Archived posting to the Leica Users Group, 2001/02/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Wouldn't it make more sense (and be a lot less expensive) to just take some regular photos with and without a filter, and see if there is any noticeable difference? Speaking for myself, I have already done this and convinced myself that there is no difference, and no amount of optical bench testing will convince me that one of my identical images appears better than the other. By the way, have any of you seen the article by Erwin in the current Leica Fotographie? Let me quote from the articles summary: "Many photographers deliberately refuse to employ filters, even in those cases where it would appear advisable. They are just too worried about image quality. However, it is quite reasonable to protect lenses by means of a filter - without paying for it through a deterioration of image quality." © Erwin Puts. Dan C. At 02:54 AM 25-02-01 -0500, Austin Franklin wrote: >I decided to find out what the REAL effects of a UV filter are on image >degradation. I arranged for an afternoon of test time at a high end optical >testing facility in Cambridge MA. > >I am bringing my Hasselblad 110/2 and Leica 75/1.4 with their respective >Hasselblad and Heliopan UV filters, and will obviously test them with and >without the UV filters. They suggested as tests, both MTF and resolution. >Center and out to the edges. I also want to test focus shift. > >If anyone has experience with doing such testing and has some CONSTRUCTIVE >input on the testing procedure, I welcome it. Those who think this is >silly, well, given that this only costs $175/hour, and one filter is near >$100, I think that if I find out filters are useless, it'll easily recoup my >money by selling all my image degrading UV filters. If I find out filters >do not degrade the image such that it is perceptible, well, then I won't >waste my time debating this subject, as I will have facts to back up my >conclusions, and that will be well worth the effort and expense. > >I will publish the raw test results, no matter what they are. I fully >expect this to be quite controversial, and I also fully expect to find there >is 'some' degradation. It is the significance of the degradation that will >have to be 'analyzed' in order to draw any 'reasonable' conclusion to >whether a UV filter does actually degrade the resultant image. > >