On Jun 8, 2007, at 8:49 PM, "" <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote:
> Hmmm. Interesting and quite contrary to my own experience and others. It depends, really. Like, I was scanning some old Ektachrome 400 today. The images were coming out at at 4374 x 6400 pixels. That's about 28 megapixels and the scanner still wasn't clearly capturing the grain structure. Looking at it closely you can see what looks like noise, but is actually imperfectly resolved grain. Now, Ektachrome wasn't the finest-grained kid on the block, but the grain is fine enough that 28 megapixels isn't getting there. Of course, some of it is undoubtedly me hitting the optical limits of my Microtek scanner. That said, I've taken 5 1/2 megapixel images with my old Olympus E-1 that give some of my Ektachrome slides a run for their money when it comes to resolving detail. It's just that the actual image on a slide doesn't begin to cover the amount of information contained in the slide and if you want it all you have to scan huge to get it. I just shot a couple of rolls of Efke 25 in my Mamiya 7. Those 6x7 negatives contain WAY more than four times the amount of information on those 35mm slides. I wouldn't be surprised if it took 175 megapixels to properly resolve the grain structure. And that's the real problem with comparing film and digital. 10-12 megapixels will certainly give you images every bit as detailed as you're used to getting from film. Yet to capture the beauty of film's grain you have to scan at a level of detail that's really kind of impractical. I had a test arrangement with a camera manufacturer last year to do a telecine of some old 8mm film to HDV. They wanted to know how it performed. They may have been thinking of looking into an HDV telecine product, I don't know. Anyway, the results were mixed. The 720x1280 images from the camera captured all the detail that the lens on the 8mm camera original delivered to the film. I'm fairly confident of that. But the camera didn't even begin to resolve the grain structure. In fact, after talking to their engineers I found out that the mpeg encoder saw the grain as high frequency noise and tried to suppress it. So I was seeing a kind of cross-hatch pattern on individual frames that had replaced the grain structure. Now, when the image was in motion you couldn't tell you weren't just looking at grain, but pausing on a frame left an impression of some kind of jpeg compression gone wrong or something. Obviously this wouldn't be the case with uncompressed recording, but then the file sizes would be immense and I'm pretty sure 720p doesn't even approach the level of detail needed to resolve the 8mm grain structure. So you've got kind of a mixed bag, IMO. You can replace film with digital at a fairly low resolution, IMO. 6-10 megapixels will usually yield comparable imagery, IMO. And yet to fully resolve the grain structure of film takes WAY more resolution than you need to replace it as a capture medium. Robert Jackson Santa Rosa, CA ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
