Mark,
Very nice images of Gehrig! Looks like your method of scanning in portions and then "stitching" together worked pretty well. That's something I never considered before just buying a new scanner, and might be a good alternative for many collectors who only have a few negatives they want to scan. Good suggestion!
It looks to me like the difference in brightness between the left and right halves could be from the scanner using different "auto-contrast" settings for each. I wonder if you might be able to eliminate the difference by either manually adjusting the contrast rather than letting the scanner software do it (keeping the same setting for each half)? Or else do the preview for the first half, allowing the software to auto-adjust, and then slide the negative over but don't do a preview for the second half (in effect, keeping the same settings for the second scan). Seems like that might help photoshop in aligning everything correctly when combining the two scans as well.
Of course, I could be way off base with the reason for the difference
Either way, thanks for sharing those.
Steve,
Have you found that there are issues with the fluorescent light in the light box introducing a certain amount of "noise" into the scan? That was one of the home-grown methods I tried for larger negatives prior to buying the 4990, but never was sure if it was just my particular lightbox causing the interference, or something that was going to happen with any other one I tried. I also had some luck with backlighting smaller negatives (35mm and medium format) using a flashlight for the light source and using the smoothest paper I could find to diffuse it (laying negative on the glass, paper on top, then standing flashlight on top of both to scan). Even the smooth paper added some "texture" to the image though at those resolutions. I suppose I could have taken the opaque plastic cover out of my light box and used that instead, but was well on my way to abandoning the homemade set-up by that point.