Leader Density: D-76 vs Rodinal and others

Fred Aspen said:

Thomas, I made an observation that 76 appears to be a much weaker developer than Rodinal as it will not develop a leader to max black as Rodinal will do. I am trying to determine if this weakness (3 full stops by my measurement suggested by ic-racer) is inherenent/intentional in the design of D-76 or I, somehow, keep mixing dodgy 76.

Did Kodak intentionally design 76 to roll off the shoulder so it will not develop beyond a density of roughly 2.3 and that's its limit while Rodinal will develop to well over a density of 3?

When I first observed this my first thought was that the negs are not fully developed and this proved the case when printing negs from 76 and Rodinal respectively. My D-76 negs are noticeably flatter than Rodinal negs. I originally expected that they would print very similarly when developed to similar CI.

Is this intentional or is my work flow flawed?

It's as simple as that.

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OK. So the leader made you suspicious, but that led you to be curious about what's in the actual negatives. Phew. I was worried about the state of film photography there for a while.

If your D76 negs are flat, try developing them longer. See what happens. I use regular tap water, and have not found it to have any adverse effect. Compared to Pyrocat, Rodinal, Xtol, HC-110, FA-1027, and PMK Pyro I am having no problems at all reaching similar contrast in the negatives with D76 1:1, for what it's worth.

Thomas Bertilsson said:

OK.
If your D76 negs are flat, try developing them longer. See what happens. I use regular tap water, and have not found it to have any adverse effect. Compared to Pyrocat, Rodinal, Xtol, HC-110, FA-1027, and PMK Pyro I am having no problems at all reaching similar contrast in the negatives with D76 1:1, for what it's worth.

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So I can assume that your neg's leaders developed by your methods in 76 1:1 reach complete opacity, max black, i.e., you cannot see any object when trying to view through them?

Fred Aspen said:

So I can assume that your neg's leaders developed by your methods in 76 1:1 reach complete opacity, max black, i.e., you cannot see any object when trying to view through them?

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I don't ever look at the leader. I look at how the negatives print, in contact sheets and in actual prints. The leader tells me zero about how the negative will print.

Thomas Bertilsson said:

I don't ever look at the leader. I look at how the negatives print, in contact sheets and in actual prints. The leader tells me zero about how the negative will print.

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Thomas, I agree.

Excerpt from Kodak Sensitometry Workbook:

"(Maximum density) This is a measurement of
the darkest a film can be. For most
black-and-white films, the D-max is not
shown on the characteristic curve because it
is beyond the scale printed from the step
tablet. If a piece of film is exposed to sunlight
for a few seconds and then developed, the
resulting density will be D-max."


Note the last line: while the leader density certainly has nothing to do with print quality, it certainly indicates if the developer is doing its job. Hence, my original questiion.

This indicates to me that the leader should be max black when normally developed. Agree?

Fred Aspen said:

Thomas, I agree.

Excerpt from Kodak Sensitometry Workbook:

"(Maximum density) This is a measurement of
the darkest a film can be. For most
black-and-white films, the D-max is not
shown on the characteristic curve because it
is beyond the scale printed from the step
tablet. If a piece of film is exposed to sunlight
for a few seconds and then developed, the
resulting density will be D-max."


Note the last line: while the leader density certainly has nothing to do with print quality, it certainly indicates if the developer is doing its job. Hence, my original questiion.

This indicates to me that the leader should be max black when normally developed. Agree?

Click to expand...

I understand where you're coming from and would also want my film leader as dense a black as possible, but that doesn't mean you can't get a decent print from what you now have. It does mean you might not be working with an optimum negative. Could be one of three things I think. 1. Not developing out your negative fully. 2. Weak or oxidized developer. 3. Highly diluted developer and not enough developing time. I ruled out temperature, but you could check your thermometer to make sure. It's also a possible water problem, but I'd say extending development is the first thing I'd try. That also means you might have to play with your exposure too in order to get the contrast you want in your negatives. I'm not using D76 at the moment, but do use Perceptol and that's pretty much the same as Kodak Microdol. Microdol and D76 are like brother and sister developers. I have very black leaders coming out of Perceptol, which is the same as Microdol. At least when I look at a 60watt bulb it looks nice and dense. Just my 2 cents and 2 cents ain't worth much anymore. JW

Fred Aspen said:

Thomas, I agree.

