PDA

View Full Version : Please help with this image



badler
24-Oct-2020, 05:47
I just rehabbed a Century 1, and using the 7inch sliding back have been working on some test images. The image below was one of the better attempts. I have a few typical problems, with the pour marks from the developer and some artifact from the edges. But the question I have is do you think I have a small light leak that is causing the burn out on the top left of the images. This would be of course the bottom edge of the plate in the holder. The camera is in pretty good shape, though the bellows are a bit dogeared. Though a flashlight doesn’t show anything but pinholes. I was also thinking it could be from reflection on the inside of the camera. The inside bellows are a light grey. Any advice is appreciated. Ok not any but the erudite and generous advice the forum is known for would be appreciated.
30cm Doppelastigmat f9, 3 Mississippi, UVX collodion, FeSo4 developer, KCN fix
208869208869

paulbarden
24-Oct-2020, 06:29
Not a light leak.
Without knowing your skill level, and the exact details of how you exposed and developed this plate, it’s difficult to offer specific advice. What developer did you use, and at what temperature? How long was the developer on the plate before rinsing it off? etc.

If I had to guess, I would say there is possibly some lens flare (backlit subject) compounded by insufficient exposure, which was compensated for by overdevelopment. In other words, it seems you’ve fogged the blacks by developing the plate too long. The Doppel-Anastigmat lenses are known to be quite flare-prone.

badler
24-Oct-2020, 06:47
Thanks for the response. The subject was sitting to the north, so the sun was behind the camera, though both are in shade. I’d say I am experienced but really only the last three months have I been able to get good plates.
Development was with FeSO4 per the doers manual, mixed with 25%old filtered developer. Everything was about 70 degrees yesterday, and development time was 10-15 seconds.

paulbarden
24-Oct-2020, 07:45
Thanks for the response. The subject was sitting to the north, so the sun was behind the camera, though both are in shade. I’d say I am experienced but really only the last three months have I been able to get good plates.
Development was with FeSO4 per the doers manual, mixed with 25%old filtered developer. Everything was about 70 degrees yesterday, and development time was 10-15 seconds.

If you’re using John Coffer’s developer recipe for positives, 15 seconds may be too long by 3 seconds or more. I’ve had trouble getting good performance using Coffer’s recipe on UVPX collodion. And don’t bother mixing in used developer: that isn’t going to help anything, even though John recommends it. It might be ok using Old Workhorse and Johns developer, but I found it only introduced problems when you used other formulas.
I still think flare contributed to the flatness of the sample photo.

There is a sure fire method to test whether unwanted effects are chemical, or from camera, or poor technique. Coat a plate with collodion as usual, but DO NOT expose it to white light. You are going to prep the plate as if making a photo, but go directly from the silver bath (after draining and wiping off the back) to the developer. Develop for exactly 10 seconds, rinse off the developer, and fix the plate. There should be nothing on the plate but black, unexposed collodion. Repeat this process adding 2 or 3 seconds to the developing time. At some point you will start to see developer fog making density on the plate. So now, make a note of the previous development time, choosing the longest time that did NOT result in developer fog. That should be your maximum development time under those conditions.
If you develop an unexposed plate for 10 seconds and still get some silver density forming on the plate, then something is wrong with your chemistry or the darkroom conditions: too warm, light leak in darkroom, or inappropriate safelight.
If you can develop an unexposed plate for 10-15 seconds and there is no fogging of the plate, then your camera/lens is possibly the issue, or you are not exposing the plate correctly. Avoid temptation to add more time to the development, to compensate for under exposure: all you will get is muddy tones and gray where black should be. Always develop for an amount of time you’ve predetermined to be optimal for your chemistry and conditions.

Also, what are you using to make plates on? Aluminum? Is it the aluminum with the plain metal backing or the one with white enamel on the back? These two aluminum products behave differently.

badler
24-Oct-2020, 08:06
Thanks
Do you have a different developer? I agree I struggle with the timing. As I have slowly improved my technique this year I have tried to be as consistent as possible changing only one factor at a time. Today I may swap lenses (Fuji 300mm) and try. Scull and Osterman is really quite close to the same formula. Quinn Jacobson’s is light on the Glacial Acetic and Alcohol. Or do you have a completely different formula?

mmerig
24-Oct-2020, 09:57
The black strip on top could be a light leak, but the picture-side of the strip is quite distinct, so maybe not. To eliminate the possibility, put a sheet of photo paper in your holder and go through the process of talking a picture, including pulling and replacing the darkslide, but of course don't trip the shutter. Then develop the paper and see if you get a leak. If you get one, try the same with just the holder and dark slide in strong light to see if it is the holder itself or a bad seal against the camera back.

