Corner fogging and air bubbles on BW 4x5

[evanmoly]

My last batch of processing revealed two possibly separate issues in the negatives. I did a bit of searching around the forum and believe I know partially what's going on. If anybody else wants to share their theory, I'd love to hear it. Thank you in advance for reading my technically inept rant :)

1. Air bubbles on the emulsion and muddy tones - Insufficient agitation? I was actually agitating more frequently than I do with roll film, though definitely not as vigorously, so how does one agitate a Yankee tank enough without the developer spilling out?
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2. Fogging in the corners - for the 30 sheets I processed from the same box of TXP320 dated 05/18:
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-22 with consistently bad fogging in the corners - see example posted. From a December 2018 road trip across the Southwest. The sheets were transferred to an empty film box for storage the day they were exposed, which was kept in a ziploc bag with a desiccant in a cooler (basically a lunchbox) for the past six months, trying to avoid excess humidity or drastic changes in temperature until I could process them.
-6 have no discernible fogging, exposed just prior to that December road trip, and stored in the same box in the same conditions.
-2 with no fogging issues, exposed about 18 months ago, stashed in a box in the basement and forgotten about until this week.

I want to blame the storage conditions for the fogging but the fact that 6 sheets with no visible issues were exposed around the same time as the problem negs and kept in the same box makes me reluctant to do that. The only thing I can think of along those lines is that the more recent sheets closer to the top of the storage stack somehow got hit with light and/or ambient radiation. I'm gonna go out on a limb and say that processing film immediately after exposing it like every manufacturer recommends would probably mitigate the fogging...


The basic setup-
Txp 320 exposed at box speed
Xtol 1:1
Yankee daylight tank
10 minutes, 30s continuous agitation at start, then 10s agitation every 30s
Chems mixed with tap water. no idea how old the stop, fix and permawash were.

[Pat Kearns]

You didn't say if you do a pre-soak before starting the development of the film. Air bells can form on the film when you pour in the developer. The air bell keeps the developer from reaching the emulsion resulting in those circular spots. Immediately after pouring in the developer you need to give the tank several good jolts to dislodge the air bells. A water presoak of about 2-3 minutes before the developer should eliminate the air bells. Some film manufacturers say not to presoak. Some photographers do presoak others don't. I am of the school that presoaks and have never had issues with the air bells. If your developer is fresh and is being used as a one shot then your agitation methods look pretty good. If your developer is old it could have oxidized leading to the muddy tones. I've never used a Yankee daylight tank so I really can't help you solve the loss of the developer with the tank. Good thing about this forum there are a lot of people here that are very generous and will share their knowledge. I'm sure others will chime in soon.

[evanmoly]

You didn't say if you do a pre-soak before starting the development of the film. Air bells can form on the film when you pour in the developer. The air bell keeps the developer from reaching the emulsion resulting in those circular spots. Immediately after pouring in the developer you need to give the tank several good jolts to dislodge the air bells. A water presoak of about 2-3 minutes before the developer should eliminate the air bells. Some film manufacturers say not to presoak. Some photographers do presoak others don't. I am of the school that presoaks and have never had issues with the air bells. If your developer is fresh and is being used as a one shot then your agitation methods look pretty good. If your developer is old it could have oxidized leading to the muddy tones. I've never used a Yankee daylight tank so I really can't help you solve the loss of the developer with the tank. Good thing about this forum there are a lot of people here that are very generous and will share their knowledge. I'm sure others will chime in soon.


Hi Pat, no I did not do a presoak. I thought a presoak was to soften the emulsion for the developer to start working as soon as it came into contact with the film, and did consider that it could affect the formation of air bells.

[Fred L]

does the corner overexposure go past the rebate ? if not, I'm thinking possible light leak somewhere in the process.

[Kevin Crisp]

My thoughts:

1. Yes, look like bubbles on the film. Pat is right, you need to give the tank a couple or three hard whacks after the chemicals go in to dislodge the bubbles. With 35 mm and metal tanks I really strike the tank down hard on a wooden surface with a towel over it. I'm not familiar with the "Yankee" daylight tank and how strong it might be.

2. Food for thought....what is the ratio of people who have development issues when using tanks and/or hangers to those who tray develop? Must be 4000:1 based on posts on this forum. I realize some people can't in their environment have an open tray in the dark for 10 minutes, but it is simple and it works. I use gentle continuous agitation (tray rocking) as recommended by Kodak in a number of their publications. I get even development even when times are down in the 4 minute range.

3. I never pre-soak. I can't think of a theoretical reason development would be more even when doing it. It takes me about 1.5 seconds to fully submerge a sheet of film in a tray. The film will evenly become wet in that period of time. It would be impossible to see a difference from one part of the sheet hitting the solution a second or two before the other parts. And in a tank the sheet isn't going to be 'all in' any faster. Maybe it helps with bubbles, I don't know. I haven't had a bubble on a negative in the last 45 years. The last time I had the problem I had just started developing film using one of those plastic (I think it was a Yankee) 35 mm tanks with the thermometer/stirring rod in the middle hole. I started using metal tanks I could whack on the counter and never had another issue.

4. The delay in processing is unimportant. I am sure I am not alone in finding a sheet in a holder that I forgot to develop. It has been sitting in the holder for a year or two and when developed looks just fine. More likely fogging is taking place in the camera or when transferring sheets into and out of a box. If you are shooting 4x5 get more holders, they can be found on Craigslist for around $7 each. Beats all that film handling in and out of boxes. The Riteway holders for whatever reason are available for very little and they are perfectly decent.

Good luck and sorry you are having problems.

[evanmoly]

does the corner overexposure go past the rebate ? if not, I'm thinking possible light leak somewhere in the process.

Hi Fred, here is a quick snap of the negative on the light table (please ignore horizontal bands from florescent backlight). The borders masked by the holder are crisp and unfogged, so if I understand correctly, that is evidence of a light leak during exposure?
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[evanmoly]

Hey Kevin, I appreciate the feedback. I look forward to someday having my own tray setup and practicing development by inspection. For now I'm on the move so much that my options are pretty limited!

[evanmoly]

does the corner overexposure go past the rebate ? if not, I'm thinking possible light leak somewhere in the process.

Fred, I also shot color negatives in many of the same places, just re-cocking the shutter and putting another holder in, and none of those have the same fogging issue at all. To me, that indicates the problem is not with the camera/bellows.

[evanmoly]

Thanks to all for walking me through the evidence, *it just clicked* - these corners developed unevenly because of the way I was rocking the tank back and forth. For the first two batches I ran (22 problem negatives) I was tilting the tank up on its left edge, then its right edge, back and forth. For the final batch, I recall that I changed up the technique a bit and shuffled the tank left and right, keeping it more in the same horizontal plane.

Hope this helps anybody else who is working through similar issues!

[Pat Kearns]

As Kevin mentioned above take a dish towel, fold it a couple of times and place on the counter. As soon as you finish pouring in the developer bang the tank on the towel several times to dislodge the air bells. You don't want to crack the plastic tank by hitting it on a bare counter top.

[Jim Jones]

I always presoak film in water with a bit of photo-flo before developing either on spiral reels or in trays. It was absolutely necessary when solarizing Tech Pan in Solarol developer.

[Randy]

...so how does one agitate a Yankee tank enough without the developer spilling out?

I don't think you can - and I don't see how one could possibly obtain uniform agitation in one (I have tried).
There are other tanks that are supposedly water-tight.
There are dip-n-dunk tanks using film hangers.
Or, as I have been doing for many years, just lay out 4-5X7 trays in the bathtub (if you can make your restroom light-tight) and process away.