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Film Calibration


charles_eliason1

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<p>I'm planning on calibrating several 35 mm films that I'm working with to four developers that I work with as described here : http://www.apogeephoto.com/mag2-6/mag2-6mfcalib.shtm.</p>

<p>If any one has any suggestions to the methodology that I referenced or any suggestions I'd appreciate it.<br>

One of the 35mm films that I shoot is Tmax 100. I also shoot Tmax 100 in 4x5 large format.<br>

Does anyone have an opinion as how my results from 35mm format might equate to the 4x5 format with identical developer, time, temperature and paper ?</p>

 

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<p>Just FYI, your link doesn't work so I can't comment on the testing process. As to your other question, I'm not familiar with any of the Tmax films, but I know that with FP4+ I don't have to make any changes in exposure or development when moving from 120 to 4x5 or 8x10 sheets to get the same results...</p>

<p>- Randy</p>

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<p>Why so complicated?<br>

I've done this for one film and one developer. I did similar testing on several rolls before I nailed the parameters (small changes in dev time/agitation intensity before it was perfect enough for me). Doing this for multiple films and multiple developers seems like a lot of work...</p>

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<p>The difficulty in applying the Zone System or any similar methodology to 35mm is that we don't often use 35mm film the same way we do large format. It's easy to expose a single sheet for a specific type of goal in developing and printing. We just take notes about the light and exposure as reminders for later development.</p>

<p>It's very difficult to expose an entire roll of 35mm the same way, unless we're shooting under very carefully controlled conditions such as in a studio. If the light or subject contrast changes, only part of the roll can be developed ideally to suit the conditions. The rest of the frames will be developed less than ideally. That's why the approach to 35mm (and even medium format in cameras without interchangeable backs) b&w photography tends to be a compromise to deliver acceptable results for most frames.</p>

<p>It is possible to apply the Zone System or similar methodology to 35mm and medium format. I've done it as an exercise. But it was a pain in the neck, especially with 36 exposure rolls. I didn't really need 36 exposures of the same white church, taken within a 30-minute window of time to ensure the lighting was consistent. But at least it enabled me to apply a specific type of development to the entire roll and get the desired results. It's a little easier to do with medium format, especially using cameras with interchangeable backs. If my white-church scenario study under late afternoon clear daylight had included some studies of a gray building under an overcast sky, I'd have been in a pickle trying to develop the entire roll to suit both scenarios.</p>

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<p>Lex, An extremely interesting response. Based on your comments it seems that for 35mm format my primary interest would be to rate the particular films that I am interested in for exposure index. I have read in this forum different ei for different films by different forum members from what the manufacturer may have rated the film. Do you have any suggestions as to how I might determine an appropriate EI for a given film for my particular darkroom setup, camera, etc. ?</p>

<p>As a side note, I bulk load my film. I could load small amounts of film, say five to ten exposures per roll and could then bracket exposure as well as development for a given scene.</p>

<p> </p>

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<p>I've used the bulk film trick you mentioned to load short rolls for projects where I knew I wanted to expose and develop specifically for the desired effects. It works well enough for 35mm, other than being a little more wasteful since leaders and tails are the same length regardless of whether we load 12, 24 or 36 exposures. But it's a reasonable compromise.</p>

<p>Another trick with commercially loaded rolls is to clip the film in the camera (in the darkroom or a changing bag). Shoot the desired number of frames, open the camera film door in the dark, carefully cut between the exposed film on the takeup spool and unexposed film and remove the exposed strip. Load the film strip on the reel or otherwise store it in a lightproof container. Be very careful to avoid damaging the shutter curtains - I put my left hand between the film and camera body and use my fingers to guide the scissors. So far, so good, no damaged shutter curtains and no bleeding onto the camera or film.</p>

<p>Regarding film EI, other than my experiments with the Zone System I don't use any particular method. I just eyeball the results and adjust until I get the desired results. For example, with TMX in ID-11 I preferred EI 64 or 80, with a little less development. At ISO 100 in ID-11 and normal development I found the contrast difficult to control. Later I switched to using TMX at the rated ISO 100 and developed in Microphen 1+1. This seemed less finicky and more forgiving of minor variations in time, temperature and agitation. Grain was very slightly more pronounced than in ID-11, but still so fine that it was virtually invisible in 11x14 prints from 35mm.</p>

<p>Using the same trial and error I settled on EI 64 for FP4+, developed in ID-11 1+1; and EI 250 for HP5+. Both delivered the desired contrast when shooting outdoors under typically harsh Texas sun. In overcast or hazy conditions, especially with lower contrast subjects, I'd shoot at or even slightly above the rated ISO and develop appropriately.</p>

<p>Not a very scientific approach but has worked well enough as a compromise to get satisfactory results from scanning or printing using a dichroic head enlarger and variable contrast papers.</p>

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<p>Based on your comments Lex I think that I will bulk load short rolls of film and shoot two or three rolls of the same scene with different EI for each. Then I can process each roll and as you say 'eyeball' what looks good.<br>

My primary goal is just to gain experience with exposure, contrast, development and overall technique. Thanks for the comments.</p>

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<p>Lex's method sounds good, although I have to admit that I no longer use 35mm film. With 120 film, I use the manufacturers rating and then adjust both exposure and development depending on the lighting conditions at the time of exposure. Regarding the procedure you posted, I've found that, at least for my purposes, there is no set EI that works well in all conditions, so I abandon the idea of a personal EI. Here's a link to how I control contrast if you're interested. It works very well with all roll film in my experience, giving me much more control over my negatives. Using this technique, my exposures tend to print well with a #2 or #2.5 filter on VC fiber paper</p>

<p>http://www.redisonellis.com/exposure.html</p>

<p>- Randy</p>

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<p>I know I am going to get fried BUT I use and suggest you try using Picker's simplified zone system which is to expose the brightest areas you want to retain detail in at zone 7 - the rational at least for me working with roll film (in my case 120 so grain isn't so much of an issue) is that using normal development you shadows will follow and the highlights will retain some detail - the catch is you need to establish your film rating (not speed) by testing with your chosen developer - zone 5 remains the middle point in any case - I use tri-x at 320 in rodinal; 1:50 - give it a try - good luck - Jeff</p>
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<p>I know I am going to get fried BUT I use and suggest you try using Picker's simplified zone system which is to expose the brightest areas you want to retain detail in at zone 7 - the rational at least for me working with roll film (in my case 120 so grain isn't so much of an issue) is that using normal development you shadows will follow and the highlights will retain some detail - the catch is you need to establish your film rating (not speed) by testing with your chosen developer - zone 5 remains the middle point in any case - I use tri-x at 320 in rodinal; 1:50 - give it a try - good luck - Jeff</p>
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<p>You'll only get fried for double posting. But Picker's simplified ZS is a very good suggestion.</p>

<p>(BTW, after hitting the back button on your browser to check your post, be sure to refresh the page from an empty cache. Otherwise it won't appear. That's what causes multiple posting on photo.net. Or just use the prompt on the page to return to the thread, instead of using the browser back button.)</p>

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