Exposure matters

Estimation of negative density is an important part of profile building process. Unknown and expired film stock is always tricky to expose well. So we’re usually shooting this kind of film at a wide range of shutter-speeds and choose three frames afterwards for multi-LUT film profile building, having a perfect negative strip at hand.

On the right you can see three printed targets — underexposed, normal and overexposed Kodak Portra 160VC film. They are printed manually directly from negatives in the darkroom using optical enlarger with color head and wet processing RA4.

On the left you can see 14 (in this case) test prints – made to achieve needed white balance and exposure. Each sample is developed, bleached, washed and dried for total of 4:20 min in RA4 paper processor.

Afterwards each print is measured with a spectrophotometer. Depending on results we add color head and exposure time corrections for the next sample.

Final prints have been scanned in a special way. With these prints we built a new mLUT film profile for Dehancer using our non-linear mathematic methods.

Users will receive at least 15 film profiles with a free alpha version – coming soon! Hopefully, we will release it and publish release notes this week.

Ambrotype multi-LUT profile creation process

A couple pictures taken during ambrotype profile creation process. Emulsion watering, shooting and the developing by Anatole Green.

We’ve took 3 negative pictures on glass plates — normal, under and over exposure. After that have scanned them on velvet background as positive and made mLUT (multi-LUT) profile using our non-linear mathematics. How it works in Dehancer you can see on example below.

Those hues are natural as it is, without desaturation or colorize post-processing. In reality, the underexposed ambrotype also looks like a bronze-green, and the overexposure is more yellow.