Myths in B&W photography #12

<p>#12: B&W film must be processed at 68 F ( 20 C ) for best quality or optimum results.</p>

<p>This is a myth. It is covered very well in an article written by Dick Dickerson and Sylvia Zawadski in the July/August 2005 edition of Photo Techniques.</p>

<p>Simply put, in the article they say that in the early days of photography it was easy to have 68F water and solutions due to the heating systems of the time. Well, this is correct as far as it goes, but why 68F? It turns out that 68F is the melting point of gelatin in water. Above that point gelatin will melt (think JELLO).</p>

<p>So, that was the maximum temperature that could be tolerated by the hardeners from the early days of photography which in many cases consisted of no hardener at all and relied on an acid hardening fix. Today, films from Fuji, Ilford and Kodak are hardened to withstand temperatures far above 68 degrees F and there are prehardeners and hardening developers that can assist so that you can process virtually any film at virually any temperature, provided you work out the right time to use for your film developer combination, and the right agitation to use.</p>

<p>The thing you must avoid is a sudden temperature change or shock, but other than that, even films from other manufacturers can be processed at high temperatures with a prehardener.</p>

<p>One such is as follows:</p>

<p>Water 700 ml<br>

Sodium Sulfate 100 g<br>

Formalin 37% 10 ml<br>

Sodium Carbonate 50 g<br>

Water to 1L, pH to 10 with 10% NaOH or 10% H2SO4.</p>

<p>Use for up to 10 minutes at your room temp, then wash in room temp water for 10 minutes and then develop at your room temp. This can work up to 100F or 38C depending on the film. Test your film before trying and avoid temperature shocks.</p>

<p>I have been asked what was the highest temperature I ever used. It was 120 F.</p>

<p>Ron Mowrey</p>

<p>When I was in college I shot for the Daily Free Press at BU. There was usually some Diafine mixed up in the darkroom but you couldn't always be sure how fresh it was. When time was really tight I would use slightly diluted and very warm Dektol for my Tri-X. That would develop the film in about two minutes. The film then got a very fast water rinse and went into Rapid Fixer of unknown temperature. That took another three or four minutes. After that there was another very short water rinse and (horrors) the hair dryer came out. Before you knew it the film was dry and was cut into strips of six frames and slapped into the negative carrier of an Omega enlarger. The paper around was usually some kind of Polycontrast which was pushed through an Ektamatic stabilization processor. The prints needed to be dry to be pasted up and then shot, with the text, by a Nu-Arc camera. Once when there was a real rush I managed to shoot the pictures and get the wet prints out in under twenty minutes. I don't think Ansel Adams would have recommended these procedures but I don't know if he ever did newspaper work.</p>

<p>Ron - my normal film developer temperature is 68 degrees while my tap water used for washing can go as high as 80 degrees. Is that 12 degree temperature swing an example of a "sudden teperature change or shock" that should be avoded?</p>

I'd be interested too in learning how large and sudden temperature changes (during the washing stage in particular) are allowed to be. I recently read in a book that it is quite difficult to provoke reticulation in modern films even when trying, and that the requirement for like +/- 2 degree consistency is a thing of the past (myth #13?). I wonder if this is true.

<p>I've even seen people claim that developing film at 24C (75F or so) "doesn't work as well" as developing at 20C. "After all, Kodak's tables all give times for 20C, that's what they design their films for!"</p>

<p>Tropical developers had a tanning element in them and could be used in water up to 98 degrees F these formulas were made in the early 1900s for plate films..... Think Glass. I think I have a book from 1938 that still has the formulas for a few of them I will look them up... I have found that with most modern films I can't even get the crunch with rapid temperature change in liquids..Reticulation I believe it is called. but I did get some EFKE/ADOX to do it a few years back But I think they may have changed the emulsion because when I tried it again this year it did not happen. .</p>

<p>Larry</p>

<p> </p>

<p>Well, lots to answer.</p>

<p>Tropical developers contained Sodium Sulfate, an antiswell agent. They also could contain tanning agents. Sulfate was more popular IIRC, as it kept better.</p>

<p>Processes can take place at up to 100 F (20 C) with no problem using the right film, right agitation and right time. If contrast or speed are allowed to vary, then the results would deviate from the 68F process in terms of grain and sharpness. It is hard to say what a shock would consist of. Some films may take 2 deg C, others 4, and others may take 10 C. So there is no rule I can give you. A gradual change in temperature is better than an abrupt change in temperature.</p>

