Re: filmscanners: Re: autolevels was re: filmscanners: Vuescan blue anomaly
It's a judgment call on your part and depends on the image. Using a reflection or glare may limit the contrast in the rest of the image more than you want, more than if you set the white point elsewhere than on the highlight. Other times the actual color of the highlight may be other than white, and the color balance in the rest of the image may be changed by using the reflection for a highlight. Or it may work out fine. Dan Margulis is the one who said not to use it, but his book doesn't go into too much detail as to why. Maris - Original Message - From: Rob Geraghty [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, July 26, 2001 1:43 AM Subject: filmscanners: Re: autolevels was re: filmscanners: Vuescan blue anomaly | Maris wrote: | Sometimes you can't use anything - rather than using the | eyedropper you just have to guestimate - trial and error - | until the number for a near-white spot are near-white but | not-quite-white numbers. | | OK, let me rephrase the question slightly - isn't the intention of the black | and white point to define where the minimum and maximum brightness points | are? If so, why is a point of sun reflection in a photograph not a good | point to use for the white point? Because it's not representative of the | majority of the image? | | Rob | | | Rob Geraghty [EMAIL PROTECTED] | http://wordweb.com | | | |
Re: filmscanners: Re: autolevels was re: filmscanners: Vuescan blue anomaly
- Original Message - From: Rob Geraghty [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, July 25, 2001 11:43 PM Subject: filmscanners: Re: autolevels was re: filmscanners: Vuescan blue anomaly Maris wrote: Sometimes you can't use anything - rather than using the eyedropper you just have to guestimate - trial and error - until the number for a near-white spot are near-white but not-quite-white numbers. OK, let me rephrase the question slightly - isn't the intention of the black and white point to define where the minimum and maximum brightness points are? If so, why is a point of sun reflection in a photograph not a good point to use for the white point? Because it's not representative of the majority of the image? Rob Generally when using the eyedroppers in Levels or Curves they are set to output target values. The black point is generally short of absolute black and the actual number represents an ink limit based on the media planned for output. The white dropper is generally set to a point less than completely white (nothing printed). When you then use the white dropper, you are defining the level of that point to the preset values, and all whiter points will be completely blown out. Therefore if the white dropper is set to RGB 244 (for example) you don't want to select a bright reflection that should be RGB 255. Bob Wright
