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duanecwilson

Lenses that take advantage of A7R ii 42MP resolution.

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I recently bought a used Sony A7R ii. If I use everyday lenses, I wonder if their relatively poor resolutions will make it so there is no advantage of having the 42MP verion (A7R ii or iii) vs the 24MP (A7R ii or iii). What I don't want is to waste 42MP if the images turn out no different than the 24MP. What lenses should I avoid and/or what lenses should I look for that would accentuate the difference rather than suppress it. And, since I have a lot of Canon lenses, will any of those take advantage of the 42MP?

Does anyone have both? Can you see a difference? If so, what lenses do you use?

Up till now, I have used a Canon 80D, and I know it is an APS-C camera, but I really wanted an upgrade in sharpness or I would have gotten an A7 ii or A7 iii.

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Image sharpness always benefits from having a higher MP count. Check e.g. DXOmark with some of the lenses with minimal sharpness like the 24-240:

On the A7R (36 MP) it has 9 perceptual megapixels while on the A7RII (42 MP) it has 15 perceptual megapixels. I'm quite sure the sharpness of the old A7R suffers from it's notorious shuttershock in this test but the difference is evident. Unfortunately DXO didn't test any lenses on the 24 MP A7x but there's plenty to be found on this subject on the web.

Edited by Pieter

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There are basically two cases to consider:

  • the resulting resolution may either be limited by the available pixel count of the sensor (lens could deliver more, but sensor does not have enough pixels to take advantage of the lens's capabilities - or:
  • the resulting resolution may be limited by the focussing capabilities of the lens. (The image of a "point size" object on the sensor is larger than one sensor pixel.)

If you want to exhaust the pixel count of your sensor as far as possible, you should pick any lens that has a higher "perceptual pixel count" (to use dxo's terminology) value than the sensor. In their lens database there are only five lenses that come close, if you include 40 pMP as being close enough to the 42 actual MP od the 7Rii.

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Thing is DXO's testing method by definition can't measure a higher perceptual megapixel count than the sensor used in the measurement. If a higher megapixel sensor was used to test those lenses you refer to, a higher number would have been obtained. Rest assured those lenses with 40-ish perceptual megapixels on an A7RII in fact outresolve the sensor.

Edited by Pieter

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Thank you for the responses. I was also wondering about Canon lenses with the adapter or off-brand Sigma, Tamron, etc, lenses. I have an number of Canon lenses and some Sigma and a Tamron.

Edited by duanecwilson
altered the content - found some answers myself.

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