Scanning and depth of field revisited -- good result from focus stacking

[AFairley]

I finally got around to trying focus stacking with scans from my CoolScan IV (which has driven me nuts trying to deal with shallow depth of field throwing areas out of focus if the film is not very very flat, a particular problem with transparencies, even though I remount them to scan in mounts with pegs for the sprocket holes to try and pull them flat), and first results are very promising.  I started by measuring focus distance at different points on the transparency to determine the overall range of focus, and then using manual focus settings, scanned a series 10 focus units apart inside that range, which gave me 3 scans.

I opened all the NEFs in ACR 64-bit via Bridge, made all adjustments to one, and synced the adjustments to the others.

Then I went into CS5, and opened the NEFs into a stack with auto alignment.  I created masks for the top two layers for each layer and with a medium feathered brush painted out the portions where the film grain sharpness had fallen off, making sure some of the live areas overlapped.

Result seems to be an image with crisp grain everywhere.  I have yet to print, but I don't see any artifacts on the screen.

Happy camper so far.

[Peter McLennan]

Good news.  I rented a Nikon to scan in a whole bunch of 120 from years ago and ran in to the same problem.
Bad news.  Now I have to rent again and re-scan.   

Thanks for the encouragement, though. : )

[dmerger]

Very helpful tip.  Thanks.

[mouse]

I opened all the NEFs in ACR 64-bit via Bridge, made all adjustments to one, and synced the adjustments to the others.

Did you really output a NEF file from the scanner?  For some reason I was under the impression that the NEF files output by Coolscans were so different from NEF files from Nikon cameras that they could not be opened by Bridge/PS5.  If this does work, is there an advantage to capturing the scanner output as a NEF as opposed to a tiff?

[AFairley]

Did you really output a NEF file from the scanner?  For some reason I was under the impression that the NEF files output by Coolscans were so different from NEF files from Nikon cameras that they could not be opened by Bridge/PS5.  If this does work, is there an advantage to capturing the scanner output as a NEF as opposed to a tiff?

AFAIK, the CoolScan NEF is just a tiff in a wrapper there is no advantage to scanning to NEF either info-wise or size-wise.  They open fine in ACR and preview fine in Bridge.  (However, if you just rename the extension from NEF to tif, what will open directly in CS5 is the embedded preview.)