Overdeveloped borders in tray develped sheet film

Hi,

 

I develop my sheet film (8x10) negatives by the tray method. As I

guess a number of us, I am disturbed by the slightly darkish borders

of the negatives which print like more or less subtle lighter border �

and quite noticeable in uniform surfaces, like a cloudless sky. I

understand that agitation is very much behind the problem: large

enough trays, and subtle movements are needed; also rotating 90º the

pile of films to avoid repeatedly touching the same border helps �.

But the whitish borders continue to appear.

 

I wander whether it may result from the fact that when the films

being developed are immersed in the developer, the pile they form is

far from perfect: thus while the center of the film is quite immobile

between the two adjacent sheets �avoiding developer agitation there -

, the borders outreach the limits of the pile, and developer moves

there even with the minimal and inevitable agitation of the developer

which results from rotating the sheets. I wander whether anybody has

essayed any method to hold the films into the pile without

outreaching its limits. Also whether developing a shorter number of

films � lets say 3, with a 10 min shift per film � results in less

border overdeveloping than developing a higher number � with more

frequent shifts and accordingly more developer agitation. And of

course I will appreciate any comment on the problem!.

 

Thanks !!

 

Eliseo Pascual

Do you presoak?

I could be wrong but I fail to see the presoak connection (and Ilford says NO to presoak).<p>I believe two things are possible here;<P>First...I believe you are correct if you're saying that stacking a dozen sheets (or half a dozen) in a small tray is a bad Idea. The exposed edges will get more fresh developer on them..the centers, that are not as exposed (if you will) to fresh developer will come along slower.<p>And two...which is connected to one...again small trays may be the problem. Small trays will produce more laminar flow along the edges then in the center, I found this to <i>really</i> be the case when I bleach back prints (to sepia tone them) in potassium ferricyanide. If you're bleaching a 8x10 print in a 10x12 tray you can see the edges bleaching <b>much</b> faster then the center...hopes this helps...jim

Yesterday I was loading some film and turned on the light for a

split second when I realized I left the stack of film on the counter.

The result was that I exposed the edges of the film, and of

course they develop in the tray. Now, I doubt you made that

mistake. I believe too many sheets of film is no good. I had

severe developing problems doing that. Now I went back to

single sheet developing and I am not having any kind of

problems like that you mention. Also some developers are more

prone to fog than others. I have switched from ABC pyro to

Pyrocat HD which reduces fog to a very minimum.

Anyway, only you can find out what it is. I would try a single sheet

in a tray with fresh developer and see if you get the same results!

I had this problem when toning an 8x10 print in an 8x10 tray. Try larger trays.

You are quite right in your assessment. This happens when you develop lots of sheets at a time in trays. The sheets do not sit in a perfect pile but are bound to move around a little. This means the sheets the bottom will have some edges exposed while the center of the sheet is covered bby sheets on top. If the rest between agitation of each sheet is very long, the developer is bound to get exhausted. But while the middle of the sheet will not get fresh developer till it is cycled from the bottom of the stack to the top, the exposed edges will get fresh developer and continue to develop. Thus, the ot edges.

 

Of course, I'm assuming other problems have been eliminated. That is, you are using the next larger size tray, the problem is not due to bellows flare (when you photograph bright objects e.g., snow, you can get this), you are presoaking or otherwise ensuring even uptake of developer and so on.

 

The solution is to develop a smaller number of sheets. That way, the developer in the emulsion does not exhaust before it is time to cycle sheets. Developing a good agitation-rest ration is a pretty important part of developing in trays. As a starting point, if it is taking longer than 30 seconds or so to move a sheet through one complete cycle, you probably should develop fewer sheets. Another techniques that minimize this problem are to use a large tray and place a pencil or something under the end of the tray so that the tray is tipped forward slightly towards you. This makes the stack slide towards you and makes it easier to sort of herd the stack together. You sshould also try to manage the stack with your free hand so that you prevent sheets at the bottom from sliding around.

 

Hope this helps. Cheers, DJ

Too many sheets, and trays too small.

For 8x10s use an 11 x 14 tray--nothing smaller. I have frequently

developed a dozen films at a time and have never had this

problem. I believe your problem is bellows flare--often

unavoidable when bright things are photographed--like skies.

Do you always use a lens shade?

Buy a Jobo and make your life easier, I did! :-)

 

CP Goerz.

Eliseo,

 

I solved a similar problem with 4x5 film by increasing the agitation and keeping the film in the stack exactly on top of one another with no edges sticking out.

 

I like to use as little agitation as possible to maximize edge effects, however, I found that my once-through-the-stack every minute agitation was too little and resulted in the problem you describe. I have since increased the agitation rate for the first half of the development time only (this is where most of the mottling and uneven development usually occurs) to once-through-the-stack each 30 seconds. I can develop up to six sheets easily with this scheme.

 

I also make sure that the top sheet is pressed down firmly onto the stack and that the stack is as perfectly aligned as possible. This has solved my problem.

 

I know many recommend 8x10 trays for 4x5, but I develop 4x5 sheets in a slightly oversize and deeper 5x7 tray with 500+ ml of solution only (PMK, Pyrocat or HC110). Film agitation is from the short side, turning the film 180° each time. Using smaller trays helps me keep the stack aligned more easily and seems to have no adverse affect on the evenness of development.

 

For those previously developed films there is always edge burning...

 

Hope this helps, ;^D)