Excerpt from Kodak Sensitometry Workbook:

"(Maximum density) This is a measurement of
the darkest a film can be. For most
black-and-white films, the D-max is not
shown on the characteristic curve because it
is beyond the scale printed from the step
tablet. If a piece of film is exposed to sunlight
for a few seconds and then developed, the
resulting density will be D-max."


Note the last line: while the leader density certainly has nothing to do with print quality, it certainly indicates if the developer is doing its job. Hence, my original questiion.

This indicates to me that the leader should be max black when normally developed. Agree?

Click to expand...

I'm sorry, Fred, but I still fail to see how it would be important. D-max is not something you print since it's a hundred miles beyond what your paper can see, which means relevance is an issue. It's a piece of film with 400 bajillion times more exposure than anything that goes through your camera lens.

Instead of being suspicious of the developer, and you say that your developed negatives are flat, you should think about technique. Flat prints means you don't have enough contrast in the negative. To increase negative contrast you develop the film longer. Try that first and see if you can make nice prints. Then, if you must, you can make a meaningful comparison between the two developers.

Never compare the results of two developers until you have negatives of the same contrast.

JW PHOTO said:

I understand where you're coming from and would also want my film leader as dense a black as possible, but that doesn't mean you can't get a decent print from what you now have. It does mean you might not be working with an optimum negative. Could be one of three things I think. 1. Not developing out your negative fully. 2. Weak or oxidized developer. 3. Highly diluted developer and not enough developing time. I ruled out temperature, but you could check your thermometer to make sure. It's also a possible water problem, but I'd say extending development is the first thing I'd try. That also means you might have to play with your exposure too in order to get the contrast you want in your negatives. I'm not using D76 at the moment, but do use Perceptol and that's pretty much the same as Kodak Microdol. Microdol and D76 are like brother and sister developers. I have very black leaders coming out of Perceptol, which is the same as Microdol. At least when I look at a 60watt bulb it looks nice and dense. Just my 2 cents and 2 cents ain't worth much anymore. JW

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JW, you get what I am asking!

On your points: 1)I am using manufacturers recommended development time (I have gotten max black with HC110, Perceptol, and others. It's the 76 that is the problem.), 2) This is the one I am presently chasing; there has to be something in the prep or dilution that is weakening the developer but I can't for the life of me put my finger on it, 3) I have a Kodak Color Process thermometer which I regularly check against a metrology lab thermometer and use a controlled temperature water bath for development.

Exposure is where I want it with ample shadow detail and is perfect with other developers.

Your analysis/observation is spot on: I am working with less than optimum negs when developed in D-76. I have used D-76 since Photography School in the early seventies and never had less than max black leaders, but something has changed. We were taught that the leader was the key to whether the developer was doing its intended job.

I will continue with 76 once I figure out what the issue is. It bothers me a lot that I can't get the same results with 76 that I have had in the past.

Fred let us know what you eventually conclude. I can't speak for anyone else but it has got me thinking. Thanks

pentaxuser

Fred Aspen said:

JW, you get what I am asking!

On your points: 1)I am using manufacturers recommended development time (I have gotten max black with HC110, Perceptol, and others. It's the 76 that is the problem.), 2) This is the one I am presently chasing; there has to be something in the prep or dilution that is weakening the developer but I can't for the life of me put my finger on it, 3) I have a Kodak Color Process thermometer which I regularly check against a metrology lab thermometer and use a controlled temperature water bath for development.

Exposure is where I want it with ample shadow detail and is perfect with other developers.

Your analysis/observation is spot on: I am working with less than optimum negs when developed in D-76. I have used D-76 since Photography School in the early seventies and never had less than max black leaders, but something has changed. We were taught that the leader was the key to whether the developer was doing its intended job.

I will continue with 76 once I figure out what the issue is. It bothers me a lot that I can't get the same results with 76 that I have had in the past.

