Re: filmscanners: VueScan and white pixel clipping SS4000
Frank Nichols wrote: (Newbie alert: Above is based on total ignorance...) Well, if you are going to be ignorant, why do it half way ;-) Art PS; personally, I think you aren't being completely truthful. ;-)
RE: filmscanners: VueScan and white pixel clipping SS4000
On Sun, 08 Jul 2001 21:03:03 -0500 Stan Schwartz ([EMAIL PROTECTED]) wrote: What's OTT? Over The Top; excessive Also, I am actually scanning at 12-bits; that's the spec on the SS4000. PS treats the image like a 16-bit. Is that introducing any problem? No. The 12 bit output is padded to 16bits for compatability, that's all. Any idea what the fairly evenly spaced whiskers on the histogram represent? If not actual subject luminances, then usually you'd expect them to indicate rounding errors during processing. They need not alarm you, you'll find they vanish on conversion to 8bit. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
RE: filmscanners: VueScan and white pixel clipping SS4000
Tony, Thanks. These whiskers only show up on high-bit scans with VueScan but not high-bit scans with Polaroid's software. You are correct that they disappear on 8-bit conversion. Stan Schwartz www.tallgrassimages.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Tony Sleep Sent: Monday, July 09, 2001 8:34 PM To: [EMAIL PROTECTED] Subject: RE: filmscanners: VueScan and white pixel clipping SS4000 Any idea what the fairly evenly spaced whiskers on the histogram represent? If not actual subject luminances, then usually you'd expect them to indicate rounding errors during processing. They need not alarm you, you'll find they vanish on conversion to 8bit. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
RE: filmscanners: VueScan and white pixel clipping SS4000
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Tony Sleep Sent: Monday, July 09, 2001 8:34 PM To: [EMAIL PROTECTED] Subject: RE: filmscanners: VueScan and white pixel clipping SS4000 On Sun, 08 Jul 2001 21:03:03 -0500 Stan Schwartz ([EMAIL PROTECTED]) wrote: What's OTT? Over The Top; excessive Also, I am actually scanning at 12-bits; that's the spec on the SS4000. PS treats the image like a 16-bit. Is that introducing any problem? No. The 12 bit output is padded to 16bits for compatability, that's all. Any idea what the fairly evenly spaced whiskers on the histogram represent? If not actual subject luminances, then usually you'd expect them to indicate rounding errors during processing. They need not alarm you, you'll find they vanish on conversion to 8bit. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
Re: filmscanners: VueScan and white pixel clipping SS4000
You might try a lower Brightness setting in Vuescan and different gamma settings to deal with the highlight clipping. Maris - Original Message - From: Stan Schwartz [EMAIL PROTECTED] To: Filmscanners (E-mail) [EMAIL PROTECTED] Sent: Sunday, July 08, 2001 11:06 AM Subject: filmscanners: VueScan and white pixel clipping SS4000 | I am making a scan of an array of bright azaleas using VueScan and an | SS4000. I am scanning at 48-bits. | | I am not sure I understand the settings correctly in VueScan. My scanned | images are showing a lot of burned out highlights. The Photoshop histogram | shows a lot of bright pixel clipping off the the right side of the | histogram, confirmed by Option_clicking the white triangle. | | I tried scanning in both white balance and autolevels. The Help information | says that I would be best with autolevels for this type image. | | Looking at other high brightness images, it appears I am getting a | significant amount of clipping if I leave the white point setting at 0.5%. | Even at white point set to 0.0%, there is a small amount of white pixel | clipping. | | I am not clear what is accomplished by having the white point setting | defaulted to 0.5%. | | One other thing the histogram shows: across the top of the histogram, even | before I make any level adjustment, I am seeing about a dozen or so | whiskers. I understand why these show up after levels adjustments, but I | am not clear why I am seeing them on the unadjust image. | | This clipping and the whiskers are not showing up when I scan with | Polaroid's software. | | | | | Stan Schwartz | | www.tallgrassimages.com | |
RE: filmscanners: VueScan and white pixel clipping SS4000
I find that the default gama of 2.2 is too high for most of my scans - try lowering the gama. I use 1.5 to 1.8 normally. Also, the white point % determines what percentage of pixels in the image are at 255/1024... (max value). So I normally set this to 0.05 and adjust in Photoshop where I have a histogram to se whats going on. /fn (Newbie alert: Above is based on total ignorance...) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Stan Schwartz Sent: Sunday, July 08, 2001 10:07 AM To: Filmscanners (E-mail) Subject: filmscanners: VueScan and white pixel clipping SS4000 I am making a scan of an array of bright azaleas using VueScan and an SS4000. I am scanning at 48-bits. I am not sure I understand the settings correctly in VueScan. My scanned images are showing a lot of burned out highlights. The Photoshop histogram shows a lot of bright pixel clipping off the the right side of the histogram, confirmed by Option_clicking the white triangle. I tried scanning in both white balance and autolevels. The Help information says that I would be best with autolevels for this type image. Looking at other high brightness images, it appears I am getting a significant amount of clipping if I leave the white point setting at 0.5%. Even at white point set to 0.0%, there is a small amount of white pixel clipping. I am not clear what is accomplished by having the white point setting defaulted to 0.5%. One other thing the histogram shows: across the top of the histogram, even before I make any level adjustment, I am seeing about a dozen or so whiskers. I understand why these show up after levels adjustments, but I am not clear why I am seeing them on the unadjust image. This clipping and the whiskers are not showing up when I scan with Polaroid's software. Stan Schwartz www.tallgrassimages.com
