Tests of the SEL 1855 - Printable Version +- Opticallimits (https://forum.opticallimits.com) +-- Forum: Forums (https://forum.opticallimits.com/forumdisplay.php?fid=4) +--- Forum: Sony (https://forum.opticallimits.com/forumdisplay.php?fid=14) +--- Thread: Tests of the SEL 1855 (/showthread.php?tid=904) Pages:
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Tests of the SEL 1855 - karelderaat - 02-09-2016 I use the NEX system since 2012. Thus I am always interested in tests of the e-mount lenses meant for the APS-C sensor size. Just browsing Photozone I discovered the very different testing results of the SEL 1855 obtained with a NEX 5 and a Nex 7. In particular the sharpness results drew my attention. How is it possible that the same lens has much higher MTF50 scores for the NEX 5 than for the NEX 7. I cannot follow the explanation by Photozone for this discrepancy. According to the explanations provided by the company that developed the test program, as they can be reached via Photozone, a higher number of mega pixels on an identical surface area (sensor size) must theoretically result in at least the same MTF50 values. Unless:
Tests of the SEL 1855 - JJ_SO - 02-09-2016 I think, one of the testers will answer your questions. But PZ and most other test labs test only one sample of a lens. If you like to know about sample variance, I can recommend a visit on lensrentals blog: http://www.lensrentals.com/blog/2015/10/sony-e-mount-lens-sharpness-bench-tests Tests of the SEL 1855 - karelderaat - 02-09-2016 Further to this. I do not understand why the SEL 18-55 is so negatively labeled as regards sharpness, while the standard zoom of the Nikon 1 system is deemed to be excellent to good. The MTF50 value over the whole sensor (picture) do not differ so much (it is the sharpness at equal print sizes that counts). Moreover, the user community (level and ambitions) will not differ very much between the Nex and the 1 system, so there is no reason to adapt the verdict to anticipated expectations of the users. Tests of the SEL 1855 - Klaus - 02-09-2016 Sony's 24mp sensor (NEX 7 / A6000) suffers from edge smearing. I mentioned this a couple of times in various NEX7-based reviews ... so the results are not cross-comparable. I don't remember for sure but I believe that this was actually the very same sample that we tested there. As you may also observe in the NEX-5 vs NEX-7 reviews, the ratings are relative to the potential max LW/PH of the underlying test system. Tests of the SEL 1855 - Brightcolours - 02-09-2016 Quote:I use the NEX system since 2012. Thus I am always interested in tests of the e-mount lenses meant for the APS-C sensor size. Just browsing Photozone I discovered the very different testing results of the SEL 1855 obtained with a NEX 5 and a Nex 7. In particular the sharpness results drew my attention.
Tests of the SEL 1855 - karelderaat - 02-09-2016 So the conclusion would be that the lens is not that bad, but that the low score on the NEX 7 is a result of NEX 7 sensor issues. Good to know! Thanks. I have a 5R and a A6000. Do I have to expect the same issues with these cameras? Tests of the SEL 1855 - Brightcolours - 02-09-2016 Quote:So the conclusion would be that the lens is not that bad, but that the low score on the NEX 7 is a result of NEX 7 sensor issues. Good to know! Thanks. I have a 5R and a A6000. Do I have to expect the same issues with these cameras?No, the 5R has a good sensor. And I have not read much about issues with the A6000 (seems like Sony fixed the sensor issue with that model). Tests of the SEL 1855 - Klaus - 02-09-2016 Quote:No, the 5R has a good sensor. And I have not read much about issues with the A6000 (seems like Sony fixed the sensor issue with that model). The 16-70/4 was tested on the A6000 so ... no ... Tests of the SEL 1855 - karelderaat - 02-09-2016 Does that mean that you did the same comparison for the 16-70/4 (i.e., testing on two different cameras/sensors), or is the lens in this case the origin of less than satisfying test results? Tests of the SEL 1855 - Klaus - 02-09-2016 Quote:Does that mean that you did the same comparison for the 16-70/4 (i.e., testing on two different cameras/sensors), or is the lens in this case the origin of less than satisfying test results? The 16-70 was as soft on the A6000 as on the NEX7. At some stage people complained that I should abandon the NEX7 so I bought the A6000. I did some tests and there was no indication that something changed. Some people claim that there's a difference but I reckon this is related to different focus settings. Thus I sold the A6000 again because the viewfinder was worse. FWIW, initially I even bought a 2nd NEX7 to verify the results but at no effect. Maybe things have changed on the A6300 ... there's always another hope. ;-) |