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Fred,
I can tell right now that this problem is going to bug you no matter what your negs/prints look like. So, until you get it solved you're probably not going to sleep well at night. I don't know for sure how you are rating your film and as for the manufacture "suggested" times they're just a good starting point. I think what is stumping you is the fact that you seem to have good shadow detail, or what you think is good and don't want to mess with developing times since it will screw your shadow detail up just a little. The truth is if you develop longer it will screw them a little, but you more than likely will end up with a much darker leader section. Once you get that leader section density you want, or think you need, you could then work on exposure to get your shadows back where you had them. The old rule of thumb applies here "Expose for the shadows and develop for the highlights". Changing your developing time doesn't move the shadow up the scale as much as it does the highlights or densest parts of your negative. I still say develop more and expose accordingly. 2 cents again! JW

JW PHOTO said:

Fred,
I can tell right now that this problem is going to bug you no matter what your negs/prints look like. So, until you get it solved you're probably not going to sleep well at night. I don't know for sure how you are rating your film and as for the manufacture "suggested" times they're just a good starting point. I think what is stumping you is the fact that you seem to have good shadow detail, or what you think is good and don't want to mess with developing times since it will screw your shadow detail up just a little. The truth is if you develop longer it will screw them a little, but you more than likely will end up with a much darker leader section. Once you get that leader section density you want, or think you need, you could then work on exposure to get your shadows back where you had them. The old rule of thumb applies here "Expose for the shadows and develop for the highlights". Changing your developing time doesn't move the shadow up the scale as much as it does the highlights or densest parts of your negative. I still say develop more and expose accordingly. 2 cents again! JW

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JW,


This afternoon I mixed another gallon of 76 but, instead of Kroger distilled water, I substituted Crystal Geyser Spring water (just good drinking water) and souped two snippets. One at 6' and one at 9', developed and fixed normally and both were solid D-max snippets. Couldn't see a thing through them. This evening I will soup a roll of Neopan 400 I shot this morning and see how that goes. Again, very early results but very promising.

I haven't a clue why Kroger distilled weakened the developer but perhaps someone one the forum might have some input. My wife, a chemist, said all along the water was the Red X but I just couldn't accept that. Turns out that she is most likely right and concluded that "who knows what that water might have in it that is not listed on the label." Also, it appears that the distilled water only affected the 76 and Xtol and didn't bother other formulations. Go figure!

I have been religiously using the same brand distilled water for years not knowing it was playing havoc with my favorite soups!

Try the contact-sheet "proof" idea I mentioned above for a guide as to what is available from your negs if/when you change something. Also, when in yucky places a couple of times I have used Spa Blau spring water, a fairly local brand here. It seems to have been consistent when everything else wasn't, so a similar idea to your new plan

MartinP said:

Try the contact-sheet "proof" idea I mentioned above for a guide as to what is available from your negs if/when you change something. Also, when in yucky places a couple of times I have used Spa Blau spring water, a fairly local brand here. It seems to have been consistent when everything else wasn't, so a similar idea to your new plan

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Thanks for the tip! I will definitely be re-evaluating dev time in keeping with my work flow.

Fred Aspen said:

JW,


This afternoon I mixed another gallon of 76 but, instead of Kroger distilled water, I substituted Crystal Geyser Spring water (just good drinking water) and souped two snippets. One at 6' and one at 9', developed and fixed normally and both were solid D-max snippets. Couldn't see a thing through them. This evening I will soup a roll of Neopan 400 I shot this morning and see how that goes. Again, very early results but very promising.

I haven't a clue why Kroger distilled weakened the developer but perhaps someone one the forum might have some input. My wife, a chemist, said all along the water was the Red X but I just couldn't accept that. Turns out that she is most likely right and concluded that "who knows what that water might have in it that is not listed on the label." Also, it appears that the distilled water only affected the 76 and Xtol and didn't bother other formulations. Go figure!

I have been religiously using the same brand distilled water for years not knowing it was playing havoc with my favorite soups!

Click to expand...

