I have had a Canon G3X, not technically a m/4/3 camera, but close enough as it does sport 20mp.
Michael Reichman on Luminous Landscape had a review of this camera before he died, and I was impressed enough to buy one and try it out. zoom from 24 to 600 equiv mm, IBIS, and pretty decent work.
My shots are all hand held so far, but decent.
My question: is there a way to compute depth of field for this camera? My bird shots, which are mostly at f5.6, have areas in very shart focus, but the entire bird, cardinals, etc is a bit softer.
Diffraction will be a concern, and of course higher iso will begat noise.
Sensor size actually doesn't effect DOF. Aperture and magnification are the only things that affect DOF.
When shooting with smaller sensors with the same focal length from the same distance, you get a tighter crop, but the magnification is actually the same. So to get the same framing as your larger sensor camera you move backwards, creating less magnification and more DOF.
So if you take the "equivalence" out of the equation for your lens, you don't have to worry about sensor size. Your 300mm acts like a 300mm on any camera, we just call them 600mm equivalent for the sake of field of view.
Or you can do it the easy way and use the link Bobby provided
Sensor size DOESs affect dof when you consider that we frame our photos for composition and cant use a 300 m43 the way one would use a FF 300. The net effect is that when you frame your shots sensibly, to include the elements as desired, both perspective and DOF are altered. Technically lenses have nothing to do with perspective, it is only the distance to subject as a ratio to distance to primary subject and other foreground and background element - but who really cares, when the way we use a 300 versus a 12mm results in an absolute need to alter ones distance, and results in the perspective characteristic we all are familiar.
Another way to put it, is that sensor size dictates of certain different focal length - and ipso facto ....
My Panasonic Lumix DMC LX5 had a lens that felt and acted like a 24-90, but due to the small sensor necessitated that the lens actually be a 5.1 to 19.2. The net result was a great camera where you had lots of depth of field or even more dof.
And so it goes. My Olympus' always deliver photos the have more dof, that my APC sized Fuji's and much more that my FF Nikon.
I don't mind it much, most of the time, because getting razor thin dof is not often my cup of tea. But it certainly is noticeable. Unfortunately with diffraction hitting at 5.6 and obvious at F11, sometimes I feel that as the megapixel counts go up, that it is THAT fact that becomes the hard to work with characteristic - for me anyways. I shoot up to F11 but quality sure takes a hit. Doesn't much bother me, but some it would others.
Herb, I was not familiar with you camera, but looking it up, it has a 1" sensor. That is actually significantly smaller that M43. The 1" has a surface area of 116 square millimeters, versus 225 for m43, and 329 sq mm for APC.
The net effect is that the Canon G3x is a far larger jump to m43, versus the jump from m43 to APC. It's normally rounded off as about a stop worth of extra dof going down from FF to APC and the same from APC to m43 - but it is likely (taking a guess here) maybe two stops more on the Canon compared to m43. I consider that huge. And at 20 megapixels, likely to suffer diffraction at about 2.8 or smaller (just taking a guess again)
So if you want small, but want more control over both ends, both narrow and great dof, I'd think you may find the m43 platform a significant improvement - and with careful lens choice, not much larger. Just a thought.
formula4speed wrote:
Sensor size actually doesn't effect DOF. Aperture and magnification are the only things that affect DOF.
Unfortunately, this is incorrect. DOF calculations are made based on pre-determined "print" sizes. Different formats need different magnifications to reach that pre-determined print size. Hence there is a different measurement for the CoC for each format. This in turn changes the perceived DoF. The same perception applies if someone changes he print or output size. The same shot but printed smaller will appear to have more DoF than a larger print, if viewed from the same viewing distance.
