Scratches will probably reduce the overall contrast of the images. So, The scratch will affect image quality, even if it is not visible or recognizable.
The only way to actually see it, is of course to compare to photographs made by the same lens model, but without the scratches. This is rarely possible. I do believe, however, that it is very difficult to measure or see any differences as long as we are talking about a few minor scratches. Scratches at the rear element will probably have a greater impact on image quality than scratches on the front element. The greatest impact that scratches have is that of the sales value ;-) Any seller will realize or experience this ;-) I recently bought a used lens with a 1x1 mm nick in the front element. This lens was tested (by Jostein) against a similar lens of a competing brand which was unscratched. No difference in image quality appeared to be visible at all. But the effect on the sales value was quite significant. Lucky for me - as long as I'm not selling it. At auctions, however, the bidders will determine the sales price ;-) Regards Jens Jens Bladt http://www.jensbladt.dk -----Oprindelig meddelelse----- Fra: Igor Roshchin [mailto:[EMAIL PROTECTED] Sendt: 14. februar 2006 00:27 Til: [email protected] Emne: scratches on lenses Every so often I see a claim in a lens description: "These scratches don't affect the quality of your photo." What does one think when writing this type of statement? That you don't see the scratch on the photos? Even if a half of the lens area is covered by scratches you might not see the scratches on the photo.. Well, this is a somewhat rhetorical question: "How do you know that the scratches don't affect the quality of your photo?!" Personally, I would say that all scratches that are within the entire beam diameter used in imaging DO affect the quality of photos. So, the meaningful interpretation of the original statement would be: "I didn't have the way of knowing any better image quality". Would you agree? Igor
