Stupid slide film ISO mistake: what to do now?

[rjstep3]

I am just back from Thailand and Myanmar and took a Nikon 35ti (which sets ISO automatically) and a Contax G2.

I shot Provia 100X.

Problem: Half way through the holiday, I realised I hadn't reset the Contax to use DX coding after I had put some 200 film through it, meaning I had shot some Provia at 200, not 100.

I am now looking at a pile of film canisters, some of which were shot with the Nikon at the correct ISO, others by the Contax pushed to 200. But I don't know which are which.

What should I tell the lab to do: develop at 150 to hedge my bets? I just don't know.

Any suggestions gratefully received.

rjstep3

 

[Ronald M]

Process as normal and some rolls will be dark. Dup them up with a duplicating set up or pay someone to do it.

Do not push as the good rolls will be too light and not be salvageable.

 

[Robert Lai]

If you know exactly which rolls are from the Contax, then you can ask for them to be push processed by 1 stop. Many labs can do this. However, if all of the films are in one big pile, then you're out of luck.

 

[pixelated]

You will have contrasty saturated slides from the rolls that were 1 stop under exposed.
Not necessarily a bad thing. I would only consider pushing if you know for certain what rolls got the bad exposure. For slides, generally slight under exposure is far more desirable than over exposure.

Another approach might be to process a subset of the rolls, and see how bad or good they look, then decide whether you want to chance pushing good rolls.

 

[Frank Petronio]

If you shot in consistent studio conditions you could do a clip test, where you process only the first few inches of a roll to see how the exposures are, then judge how much to push the rest of the roll. But given that they are probably random travel shots and have a variety of exposures anyway I would just process normally and deal with the results in post.

 

[rjstep3]

Thanks: looks like the consensus is process as normal, and do what I can in post.

rjstep3

 

[Robert Lai]

An expensive way to check is to do a clip test for each roll. They would develop only part of the roll, and see how it turns out. If they guess wrong, you'll lose the images on that part of the roll.

Also, more than likely the film will get cut at the image that you thought was the best from the entire trip.

 

[HHPhoto]

Thanks: looks like the consensus is process as normal, and do what I can in post.

rjstep3

+1.
I guess more than half of your films are exposed with the right ISO 100 setting? Than normal processing would be the best compromise.

And besides: Provia 100F is quite tolerant (compared to other reversal films like the Velvias or E100VS) when underexposed 1 stop: You results will not be perfect, but still usable.

Cheers, Jan

P.S. Identifiying the underexposed rolls by clip tests which each roll is of course the perfect solution: After the clip test you know whether that roll is correct exposed, or underexposed. Then the film can after that be developed normally, or the identified underexposed rolls can be pushed one stop.
Results with Provia 100F pushed one stop are very good.
Of course a clip test cost more.
But certainly only a fraction of the costs of your travel. And memories are unique.

 

[rjstep3]

Well I'm popping to the lab this lunchtime, so will find out the truth later on today.

Thanks for replies everyone!

rjstep3

 

[GarageBoy]

How'd it go?