View Full Version : Adjusting Histogram - pre or post scan?


CarlRadford
09-25-2006, 03:53 AM
Hi Folks

On a learning curve - I am trying to find a workflow for scanning film with an epson 2450 with the ultimate aim of digi negs with PDN (just waiting for the software to arrive) and need a little advice. Should one adjust the histogram pre or post scan - I have vuescan & CS2! Surely if the negs has been made for the tonality of the final image adjusting the histogram pre-scan would appear to be counter productice or am I missing something?

Thanks, Carl

buze
09-25-2006, 06:27 AM
I adjust the black & white point pre-scan -just- so that I get the lowest and highest tone in the file, then I scan in 16 bits and I do the final adjust using level/curve masks in CS2.

xvvvz
09-25-2006, 08:35 AM
Since you will have access to Vuescan, you might want to explore the raw scanning function. That will allow you to make one initial scan and then easily process the raw data in many different "what if" scenarios to help achieve the scan you want.

Doug
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www.BetterScanning.com

Kai Hamann
09-26-2006, 09:57 AM
Hi Carl,

IMO the best way is to scan with 48 bit resolution and only set white/black point in the scan program. Then make adjustments in PS and convert to 24 bit. You´ll see, that even white/black point of the scan are not accurate. That´s explicable because the preview scan is made with a very low resolution -- tiny dark and light spots are not recognised by the scan program.

All the best
Kai

Baxter Bradford
09-26-2006, 10:25 AM
Carl

I set black point by intentionally misalighning the neg to show rebate for the preview scan. Then sample rebate with dropper tool to get true black, thus you are getting shadow detail. Agree use of highest bit depth right and using adjustment layers to get file looking as you want. Monitor and scanner ICC profiling is important if working accurately and in case of latter to iron out irregularities induce by scanner.

CarlRadford
09-26-2006, 11:39 AM
Thanks for the advice folks. Baxter the rebate bit sounds logical - I can relate that to printing times and max black in the darkroom. ICC profiles is something I need to read up on - along with RIPs etc.

Baxter Bradford
09-26-2006, 01:25 PM
ICC profiles is something I need to read up on - along with RIPs etc.

You won't need a RIP Carl.

However ICC profiling is essential to get printed output matched to screen and obviate need for endless test prints for output and for scanning desn't mess up your hard fought tonal curve of the film/dev combo. Brings everything into line with common benchmark(s) and ability to transfer to other machines etc.

You'll never go back to sheets and blankets once you have seen/used a colour managed set-up!

CarlRadford
09-26-2006, 01:30 PM
I take it the software and hardware are pretty expensive but worth the investment then - wonder if it is possible to hire?

Cheers, Carl

You won't need a RIP Carl.

However ICC profiling is essential to get printed output matched to screen and obviate need for endless test prints for output and for scanning desn't mess up your hard fought tonal curve of the film/dev combo. Brings everything into line with common benchmark(s) and ability to transfer to other machines etc.

You'll never go back to sheets and blankets once you have seen/used a colour managed set-up!

Baxter Bradford
09-26-2006, 01:41 PM
I take it the software and hardware are pretty expensive but worth the investment then - wonder if it is possible to hire?

Cheers, Carl

RIPS are hundred of pounds, i don't have one.

There are lots of products around to do this task. Most cost effective is to get monitor device and buy in scanner/printer profiles. You might find someone local who has the gear to do these. Beware, quality does vary. Suggest speaking to Stu at Robert White or your local dealer. Another thought is that a local Camera club might have bought one for their members.

Eye one display2 or similar for monitor. need to redo every 4 weeks or less. They do drift noticably!
http://www.robertwhite.co.uk/colour%20management.htm#Gretag

I then got one printer profile for my most common paper rather than buy the gear to do it myself.
http://www.robertwhite.co.uk/colour%20management.htm#PProf

Scanner
http://www.robertwhite.co.uk/colour%20management.htm#SProf

HTH


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