Well, I don't have Kroger near me, but it is hard to believe it was the distilled water causing the problem, but the proof is in the pudding, as they say. I also used distilled water religiously until about 8 mos. ago. Now, it's back to filter tap water and my negatives are just as good, if not better, with the filtered tap water. The only time I don't use the tap water is on Wed. and Thurs. once in a while as my city/village they must do a chlorine charge or something and the water has heavy chlorine smell. Fred, I'm glad you got to the root of the problem and this should be a lesson for everyone here. Don't trust nothing! JW

JW PHOTO said:

Well, I don't have Kroger near me, but it is hard to believe it was the distilled water causing the problem, but the proof is in the pudding, as they say. I also used distilled water religiously until about 8 mos. ago. Now, it's back to filter tap water and my negatives are just as good, if not better, with the filtered tap water. The only time I don't use the tap water is on Wed. and Thurs. once in a while as my city/village they must do a chlorine charge or something and the water has heavy chlorine smell. Fred, I'm glad you got to the root of the problem and this should be a lesson for everyone here. Don't trust nothing! JW

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Don't ask me why/how changing water solved the problem because I'm completely baffled! But the problem is solved. Ran another snippet, completely opaque (PX125). Souped a 36 roll of Neopan 400 with excellent results; leader on the 400 speed film was opaque, as it should be. Per Bill Burk I ran several sequences and bracketed; Normal/1 & 2 stops over of scenes including concrete structures (grey card simulation). Will be printing tomorrow and checking print times; I expect they will be 2-3 times the exposure times with the flat/thin negs.

Yay! Thanks all!

PS. My wife, the chemist, thinks the cause might be the ozonation, which bubbles ozone through the water for purification but I can't begin to imagine this was the problem. Will try Brita filtered tap water in the next few days.

Fred Aspen said:

Don't ask me why/how changing water solved the problem because I'm completely baffled! But the problem is solved. Ran another snippet, completely opaque (PX125). Souped a 36 roll of Neopan 400 with excellent results; leader on the 400 speed film was opaque, as it should be. Per Bill Burk I ran several sequences and bracketed; Normal/1 & 2 stops over of scenes including concrete structures (grey card simulation). Will be printing tomorrow and checking print times; I expect they will be 2-3 times the exposure times with the flat/thin negs.

Yay! Thanks all!

PS. My wife, the chemist, thinks the cause might be the ozonation, which bubbles ozone through the water for purification but I can't begin to imagine this was the problem. Will try Brita filtered tap water in the next few days.

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Well Fred, if your wife is anything like my wife she's right more times than I am. According to her anyway??? The reason I went back to tap water was I got tired of running out just when I wanted to do something. Also, back in College Photo 101 we used HC110 dilution B with nothing but tap water and never had a problem. I think it would be wise for any "newbies" here to use their tap water first and then if there are problems switch over to distilled. If you have good tap water you can calibrate everything to that, but if you should move things might be different. I want to set up a darkroom at my cottage in the north country and it has well water run through a water-softener. I'd have to watch out for gremlins with that setup, but it might be close to what I have here now. For now it's tap water for me unless I have problems. Glad you got your problem under control. Have fun! JW

JW PHOTO said:

Well Fred, if your wife is anything like my wife she's right more times than I am. According to her anyway??? The reason I went back to tap water was I got tired of running out just when I wanted to do something. Also, back in College Photo 101 we used HC110 dilution B with nothing but tap water and never had a problem. I think it would be wise for any "newbies" here to use their tap water first and then if there are problems switch over to distilled. If you have good tap water you can calibrate everything to that, but if you should move things might be different. I want to set up a darkroom at my cottage in the north country and it has well water run through a water-softener. I'd have to watch out for gremlins with that setup, but it might be close to what I have here now. For now it's tap water for me unless I have problems. Glad you got your problem under control. Have fun! JW

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Oddly, HC110 worked okay with the Kroger water. Go figure!

I still don't believe the water theory. You need to do a split test. Exposed a couple feet of film to light and develop half in the suspect water and half in the "good" water for identical times and temps. If you can still see a difference I will believe it.

