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Full Version: Any reason not to test outer center?
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Guest

I noticed on full frame tests, a lot of lenses just take a dump for borders and extreme borders but do very well in the center. Is there any reason not to test the outer center, roughly between the center and borders?
The simple reason is: lack of time <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='Wink' />



Seriously: of course we could test more than just 3 spots. But there's simply a limit of what we can do in the time we have available.



-- Markus

Guest

perhaps move the borders just a little closer to the center?
[quote name='mst' timestamp='1297673412' post='6097']

The simple reason is: lack of time <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='Wink' />



Seriously: of course we could test more than just 3 spots. But there's simply a limit of what we can do in the time we have available.



-- Markus

[/quote]



It's also a question of real value-add. For tele lenses you're primarily interested about what happens in the center region and for standard lenses or wide-angles you'd like to have a good performance across the image field.

So an additional "mid-field" spot doesn't seem to be that hot.
[quote name='ben4345' timestamp='1297673729' post='6098']

perhaps move the borders just a little closer to the center?

[/quote]



Well, the "borders" are ~75% off the center towards the corners.
[quote name='ben4345' timestamp='1297672954' post='6096']

I noticed on full frame tests, a lot of lenses just take a dump for borders and extreme borders but do very well in the center. Is there any reason not to test the outer center, roughly between the center and borders?

[/quote]



On PZ many lenses get reviewed twice: Full frame and APS-C. Since you seem interested in FF, the APS-C results give some guidance about the points you ask about. For sure there are many caveats to this - as Klaus for good reasons tends to point out fairly regularly: measurements are not comparible between systems. So take my statement with a grain of salt.

genotypewriter

[quote name='Klaus' timestamp='1297675266' post='6100']

Well, the "borders" are ~75% off the center towards the corners.

[/quote]

As I've said before, 75% off the image circle center doesn't correspond to a significant area of the frame:



http://www.flickr.com/photos/genotypewriter/5207301499/



Sorry, I have to agree with the OP...



GTW
[quote name='genotypewriter' timestamp='1297750262' post='6119']

As I've said before, 75% off the image circle center doesn't correspond to a significant area of the frame:



[url="http://www.flickr.com/photos/genotypewriter/5207301499/"]http://www.flickr.co...ter/5207301499/[/url]



Sorry, I have to agree with the OP...



GTW

[/quote]



Sorry, we will not do this. There're are other, more important enhancements that we're thinking about (flare).

If we test the lens on APS-C and FF you can get an idea about the outer center in the ASP-C test.

Guest

[quote name='Klaus' timestamp='1297753911' post='6121']

Sorry, we will not do this. There're are other, more important enhancements that we're thinking about (flare).

If we test the lens on APS-C and FF you can get an idea about the outer center in the ASP-C test.

[/quote]





But not all lenses you test on full frame never make it to the APS-C review. Nikon 24-120mm f/4 VR2 *hint hint.
[quote name='ben4345' timestamp='1297758428' post='6122']

Nikon 24-120mm f/4 VR2 *hint hint.

[/quote]



Will follow.



-- Markus
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