It's odd, how these things behave. There have been so many reports of contributing factors and remedies that it's really hard to find the common thread. Loose Gravel's report that diffuse light sources diminish the NR effects is directly opposite my own. I'm sure LG's report is factual, but I HAD to use use a diffuse source to see the problem with Kevin's frame. When I first tried to see the rings, I tried sunlight. All I could see were a few small patterns (even with a magnifying glass). I tried incandescent light, but still no results. When I got the little light box I use to view slides (very diffuse), and looked at the reflection of it in the printing frame the NR's were everywhere, and very well defined. Could be the difference is transmission vs reflection. Anyway I'm glad to hear that menglert's problem is fixed.