Tuesday, August 30, 2016

Stereo variations

On Facebook, in relation to my post on Victorian Stereoscopy, Lena Kallberg commented that she had also enjoyed the on-line course and wished they had dealt a little bit more with the technical aspects. She asked if I knew any good references on things such as what is the optimal focal length for stereo? I didn't know but had done a bit of stereo with several different formats and focal lengths where it worked. I said I thought distance between the pinholes (or lenses if you're in to that kind of thing) might have more effect on the stereo imaging.  So I thought it might be fun to riff on that theme.

I think there's a relationship between focal length, baseline between pinholes, and distance to the subject.  Not sure how to express this mathematically, but you can get good pairs closer up with wide angles, but wider baselines are hard to integrate back into stereo, especially when you're close up. With longer pinhole to film distances, you can take advantage of longer baselines, but you can't be too close to your subject. Not very clear.

The images embedded in this blog are set up for the crossed eye method.  If you want to play along and you've got a lorgnette,  Brian May's Owl, Google Cardboard or an Oculus rift, here's a link to a PDF with them set up for stereo viewers, in the same order they're in the blog.

If you want to learn cross eyed stereo viewing, check this PDF for instruction.

I had lots of 4x5 paper left over from my August workshop, and the paper developer I bought wasn't going to last forever.

I'm not going to get really organized and quantitative.  I just tried a bunch of different things to see if it made a viewable stereo pair, not whether one was best.

About the most outrageous arrangement I could think of was 14oz vegetable cans, which of course would have curved film planes and extemely wide angles. Oddly enough, I tried this before circa Y2K, and I vaguely remember that it worked.

My neighbors ripped out the hedge and part of a fence while we were out of town last weekend, and left it looking really ugly (They plan to put lawn there).

This pair is a little tricky to view, but it works.  (Work on getting the pipes at the top of the fences to align, By the way, this one doesn't work at all with a stereo viewer - see below)

With crossed-eye, the left image goes on the right and vice versa.  Looking at this pair, it seems like there's lot of wall in the right image, and a lot of trees and drive way in the left image.  If you look at the angle of the fence coming out from the house, you can see the left image is on the right and vice versa. I think the cans rotated a little bit without me noticing when I put rubber bands around them to hold to the tripod, so they're actually pointing in a little bit different directions. But where they do overlap, you get a stereo image. By the way, this doesn't work at all with a stereo viewer because you can't vary the placement of the objects in the image the way you can by crossing your eyes.

Tried it again with a little less angular subject matter, and was really careful that they were correctly aligned.

That goes together very easily.  I think it helps that I'm a little farther away as well.  This is the first picture I've done that I could probably pass off as a Victorian stereogram. It's also kind of interesting that without any straight lines in the middle, you could hardly tell this was a curved film plane.

Next up were the one pound Oaks Candy boxes, with the pinhole 2 inches from the paper, pretty darn wide angle. I started with the vertical format with the boxes right next to each other so the baseline was 4 inches. Started fairly close-up about four feet from the baker's rack.

Very 3D.

I went on to try them horizontal.  The boxes are wider than the paper so the baseline is now 8 inches.

I can still get it integrated.  I thought the longer baseline would give me a more prominent stereo effect, but I really don't see much difference and it does make you cross you're eyes harder to get it into 3D.

So now to the 5 inch workshop camera. First with the cameras side by side.

This is an example of an extremely messy compostion with very few cues to depth, but in 3D the pine branch at the top is noticeably closer with the herb garden, the plants along the path, the arbor and hedge at the back of the yard separated in their respective planes.

I'm doing this with a 15 inch piece of board attached to the tripod, and next I put the cameras at the opposite ends, so a baseline of 11 inches.

I think this one doesn't really work. I can get from the herb garden and back into 3D, but can't get the pine branch at the top to come together. When you increase the baseline, you definitely can't get as close as you can when the cameras are closer together.

I've always thought that stereo views of really grand vistas often suffer because distant objects don't have as much difference as those close-up.  Well, telephoto is the photographic solution to getting a closer look at something, and I thought would allow a wider baseline, and end up with better stereo separation.

I got out my 10 inch foamcore camera.  I only had one, so I had to use the cha-cha method, successive exposures with the camera moved between exposures. The house across the street isn't going anywhere, and on an overcast day, exposure and lighting would remain consisent.

First, with a 4 inch baseline as though I had two cameras side by side.

Still works in stereo.  Now out to the 11 inch baseline.

I think I can detect a little bit of an enhancement to the stereo effect with the longer baseline, especially for more distant objects.  I think I can see a little better separation between the house and the trees in the background.  One thing you might not have noticed is that giant rut in the lawn the neighbors made by driving a truck up to the hedge, and I think this closer object is more prominently 3D in the pair with the shorter baseline.

I'm afraid I don't have any succinct summary conclusions after all this. You can use a lot of variations of focal length, and you can use longer baselines with longer cameras, but it makes a difference how far away what you're trying to photograph is.

If anyone knows of mathematical rules that determines all this, or just a better explanation, I'd love to see the link.

