...which is why I suggested a film speed and development test a few posts back. You can 'save' a lot at the printing stage, but getting a decent work print should not be this difficult.
Originally Posted by clayne
While the problems showing up in the first post have been decimated, the prints could be a lot better if the negatives were better and printing with ease at Grade 2. Getting an idea of film exposure and development time first saves a lot of agony later.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh
Thanks for the excellent feedback! This case is closed in my view with respect to the printing. I agree with the comments about the negatives.
Originally Posted by ROL
I LOVE your article!! I found it some months ago, and bookmarked it then. Since that time, I've read it multiple times and keep it handy for reference!
Originally Posted by winger
I'm quite certain that is one of my issues as well. I have a terrible fear of over exposing film, because as we all know, there isn't a 'recovery' slider for that after the fact. I'll second guess an exposure two, three, or four times, and then end up underexposing it instead.
This fear is only justified with slide-film. With negative-film, a stop overexposure usually does more good than harm. It's underexposure you should avoid like the plague!
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That's good info. I'll keep that in mind.
Given the detail that appears to be available in the shadows and the lack of detail available in the highlights and the small print size in question, I don't see why under-exposure of the film is being suggested.
What am I missing?
Mark Barendt, Ignacio, CO
"We do not see things the way they are. We see things the way we are." Anaïs Nin
HI, I use 2 stop ND (+ 00 to 3.5 contrast filter) to get f/11 for 5x7 and 1 stop ND for 8x10 for medium format negative. My usual exposure time is 15 sec in my Beseler 23C with a new bulb (PH140 75W). I bought a 20x24 ND sheet from BH to cut the filters for Beseler 23C filter housing.
Originally Posted by jeffreyg
This post stuck with me, and today I went back to read it. And then I read it again. And then again. And I think after the fourth time I understand how to go about the process, and what its for.
But when you say 'personal ISO', what does that mean?
I have typically been using TriX-400. The negatives in question were shot on my Mamiya C33, but I now have a Hassie 500cm. I could be wrong, but the Hassie doesn't have a dial to change the camera from one ISO to another, so I dont understand how I can shoot 400 speed film at a different speed. Except to shoot it at different shutter speeds and then pull/push process. I vaguely get the meaning of push/pull processing, and understand that its either lengthened or shortened times, but I'm not at the point that I understand it enough to pull it off.
"Establishing your personal ISO" (more properly "Establishing your personal EI") is a shorthand reference to an approach to metering.
EI means Exposure Index. Different photographers will use different EIs, in different situations.
The number on your box of film - the ISO speed - is a measurement of the sensitivity of film under ISO specified conditions.
The conditions you work under will be similar to ISO specified conditions, but not identical.
Establishing a personal Exposure Index allows you to take into account a number of factors particular to you, like:
- the sensitivity and calibration of your meter
- your metering technique
- the accuracy and tendencies of your shutter
- the accuracy and tendencies of your apertures
- the film you are using
- the developer you are using
- the accuracy and tendencies of your thermometer
- your timing scheme
- your agitation scheme
- the type of enlarger you are using
- your subjective preferences respecting shadow details and highlight details
- and a few others ...
All these factors have an effect on the density of the shadows in your negatives. Adjusting how you set the film speed (EI) on your meter can either offset or take advantage of those effects.
Many of us find that, when setting the film sensitivity on our meter, using an EI of, e.g., 320 or 250 for Tri-X (1/3 to 2/3 of a stop more light hitting the film) results in negatives that work better for us. But others might get better results from their meter using an EI of 500 for Tri-X (1/3 of a stop less light hitting the film).
And of course many photographers end up with a personal EI identical to the "box" or ISO speed.
The important thing to realize is that the film itself doesn't change from photographer to photographer. What changes are the conditions under which the film is used.
With respect to questions of push/pull developing, those questions actually relate more to the contrast (not intensity) of the image forming light. You can use those controls to adjust for unusual light situations. You can also use them to help rescue (to an extent) the results from under-exposed or over-exposed film.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2