[Klaus]

The camera drive me nuts. The MTFs have an excessive variation between ultra-sharp center and very soft corners. I'm starting to wonder whether I'm seeing a sensor issue here.



Has anyone heard something about such effects (other than for symmetrical designs).

[joachim]

Which lenses did you try? Do they show strong distortion, requiring in-software correction? You got any lens with a nice long exit pupil? Could the semi- transparent mirror in the adapter be playing tricks?



Just a few ideas to check for. I assume you went and searched for available full scale samples available from other sides. If the effect is as strong as I understand from you post, one should see that in real world stuff.



J.

[Klaus]

[quote name='joachim' timestamp='1327354496' post='15171']

Which lenses did you try? Do they show strong distortion, requiring in-software correction? You got any lens with a nice long exit pupil? Could the semi- transparent mirror in the adapter be playing tricks?



Just a few ideas to check for. I assume you went and searched for available full scale samples available from other sides. If the effect is as strong as I understand from you post, one should see that in real world stuff.



J.

[/quote]



So far - the Zeiss ZA 85mm and Sony E 30mm. The Zeiss is "Ok" although with worse borders compared to the initial test. The E lens is sharper in the center but the borders are soft. I haven't analysed the data from the E 18-55 and A 16-50 yet but subjectively (based on the viewfinder feedback) I'm not expecting wonders in the border region either.

[joachim]

The 30mm was reviewed on slrgear. They also thought the corners are weak.



With the Zeiss, which Adapter are you using? I am suspicious of that semi-transp mirror. Also I remember you writing about funnies when using adapters on the Oly E-620. Did you ever understand those?

[Klaus]

[quote name='joachim' timestamp='1327357666' post='15173']

The 30mm was reviewed on slrgear. They also thought the corners are weak.



With the Zeiss, which Adapter are you using? I am suspicious of that semi-transp mirror. Also I remember you writing about funnies when using adapters on the Oly E-620. Did you ever understand those?

[/quote]



slrgear used the NEX 5. I will do another test on the 5 as well and I suspect that the results will be substantially better here. We are talking about rather dismal corners which isn't quite reflected in the slrgear test.



The ZA 85mm was tested using the LA-EA1 - not EA2 - thus without a potentially disturbing mirror. I did a reference test with the LA-EA2 actually but the results were only marginally worse (less than 5%).



There was something with the E-620. I suspect that the in-body IS had something to do with it. We had problems with the in-body IS on the E-P1 and E-PL3 as well. The Pentax K5 has also effects here - the sensor isn't really locked without IS but just kept in position.

[wim]

Hi Klaus,



If those bad corners are symmetrical, and those lenses have better results on other cameras, I guess it must be a sensor issue.



I stil lthink in-body IS is not a good thing, despite many people seeming to clamor for it: position of the sensor is even more critical than positioning of a few lens elements, and much harder to control <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.



Kind regards, Wim

[Guest]

[quote name='Klaus' timestamp='1327355217' post='15172']

So far - the Zeiss ZA 85mm and Sony E 30mm. The Zeiss is "Ok" although with worse borders compared to the initial test. The E lens is sharper in the center but the borders are soft. I haven't analysed the data from the E 18-55 and A 16-50 yet but subjectively (based on the viewfinder feedback) I'm not expecting wonders in the border region either.

[/quote]



All I can say is that the 18-55 was ultra sharp in the center and extremly soft in both the border and corner regions at all apertures. There was no improvement whatsoever on stopping down. That was on the nex-5n , though. Subjectivly the lens was far worth then Canons and Nikons 18-55 offerings. Image stabilization and build quality was better, though.

[joachim]

[quote name='Klaus' timestamp='1327359590' post='15174']

slrgear used the NEX 5. I will do another test on the 5 as well and I suspect that the results will be substantially better here. We are talking about rather dismal corners which isn't quite reflected in the slrgear test.





There was something with the E-620. I suspect that the in-body IS had something to do with it. We had problems with the in-body IS on the E-P1 and E-PL3 as well. The Pentax K5 has also effects here - the sensor isn't really locked without IS but just kept in position.

[/quote]



On the nex 7 vs 5 what do absolute numbers look like? Say a lens can only do 1500 lph resolution. At some point that must result to the same results whenever a sensor with a resolution much better than this is used.



You are suspecting minor sensor movements with IBS cameras? What are typical exposure times you are using? Ever considered.using flash?



Thanks

Joachim

[Klaus]

[quote name='joachim' timestamp='1327388191' post='15177']

On the nex 7 vs 5 what do absolute numbers look like? Say a lens can only do 1500 lph resolution. At some point that must result to the same results whenever a sensor with a resolution much better than this is used.



You are suspecting minor sensor movements with IBS cameras? What are typical exposure times you are using? Ever considered.using flash?



Thanks

Joachim

[/quote]



It all depends on the conversion parameters, of course, but the E 30mm shows about 3500+ LW/PH in the center at f/3.5 whereas the corners are down to 1500 LW/PH. That alone may not be worrisome but even the peak isn't impressive at about 2300 LW/PH for the borders/corners (vs 3900 LW/PH for the center). The lens has "fairly" high CAs which may dampen the results a bit. The curve remains highly suspicious in any case.



Observations:



While I haven't tested it formally I can confidently state that the GH-2 sensor is capable of delivering tack sharp results to the very edges. The Nikon V1 is also fine as far as Markus can tell. Possibly because the sensor is comparatively small compared to comparatively big lenses ?

The Samsung NX200 sensor shows no suspicious results either but the mount-to-sensor distance is also bigger here.

The upcoming Fuji X-Pro 1 has a very shallow register distance and the results from the 18/2 are also discouraging.



I'm still in the "tuning phase" which is why I haven't released any tests during the last weeks - therefore take all this with a grain of salt at this stage.

[Guest]

[quote name='Klaus' timestamp='1327389622' post='15178']

It all depends on the conversion parameters, of course, but the E 30mm shows about 3500+ LW/PH in the center at f/3.5 whereas the corners are down to 1500 LW/PH. That alone may not be worrisome but even the peak isn't impressive at about 2300 LW/PH for the borders/corners (vs 3900 LW/PH for the center). The lens has "fairly" high CAs which may dampen the results a bit. The curve remains highly suspicious in any case.

[/quote]



That problem is specific to 30mm macro.



See this review



http://erphotoreview.com/wordpress/?p=1488



He was using Nex-3