Sunday, August 28, 2016

Boston & environs: JFK and Wollaston

From Quincy, the first stop on the T you encounter after going across the Neponset River is the JFK Library, but we'd never stopped there.

Space-age architecture by I.M.Pei. I was surprised about how much space they devoted to space. They've got the Freedom 7 Mercury capsule and a pretty big moon rock.

This is about the best I could do for an interior in the exhibits - a replica of the desk end of the Oval Office with a giant video screen in place of the president. The visit was more emotional than I expected. Artifacts included notes from meetings and teleprompter reels from notable events and a neat seating chart for a dinner with the French ambassador that included many of the major American artists and writers of the day. It was strange hearing everybody else around us also explaining to their children or grandchildren about memories associated with the exhibits. I definitely remember the imminent possibility of nuclear war and of course, the assassination.

The exhibits dump you out into this giant glass lobby overlooking Boston Harbor.

Kind of fun fooling around with pinholey angles with the little tripod on the floor (and bright enough to get exposures without being in anyone's way).

Then we drove down to Cohasset to see the cute little New England harbor where Andy and Kristin are getting married in October.

It was still extraordinarily hot, so in addition to giving Jeremy a little company, we returned to Quincy to recover from the heat.

Went out for drinks before dinner at the Wollaston Yacht Club. (Andy and Kristin have a social membership).

Well actually it was for beer...some of the yachts.

Dusk at Wollaston Beach.

All with the Populist. .15mm pinhole 24mm from 24x36 frame.

Thursday, August 25, 2016

Boston & environs: A portly day

We started in Milwaukee. When I went through security and emptied my pockets, I forgot I had two rolls of film that I didn't want to go through the radiation in checked baggage.  They got caught by the full body scanner (knee replacement, ya know).  The TSA guy asked me what they were.  I think that's just part of the procedure. He was old enough to have seen film before. He took them over to the electronic sniffing device just to make sure.  We put them in Sarah's purse on the way back so that didn't happen again.

For days Weatherbug had been predicting 50 to 70 per cent chance of storms for our departure time, and the expected storm had been moving across Wisconsin all day at what seemed to be a variable rate.

Got boarded and the storm held off so, out on time though.

Andy and Kristin thought going to Maine was a good thing to do on a hot summer day in Boston.

First stop for lunch was in Portsmouth, N.H.  Very historic town, but also some rather new looking hip passages. That's the restaurant to the left, but no one was outside in the heat.

The restaurant was Friendly Toast, which also has a location in Cambridge.  They describe it as eclectic, but that actually means they exhibit a large collection of often kitsch memorabilia.

We sat right next to this rather long fellow.

Which foreshadowed our next stop. Henry Wadsworth Longfellow's childhood home in Portland, Maine.

Not the best day to tour an authentic 18th century house, except the authentic cooling systems like opening windows weren't used and all the windows were covered by shades to protect against UV damage to the furnishings which were the actual ones from the family. Kind of seered the experience into your brain somehow though.

Lovely garden in the back, begun by Longfellow's sister, Anne, who lived there with no modern renovations until 1901, when she gave it to the historical society.

The Historical Society is just off Monument Square. Even after all these years it's still a little odd to see pictures of what was a rather busy street deserted by a 6 second exposure.

Before the internet, time and temperature signs used to be the only other way to find out how hot it is was other than by calling on a land-line phone. Must still be a big deal in Portland because they have a whole skyscraper named the Time and Temperature Building.  Anyway, this device changed on a one second cycle.  I tried to get two temperature appearances and one time so you could see it was 98 degrees (F), but it didn't quite work. (Duh, I could have just covered it with my finger when the time was displayed?!)

We figured we would at least imagine it was cooler in the Scandinavian Import Store.  Actually, Andy needed a lefse-flipping stick. Kind of interesting trading being-raised-with-Norwegian-traditions in the Northeast and the Midwest stories with the owner.

Proceeded to the also cooly named Portland Hunt and Alpine Club, a cocktail and inventive appetizers establishment nearby for refreshment.

Kind of rustic decor, but with a sophisticated menu. Inspired by the Scandinavian experience Sarah and Andy had browned butter-washed Acquavit cocktails. The very tasty flatbread with slabs of locally sourced blue cheese and honeycomb hors d'oeuvres seemed appropriate too.

While we were there the hot humid air we had been sitting in met with some colder air from inland and clashed overhead, dropping an impressive amount of rain.

There was a break so we headed out again.  Here's the view of the harbor with the still threatening clouds.

Headed down to the Portland Museum of Art which had an enlightening exhibition of women in modern art and abstraction in the early 20th century..

The museum had a rather impressive collection for a regional institution. Didn't display any photography, but I saw my second painting by Steichen.

While there, the rain started up again - a little more consistently this time.  This scene out the third floor windows reminded me of impressionists paintings of evenings in Paris, but the long exposure erased the taillights which gave great highlights to the scene, and the overexposed sky disguises the gloomy aspect of the weather.

All with the Populist. .15mm pinhole 24mm from 24x36mm frame.

