Another entry in what is almost turning into a personal blog regarding my thinking processes in choosing a CSC.
Today I've been re-evaluating the micro four-thirds offerings and comparing against the Sony NEX system. My first step was the aspect ratio with micro four-thirds having an, ahem, 4:3 aspect ratio while the NEX uses 3:2. It sounds like a big difference but if the ratios are expressed with a common "width" we have 12:9 and 12:8 respectively, a difference of height of about 12.5% which isn't much.
Next up is resolution and that's much more difficult to compare. Relying on the PhotoZone
test results one can compare the 12MP GF1 against the 14MP NEX-5 or the 24MP NEX-7. This should be a hands down win for the NEX-7 but for the shorter focal lengths my reading of the test results is that away from the centre of the image the NEX-5 comfortably outperforms the NEX-7.
Another surprise is the performance of the various micro four-thirds kit lenses on the GF1. They struggle in peak resolution in the centre of the image, as would be expected when comparing against the higher resolution NEX sensors, but actually do very well out at the edges when comparing the shorter focal lengths even after factoring in (or out), as I believe one should, the 12.5% factor that micro four-thirds enjoys in line widths per picture height because of the 4:3 aspect ratio. I'd love to see the results of the micro four-thirds lenses on the higher resolution 16MP sensors that are now available but it's hard, in my very unscientific way, not to draw the conclusion that the micro four-thirds offerings are better balanced over the whole frame while the Sony lens has been too heavily optimised for centre resolution.
Of course there are many more options than just the kit lens and it's only fair to point out that the NEX-7 does do rather better when fitted with the 16-50mm f/2.8 DT SSM via the EA-LA2 adaptor but that is a combination which rather negates a lot of what CSC cameras are about. On the extreme wide angle front the picture is even rosier for the GF1 not least because there is no E-mount alternative to the Lumix G 7-14mm f/4 ASPH. You'd also think that the NEX-7 would beat the GF1 hands down when comparing the resolution of the Sony E 55-210mm f/4.5-6.3 OSS against the Lumix G X Vario PZ 45-175mm f/4-5.6 ASPH OIS but the same pattern recurs away from the image centre. How is it possible that the 12MP GF1 with the lens at 175mm and f/5.6 can out-resolve (line widths per picture height) the 24MP NEX-7 with the lens at 210mm and f/6.3 at the image borders? Answers on a postcard please!
Gordon's own tests have highlighted the better high ISO performance of the NEX-5N compared, most recently, with the Lumix GX1 (here
) but the performance difference isn't massive so far as I'm concerned and may disappear altogether if one factors in the availability of fast glass. Again, this is not scientific analysis on my part but just a "seat of the pants" feeling I'm getting so I'll be delighted to be educated about this.
I've not tried to factor price into the discussion as that is just so difficult to do without a very tightly defined shopping list but the bottom line is that I am seriously re-evaluating my prior prejudice against m4/3 which I held on the grounds of both aspect ratio and "smaller than APS-C". I'm even considering putting the Olympus OM-D E-M5 near the top of my list of contenders! "What took you so long" I can hear some folks mutter but I'll take some comfort from at least being able to admit to my sin!
I've just been reading the SLR Gear review
of the new Lumix G X Vario PZ 14-42mm ƒ/3.5-5.6 ASPH Power OIS where they state "the new 14-42mm 'X' version is much sharper than the previous version; it's also much more resistant to chromatic aberration, shows less corner shading, and has a better profile for distortion". Given the "previous version" referred to was the one that PhotoZone were using in their tests it would seem that the Sony offering looks even shabbier by comparison but I'll add a health warning that it's difficult enough comparing two reviews from the same site without then trying to cross reference with reviews on a second site!