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D76 dying in open trays quickly

BetterSense

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I've been developing xray film in a tray, using D76 1+3. The developer completely dies after a couple hours in the tray. Is this normal or is there something wrong with my D76 stock solution?
 
I think this may be normal. D76 1+3 will die pretty quick with normal film. I don't have much experience w/ XRAY film but I will bet it exhausts such a dilute developer pretty quickly given the size of the grain - sort of like TMZ burns up developer.

You may want to try something with more activity and/or less dilute.

RB
 
How much film have you run through that tray in a couple of hours? Or, is it unused as it sits in the tray? D-76 full strength is rated to handle the equivalent of 4 sheets of 8x10 film per liter in a tray - so D-76 1:3 should handle only 1 sheet. Funny, doesn't sound like much capacity does it?

So, if you are processing very much film in your tray, you are possibly just running the developer into exhaustion. Developer diluted with three parts extra of water is pretty heavily watered down.
 
BetterSense said:
I've been developing xray film in a tray, using D76 1+3. The developer completely dies after a couple hours in the tray. Is this normal or is there something wrong with my D76 stock solution?
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With that dilution, I would say it is normal.
 

And not only does it seem to have little capacity, but most x-ray films have emulsion on both sides IIRC. That probably halves the stated capacity.
 
In the past, I was short on developer, and in a hurry, so I developed three rolls of film in the same batch of D-76 1+1 one roll at a time and no discernable difference between first and last roll. I did add 5%(if memory servers)time increase between rolls. According to Kodak, this is not possible, but we all know their reasoning for underrating their product life. Anon is correct about the double-sided emulsion, that would be a good reason for short life in the tray. Possibly adding D-76R between batches would help extend tray life.

Rick
 
ralnphot said:
According to Kodak, this is not possible, but we all know their reasoning for underrating their product life.
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Come on now. They're not all evil. Kodak, and indeed any reputable manufacturer of any sort of product, wants you to have good and consistent results. It generates customer loyalty, and what's wrong with that?
 
Have been using dektol 1:7 solution roughly for 8x10 shts of litho film.Even this has died on me but is good for about 5 shts at 400ml to 2500ml water.2 1/2 min development time
 
mike c said:
Have been using dektol 1:7 solution roughly for 8x10 shts of litho film.Even this has died on me but is good for about 5 shts at 400ml to 2500ml water.2 1/2 min development time
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The more dilute the developer, the faster it goes bad. I still think it a good idea to replenish after a specific number of sheets.
Frank, that was just some good natured sarcasm about marketing. We all know that manufacturers want us to be happy and have consistant results, so they always give conservative numbers in their info.

Rick
 
mike c said:
Have been using dektol 1:7 solution roughly for 8x10 shts of litho film.Even this has died on me but is good for about 5 shts at 400ml to 2500ml water.2 1/2 min development time
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With Dektol at 1:7, it is more normal to use 7 minutes development for most films and at 1:3 it is more normal to use 3 minutes. I have used this rule of thumb for years, and it is taught by both Al Weber and Dave Vestal at their Workshops.

As for processing X-Ray film, it contains over 2x the amount of silver than any other film product. Therefore, one 8x10 sheet is equivalent to nearly 4 sheets of normal 8x10. So yes, at this dilution, D-76 would be used very rapidly, especially in a tray.

PE
 
The way it worked on two separate occasions is I developed 1-2 sheets max in about 500ml of working solution, then left the tray for several hours, and then when I tried to develop another it was completely dead. I didn't think about exhausting the developer with only 1 or 2 sheets. I think when I use D23 I will double my replenishment rates.
 
BetterSense said:
... I developed 1-2 sheets max in about 500ml of working solution, then left the tray for several hours, and then when I tried to develop another it was completely dead. ...
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What size sheets? 4x5, 5x7, 8x10, some other size?
 
One way to get more sheets through it and better consistency would be to work with a greater volume - a liter or two or three of your dilute developer. I would not want developer to die on me halfway through a critical sheet of film.
 