Re: filmscanners: VueScan and white pixel clipping SS4000
On Sun, 08 Jul 2001 11:06:56 -0500 Stan Schwartz ([EMAIL PROTECTED]) wrote: I am making a scan of an array of bright azaleas using VueScan and an SS4000. I am scanning at 48-bits. Try a white point setting of 0.01% (0.0% is usually OTT), and adjust Color|Image Brightness to a smaller number to give a duller, greyer preview (hit Prev Mem after adjusting). EG, if currently 1.0, try 0.8 or so. This will avoid the clipping, and you can then adjust levels precisely in PS. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
RE: filmscanners: VueScan and white pixel clipping SS4000
Thanks. What's OTT? Also, I am actually scanning at 12-bits; that's the spec on the SS4000. PS treats the image like a 16-bit. Is that introducing any problem? Any idea what the fairly evenly spaced whiskers on the histogram represent? By the way, I am not able to access your website. I am getting an announcement message from the ISP, it seems. Stan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Tony Sleep Sent: Sunday, July 08, 2001 6:20 PM To: [EMAIL PROTECTED] Subject: Re: filmscanners: VueScan and white pixel clipping SS4000 On Sun, 08 Jul 2001 11:06:56 -0500 Stan Schwartz ([EMAIL PROTECTED]) wrote: I am making a scan of an array of bright azaleas using VueScan and an SS4000. I am scanning at 48-bits. Try a white point setting of 0.01% (0.0% is usually OTT), and adjust Color|Image Brightness to a smaller number to give a duller, greyer preview (hit Prev Mem after adjusting). EG, if currently 1.0, try 0.8 or so. This will avoid the clipping, and you can then adjust levels precisely in PS. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
RE: filmscanners: VueScan and white pixel clipping SS4000
Stan, Your computer (and most programs) can't deal with 12 bit packages of data, so the program is converting it to the next larger package and pading the top 4 bits for you. This has no affect of the image data - just just have 3 quarts and the closest bottle it can find is a gallon. /fn -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Stan Schwartz Sent: Sunday, July 08, 2001 8:03 PM To: [EMAIL PROTECTED] Subject: RE: filmscanners: VueScan and white pixel clipping SS4000 Thanks. What's OTT? Also, I am actually scanning at 12-bits; that's the spec on the SS4000. PS treats the image like a 16-bit. Is that introducing any problem? Any idea what the fairly evenly spaced whiskers on the histogram represent? By the way, I am not able to access your website. I am getting an announcement message from the ISP, it seems. Stan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Tony Sleep Sent: Sunday, July 08, 2001 6:20 PM To: [EMAIL PROTECTED] Subject: Re: filmscanners: VueScan and white pixel clipping SS4000 On Sun, 08 Jul 2001 11:06:56 -0500 Stan Schwartz ([EMAIL PROTECTED]) wrote: I am making a scan of an array of bright azaleas using VueScan and an SS4000. I am scanning at 48-bits. Try a white point setting of 0.01% (0.0% is usually OTT), and adjust Color|Image Brightness to a smaller number to give a duller, greyer preview (hit Prev Mem after adjusting). EG, if currently 1.0, try 0.8 or so. This will avoid the clipping, and you can then adjust levels precisely in PS. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio exhibit; + film scanner info comparisons
Re: filmscanners: VueScan and white pixel clipping SS4000
I don't know what OTT means either. Maybe, "over the top?" As for 12-bit scans from the SS4000 that get treated as 16-bit: it's because the folks who invented the TIF file formats only invented two of them. A 24-bit TIF format (for 8-bit per each RGB channel) and a 48-bit TIF format (for up to 16 bits per each RGB channel). The SS4000 gives you 12 bits per channel, so it would be ideal if there were a 36-bit TIF format for storing your image. But there isn't. You must use either a 24-bit or 48-bit format. If you use the 24-bit format, then you must tell your scanner software how you want it to do the scan and it will throw away the least import bits of information, per your instructions, such that the scanned image gets reduced to 8-bits per channel and will fit into a 24-bit TIF file. That method works very well if you set up the scan correctly. But some people like to do a "raw" scan that contains all 12 bits per channel because they want to use Photoshop (or some other software), rather than the scanner software, to decide which bits to throw away when they create the final 8-bit per channel image. For those people, they have no choice but to put the image (36 total bits from a SS4000) into a 48-bit file. Some extra null bits get added to "pad" the 36 bits of information so they don't rattle around too much inside the 48-bit file, but that does no harm. They'll be ignored with what ever software looks inside the 48-bit file. The only down side is that a 48-bit file takes a bit (no pun intended) more storage space than would a 36-bit file. In a message dated 7/8/2001 7:12:11 PM Pacific Daylight Time, [EMAIL PROTECTED] writes: What's OTT? Also, I am actually scanning at 12-bits; that's the spec on the SS4000. PS treats the image like a 16-bit. Is that introducing any problem?