BetterSense said:

I still don't believe the water theory. You need to do a split test. Exposed a couple feet of film to light and develop half in the suspect water and half in the "good" water for identical times and temps. If you can still see a difference I will believe it.

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Why does Fred have to do anything? He's already satisfied he's found the culprit. Now, if it happens again then it's time to do some more testing. Analysis - paralysis! JW

Think I found the root cause. Distilled water from the market comes in HDPE containers, a gas permeable plastic. The water sits on grocer's shelves absorbing and dissolving oxygen. The jug is purchased and you take it home, warm it up and add your powdered developer to water that has a built in oxidizer. Oxidation begins and the developer progressively weakens all the while the HDPE container is continuing to absorb additional oxygen if kept in the HDPE container. Even if mixed in a glass container the water is saturated with dissolved oxygen and will oxidize the developer.

Check out this table: http://www.alphap.com/basics/compare.html and notice the OTR values.

The reason liquid developers aren't affected is that mixing takes place immediately before use and uses a much smaller quantity so virtually no oxidation takes place.

I have read numerous times to never store developer in an HDPE container for this very reason. I believe the old accordion bottles were made of HDPE and they were notorious developer oxidizers.

The way around this is to boil the distilled water to drive off the dissolved oxygen, cool the water to 125F and add the powdered developer. Then decant the mixed developer into small, completely full glass bottles to prevent the absorption of oxygen.

Or, use bottled drinking water which comes in PET plastic containers and has a far lower oxygen absorption rate (see table). My next batch will be brewed with boiled distilled water and stored in glass containers. I will report the results.

Fred,

Boiling is the way to go. Try that with tap water too. Works great.

Fred Aspen said:

...My wife, the chemist, seems to think it may relate to the ozonation process, which adds oxidants to the water...

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I mix XTOL in similar steam-distilled, ozonated water, but process only sheet film with it so have no d-max leader to measure. However, I've never noticed any lack of appropriate density in image high values.

It's been more than four decades since I last took a chemistry course and never used any of the information "learned" ( ), so a search seemed in order. On the bottom of page 9 of this document


it indicates that the half-life of ozone dissolved in pure water at 20ºC is 165 minutes. Given the length of time that must elapse between preparation of the water product, packaging and transporting it to retail stores, sitting on the shelf, us purchasing it and bringing it home, I can't imagine there's much residual ozone left by the time we use it to mix developers. Does the dissipated ozone become oxygen and that's what one finds in those HDPE containers? Does boiling do anything that extended sitting doesn't?

Thomas Bertilsson said:

I'm sorry, Fred, but I still fail to see how it would be important. D-max is not something you print since it's a hundred miles beyond what your paper can see.

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You're right that the contrast is very important, but Fred saw a red flag when his leader was gray. It's a sign the developer is bad.

Anyone would be wise to drop a piece of film in developer to watch it turn black.... before pouring the developer in a tank.

Just as a quick check that the developer is active.

And when the film comes out, and the leader isn't anywhere near what you normally see... then you know there's a problem.

Sal Santamaura said:

Does the dissipated ozone become oxygen and that's what one finds in those HDPE containers? Does boiling do anything that extended sitting doesn't?

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No, HDPE containers are made of gas permeable plastic. They will absorb oxygen from the atmosphere.

Fred Aspen said:

No, HDPE containers are made of gas permeable plastic. They will absorb oxygen from the atmosphere.

Click to expand...

Boiling should take care of that. Perhaps once you buy the water you could also store it in a better container?

pH may also be a factor...

One more piece of information: the pH of the Kroger distilled water measured between 5.2 - 5.5 pH. Tap water measured between 7.5 -7.8 and the bottled drinking water I used to mix the 76 came in just a smidge above 7.8.

Distilled water isn't even close to the 6.5 - 7.0 I expected!

I also found a thread from '08 where PE also indicated that distilled water is typically acidic. Since 76 is only around pH 8.5, mixing with distilled water would certainly seem to be capable of degrading 76, especially when diluting 1:1 with distilled water.

This might also explain what was constantly killing my Xtol in just a week or two, in addition to the DO.