The clipping is worse, as I would expect, if I use anything above zero for the white point and black point % setting.
For what it's worth, if I change Media Type from Image to Slide and then go to Color tab and change Generic to Koday and type to E6, the clipping seems to be significantly reduced. However, the scan is flatter and the colors have more of a yellow cast. By the way, I am using Koday Elite Extra Color EBX for these tests. Stan -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Bob Armstrong Sent: Thursday, November 22, 2001 9:13 AM To: [EMAIL PROTECTED] Subject: Re: filmscanners: VueScan clipping & flat images The following is taken from VueScan's help file. It seems to me that B&W points of 0% should leave all of the pixels in the scan. (Having said that, when looking at a histogram, it does seem that some pixels either go beyond the black point or there are a mumber of pixels _at_ the black point.) It seems to me that setting B/W to 0% results in what Jawed is calling a flat image. Jawed (if you're reading this!) does a histogram of one of your flat VueScan images extend all, or most of the way, from 0 to 255? I find with my flat VueScan mages that do not range across the histogram but leave, particularly at the white point end, a lot of unused values. If that is the case with your images I wonder if you would try to increase the white point to 0.05 or 0.1 and see what that does to the image. I would be interested in your results compared to Nikonscan especially if you set the white point to _just_ fill the histogram. Black point (%) The black point is used by the color balance algorithm and is computed by using the histogram of each color in the image. Use this option to leave the black point at the minimum intensity (0%), or to choose the black point such that some percentage of the pixels in the image are below the black point. White point (%) The white point is used by the color balance algorithm and is computed by using the histogram of each color in the image. Use this option to leave the white point at the maximum intensity (0%), or to choose the white point such that some percentage of the pixels in the image are above the white point. Bob Armstrong Alessandro Pardi wrote: >Stan, Leif, >I think you shouldn't use 0% for the white and black point, as this sets the >deepest shadows to 0 and the brightest lights to 255, and may result in >clipping. My usual settings are 0.1% for the black point and 0.5% for the >white point, but I seem to remember a post by Hamrick about this, so you may >want to dig in the archives. > From: Goodwin, Leif [mailto:[EMAIL PROTECTED]] > Sent: giovedì 22 novembre 2001 08.15 > To: '[EMAIL PROTECTED]' > Subject: RE: filmscanners: VueScan and highlight/shadow pixel > clipping--wh y? (SS4000) > > > Stan. I see the same with Vuescan and the Microtek 4000T > scanner. Don't know > why. Leif. > > > -----Original Message----- > > From: S Schwartz [SMTP:[EMAIL PROTECTED]] > > Sent: Thursday, November 22, 2001 3:27 AM > > To: Filmscanners (E-mail) > > Subject: filmscanners: VueScan and highlight/shadow pixel > > clipping--why? (SS4000) > > > > I posted this question a few days ago but got no response > so I am posting > > it > > again. > > > > I like using VueScan with my SS4000 scanner but I am > consistently seeing > > highlight and shadow pixel clipping on my transparency > scans. When I use > > Polaroid's Insight software for scanning, I get a nice > histogram with no > > pixel clipping. > > > > I have tried Vuescan with 0% white point and 0% black point > and still get > > the same clipping. I am using ordinary settings on the color tab: > > brightness > > 1.1, gamma 2.2, etc. > > > > Any reason this is happening? > > > > Stan > > > ************************************************************** > ***************************************** > The information contained in this e-mail is confidential. It > may also be legally privileged. It is intended only for the > stated addressee(s) and access to it by any other person is > unauthorised. If you are not an addressee, you must not > disclose, copy, circulate or in any other way use or rely on > the information contained in this e-mail. Such unauthorised > use may be unlawful. > > If you have received this e-mail in error, please inform > RACAL INSTRUMENTS LTD. immediately by phoning +44 (0)1628 > 604455 (ask for the I.T. dept) and delete it and all copies > from your system. > ************************************************************** > ***************************************** >