Size comparison of FE 4/2470 on A7 vs Olympus 12-40 f2.8 on GX7

Started Feb 6, 2014 | Discussions thread
joe6pack Senior Member • Posts: 1,590
Re: apples and oranges

viking79 wrote:

Dennis wrote:

Emacs23 wrote:

I bet 24-70 is better. Larger sensor — easier to design.

Since when ?

A7 has 4000 pixel high image and 24mm page height, or 2000 line pair high image and 24mm = 83 LP/mm.

E-M1 has 3456 and 13mm page height, or 133 lp/mm requirement.

Which do you think is harder to design a lens for? A sensor that requires 133 lp/mm or 83 lp/mm? Even A7R has only 103 lp/mm requirement.

To look at this another way, pretend I wanted to get a "16 MP" image out of the camera. For the E-M1 that would require 133 lp/mm, but a lens with only 68 lp/mm would be fine on A7 or A7R. This is very low and easy to design, where 133 lp/mm is getting exceedingly difficult and expensive.


Seems to me 68 and 133 difference is just 1 stop. Which is offset by the f-stop difference between F2.8 and F4. And then the Olympus has longer reach. Seems to me Olympus wins here.

Ease of design also needs to take into account the coverage area. All things including aperture being equal, it is easier to design a lens for a smaller sensor too.

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