Exposing for Scanning

[Stealth3kpl]

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When exposing for scanning, would it be wise to err on the side of overexposure to give more tonal range in the shaddows? Presumably, with colour film, this would be at the expense of saturation but this could be addressed in post processing.

Pete

[StS]

I'm afraid this depends strongly on the scanner technology. Following similar discussions in this forum, I got the impression most people using LED based scannes expose and develop their films to be rather flat.

 

I had some negatives having a very strong contrast scanned by my lab's Noritsu and found it to be able to handle even very dense negatives. However, the purchasing price of it will buy a very decent car.

 

I'm afraid, there is no general answer. My suggestion would be to try test films for the favourite film/scanner combinations.

 

Owners

[Guest joewehry]

If you not doing the scans yourself, ask the lab what their recommendations are for the film type and speed. Alternately, bracket exposure on a test roll of varying scenes and see what results match your vision.

[Stealth3kpl]

Thanks for your reply chaps. It's certainly worth sacrificing a few frames.

Cheers,

Pete

[jbl]

For whatever it's worth (and this was for black and white), I did a several calibration rolls where I exposed for zones 0-10 at half-stop increments, then processed, then scanned, then messed around with settings until I got a reliable set of tones. Then it's the usual thing of where Zone I appears being used to set the effective film speed, Zone III at around 12.5% luminance, Zone V around 50% luminance and Zone X just clipping on the white end. Rinse repeat, until you get what's usable.

 

One thing to keep in mind is that you'll want to make sure your scanning software is producing a linear scan so that you don't get it applying a log curve to the film which already had a log curve.

 

For me---and this was just for what I ended up with---for Tri-X, I found that exposing it at 320, processing for 9.5 minutes in HC-110 (1+49) with 30 seconds initial agitation and 4 inversions over 10 seconds at the start of each minute thereafter worked for me. Scanning side, I scanned into DNG using Viewscan, imported it into Lightroom, set the curve to linear, 0 on the black clipping, 25/0 on brightness and contrast, zero sharpening and noise reduction and we were good to go.

 

For other films, I've kept the scanning/Lightroom workflow constant, just varied the exposure and processing time accordingly until I got what I was looking for. Usually it's pretty obvious when you're off one way or another. You're basically looking to get Zone V in a particular position, but you're also interested in the variation between frames as you proceed up to Zone X. If it goes to white too fast, you're over processing (or over exposing, but that depends on where the shadows are).

 

I also found it fairly useful to start the test shots at Zone -1 because that made it easier to spot Zone I, but that was just what I found.

 

I've never bothered doing this with color negative or reversal film.

 

-jbl