As I mentioned in another thread (
http://www.luminous-landscape.com/forum/index.php?topic=95742.msg783766#msg783766) although I love the feel of Kodachrome scans from the Coolscan IV and V, I can’t use them because of flare around high contractst boundaries. This apparently is caused by low quality cover glass on the CCD (see these threads
http://photo.net/digital-darkroom-forum/00CTcF?start=10 and
http://www.pcreview.co.uk/forums/ccd-flare-nikon-coolscan-5000ed-t1939510.html). In one place I read that the CCD cover is not even glass but plastic. There was a fellow in Europe who offered replacement of the cover with high quality optical glass as a service. Unfortunately, I cannot provide links for the above since I researched the issue a couple years ago and did not keep notes. Anyway, here are some photos that illustrate the problem I had along with a comparison to a digital camera “scan.” Note that with both the IV and the V I had cleaned the scanner mirror and lens, so that the issue was not caused by built up mirror dust, a common cause of poor scan results with the Coolscans. The flare is directional; if you rotate the slide when scanning, the flare goes in the opposite direction.
In my case, this is what it is, but I am wondering if others see it or if I just happened to luck into two bad samples of the scanners.
Below is the original scan from the CS IV (I do a hardware adjustment of exposure in the scanner so that I don't blow the highlights, but don't apply any other corrections) and then scans from the IV and V with exposure of the scanner dngs boosted in Lightroom to show the flare issue more clearly and comparison of a "scan" with an Olympus E-M5 with the orf exposure similarly boosted. No other LR adjustments applied. Take a look at the top of the umbrella.
Image order:
Coolscan IV out of scanner
Coolscan IV lightened
Coolscan V lightened
Olympus E-M5 lightened