At 11:35 AM -0500 1/6/2009, Sam Macomber wrote: >On Jan 5, 2009, at 10:20 PM, Dan wrote: > > At 5:42 PM -0500 1/5/2009, Sam Macomber wrote: > >> From a pro perspective image quality of a TIFF is not good enough, >>> RAW is much better. >> >> Never heard that before. In what way is TIFF lacking? > >RAW format is all the information captured by the camera's sensor in >an unaltered state(though sometimes lossless compression is used, >depends on the camera). To generate a TIFF that sensor data has to be >altered and when you do so information is lost.
Ok. Been reading up on raw... It's interesting,,, and complicated. The direct CCD data (raw) is unusable unless you have a profile containing the necessary metrics, regarding that particular camera's ccd performance. Said profile is sometimes included in the metadata buried within the raw file, but not always. IOW, iffa you no gots that profile, the raw data is all but useless. My take: Like color profiles for printers and displays, this is a nightmare waiting to happen. We're going to have to have libraries of thousands of these profiles - just to hope to be able to handle a random raw image. The advantage of the raw data is that it hasn't had its range clipped yet; its still up to 14 bits per pixel (jpeg clips to 8 bits after gamma correction). That's good - if you can process it correctly. Bad - if you cannot process it fully - it leaves you with extra white noise. Most RAW file formats (note the caps now) are "undocumented" (trying to not say "proprietary") extensions of TIFF 6.0. (DNG is also an extension to TIFF 6.0). ...This is kindof like what people are doing to MPEG-4, to create things like DivX and Xvid. LOL - a gotcha to be aware of - many cameras use a *lossy* compression on RAW by default. I'd venture anyone serious about wanting RAW needs to turn that off! In four diff places, I've now read comments to the affect that because RAW is a non-standard, it is NOT appropriate for long-term / archival storage use. They recommend TIFF or JPEG with a lossless or zero compression. I can see why RAW is good for a professional photographer's use in the short term. But all the above, taken together, makes me think this is a format that's not useful for archival / long-term use. For said archive, I guess it can't hurt to keep the RAW file, and the profile, as long as you *also* do a TIFF or something. > >> At this point with newer systems they're generally all supported by >>> Photoshop CameraRAW and can be converted to DNG. i feel that's >>> reasonably safe since I'm seeling the useful life right around 10 >>> years for an image, >> >> DNG still bothers me a bit. It's an Adobe format, a container for >> their particular variant of RAW, based on TIFF. >> >> I don't trust Adobe much. > >Part of the reason we have not yet started to convert to DNG, I love >the format but you are right all the eggs in one basket. heh. Just ran across some old PDF files that I cannot seem to open anymore. Preview gives an empty window. Adobe Reader crashes. Tried full Acrobat on XP - it blue screens. That's a good example of how Adobe formats work - even the "open" ones. - Dan. -- - Psychoceramic Emeritus; South Jersey, USA, Earth --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
