Well, after watching this we are probably cheated. The guy in this video perhaps misleads people about how mirrorless manufacturers(Sony, Olympus and Panasonic) cheating people in advertising. He stated that Sony, Panasonic and Olympus mislead us with the 135FF equivalent conversion, as well as Fujifilm ISO cheat.
Tony, the presenter in the video, said these manufacturers should have marked the converted F-number on lenses because of DoF is different while not refering to the lens speed. At the end, he praises the big DSLR brands(Canon & Nikon) as a good honest guy.
His statement seems reasonable. As we know, it is a common sense and important photography principle, aperture controls the light volume through the lens to the sensor, which is what does it work for. However he informed us different terms of them. He thinks aperture is a depth of field(DoF) controller, so that manufactor should have convert the F-number on lens label, such as Panasonic 12-35mm f/2.8 should be labeled 24-70mm f/5.6 due to the MTF has 2x deeper DoF. Seems correct? well, let’s think about when we use M-mode and sunny-16 rule without metering, it would be a problem, because the metering is under 2EV (MTF) or 1EV (APSC).
Do you think Sony, Olympus and Panasonic cheat us?
UPDATE: This is an important update by Ale (Mirrorlessrumors administrator)
There are a couple of logical errors made by Tony Northrup.
First: No one cheats. All company aperture lens info are correct! The Panasonic 12-35mm f/2.8 has a f/2.8 aperture and not a f/5.6 aperture. You don’t have to make the equivalence he says has to be done! Use the Sony A7r and Sony A6000 for the same shot. To get same result the camera automatically sets on both the same ISO and same lens aperture despite the different sensor size. Just to say that the aperture remains CONSTANT and is not relative! There is no equivalence to make on that!
Please read that article why you cannot apply the aperture equivalence you mention on no other than the “depth of field” and “field of view” only:
The focal length and aperture do remain constant!!!!
Second: He says Olympus, Panasonic and Sony do cheat. Nope. All companies use the same kind of measuring aperture for all lens formats (medium format, MFT format, APS-C and so on).
UPDATE of the UPDATE: After re-watching the video I am sure Tony confused “Focal length” with “Field of view” ! It’s the field of view where you can make the equivalence and not the focal length. Tony has been misleaded by the companies because they do that (small) error too. That’s why when he did the math in the video to explain how aperture gets calculated he made the mistake to change the focal length variable. But actually that variable doesn’t change at all! What changes is the “field of view” which has no influence on aperture. Hope you got the message :)
LIke Admiringlight says:
“I’ve heard many times “Yeah, your 75mm f/1.8 is crap – it’s like a 150mm f/3.6.” No, it’s not, it’s a 75mm lens with an f/1.8 aperture and a field of view that is the same as a 150mm lens on full frame.”
I know Tony had good intentions and I wrote him and hope to will remove the video soon. But please guys, spread the word that what he tells about the equivalence is plain wrong. Don’t worry your f/2.8 MFT or APS-C lens is really a f/2.8 lens!