Archived posting to the Leica Users Group, 1997/06/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]In einer eMail vom 15.06.97 23:25:53, schreiben Sie: << The BAS tests are not considered as serious reports by many knowledgable people. The testing method (using a TV screen as a substitute for an optical measuring device is quite crude). Quite a few optical experts (among others at Zeiss and Leica) keep quite a distance to his writings and conclusions. If he is unable to show significant differences, then his testing method is quite wrong and/or not focused to the important optical parameters. >> Sorry to disturb you, but I think this is not true. When I had the honor to accompany Mr. Schulze during Photokina 1994, where he visited both the Leica and the Zeiss booth, the people there were not at all giving the expression that Mr. Schulze's test scheme is not good. In fact Leica has asked him several times to test their entire lens range for them. BAS does not use a TV screen instead of an optical instrument, this is rubbish. The BAS Pro test works - in brief - as follows. A highly defined slide (made by Zeiss, about 20.000$ worth) is being projected by the lens to a large screen. At that screen a high definition CCD camera analyzes certain areas of this projection, a computer compares the projected grid with the ideal grid. This lab test is accompanied by a field test, where the lens has to show his performance in real photography. Of course BAS is able to show any optical difference which is there (he is also able to spot customized lenses, which were prepared for the test). But the problem is that many people are not aware about the meaning of his results. They sell a lens with a huge loss, because it has only 9.3 optical quality, while another lens has 9.5. And then they are too lazy to carry a tripod... And they are not talented enough to make good pictures instead of buying one lens after another... The only people I know which are talking bad on BAS test results are the Normtest guys - they are the competition of BAS. It is my strong belief that there is not much sense in lens tests, when most lenese can be regarded as "very good". And my last remark: If you do not trust his results, you cannot trust any test results. So you have to find out if you think that the lens you are using meets your requirements. And if you personally think, that the lens you are using is the best in the world - it's okay with me. Everybody is free to believe what he/she wants. Frank