11/19/2023 0 Comments Zeiss siemens star chartThis test can be used to detect front or back focus issues with a particular lens or a camera body. After publishing the findings about my 50s in the last articles, I’ve been following the chatter that I created on various forum webites.Below is the easiest and quickest way to test if your DSLR has an autofocus issue, along with a recommendation on what to do if there is a problem. I’ve read a few opinions complaining about the subjectivity of my method.Īlthough I reviewed all images very carefully and very closely they are probably right. Whenever the human component is key, much of it simply is a matter of perception or maybe even taste.ĭon’t get me wrong I still feel confident that my findings are mostly valid, but I wouldn’t bet a large sum on it. Since then I did quite a few more real life testshots with the purpose to validify my results by repeating them in a different context. But, the problem remained: If I wanted to shoot real life images, the results would only be compared by my eye. While I could (and can) provide many more shots for you to judge yourselves, I don’t think it would be worth it, because you won’t do it. In my experience people want results, some probably only want to know the winner (typical question: what’s the one lens you would keep yourself?).Īt some point I decided, that I needed to objectify my findings and do test charts. I never wanted to do this, but with 50+ lenses it is probably the only satisfying way. I started out trying to use the USAF chart. This chart is all about numbered pairs of three lines becoming smaller and smaller until finally the camera can’t resolve the three lines anymore and they blur together into one undifferentiable mass. The numbers of the last pair of resolved lines make it possible to calculate the largest possible resolution of the lens-sensor combination. The following image is a small crop (409 x 280 px) from the center area of the 6000×4000 px frame. It is taken from a shot with the Auto Revuenon 1.4/50 MC shot at f/2.8. Trying to evaluate the results, I found myself again BEING THE JUDGE (so: no objectivity as well).
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