Monday, August 22, 2016

ArtsCore Summer Colony

My pinhole workshop for teachers was part of the 3 day ArtsCore summer colony.

To see how I fit into the whole program, and meet the participants, I attended the opening session on Monday morning.

It was held at the Paine Art Center and Arboretum carriage house and conservatory.

This might show a lack of editorial discipline, but here's a closer shot with the sun rising over the conservatory. It was the first time since I retired I had to be anywhere except the hospital first thing in the morning.

Introductory remarks and introductions were held in the carriage house side.

The director of the Art Center just happened to be standing right behind me and gave a few welcoming remarks.

The actual workshop was held in the conservatory.  During the presentation, the art center director was spotlit by a sunbeam from the skylight.  I wonder if he was aware of it?

The exercise used a history/sociology lesson about Cesar Chavez and the Farm Workers Union. A painting by Octavio Ocampo was used to stimulate discussion and the small-group, active-learning, arts-integrating method was to create a tableau vivant with a six or seven word script to interpret his life and accomplishments. The instructor's caveat to think about how you were going to hold a pose for a minute or two sounded like it would be useful for working with pinhole tomorrow afternoon.

Started out on chairs, but with a room full of twenty-somethings, when the active-learning group work started, there was a lot of sitting on the floor.

The morning ended with lunch.

The next afternoon was my turn. No darkroom at the Paine, so we were two blocks down Elmwood Ave. in the Arts & Communication Building at the University.

Tried to have everything ready when they arrived.

It was kind of odd to be introduced as someone who for a long time has had pinhole photography as a hobby. That's what I get for my lack of ambition and conceptual discipline.

Drilling the pinholes and installing them on the cameras.

I spent most of the afternoon in the darkroom and looking at the pictures as positive images on a document camera and discussing them with the participants.  With 23 of them, it felt like I hardly got to work with them at all. When I did get out side, there was only this one group nearby to capture with the Populist.

I got him to get closer.

We had looked through the cameras before installing pinholes to get an idea of the angle of view and had gun site indicators on the camera to determine what was in the frame.  Despite the cameras being about the angle of view of the cell phone cameras they use all the time, when setting up a picture without a viewfinder, most of them seemed to revert to framing the picture about the way how they thought they would frame it with the normal perspective of their eyes instead of getting as close as they needed to with these wide angle cameras. Pre-visualizing the pictures with a wide angle pinhole camera seems to be something that you have to learn to do (...the zen of pinhole?).  I wish I had another day with them.  You can only accomplish so much in a one-day workshop.

It was a brilliant, bright sunny day. I was distressed that there were so many issues with light leaks that had to be fixed.  I think I'm going to get a tattoo that says "The sun is a vengeful benefactor" Anyway, the only picture I took with the workshop materials, in order to test the light-tightness of a camera, was this self-portrait, posed so I could hold it for a minute or two.

All the color with the Populist, .15mm pinhole 24mm from 24x36mm frame.

The black and white with a .5mm pinhole 5 inches from a 4x5 frame.

Thursday, August 18, 2016

Inspired by Victorian Stereoscopy

I just took a short MOOC (massive open on-line course) on Victorian Stereoscopy from the University of Edinburgh.

Stereoscopy was the virtual reality of it's day in the late nineteenth century, and just about everyone had a viewer and collected stereo cards.

After looking at hundreds of black and white stereo images, I decided to haul out the 120 stereo populist and load it up with some Arista 400 and try my hand at it.  I've done lot's of stereo in color but in black and white only did one or two experiments with 4x5 cameras a long time ago.

The Victorians were big into genre scenes in quaint villages, spectacular landscapes, and humorous images of women negotiating hoop skirts.  I didn't have access to those things, so I went out into the garden.

These are all set up for crossed eyed viewing (which is the easiest way to set them up - you just scan the pairs as they are).  If you're not familiar with that method of stereo viewing, try this little instructional piece I did several years ago.

Some of my favorite stereo images are scenes with relatively little depth, so I started with Sarah's pet oaks on the side of the driveway.

The effect is more obvious when there is a bit of depth to play with.

I think it does help when the image itself has the standard 2D methods to create the illusion of depth such as this sunlit papyrus in front of the shaded garage door.

Although sometimes the effect is most impressive with a messy composition where you almost can't tell what's what until it's viewed in stereo.

It's pretty rare in victorian stereoscopy, I think close-ups are particularly fun in 3D, but maybe this one is a little too close.

One of the popular themes for the Victorians were scenes of ghosts, and there's a particular connection to pinhole.  The first instance of anybody actually taking a pinhole image is recorded by the Scottish scientist David Brewster in his book, The Stereoscope. Brewster is also the person who first suggested you could record ghostly figures by having the model move out of the scene half way through the exposure.  I thought this striped chair would be a good background for a ghostly image and I was hoping the image on my Motorhead t-shirt would show up more, but I think I may have moved out of the scene a little too soon.

All with the 120 Stereo Populist, side by side chambers with .3mm pinholes 6cm from 6x6cm frames. Arista.edu 400 developed in Microphen 1:1.