06-15-2016, 10:29 PM
Quote:Uhmm, no. Here you are confusing your fantasy with my facts again. Yes, fantasy is written with an F.
Evidence of what? I already gave you the calculations (= evidence B) ) to show you that indeed, 12mm f1.4 on MFT is equivalent (as equivalent as things can be with different aspect ratios) to 24mm f2.8 on full frame 135 format. What more "evidence" do you require?
And you have the odd idea that it is in any sense valuable to use the same ISO number setting on different cameras. No idea why you think that is in any way meaningful.
Nor is it meaningful to use the same f-value, as the f-value stands for apparent aperture size. Which means that you oddly enough place importance of setting one camera a f/1.4 where f = 12mm and the other camera at f/1.4 where f = 24mm. So you find it meaningful/logical to set one camera at 12 / 1.4 = 8.5mm aperture, and the other at 24 / 1.4 = 17mm aperture.
Yeah, that makes so much sense. Well actually, it does not, and never has.
So, not only does the f1.4 not mean the same on the different lenses, and does for instance "ISO 100" not have an actual significant meaning or importance, you end up with very different images due to the different DOF. How interesting to keep on repeating that useless "comparison".
Why not compare 50mm f1.4 on MFT to 50mm f1.4 on FF? You will find that with the same ISO number setting you will get the same exposure time when using a similar exposure metering method.
Or how about putting a 500mm f8 lens on a Nikon D700 at ISO 3200 and a 20mm f1.4 lens on a Nikon D5 at ISO 100. Again, similar exposure times. Now you not only have different DOF, but also different FOV!
It is not that hard to come up with pretty senseless comparisons :lol:
Actually aperture is just about the relation between light outside the camera ("F/1") and how much it lets through, not taking glass surface etc. losses into account. Therefore, f/1.4 is F/1.4 with any lens, FL is totally immaterial in this regard.
A specific f-stop just means that it let's a specific light ratio pass through the lens, compared to the light outside. Becuase of the way a lens images the outside world, this happens to be directly related to the FL, diameter wise, but that is immaterial. It still lets through the same amount of light per area unit. That is what the f-stop number is about.
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....