still gnawing on that

Some criticism of my "method" led me to go out and reshoot a test between the Pansonic 25f1.7 on my GH1 and the FD50f1.4 on my A7

Taken on its own the Panasonic yeilds good results:

and allows a very nice rendering of concentration on a subject with sufficient DoF control to make the background a visible background while creating the effect of focus on the subject.

To me that is precisely what a "shallow normal" is for ... normal shooting distances (not 30cm away shots of you SuperMarioBros pencil decoration model on your keyboard in the office and dribbling about shallow DoF ... my phone does that). Distances where (say) your friend could have been standing beside that fence post and you want the background to be observable as a background, but attention to your friend.

In this role the little Panasonic is a champion, indeed it or the Panasonic 20mm f1.7 are excellent choices but I digress.

It however becomes apparent when you compare it to larger formats (even with 1970's lenses like the FD50f1.4) that sharpness is not up to it. It first strikes you when you are attempting to use manual focus (in the above that was on the wire at the top of the post) magnification and it just doesn't look "sharp". Its like that old saying about Volvo not wanting you to drive a BMW in case you don't come back to Volvo.

So while for general picture taking I find the m43 perfectly suited, when I am specifically going out to shoot a landscape and both wanting and needing that extra detail, the Sony A7 just allows me to get that.

Method

Now all the following shots were on a tripod (of course I needed to change the camera, so alignment is not perfect). All shots were developed from RAW using DCRAW to equalize the parameters and avoid sharpening in-camera (or post processing) effects (which Adobe does by default if you don't watch out).

Results

For instance lets look at what the Panasonic 25mm got, and lets give it the beneift of being stopped down a bit (f2) to put it at its optimum sharpness.

it is in fact almost indistinguishable from the f1.7 shot (and a small amount of thought would confirm that 2/3rds of a stop won't really impact on DoF control but will on cleaning up a lens)

So in keeping with my 50% pixel view of an image reveals close to what you see with a fine print at maximum size:

So this is the central portion scaled to 50%

Now ... lets have a look at what we could get from the A7 to be "fair" I've scaled it down to the same width as the GH1 image first for the overview (which blogger will also scale a tiny bit more)

and now a central segment

They are fairly close, however my nod goes to the A7 as being a smidge sharper (and there has been no software sharpening done).

For any print except "at the maximum" this isn't even going to factor for anything more than the most carefully inspected print. I would comfortably say "99% of people just won't pick any difference even side to side.

Ok, but I've hamstrung the A7 by scaling it back to what the GH1 could yeild, and its important to keep in mind that we're talking about a big print here: 70 x 46 cm

But should one want for some reason to go out and plan a photograph that will be printed bigger then what difference does the 6000x4000 pixels (vs 4144 x 2768 of the GH1) make?

so a bit more again. Are you able to see the bit of lichen on the left side near the top of the post in the m43 shot? Not really, and the fine details in the lichen on the fence are missing too.

Perhaps with a better lens (than a 1977 model) I may do better, but perhaps not by much. Thus for the $50 I paid for the FD50f1.4 (and they sell for about $150 now, which is still less than a new AF lens by nearly a factor of ten times) its hard to get better value.

Discussion

So is this worth it to you? To me its totally worth it (I paid less for the used A7 than I would for a later model perhaps better m43 camera), bang for buck I get something which isn't far from the results I could get with my 4x5 camera. Sure, that's better (typically good for 10,000 x 8000 quality scanned pixels) but I'm having a hard time getting colour negative anymore and processing other than my own black and white is hard to come by, plus that camera works out at $15 per image and this is ... well digital.

I have not touched on the other advantages the A7 brings, such as

• good access to high quality legacy 35mm lenses (and used as they were designed, not halving the apparent contrast by the x2 crop)
• better high ISO results
• better bit depth at any given ISO

I know that someone will probably say "oh, but you could shoot the m43 camera at f1.7 and not at f4 ... well that's true ... but I could also shoot the FD50f1.4 at f1.7 and get a lovely result too ... so in summary here is that image for your consideration

as always I recommend viewing this on a good PC with a good screen and loading the images (center click on a windows machine) and viewing as big as Blogger will deliver.

I always enjoy being out in the forest and hanging around (and walking to this place) makes testing as much fun as anything else ... besides one of these is going on my wall ;-)