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

Started Jun 15, 2014 | Discussions thread
Just another Canon shooter
Just another Canon shooter Veteran Member • Posts: 4,691
Re: A picture is worth...

Anders W wrote:

Just another Canon shooter wrote:

Anders W wrote:

Just another Canon shooter wrote:

Anders W wrote:

Yes it is. I compared ISO 3200 on MFT with ISO 12800 on FF, i.e., a two EV difference.

Wrong. ISO has nothing to do with EV.

Yes it does. Let me explain:

Suppose the MFT user can take a certain photo at 25 mm, f/2.8, 1/100 s, and ISO 3200. To capture the same photo, the FF user needs 50 mm, f/5.6, 1/100 s, and ISO 12800. Do you get it?

Remove the ISO from that, and you (and I) would be right.

Here is the formula for EV (wikipedia):

where

Do you see ISO there?

You already recognized your own mistake here:

http://www.dpreview.com/forums/post/53862916

That was a different thing.

So why keep quibbling about what EV is? What I meant when I said that the difference between ISO 3200 and ISO 12800 is two EV is that the former requires two EV more exposure. Do you get it?

Nice spin. Do you get it that "requires two EV more exposure" is not the same as "received two EV more exposure"? Exposure on those charts is all over the place, switch to daylight, and you cannot make them equal or different by 2 stops. It is just a coincidence that the total light was the same in that particular case.

Do you agree that ISO has nothing to do with EV?

 Just another Canon shooter's gear list:Just another Canon shooter's gear list
Canon EOS 5D Mark II Canon EF 15mm f/2.8 Fisheye Canon EF 35mm F1.4L USM Canon EF 50mm f/1.2L USM Canon EF 135mm F2L USM +4 more
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