<p>Kodak gives tables for about 60 - 80 deg C in their manuals, but 68 is preferred except for T-Max, which is given as being used at 75 deg F (24 C).</p>

<p>Ron Mowrey</p>

<p>I always wondered that about TMAX. but I think that also has to be with the use of XTOL that is also a higher temp developer.</p>

<p>I always thought that a developer with more than one developing agent (like an MQ developer) was "balanced" for a given temperature. For example, say 20C for comparison. If you raise the temperature to say 24C you'd get more activity from the metol and therefore comparatively less from the hydroquinone, which could change the look of the results. IOW, all else being equal, two films shot of the same scene with the same lighting, exposure, etc. developed in the same developer at two different temperatures (times adjusted to give the same contrast index) would look a little different -- that is the respective tones would not be an exact match.</p>

<p>You're saying that they won't look any different, correct? Not even in graininess? I thought I read in Haist that increased development temperature would increase grain size a bit. But he wrote that like 30 years ago.</p>

<p>What I said was that if you balanced speed and contrast by means of proper dilution, time, temperataure and agitation, there would be little difference. These adjustments will compensate for the differences in activity of the developers which try to unbalance speed and contrast.</p>

<p>If this were not true, then the time - temperature charts offered by Kodak and others would not work, or they would have to put up warning notes about the problems you cite.</p>

<p>Ron Mowrey</p>

<p>Is the optimal temperature for T-max developer <em>really</em> 75 degrees?</p>

<p>I know that T-max developer was often employed in dip 'n dunk processing lines when it was introduced. Could it be that the higher temperature is designed to maximize throughput via faster development times rather than image quality?</p>

<p>I think the old Ilford DD (introduced in the 80s) used in dip 'n dunk processing lines also published developing times using a temperature of 24 C, but I could be wrong. In any case, DD-X publishes for 20C.</p>

<p>Thanks, Rowland,</p>

<p>I agree basically with all of your "Myths". My professional experience goes back to the late 1940's and I have been a genuine expert in quality control, especially b/w. I note that Dick and Sylvia were retired Kodak employees and were financed by Kodak for their many seminars. Perhaps that is why they published "blind" results on b/w papers. Kodak's curve shape was so terrible that only certain negatives could be printed with them. Because for 30 yers, I wrote for all issues of Rangefinder Publications, I had several conversations with Sylvia, a very capable Russian photo scientist, only a couple with Dick, whom I confess I didn't respect very much.</p>

<p>My favorite VC paper for many years was Varigam plus the fact that the tonalities were identical with Velour Black. I could deliver prints from both products and they were identical. Interestingly, after 10 years in the business, I went to Brooks and found that those products were required. I shifted to my next favorite, Ilford, when duPont changed from natural gelatin to synthetic gelatin and those papers just couldn't hack it anymore. </p>

<p>In the 1940's and 50's "silver rich/thick emuslion" films would have a bit less sharpness and higher granularity in higher temperatures. When processed to the same gamma/GBar there would be a difference in granularity between 65F and 75F. As you say higher temps in these films usually required special chemicals frequently including formalin. This was not true with Kodak's Panatomic X, C. Schleusner's Adox films, Gevaert's lower speed films, and Agfa's 100 or slower films. They were much thinner emulsions. Those and a couple of others were really great products.</p>

<p>Thanks very much for your technical contributions, hopefully they will reduce the fantasy factors in our field.</p>

<p>Lynn </p>

<p>Lynn;</p>

<p>The only reason that I would concede a change in grain would be with a direct comparison, however, I can understand how the need for additional prehardening would alter the characteristics of a given film. Hardening often changes the way a given emulsion develops including speed, and for of the silver metal which forms during development.</p>

<p>So, there may be a few cases that required special handling that would change things. For example, the harder (prehardened) film might develop more slowly and therefore need more development to get to a given contrast. This might increase speed and fog thereby increasing grain. So, all things were 'not' equal even though gamma was.</p>

<p>In the final analysis, a very rigorous comparison would have to be made but the general rule in the "myth" would be proven true in most all cases with few exceptions such as in the paragraph above. And, the exception(s) could be explained.</p>

<p>Ron Mowrey</p>

<p>I agree with you Rowland, as I said, the only times that temp made a difference was with certain 55 or 60 year old films and those by direct comparison. With Ilford HPS the original 400 speed pan film ca 1952 and Kodak Tri X 1954, there was no difference from then on. I was a student in USN Medical Photography School at that time and when we found out about Tri X it was a miracle, 2 stops faster than Super XX, sharper, and with finer grain!</p>

<p>Lynn </p>