That is so stupid…just by making the sensor smaller the lens will be sharper across the frame at lower F#s. You *instantly* improve the relative performance of the lens. The only thing they do by doing this is make the body a little thinner, and perhaps the lens a little smaller and lighter, but now you have to stop down just as much if not more to get the same sharpness across the frame, so the only optical benefit is weight but in exchange for that you’re using a smaller sensor reduced pixel count or more diffraction and in any case more noise at every ISO

Overall just a worse camera

And that’s hy you don’t see a wholesale move from subframes or even fullframes to 4/3rds.

On the other hand you don’t see a move from point & shoots to micro 4/3rds because every problem and every *benefit* with 4/3rds is already in the point & shoot market. They just had to put faster glass on the point & shoots and they’re back to square 1. In the long run it’s a dead market for those simple reasons. On one hand they’re nothing more than overgrown point & shoots, on the other they are just slightly-shrunken, noisy, low-resolution DSLRs with no mirrors. If weight is really an issue you’ll just get a point & shoot, if IQ is your main concern you’ll sling a fullframe DSLR & put up with the size & weight, or at least get an APS-C sized mirrorless camera.

4/3rds is a domestic-made electric car in a world full of mopeds, buses, subways and quality gas-powered imports. Losing the mirror is one thing but the sensor is both too small and not small enough. Just as electric cars use cheap power but cost way too much and take too long to recharge. 4/3rdss cameras are not small enough to fit in a normal pocket with a good lens and they are not large enough to have IQ that’s much better than a good p&s. You might as well just buy a good p&s.

Canon likewise, it would take any EF-S or EF lens
Sony, any alpha lens

these were no-brainer choices

There’s virtually no benefit at all to micro 4/3rds in terms of a lens-mount.
Saving a quarter-inch in backfocus distance is easily made up for by the wider diameter of the lens. I’d take that over a shorter backfocus distance any day of the week. Nothing better than putting a fullframe lens on a subframe camera.

The main benefit for it is for the mfgs, who can lean on each other to bring lenses to market. It’s a desperate move for fringe-market players, as the obvious downside is that you make the camera but can’t sell glass for it.

Meanwhile Nikon Canon and Sony will continue on their merry way making and selling cameras that take all their legacy lenses, or at least their CPU lenses. You didn’t see Sony switch to a micro 4/3rds mount for their new NEX cameras, for that reason and a bunch of others. Soon enough Panasonic will take the mount one way and Olympus will take it another.

They are the worst part of point & shoots combined with the worst part of DSLRs.

and it doesn’t really matter if the lens format is “open” if you only need to buy one lens. If you’re talking multiple lenses then you’re carrying more lens than camera. If 4/3rds camera mfgs are going to make the same lenses anyway what difference doe it make. 15 companies make SD cards, does that mean that you would happily buy any of them and put them in your camera? No. Same with USB, there are only a few mfgs that I would trust for computer peripherals.

With size I really don’t see the issue, even a big old SLR will sling around your neck or shoulders, and regardless of how small the camera is you’re still carrying a camera. Vs “not carrying a camera”. If it weighs 2kg with a lens that’s one thing, but a 500-600g DSLR and lens isn’t goin to slow anyone down.

A Nikon D3100 or Sony A200 is not going to slow anyone down.
So the only real benefit here is the pancake wide-angle. Once you put a barrel on the front, they are pretty-much all the same.

Cellphones will beat micro 4/3rds in terms of convenience any day of the week.

it either fits in your pocket or it doesn’t

Wrong.

even ignoring 0.7x adapters the LX3, LX5, S90 and S95 are 24-70mm effective F2.0 wide-angle with IS.

Plus Olympus has the XZ-1 which is F1.8 28-120mm effective.

just wrong.
Every size & weight related benefit of mirrorless 4/3rds also applies to point & shoots And likewise it’s just a matter of time before someone makes a mirrorless fullframe. They are all going to have to deal with the fact that the smaller the sensor, the smaller and lighter the glass can be to get the same optical performance.

But here’s the deal. I am sure these are good for what you say, but you dont list any negative points. Surely there must be somethings that dont jive. In other words, are there any cons to these cameras? The people need to know.

Thanks for the article Ryan.