Kodak Technical Pan Exposure

[s162216]

Hi,

I am currently working my way through one of my 3 rolls of frozen Kodak Technical Pan that I aquired a few months ago, I'm exposing it at ISO 25 and all of the shots that I've taken so far have been 1 sec with an orange filter.

According to the tech pub, for exposures of 1 - 10 secs a 10% reduction in developing time is needed with no increase in lens opening/exposure length, the thing is that I might be shooting some portraits with a yellow-green filter shortly with it, so obviously 1 sec is no good for that. My thoughts are that if I opened the aperture slightly more than that would cancel out the effects of the 10% reduction in dev time, but I'm not sure how much by, perhaps half a stop? Or is it just too small a decrease to be able to anything about it?

I have found somewhere where I can get it processed with normal contrast BTW, Palm Labs do a special service with very ultra dilute rodinal. The other alternative is to do it myself with 1:5 Xtol (according to a very old Xtol datasheet which has times for dilutions greater than 1:1) but its unlikely that I would ever be able to use 5L of Xtol by the time it expires...

 

[s162216]

Anyone??

Basically all I am asking is: how much of an increase in aperture do you think I should use if exposing shorter than 1 second and reducing the development time by 10%? (to compensate for reciprocal effect of the 1 sec exposures that most of the current shots are)

 

[AlanSmithee]

I haven't shot that film for years now and I used that special developer for it (don't recall the name).

Sorry, but I really don't understand the question very well. You are saying 1 sec is too slow for a portrait (under ambient light?) so you want to open the lens up to get more shutter speed (a good idea). Then you ask what aperture would that be?

Well, if your shutter speed is, say, 1/60 at a given aperture and you open the lens up one more stop, your shutter speed should now be 1/125 as an example.

 

[s162216]

The special developer that allowed Tech Pan to be used pictorially was Technidol, unfortunately it was discontinued with the film and it commands a high price now, I've been able to find a place that will develop it for me though using ultra-dilute rodinal to get the same low contrast effect as Technidol.

Basically all of the frames I've taken so far have been 1 sec long landscapes with an orange filter, according to the datasheet for exposures of 1 - 10 seconds a 10% decrease in dev time should be used. I'm now looking at shooting some portraits with it using no filter and possibly with flash so obviously the exposure is likely to be much shorter than 1 sec if I'm using wider apertures.

What I want to know is, what increase (if any?) in aperture should I use to counteract the effects of the 10% reduction in dev time for exposures which are shorter than 1 sec because otherwise surely they will be 10% underdeveloped?

Or basically should I just shoot it normally?

 

[AlanSmithee]

What I want to know is, what increase (if any?) in aperture should I use to counteract the effects of the 10% reduction in dev time for exposures which are shorter than 1 sec because otherwise surely they will be 10% underdeveloped?

Or basically should I just shoot it normally?

You said 1 to 10 seconds needs a 10% dev reduction. But you're shooting shorter than one second. So why do you need to correct at all?

Frankly, at 1-second, I'd say it's not that significant to adjust your dev time. Kodak also says for their other films ( eg 125PX, 400TX ) to decrease the development time for long exposures. But I don't do that for shots under 10 seconds and it has yielded fine results for me with scanning (scanning is way more forgiving than wet printing).

Increasing your exposure and decreasing your development time is a method that can compress the highlights (helps bring in more DR) assuming you metered for the low values properly. So maybe there is some of that going on with those instructions from Kodak.

 

[s162216]

I'm shooting this on 135, thats the reason why I'm asking as the first 12 or so frames that I've shot have been 1 sec long and I want to use some of the rest of the roll for portraits, which hence will likely be much shorter than a second and as so if you take the datasheet literally, won't need the 10% reduction.

So you think that it won't make too much of a difference if I forgo the 10% reduction or use it and forget about it as it won't affect it?

Obviously if I was shooting on 120 then that wouldn't be so bad as I could just finish the rest of it and then use another for portraits or even better in sheet. Looking at the detail in some pictures online taken with 135 Tech Pan makes me shudder to think how much there must have been on 11"x14" sheet Tech Pan, hopefully my 3 135 rolls will last a while...

 

[AlanSmithee]

...
So you think that it won't make too much of a difference if I forgo the 10% reduction or use it and forget about it as it won't affect it?

All I can say is that if I develop any other roll of BW film 10% longer than normal, my results will not be affected that noticeably. I suppose if you had some detail in the highlights that were on the edge of being lost, 10% might push those over to accent white.

Back when I did shoot Tech Pan, it was like shooting IR film in terms of use. Only once in a while so I really never learned it well.