DxOMark: Is the 75 1.8 the best m43 lens Available?

Started 5 months ago | Discussions thread
marike6
Senior MemberPosts: 4,167
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Re: But what about...
In reply to micksh6, 5 months ago

micksh6 wrote:

marike6 wrote:

micksh6 wrote:

dcassat wrote:

If you look at the test results at slrgear.com and compare the Nikon and Olympus, you will come back with a different conclusion, okay the Nikon is slightly sharper at 2.8.

I would like to see others' comments regarding the statements made when other data does not back this up.

"Not in the same leaque," come on!

FF vs 4/3, no contest but sharpness?


When DxO introduced their new rating system few months ago I already said it was BS.
They arbitrary choose aperture for their best rating. Their ratings don't match what other review sites measure. And they are body-dependent.

A rating system that is body dependent makes total sense as the MTFs a lens produces is very much dependent on the sensor size, megapixel count and pixel density. Read any Lenstip review to see how MTFs go up or down depending on what body they use as a test camera. DxOMark factors this reality into their tests.


Lenstip tests all m4/3 lenses on one body and results are consistent.

Dependence on the body is not the main thing I don't like about DxO ratings, there are more important things - their poor consistency with other reviews and worthless megapixel rating.

So you think DxOMark's detailed testing, and attention to how a given lens performs on different bodies is worthless, but below Lensrentals number pairs to be useful? The fact is most m43 lenses are sharpest at f2.8-4, and most FF lenses are sharpest at f5.6-f8.

Lenses will produce different MFT resolution results on the same format sensor of different MP counts. See Photozone's test index for Nikon APS-C and you'll see a 10 mp index and a 16 mp index. They do this because of the varying resolution scores between older 10 mp Nikon's like the D200 and newer ones like the D7000. DxOMark is doing something similar but on a larger scale.

Photozone APS-C Nikon tests (notice two sets of tests, 10 mp and 16 mp), like DxOMark, Photozone recognizes that sensor and lens produce resolution scores which vary by mp count and pixel density.

http://www.photozone.de/nikon--nikkor-aps-c-lens-tests

If you try to cross-check DxO ratings with other reputable review sites you will find some conflicting results. For example, regarding that Nikon 85mm F1.8G lens, resolution measured by Roger Cicala:

Oly 75mm: 1020/925 line pairs/image height (at F2.8, F4 would be sharper).
http://www.lensrentals.com/blog/2012/07/the-olympus-75mm-f1-8-is-expensive-because-its-worth-it
Nikon 85mm f/1.8: 1053/942 lp/ih at F8 and measured on 36MP D800:
http://www.lensrentals.com/blog/2012/03/d800-lens-selection

Another example - unusually high DxO rating of Samyang 85mm F1.4 lens. This lens becomes sharp close to F5.6, that's not the aperture people buy this lens for. So, their rating system isn't realistic.

As I said, most FF lenses show peak performance at f5.6 or f8 where sharpness in the center and across the frame is highest.

Edited 5 months ago by marike6
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