Exposure, development and tungsten lighting with Tmax 400 120

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bascom49

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I set up a portrait studio using Mole Richardson hot lights and exposed a few test rolls of Tmax400 120.
I used two Mole Richardson 2K super softlights and my recently acquired Fuji 680gx III.

I metered well with a sekonic meter, f22 at 1/4" and developed in Xtol 1:1 with a Jobo at 9' 15". I exposed at box speed of 400 assuming that Xtol would get me fairly close to 400 EI.

I used a blank frame shot with the lens cap on to determine my enlarging time for maximum black, 15" at f11 with my Durst 138 condensor and a grade 2 filter and then made a test print of one of the exposed frames.

The print is very light and washed out.
I though that perhaps the film speed was two low but the areas of the model with a black wool coat and black shoes are light as well. I have an X-rite densitometer, the black shoe measured 0.45 above base plus flog. Rating Tmax higher than 400 EI seems unlikely.

It seems to me that I have over exposed, not over developed.

If anyone can give me any pointers or advice I would really appreciate it. I'm making more test rolls this evening and welcome any thoughts that anyone may have.

Thanks,
Charles
 

Mr Bill

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Hi, just to confirm that I am understanding, let me restate: you are setting enlarger exposure to just barely give a visual "black" on the print when exposing through a clear, unexposed piece of film. Then, when you use this same enlarger exposure with a real negative, the parts that should print black, or nearly so, actually print much lighter. (Do I have this correct?)

Additionally, when you read the film density of the desired black objects, you find that the film density is significantly higher than the clear film, by about 0.45 density units (which is quite a lot).

It seems to me that you have quite a lot more camera exposure than you need. These fairly dark areas are not much affected by development errors, so I disregard such possible issues. It seems pretty clear to me that you have overexposed the film, at least with respect to how you want the scene to print. Since you also came to this same conclusion, I'd just say that I agree with you.

Obviously the immediate solution is to increase enlarger exposure; I personally don't put too much emphasis on that "clear film to print black" exposure routine, so I wouldn't be caught in your conundrum.

If your real question is, how does this happen, I'd suggest three possibilities. First, you might have a poor metering technique (also, there might be a defect with either the meter or the camera shutter/aperture). Second, the scene may have produced a lot of flare light inside of the camera, similar to an overall "fog" on the film. Or third, it may have been an issue with the "color" of the hot lights. Such lights have low "blue" output and a great deal of "reddish" output. In this situation, even films with the same daylight ISO speed can require different camera exposures depending on how far their red sensitivity goes. I haven't looked up your film, but if it has an "extended red sensitivity," this is a possible factor.

If I were in your shoes, I'd double check my meter, either against another or vs a standard daylight exposure. Then I'd visually check the stop-down performance of the lens, as well as the range of shutter speeds. Then finally, in the new test shoot you are planning, I'd include a range of exposure tests. From those, I could pick a "best minimum exposure," and use that to estimate a new film speed rating that I would use only for this film combined with this light source.

Just my thoughts on the situation.
 
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bascom49

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Bill, your understanding is correct. Thanks for the tips.


Thanks,
Charles
 
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Well, it seems your film is overexposed... But I would look at your meter (perhaps it doesn't perform so well for hot lights?), shutter, etc., etc. before re-rating the film.

FWIW, TMY has a large latitude so you should be able to make good prints from the negatives you have; just expose longer under the enlarger.

Doremus
 

David Allen

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Hi, just to confirm that I am understanding, let me restate: you are setting enlarger exposure to just barely give a visual "black" on the print when exposing through a clear, unexposed piece of film. Then, when you use this same enlarger exposure with a real negative, the parts that should print black, or nearly so, actually print much lighter. (Do I have this correct?)

This is a mistake a lot of people make - it will not give you an accurate time because the frame will not have received in camera flare, related processing fog, etc. To test for minimum black, you need a frame that has been accurately (i.e. you have tested for your personal EI with the camera, lens, film and developer that you plan to use) exposed at Zone 0 AND have determined the minimum print development time to achieve a good black.

You use the Zone 0 negative to do one test strip (at grade 2 for a condenser enlarger and at grade 3 for a diffusion/multigrade/colour head enlarger) to identify roughly what is the minimum exposure time to achieve black will be. Then do a series of 5 small test prints where you expose each of them for double the time you identified as being the rough minimum exposure (i.e if your very first test indicated 10 seconds then expose the 5 test prints for 20 seconds). Number the test prints on the back from 1 - 5 and then develop them for 1 minute, 2 minutes, etc. Give the prints your normal fixing and give them a quick wash and then dry them (this is very important for FB paper and the easiest way of doing this quickly is to get a cheap second-hand microwave oven and use this to dry them).

Line the 5 prints side by side with the print with 1 minute development to the far left and the print with 5 minutes development to the far right. Now comes the key part of the test, look at each test print and identify which print has a maximum black. Usually, you will find that (with FB) the one with 1 minute development will look OK until you compare it to the one with 2 minutes development which will look darker, etc. Then repeat until you find the print that is darker than the one to its left but the one to its right is not any darker. The print that does this is your absolute minimum development time to achieve a true maximum black. You can always develop for longer than the minimum for the purpose of changing tonality, etc but never less.

In general, with the discontinued Polywarmtone, the discontinued Adox FPVC, the discontinued Kentmere FPVC and the current Foma Variant III and Adox MCC 110, I have found that, irrespective of a ± 5˚ degree variation from 20˚C, all of them require at least 3 minutes when developed in Tetenal Dokumol 1 + 6 to fully achieve a real black.

Now that you have found the required time to get a good black you can move forward with some more 'real world' tests. Take a negative and expose it for the exposure and development time that you have found is required for achieving a good black.
  • If the subsequent print has too little detail in the highlights then you will have to burn in your highlights (this means giving more exposure to the highlights in your image) or reduce the contrast setting on your enlarger.
  • If the subsequent print has too much detail in the highlights then you will have to dodge your highlights (this means giving less exposure to the highlights in your image) or increase the contrast setting on your enlarger.
Now you are getting near to a good print and will have learnt a great deal about manipulating the tonal range of your prints.
If, for example, you are now happy with the print overall but unhappy with the separation of tonal values in the darker shadow areas, this will indicate that your shadow areas require the use of a higher grade of contrast to achieve the required separation that you would like and this will then necessitate you burning in your highlights (this means giving more exposure to the highlights in your image) and/or reducing the contrast setting on your enlarger. when burning in.

Once you are happy with the result, you can then determine the following:
  • If, using the maximum black exposure, your print looks fine then you have truly fixed all of the variables.
  • If, using the maximum black exposure, your prints are always too grey, you need to increase the development time for your films.
  • If, using the maximum black exposure, your prints are always too contrasty, you need to decrease the development time for your films.
  • If, using the maximum black exposure, your shadows are consistently too light, you are overexposing your film and will need to adjust your E.I.
  • If, using the maximum black exposure, your shadows are consistently too dark, you are underexposing your film and will need to adjust your E.I.
It all sound damned time consuming I know. However, in reality it does not take very long to do and you will have pinned down all the major variables so that you can abandon further testing and get on with making photographs.

Bests,

David.
www.dsallen.de
 
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