Polariod type 55 question.

[raucousimages]

Situation. You have a portrait to shoot on location with studio strobes. Everything will be pre-set. You have 30 seconds and only one exposure of the subject. You will be using Type 55. You will be exposing for the negative not the instant print.

What ISO would you use?

 

[E76]

I believe ISO 25 is considered best if you're exposing for the negative. IIRC, Polaroid rates Type 55 at ISO 50.

 

[Vaughn]

I would use ASA 25 for the negative...but since life is not that simple, I would also add a half-stop of light to the meter reading since the actual ASA is also determined by one's shutter, consistancy of the strobe output, age of the Type 55, one's mental state and who knows what else! So for a one-shot only, I'd rather risk a slight over-exposure than being under-exposed.

Vaughn

 

[Kimberly Anderson]

Listen to Vaughn.

 

[ann]

i used 25 as well, but also used 1 minute as the processing time

 

[BrianShaw]

I hate to be negative (in a manner of speaking), but for a once-in-a-lifetime shot I think I'd reconsider using T-55 and use something more like a "real" sheet film. If the OP had more T-55 experience I wouldn't be so strong in this recommendation, but I remember that it took a while to get proficient with T-55. Exposure took time, development took time, and clearing took time before I felt I could take one shot and be successful. Maybe I was a slow learner???

Ann makes a good point that underdevelopment will make any exposure not very good.

 

[raucousimages]

Thanks for the input. Myself and the other shooter have a lot of Type 55 under out belts but we may have a chance at a unique portrait. The problem is the people in charge as it were, want to see it before we leave. They are thinking digital so the compromise is Type 55. This pretty much confirms what we were thinking so thanks again.

 

[Vaughn]

i used 25 as well, but also used 1 minute as the processing time

I was under the impression that going extra time had little to no effect..I believe because of the monobath (proper term?) nature of the developer/fixer. It would not be the same as developing a negative longer, as the fixer incorporated in the developer would prevent the development of the negative from continueing.

This assumes the temperature to be the same.

But I have been wrong before and I see no hope in changing that!

RI -- best of luck! Of course the best thing to do would be to duplicate the anticpated set-up and lighting conditions and do practice run. And who knows, the subject (and/or handlers) might be so impressed with the first shot (though the print will be too light and not impressive at all) that they'll grant you a couple more shots!

Vaughn

 

[Bosaiya]

I meter at 25 and let sit for a solid minute just for kicks. It's somewhat temperature dependent and I prefer being safe to sorry.

 

[ann]

i did a few test years ago, and the iso and times worked well for my equipment and method of working.

 

[E76]

I meter at 25 and let sit for a solid minute just for kicks. It's somewhat temperature dependent and I prefer being safe to sorry.

I think Vaughn is right when he says developing for longer than the recommended time probably doesn't do much because of the reasons stated. In fact, it may reduce density in the negative and make the positive darker, as it could allow more silver to move from the negative to the positive.

 

[BrianShaw]

All please genuflect... a reading from book of St. Ansel

Polaroid Land Photography, pg. 228.

"Effects of development changes: Essentially none, since the print and negative develop to completion. A very slight decrease of the base-plus-fog density of the negative occured at 60 second. Insufficient development must be avoided, since it produces discoloraton of the negative when it is exposed to light."

"Tested optimum development time: 30 seconds at 70 deg. F"

 

[Vaughn]

"A very slight decrease of the base-plus-fog density of the negative occured at 60 second." That actually sounds nice...

Vaughn