It was 8x10 film.

I would have been being more careful all around if the shots were important. I'm building a box camera and the negatives were only being used to verify the focus distance.
 
Remember that 2 sheets of your 8x10 are roughly the equivalent of 4 - 12 sheets of normal 8x10 in 125 ml of concentrate. It depends on the type of X-Ray film.

PE
 
Remember that 2 sheets of your 8x10 are roughly the equivalent of 4 - 12 sheets of normal 8x10
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Really? I've been wondering if I should replenish my D23 (my normal developer) at a higher rate than I would if I were using normal film rather than Xray film. Since I don't have process control strips or anything there was really no way to tell, so I continued replenishing normally.
 
Normal B&W camera film contains about 300 mg / ft square of Silver. Industrial X-Ray film contains about 1 - 2 GRAMS / ft square of Silver. Medical X-ray contains about 2 GRAMS / ft square of silver. Does this put it in perspective?

Remember too that many types of X-Ray film is coated on both sides. This is taken into consideration in my figures above.

People continue to overestimate the Silver in B&W film and underestimate the Silver in X-Ray film.

PE
 
Normal B&W camera film contains about 300 mg / ft square of Silver. Industrial X-Ray film contains about 1 - 2 GRAMS / ft square of Silver. Medical X-ray contains about 2 GRAMS / ft square of silver.
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You sure about that? Current spot price of silver is about 17 dollars per ounce. So 1 gram is .0352739619*17=about 60 cents. So a square foot of the film should cost over a dollar just in silver.

I think I might go to using a different batch of developer for xray film. Or use something like HC110 one-shot
 
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Photo Engineer said:
People continue to overestimate the Silver in B&W film and underestimate the Silver in X-Ray film.

PE
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Yes... by coincidence, I was just looking over some figures and it seems though, that the range of silver for both is quite wide and some X-ray films made for semi-rapid processing (90sec dry to dry) may contain less than 750 mg per Ft.... a figure which some camera films are said to have approached as well....

Better Sense,

Sorry if I missed it, but out of curiosity... are the exposures... X-rays?
I have forgotten what they are called but I have seen some very stunningly beautiful, low powered x-ray images of flowers.
 
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No, the images are not X-ray images. It takes X-rays to make X-ray images, and it may not work as you think. X-ray film is loaded into special holders that have phosphors that glow either green or blue when exposed to X-ray. The majority of the exposure is made by the glowing phosphors and very little by the X-rays directly.
 
Frank is correct, and that is why the film is coated on both sides. One captures the X-rays and the other captures the glow from the phosphors. And, it is why some films are very high in silver content. And yes, I am sure of the values that Silver can reach in films of this type, and yes, I know the spot price of Silver. I am also aware of how inexpensive the film is compared to your calculated price but remember that EK and Fuji buy in huge quantities and they buy in advance of expected price increases.

Fuji X ray film (10x12 medical) is about $40/100 sheets which is dirt cheap even figuring Ray's level of Silver. I said it varies, right? And the cost is not related to the spot price of Silver today. Kodak buys Silver waste and makes their own Silver Nitrate. See the film on that posted by Marco. They save a lot this way.

PE
 

I must have missed the part where the white light exposure was mentioned.

There are two types of X-ray images, the fuzzy screen radiographs that you describe, made with intensifying screens and the sharper, direct X-ray images made without such phosphor screens.
 

Adding to those comments the recycling of X-ray film as well as the fixers has always been a profitable business.

In the UK the NHS only stores X-ray films for 7 years then it's bought for recycling & silver recovery. Usually spent fixer or Bleach fix is used in the recovery process, the film is rehalogenated then the silver removed using fixer which is itself recycled through plating units.

Ian
 
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Ray Rogers said:

I had the same reaction when I first looked at the numbers!

Kind of hard to believe at first...
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If PE says it, I tend to listen very closely. His statements derive from a career in photographic chemistry at Kodak. What better source could there be?
 
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