My photo
... is a freelance photographer working in Middle Georgia

Wednesday, September 10, 2008

A Bit of Trivia

Here we go with some more old pictures. Got a combo of some of my favorite things here. You have a dancer, huge windows with nice light, hardwood floors and Tri-X film. Can it get any better? Oh, yes, pushed in Acufine to 1600 ISO.

For those of you too young to have ever dealth with film, let me explain. Tri-X is normally rated at 400 ISO. Want to shoot at a higher shutter speed in low light? You kick up your ISO in increments of you would go 400 to 800, then 1200, up to 1600.

You shoot your pictures rating the film at 1600 ISO, then compensate when you develope. The normal developer for Tri-X is (or was) D-76. gave nice even tones,
typical development time was 8 minutes at 68 degrees. Time changed as temp went up or down. Warmer developer, less time, cooler meant more time.
To push process your film, you increased the development time by half for each stop(400 to 800 meant you added 4 minutes.)

With each increase in time, you increased the grain in your film, lost shadow detail and blocked up highlites. The more you pushed the worse it got.

So along comes developers like Acufine and Diafine. Acufine was good for 1600 ISO and Diafine was good for 2400ISO. Acufine made nicer negatives, Diafine made more grain and got really contrasty.

So, now you have a good bit of trivia.

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