Crop Factor, Low Light and Aperture with m4/3 lenses? Part 2

Started 4 months ago | Discussions thread
bobn2
Forum ProPosts: 30,714
Like?
Re: Crop Factor, Low Light and Aperture with m4/3 lenses? Part 2
In reply to knickerhawk, 4 months ago

knickerhawk wrote:

Truthiness wrote:

Although we don't have any perfect physical speedboosters, we have some pretty good ones, and I think it's clear that the difference in resolution between two 20cm X 30cm prints generated with the same FF lens on an FF camera and on an m43 camera (with a sensor having the same resolution as the FF camera) using a good speedbooster will be much smaller than the difference suggested by the 69 and 267 times required enlargement factors you mentioned, or do you disagree?

You're right for most cases of course - I never claimed anything else.

However the problem is that this thought experiment has no relevancy for this issue: when you use the booster you downsize the image from 43mm diagonal to 21.6mm, thus you use the original lens as intended, all of it's lens area including all of the original image circle. The situation is quite different when you only use the center part of the image circle and enlarge that.

So, in other words, all we need to do is design all m4/3 lenses with FF image circles and speedboosters built in and your "inherent" advantage for FF magnification disappears. Hmmmm...

This was the approach used by Olympus for their SHG zooms. Unfortunately, do it that way, all size advantage for the smaller sensor disappears.

In the end, sensor size doesn't matter very much, it is the size of the lens. The time when sensor size does matter is when common use-cases get too close to the f/0.5 limit of a lens.

-- hide signature --

Bob

Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow