This should get everyone's juices flowing.  I did a comparison of my GH2 and GX1 to my 1Ds Mark II to see if a modern micro 4/3 camera could stand up to a slightly older full frame body. Hint - they're pretty darn close.

http://admiringlight.com/blog/micro-43-vs-a-full-frame-legend/

Thank you for posting this, now I don't feel alone and insane.

Yes...all firmware is up to date. You can now see why I've been saying the GX1 bests it at high ISO.

 im tremendously impressed by the scope and care you took to make this fascinating comparison

m 43 is maturing into a real contender… i no longer use my Nikon d 80 for the bulk
,i cant wait for your review of the Olympus pro…. ihope you can review one when they come out

the clarity and style of the review are impeccable i like your approach better than dp review
your iso 6400 iso with the pushing of the canon was very cool
your commentary is nicely written too

What do you think about dof and bokeh between a full frame and a m4/3 ?

more drawbacks than advantages if you ask me. There's two or three shots were you'll go wide open for bokeh and it'll be beautiful, but realistically you'll be at the least at f8. Even if 3 things are but a few feet apart only, you'll be lucky to get everything in focus at f11. So most of the time you'll be using those lenses outside of their optimal range.
Then there's focusing, phase detection gets it were you want it 60% of the time at f1.4, 40% at f1.2 and unless the subject is absolutely static, manual focusing is worse. It's why NIKON keeps desperately adding focusing points and 3d mapping. I understand full frame users, I do, but ask any of them, their "keepers" percentage bellow f11 is far lower than APS C or 4/3s.

BTW, F/11 is not a problem with FF, and not even with APS-C. Not in m4/3 either, unless you want to print to a tennis-field size.

I'm not saying diffraction wise, which is a whole other subject in which FF handily beats everything, I'm saying lenses optimal range. A lens is usually sharpest 2-3 stops closed down, and things go south from there.

Subject separation is something were FF shines abundantly, its easier anyway, but it becomes a pain really fast otherwise.

I'm not saying diffraction wise, which is a whole other subject in which FF handily beats everything, I'm saying lenses optimal range. A lens is usually sharpest 2-3 stops closed down, and things go south from there.

If it wasn't for diffraction, lens resolution would increase infinitely when stopping it down. The truth is that due to the larger pixel size, FF is more tolerant to diffraction, i.e. "going south" starts at one or two stops more closed than m4/3.
On the other side, FF will never be as small as m4/3, and if they don't rush into the megapixel war, m4/3 can perform equally well in moderate and high ISO.

That entirely depends on the focal length, your shooting style, and what you are shooting. When I was using my Nikon D90, I shot with a 50mm f/1.8 lens like 90% of the time, and most of the time I shot as close to wide open as the lighting conditions would allow. I had many problems with that camera, but lack of DOF wasn't one of them. I occasionally shoot with an Olympus OM-2 (full frame) and a 50/1.8 or a 50/1.4, and not one single time have I wished for more DOF.

If you're shooting landscapes, architecture, sports, group portraits and stuff like that, I can definitely see how shallow DOF could become a problem though.

Sorry, - it's got to do with my English language comprehension, - but, please explain, - what does " - APS-C sensor wide open . . ." mean?  When is a sensor 'open', - or 'closed', - and, when or if that occur, what is the connection to 'in focus'?

OK, comprende!  "Even with the LENS wide open, it's hard to get what you want in focus, with a APS-C sensor".  Then 'close' it (the lens) almost 'all the way' (e.g. f16), and 'most of it (the motif) will be 'in focus'.  At least if the sensor is small enough.  

Quote from: adash on January 25, 2012, 09:41:18 AM

Quote

I'm not saying diffraction wise, which is a whole other subject in which FF handily beats everything, I'm saying lenses optimal range. A lens is usually sharpest 2-3 stops closed down, and things go south from there.

If it wasn't for diffraction, lens resolution would increase infinitely when stopping it down. The truth is that due to the larger pixel size, FF is more tolerant to diffraction, i.e. "going south" starts at one or two stops more closed than m4/3.
On the other side, FF will never be as small as m4/3, and if they don't rush into the megapixel war, m4/3 can perform equally well in moderate and high ISO.

then I dont get it. I thought things were like you said, but then the lens tests show equal performance loss across all formats. They start losing resolution from 5.6 onward. Is there something that can account for this?

Maybe sensor size may account for diffraction at an earlier f/stop. As Adash mentioned.  And small sensor p/s don't go below f/8, M4/3 can go smaller (f/22 on some lenses), and you will see the MTF charts go down as low as 700, with 1100+ being a norm for better detail.

So  for landscape what do you for m4/3?  Get a higher Quality lens that optimizes the Optical IQ. That can be expensive though 
I think it a combination of Lens IQ AND f/stop used. I'd think that these lenses suffer less at similar f/stops with more consumer based designs.

The closer you are to your subject, the thinner the DOF will be.

With m4/3 you need at least f1.4 to have a DOF f/2.8 in FF equals.  And, the Nifty 50 is a bargain for fast glass, and  f/1.4 lenses were, in the day, 200% higher in price, than the f/2 or f/1.8 version. And made with a better Optical IQ and build.

Quote from: adash on January 25, 2012, 09:41:18 AM

Quote

I'm not saying diffraction wise, which is a whole other subject in which FF handily beats everything, I'm saying lenses optimal range. A lens is usually sharpest 2-3 stops closed down, and things go south from there.

If it wasn't for diffraction, lens resolution would increase infinitely when stopping it down. The truth is that due to the larger pixel size, FF is more tolerant to diffraction, i.e. "going south" starts at one or two stops more closed than m4/3.
On the other side, FF will never be as small as m4/3, and if they don't rush into the megapixel war, m4/3 can perform equally well in moderate and high ISO.

then I dont get it. I thought things were like you said, but then the lens tests show equal performance loss across all formats. They start losing resolution from 5.6 onward. Is there something that can account for this?

Lens tests don't care about the sensor, they're just measuring performance in lp/mm.  Because a m4/3 sensor has individual sensors that are 1/4 the area of a FF sensor of the same resolution, the m4/3 sensor is much more sensitive to the limitations of the lens.  The effect of diffraction (or any other aberration) may spread across an area of 4 pixels on a m4/3 sensor, yet it has no effect on sharpness on the FF sensor.

So assuming that the lenses are designed properly for their format and all other aberrations become smaller than the size of 1 pixel on their respective sensors aaaand that the two sensors have the same resolution, the effect of diffraction should be about equal when a FF lens is 2 stops smaller than a m4/3 lens.

That said, the lens should always be sharpest where the lens performance charts says it's sharpest, irrespective of the sensor.  But a lens designed for m4/3 *should* have tolerances that are much tighter than one designed for FF, pushing the optimal range for the lens to a wider aperture. 

Great test. The thing that has to be stressed is: just how much you need to blow-up into an image to see resolution differences between the sensor sizes.

This is even more of an issue in video-land, people are reduced to using frame grabs to demonstrate their compression codec "fetish" when in reality almost nobody could choose between the the different sensors and codecs in a controlled double-blind test.

The real and important differences in sensors are dynamic-range and color gamut, bigger sensors have some advantage here but probably not for long. The one common trend in almost all technology is miniaturization and its not going to stop any time soon. Anyone out there ever owned a motorola "brick" cel phone?