architectural work of entire buildings, I think you need a little longer baseline. I should have put a pinhole in that space between the chambers and could have directly compared the views with the 60 and 120mm baselines. For longer baselines, thanks to the many factors of the number 12, you could make a camera that made exposures 2 frames apart (1-4, 2-5, 3-6, 7-10, 8-11, 9-12) or separated by 4 or 6 frames with similar schemes. Definitely have to load those in the dark. But right now my brain hurts and I think I'm going to load a regular camera with monochrome film.

The 30mm Extended Baseline Stereo Populist has hand drilled .25mm pinholes on the axis and 11mm above it. The 90mm Extended Baseline Stereo Populist has .40mm Gilder Electron Microscope Apertures on the axis and 13mm above it. The first roll through both cameras was Kodak Gold 200, the second Lomography 100. Kodaks developed in Arista.edu C-41 liquid kit, Lomos in Cinestill's liquid kit.