Luckypenguin wrote in post #14549086
If anyone wants to learn (I use the term loosely) about the theory of depth-of-field equivalence on Micro 4/3 cameras I would direct them to visit the Micro 4/3 forum at DPReview. There they can find many long and drawn out threads on the topic. After doing so they will probably want to throw their computer out the window and scratch their eyes out, so I would also recommend they proceed with caution. That forum contains a healthy population of individuals (who seemingly don't even use Micro 4/3 cameras) that will happily and repeatedly dispense the theory with or without provocation.
As usual, POTN is a better place. I happen to own a 5D as well as a m4:3 body. I like my Panasonic GF-1, and I tend to use the 20/1.7 lens with it a lot.
But from direct experience I can tell you that the 20/1.7 is capable of somewhat thin DOF on the panny, about the same as what I can achieve with my 24-105/4 lens on the 5D.
That's right.....f/1.7 on the m4:3 format is a lot like f/4 on my 5D Mark III, both for DOF and for low light work (since the 5D3 is usable at higher ISO levels IMO).
I like my m4:3 camera, but I am also aware of the differences and limitations of it compared to larger formats. I see no value in glossing over these.
The strangest thing about depth-of-field equivalence is that in the EOS forum here at POTN which is represented by users of Canon DSLRs of varying sensor sizes, the topic seems to be strangely quiet. This is in spite of the fact that there is a larger difference in sensor size between a 5D and a 7D then there is between a 7D and an E-M5. I gather that the Micro 4/3 format has obviously crossed some kind of magical threshold where DOF equivalence suddenly becomes a point of contention.
You must have missed a huge number of threads on this very topic. I'd also say that I did notice a DOF difference when I personally moved from a 1.6X body to FF, and I even can notice differences (however subtle) when I go back and forth between 1.3X and FF.
On the topic of 1.6X and FF, what I noticed was that where I often found f/2.8 zooms to restrict what I wanted to do on DOF, once I got to a FF body I find this aperture is quite often as thin as I ever want.
On the same tack, I used to shoot very fast primes wide open a lot on 1.6X, and I do so less often with FF. My use of fast apertures tends to move to ever wider focal lengths on larger formats. I love the 24L on FF for example.
The other thing to note is that it is not hard to find images taken by Micro 4/3 cameras that contain blurry, "bokehlicious" backgrounds. To me this goes to show that rather than obsessing about a supposed lack of shallow depth-of-field capability, the average Micro 4/3 user is happy just to get on with the job of taking photographs.
I don't know what to make of this comment overall. As I said, I can certainly blur a background with my GF-1 and 20/1.7 provided the subject is close enough, just like I can blur a background with my 24-105/4L on the 5D when the subject is close enough.
The m4:3 camera will always be more portable. It will also never be able to take the kind of shot that I can take with the 5D3 at 16mm and f/2.8 or 24mm and f/1.4. That is a clear difference.
And so while a $1300 12-35/2.8 would be a usable lens on m4:3, it is not the same thing as a 24-70/2.8 on a FF dSLR.