I know this is a very old thread, but I wanted to say that after a week of failing to make a polymer photogravure using the standard 2-exposure method, I saw this comment and tested directly printing...
Type: Posts; User: Sam L; Keyword(s):
I know this is a very old thread, but I wanted to say that after a week of failing to make a polymer photogravure using the standard 2-exposure method, I saw this comment and tested directly printing...
For me, the most interesting part would be to do some simple design work and learn basic optical engineering (I'm an engineer by training -- always fun to do someone else's real job for a while).
...
This is fascinating. I would really like to build a lens, maybe from surplus elements.
Is there a good book or web resource for learning how to do this? Ideally, more than just recipes but not...
John,
Yes, I believe plastic would work but you might need to design your tanks around it. PVC is a lot thicker than metal tubing. I only had about 3/4" at the bottom of my tanks and 1/2" at the...
Bernice, thanks! Very helpful.
Maybe a plastic coating or electroplating it. The holes in the plenum are so tiny (1/64") that any kind of coating is likely to clog them. They can be cleared out by re-drilling them but it's very...
D-23
D-23 produced dramatically softer negatives than the other developers tested and it was the most well behaved. Shadow detail was dramatically better than the other three. However, I can't say...
PaRodinal (Tylenol developer)
After seeing the smooth dense areas that Rodinal delivered, I decided to try making it. PaRodinal isn't Rodinal but it has the same developer (p-aminophenol). You...
R09 One Shot Rodinal
R09 Rodinal delivered a contrasty and noticeably sharper (higher acutance) negative than 510 Pyro. Dense (white) background areas were smoother and it masked uneven agitation...
Now that I have my 8x10 gas burst system working, I decided to see which developers work the best with it and Fuji HR-U x-ray film.
I think I still like 510 Pyro the best but the others I tested...
JBB, happy to share the code, though I think you should do something much simpler. PM me and I'll send you a link.
My solution ended up being clean but is way overkill. If I were to do it again,...
John, you're right -- the dead-end tube didn't end up working well so I replaced it with a Tee version (picture in my second post).
Thanks for the ideas! There are a lot of cheap cold shoe options on amazon. I was thinking of buying one and making a mount for it to the camera.
Bernice, could you tell me how the Sinar shoe...
Is there a known good solution for holding up the wireless flash trigger when connected via a wire to a shutter?
The one I have is meant to mount in a hot shoe.
I wanted to add that if you are willing to pay for standard full-strength chemicals and name-brand film, you will probably get excellent results with unmodified hangers and dip-and-dunk agitation....
No, I don't use photoflo. But, I will try scrubbing the hangers. Maybe they're contaminated from a past life or with other stuff. Thanks for the idea!
That's an impressive set up!
Are you seeing corrosion on non-stainless fittings?
Hi Matt,
For whatever reason, I don't get surge marks with my unmodified 4-up kodak hangers, even with 1:250 pyro and dip-and-dunk agitation. My agitation technique is: lift, tip >45 degrees away...
Finally, the gas source. Everything I read suggested an industrial gas bottle of nitrogen, which is inert and so won't oxidize the developer. I don't have a nitrogen bottle, but I do have argon for...
The next challenge was to control the gas bursts. In spirit, the mechanism is very simple: a solenoid on a timer. Amazon has 12VDC normally closed solenoids for about $10. These can be controlled in...
From the first plenum, there were a few things I wanted to improve:
1. 1/32" holes were too big. Too much pressure was dropping in the first few inches of tubing because it wasn't restrictive...
I spent some time making gas burst agitation for my 1-gallon arkay style tanks and wanted to share what I learned.
This older thread was extremely helpful:...
Hi Michael!
I got a copy of that edition of View Camera and read your article while doing this! Thanks for the inspiration.
Spinel black pigment is available from Kremer:
https://shop.kremerpigments.com/us/shop/pigments/47400-spinel-black.html
At Tin Can's suggestion, I tried compressed air. It works!
I used Fuji HR-U x-ray film with 510 pyro at 1:100. The photo was normally exposed at ISO 80 using a sekonic light meter and 5600K LED...
Neal, interesting idea about temperature being an issue. I develop at room temperature, but I pre-soak the hangers and negatives in tap water, which is much cooler to start. I wonder if that's...
Vaughn,
X-ray film hangers are similar to what you suggest. The clips at the edges actually punch holes in the film with a little spike. Here are some for 14x17 film:
223469
223470
I...
Tin Can, Could you zoom in on one of your reference scans and see if you're getting spots too?
I can't see them at 8x10 but they are clear in a 1000 dpi scan at 100% zoom.
RockAndRolf, can you see the spots on the film (not just the print)?
More details:
- 4 minute pre-soak in tap water. San Francisco water is very pure.
- Reverse osmosis filtered water used for Rodinal dilution
- Rodinal mixed a few minutes before using (maybe sat...
I tested 510 pyro and rodinal bracketed from 3-6 minutes 68F 1:100 on Fuji HR-U. 3 minutes was thin, 4:30 - 5:30 was about right, 6:00 was getting too dense. However, the 6:00 negative had the most...
Hanger modifications are cataloged here:
https://www.largeformatphotography.info/forum/showthread.php?166968-Modifications-to-Kodak-8x10-hangers-for-even-development-of-double-sided-X-Ray-film
I've been chasing even development with dilute developers on Fuji HR-U x-ray film.
I've gotten good results with 510-Pyro at 1:100 for 5 minutes but Rodinal at 1:100 looks even smoother. The...
The third change I made was to address the marks left on the rear emulsion by the clip at the top that holds the film in. It hangs down relatively far below what I consider the margin of the film. On...
To fix the remaining surge marks at the bottom of the hanger, I used a cutoff wheel and a file to remove most of the metal in the bottom, creating long open slots:
223439
The result was no more...
Kodak 4A hangers have holes all the way around the sides facing out and holes on one of the faces. I thought the holes on the face were to improve chemical flow to the emulsion but the holes appear...
I've been working on developing Fuji HR-U double-sided x-ray film in 1-gallon vertical tanks with Kodak 4A hangers and have made some good improvements that I wanted to share.
I created a...
I've put a lot of work into this over the past few weeks and I'm starting to get satisfactory results. Here's a photo taken today against a white canvas backdrop:
223417
I ended up needing to...
Well, technically it affects every scan of every negative. It's not a good choice for, say, archival preservation of large format negatives.
However, it is rare that you will see the unevenness...
I suspect it is a feature of the scanner -- specifically what it's doing with its calibration area. I just think it isn't very good at it over large areas. I'm sure it's a hard problem.
If you...