Sunday, January 29, 2017

Brass or aluminum

June 2019. When my university retiree account disappeared with a new change in policy, the pictures I uploaded to this blog while logged into that account disappeared. I'm working on fixing that but it's going to be at least a summer long project. 

I recently ran across a blog (Sorry, don't remember whose) which discussed the quality of image and how pinholes drilled in soda can aluminum were inferior to those drilled in brass foil which were inferior to the pinholes you got with a premium pinhole camera like a Zero.  So I thought I'd take a look.

The pinholes below were made with my standard technique for pinholes which are smaller than the diameter of the needle I'm using.  I drill against a hard table top that the needle won't penetrate with some cardstock underneath it depending how far I want the needle tip to penetrate depending on the size pinhole I want.  For pinholes approximately .15mm, I drill right against the table.  For pinholes approximately .3mm, I use a matchbook cover, and for about .4mm a cereal box.  The following examples are about .3mm.  I then sand the burr that forms on the bottom side off with a piece of 400 grade emery paper.  The pictures are all of the top side that the needle drilled into.

First the aluminum.  When first drilled, it looks like the needle point splashed out a crown around the hole, and when sanded left all sorts of crap in the hole.  Not a very good pinhole. Removing the debris was fairly easy by placing the needle back in being very careful not to enlarge the hole and giving it a spin.  I wondered if I could get rid of this rough crown by sanding the side the needle entered.  I knocked it down a little bit as in the middle picture and then really worked it over and did succeeded in minimizing it, but it looks like I distorted the edge a little bit.

I'm afraid my scanner freaks out when faced with extremely bright highlights on a shiny surface, so I had to switch to a cheapo microscope attachment on my phone so the image quality and scale is different, but the hole is actually about the same size

So now with the brass. What you might notice is that with the brass, the needle first formed a dimple in the material and then created the hole.  The brass is a little thinner than the aluminum in the first place, and this dimpling makes it even thinner at the edge of the hole.  There's still a little bit of a splash, but it's much smaller than with the aluminum.  And this is right on the first go.

Then I wondered if it made much of a difference when completely drilling the pinhole through the material without the hard surface beneath it, so I drilled a couple with a piece of styrofoam under the material and pierced it completely with my number 10 needle to make a hole about .5mm.

Looks like that didn't make too much difference. The aluminum still creates that ragged crown before the needle goes through, and the brass looks about the same too.

I don't have a premium pinhole camera, but I thought it might be instructive to make a comparison to a Gilder electron microscope grid, which in addition is made in some even thinner brass.

This one happens to be a .15mm so it's also magnified a lot more

I guess technically it's a lot better.

At this point I should probably mount these on cameras and do an exhaustive comparison of image quality, but it's late.

Comparing 120 format images done with my 45mm Glenlivet Vertical Populist and 60mm Portrait Cameras, which have .3mm Gilder apertures, and the 45mm camera I made a few weeks ago,  and the 60mm new Evil cube which have .3mm hand drilled pinholes in brass, I really can't see that significant a difference.  I know I did the pictures for my experiments with developing paper in Caffenol with pinholes drilled in aluminum (although those negatives were 4x5), so you can still get some pretty decent pictures with that universally available material.

On f295, there would occasionally be an inquiry about how to make the sharpest pinhole images, and the discussion would inevitably devolve into statements that pinhole really isn't about sharpness so you probably shouldn't get too hung up about it.

Friday, January 13, 2017

New 6x6 at 45 and better results with caffenol

June 2019. When my university retiree account disappeared with a new change in policy, the pictures I uploaded to this blog while logged into that account disappeared. I'm working on fixing that but it's going to be at least a summer long project. The pictures I took with the camera are restored below.

Although I built the Evil Cube specifically for photographing the mansion at the Paine Art Center, when I went over there I also took the Glenlivet Vertical Populist.  I discovered I probably had more opportunities with the wider angle and if I had a second 45mm camera, I could take better advantage of the time I was there.

So I took the template I made for the 120 Populist, cut 3 cm out of the middle to make it 6x6 cm and cut the flaps and the film bay spacers down to 45mm and put the film counter hole in the middle.  Otherwise, follow the recipe.  There are some modern improvements such as three layer shutters and using cut off nails to keep the film reels parallel. The Student Services from the University were giving away those rubber wristbands (how can anybody stand to have those on their wrist?) in the school colors, black and gold. They turn out to be just the right size for the 120 populist and wide enough that you can cut them in half so placed on both sides, they hold the winders on very securely, and turned with the lettering inside, give that professional black body look. I hand drilled the pinhole which is .27mm.

I had been experimenting with caffenol developer last year using my old Compact 120 6x9, and had significant issues with background fogging - I thought.  I got some improvement working with table salt as a restrainer, but the pattern of the fogging increasing toward the edges of the film made me a little suspicious so I shot another roll and developed it in Microphen.  Turns out the Compact 120 6x9 has a low level general light leak, probably where the pieces go together but maybe also through the winders. Time to experiment with another camera.

I intended to develop the first role through this new camera with Microphen to double check for light-tightness, but I used the last of it on the roll from the Compact 120. I've had very little problem with light leaks with the Populist scheme, so I decided to go ahead with caffenol.  I used the standard C-M formula, but I added 6 grams of table salt (in 500 ml) as a restrainer since I was still using Arista 400.

I was very pleasantly surprised how well it turned out.

I started out on my bicycle to get some historic sights in Oshkosh.

I had to move into the middle of the street to get one of my favorite scenes - Boots Saloon, right across the street from a Catholic Church and Grade School. Only in Wisconsin.

An overgrown window in a dilapidated abandoned factory.  Once again, I wasn't paying close enough attention to making sure the film was tightly wound, and ended up with a curved film plane, which many people consider pinhole fun.

The giant sundial downtown in Opera square.

Speedboats stored on racks at the Mercury Marine Engineering Lab.

The roll sat in the camera for quite awhile while I waited for inspiration, but finally last weekend I decided to just finish it off around the house.

A sunbeam on the crystal doorknob in the bathroom.

A decorative pull on the curtains in the upstairs hallway window.

And another sunbeam in the corner of the kitchen next to the refrigerator.

I guess I'm warming up to black and white again. I've got plenty of washing soda, vitamin C and instant coffee left. I thought the Arista 400 was a bit grainy so I've gotten some of the 100.  Another lesson I had to relearn was to get some wetting agent.  I had significant scum marks on these negatives that took forever to retouch out.

Friday, January 6, 2017

A small dog

Regular followers may recall me mentioning a character missing from my posts in Boston who has no respect for pinhole time.

When he was just a puppy, I did get one photograph of Jeremy just after I had taken him for a long walk with the specific intent to wear him out.

He and his roommates recently visited Wisconsin, so I had the chance to pursue some other schemes.

Even the fastest moving animal will stay relatively still while they're asleep.

Another method is to take advantage of lighting situations where the exposure is only a second or two.

I'm not above using bribes to increase my chances.

When you become familiar with his routine, you find opportunities.

Things can change quickly when something gets his attention.

Petting is another good trick to keep him in one place.

But sometimes, he just seems to know he's having his portrait done.

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