Hello for everybody!
My question maybe looks strange for the first sight :), but I'm trying to make this decision for a long time.
I have EA50 with kit 18-200 and two M42 lens (50mm f:1.8, 85mm f:2.8) with adapter.
Also I have Minolta Dynax 5D (yeap, too old...) with 2 kits 28-80 and 70-300 and flash.
Mainly I work as videographer, almost have no jobs as photographer.
I'm looking to upgrade my photo camera. For traveling, family, second unit video...
There are too many options in the market. The mirrorless e-mount of EA50 gives the great option to use almost any optical system by adapter. Of course, the simplest answer is to stick Sony/Minolta A-mount or NEX mirrorless e-mount - this way I will stay in one brand. But it looks like Canon and Nikon are still better photographic systems than Alpha/NEX are and there are much more optics for them than for Alpha/NEX.
So, here my question comes. Probably most of You, dear colleagues, are using some DSLR aside EA50. On Your opinion, which system (Nikon F or Canon EF) will provide better compatibility for EA50's options? Like optical stabilizer, autofocus, etc. Metabones EF to NEX Mark III promise that EA50 feels Canon's Optics like its own e-mount optics. Is it true? What about Nikon's optics with EA50?
Or, maybe, I'm totally wrong about my rumors based opinion that Alpha/NEX is not that good as Canon/Nikon? But still, optics for Alpha/NEX are much more expensive, third manufacturers (Sigma, Tamron, Tokina etc.) make much less versions of their lens for A-mount and e-mount...
So, what kind of experience do You have combining in Your work EA50 with some photo system?
Thank You all in advance for Your patience reading and answering this.

Simple. Locate some vintage Carl Zeiss 'Contax' manual lenses in the C/Y mount. Cameras come and go and are almost obsolete as soon as you buy them but an investment is good glass can last a lifetime. There are cheap C/Y to Nikon and C/Y to Canon adapters available every where, plus the superb Metabones 'Speed Booster' in C/Y to NEX (or C/Y to MFT).

Forget 'optical image stabilization' and 'auto focus'. IMHO, these features are handy but largely unnecessary 'consumer' gimmicks.

The Zeiss Contax series of prime and zoom lenses use the same T* coating as the legendary Zeiss CP2 Cine lenses so they inter-cut beautifully and have the same 'look' as these classic cinema lenses for a fraction of the price. They are also made of brass with 'huge' focus rotation so are ideal for precision and follow focus work. The Zeiss 28-70mm zoom lens is ideal for cine work as it has three rings so does not extend more then 10mm or so but the 35-70 zoom is rated as good as any set of primes. 'Extra' fast versions of most of the primes are available but you will pay a premium for these and like many super fast lenses, they are a bit soft wide open. I recommend you buy the 50mm F1.7 (as opposed to the 1.4 version) for example, because it is sharp as a tack wide open.

I use my Contax primes on the NEX VG20 which uses the same APS-C sensor as your EA-50 but will shoot in RAW mode for still photography. See this article I wrote last year but be quick as Zeiss 'Contax' primes are rapidly rising in price on ebay!

Craig Marshall, thank You very much for Your reply. But actually I use two primes of Pentacon (East-German Zeiss), so this 'cheap good old optics trick' is familiar to me ;).
My question is about DSLR or Mirrorless for every-day-grabbing-with-me, touristic etc. Anyway, I want to buy a new body to upgrade my old good Minolta Dynax 5D. So my question is what option to choose:
a. Upgrade to Sony Alpha to continue using all my Minolta stuff?
b. Upgrade to Sony NEX to continue using all EA50 stuff and all Minolta stuff by adapters?
c. Upgrade to Canon to use a large variety of optics of Canon and third manufacturers, but to spend a lot of money for some different bayonet systems, etc. (Ergonomically, as I know, Canon fits more my habits)
d. Upgrade to Nikon to use ONE SINGLE bayonet adapter for all Nikon optics on my EA50, but I heart that the structure of this bayonet has some limitations of use on non-Nikon equipment (is that true?)
Hope to read some shared experience of You, my dear colleagues, what is the easiest and (not less important!) cheapest way to 'make friends' between different photo equipment systems with our lovely EA50.
Thank You all in advance!

Go Canon! But get a model in the EF mount, not EF-S. It will serve you as the still camera you want. It will also be a second video camera. And EF lenses are available in every configuration imaginable.

No matter what you get stay away from cheap adapters.

I love my Metabones. Search this forum, there is a ton of info on them. But be aware in the EF to Sony E-mount some aftermarket EF lenses do not work well with them.

Steve

Thank You, Steven Digges, very much! But what do You mean by "EF and not EF-S"? Should I go for Full Frame Body instead of APS (cropped) Body? 'Cause actually EA50 has APS, so why should I go for FF in photo? Or You mean to go for optics with EF and not EF-S mount?
I thought to go for Canon 600D/650D and to invest the price difference of buying not that expensive body for more expensive optics. Unfortunatelly, my budget is not that big.
Another question is about adapters. What about simple "tube" adapters with build-in aperture? Even in that mechanical piece of metal should I choose more expencive option?
Thank You in advance.