Is it possible that the emulsion pealed off at the edge?

paulbarden
24-Oct-2020, 10:47
Thanks
Do you have a different developer? I agree I struggle with the timing. As I have slowly improved my technique this year I have tried to be as consistent as possible changing only one factor at a time. Today I may swap lenses (Fuji 300mm) and try. Scull and Osterman is really quite close to the same formula. Quinn Jacobson’s is light on the Glacial Acetic and Alcohol. Or do you have a completely different formula?

To troubleshoot this process, it is very important to change only one variable at a time. I suggest changing out the lens first, and go from there.
But I strongly recommend doing the developer tolerance limits test: develop a sensitized, but unexposed plate, and determine the maximum number of seconds you can leave developer on the plate. Many problems I see people having are related to overdevelopment. If you have difficulty counting out an exact amount of time, find a way to get good at it. Duration of the development is critical to nailing down good process.

For now, stick with Coffer's developer recipe: you're right - it has more acetic acid than Quinn's recipe. When you encounter a problem where unexposed silver is being reduced on the plate, you need all the acid restrainer you can get.

badler
24-Oct-2020, 12:25
Well I did 1/2 of what you said. I did a test and actually came up with 5-7 secs. But I did switch to Quinn’s formula. I would love to lengthen the time, if just to better appreciate the detail before I stop. The plates today came out quite well. I do hope that the temp doesn’t drop much for the next few weeks. No such flare today, but I bet it was the over development. Thanks for the help.

paulbarden
24-Oct-2020, 14:12
Well I did 1/2 of what you said. I did a test and actually came up with 5-7 secs. But I did switch to Quinn’s formula. I would love to lengthen the time, if just to better appreciate the detail before I stop. The plates today came out quite well. I do hope that the temp doesn’t drop much for the next few weeks. No such flare today, but I bet it was the over development. Thanks for the help.

If you are getting silver developing out on an unexposed plate at 7+ seconds, then there's something else wrong. Are you using exactly the correct ingredients for the developer recipe? (IE; not substituting ethanol for ??, or using vinegar instead of glacial acetic acid) What are you using for a safelight? the Amber/orange types are often NOT safe for collodion work. You should easily get at least 10 seconds of developing time on an unexposed plate without fogging.

badler
25-Oct-2020, 05:55
I’ll do some more work. The formula is correct. The safe light is a red led so good there.

paulbarden
25-Oct-2020, 08:43
I’ll do some more work. The formula is correct. The safe light is a red led so good there.

Don't be too sure about the red LED. When I started wet plate work three+ years ago, I bought a couple of red LED bulbs for the darkroom and they were great - for a while. Turns out these were white LEDs with a red coating on the shell of the bulb which faded over a period of months. They started leaking orange and yellow light which fogged my work more and more. It took a while to figure out what the culprit was, because I assumed the LEDs were not the problem.
If its an actual red light LED, you're safe. But watch out for those color-coated bulbs.

badler
26-Oct-2020, 13:07
Went back into the box today and worked through the development time of the Quinn Jacobson solution and came up with between 30-45 seconds. Then did a few plates. I am certain I was overexposing and underdeveloping. Thank’s for your help.

paulbarden
26-Oct-2020, 13:20
Went back into the box today and worked through the development time of the Quinn Jacobson solution and came up with between 30-45 seconds. Then did a few plates. I am certain I was overexposing and underdeveloping. Thank’s for your help.

Would you care to show us a sample of more recent plates?

badler
26-Oct-2020, 18:37
Here is today’s test plate. 4 Mississippi, 30cm f 6.3 Quinn’s FeSO4 30 sec dev time. Not much of a composition but the subject held still208939

paulbarden
26-Oct-2020, 20:27
Here is today’s test plate. 4 Mississippi, 30cm f 6.3 Quinn’s FeSO4 30 sec dev time. Not much of a composition but the subject held still208939

Success!
Working out the technical aspects of the wet plate process is serious business: it takes time and you have to be meticulous about things. But when you get it all working well, it becomes almost effortless, believe it or not. Keep going!

goamules
29-Oct-2020, 11:01
Yep, just read this, and the first thing I thought looking at your first example was "overexposed". It can show up a weird places looking like brighter areas or swirling flows, simulating other problems.

On too fast developer, you can always add sugar. I use 2 TBS for a batch of about 600ML developer. I use vinegar for my acetic acid.