A universal digital back?

I’ve read an almost similar quote in the past already, and in fact it was partly the reason for me to get into the mirrorless µ43rds system. But it’s even more true for the Sony A7 family with their “full frame” sensors which almost have the exact same size like 135 film used to have. To quote Giles about it:

“So , if you are familiar with mirrorless cameras, they aspired to become a universal digital back, because their short distance to flange allowed them to accommodate any FF35 lens, with no need to correct the crop factor which other systems have (as high as 2x, in the case of m4/3) with a focal reducer.”

(from his article in “Sony A7, or the Lego FF System“)

Right. The price, body-only of the basic A7 (24MP) model here in Germany is 1230€ (at Amazon and others, partly with free shipping). And I would have a really good Olympus OM 50mm/1.4 which would be very nice to have on such a camera.


Those 50mm lenses on the “Pens” (I used the OM Zuiko 50mm/1.8 at f/5.6 here, hand-held at 1/8 of a second at ISO 800, which wouldn’t have been possible on these Sony cameras, since they don’t have image stabilization built in. So using these I would have had to use an even higher ISO setting, or a tripod. Cropped to 3:2 format during post to get a feeling for that other format again.)

My brother Willi has a Canon FD 50mm/1.8, a Canon FD 24mm/2.8, and a Sigma Zoom with Canon FD mount which would also be very nice when used with such a non-crop digital sensor. Both the resolution and also the dynamic range couldn’t be met with smaller systems like APS-C or µ43rds, which makes that thought a very tempting one indeed. That new Sony system doesn’t have all the native lens options that Canon or Nikon have for their DSLRs, but as a mirrorless system with a built-in electronic viewfinder at an even lower price than these older DSLRs, the Sony would be superior at least when used with these “legacy” lenses anyway.

Thinking about it since a while already…

8 Replies to “A universal digital back?”

  1. I doubt most of those old lenses have enough resolving power to satisfy the 24MP sensor. My OM Zuiko 1.8 50 needs to be stopped down by 2 stops to give sharp results at my OM-D and only the central part of the image will be really crispy.

    1. Could be, yes. But some people (like Karel who was mentioned in the blog I linked to), or like Andrew tested lots of these lenses, and some aren’t really bad.

      I’m undecided anyway – the missing part of all these “full frame” options is IBIS. If you use a 3 stop higher ISO on these cameras, you pretty much give up what you could theretically gain in image quality.

      Oh, and I think the Zuiko 50/1.4 is sharper than my 50/1.8 – and the 50/3.5 macro could be even better (my wife has that, but I really never took any photos of newspapers glued to the wall or such).

      Anyway – thanks for your comment.

      P.S.: just searched for examples, and some aren’t bad at all…

  2. Yes, Wolfgang, we are exactly on the same page.

    I am undecided too, that why I advised to wait for Photokina. Fuji might be there with a FF35, and who knows, Olympus too?

    So far IBIS is the great equalizer between formats.

    1. Just converted a raw file (the DPReview “daylight” test target) from the A7, after making a profile from it, and converting the .arw to .dng (my ColorChecker Passport only accepts .dng raw files for making profiles). The result is pretty awesome I have to say. 24MP is definitely more resolution than 16MP, and they also used a very good lens (the 85mm/1.4 ZA from the A-mount I suppose). Hmmm. The camera price is tempting. 300€ less than other ‘cheap’ full framers, and even with an EVF which I prefer anyway…

  3. Hi again. I think much depends on the lenses, W.

    When I use the mean 14/2.5 with the E-M5, which according to Lensrentals some 1100 lpmm, I can’t really see the difference with the A7 using the Zeiss 35mm FE 2.8 which has 1320 lpmm.

    Couldn’t show the full Jpegs on my blog for copyright reason, but I checked. With the A7r However there is a visible difference. But again you need a tripod to tap the extra resolution. And that is what stops me.

    Note also that I am a mean Jpeg shooter, so I might miss the highlights and shadow recovery that a larger sensor might offer in RAW. DPR says that the A7 RAW are excellent, not so Jpegs.
    Other stop.

    That is why I’d rather wait Photokina and see if Olympus and Fuji, which are Jpeg champions, issue a FF35.

    1. You’re right Giles. Just got an analog film back from development, and the results were sub-par. Except two landscape shots with good weather. So “full frame” without IBIS is nothing for me as it seems (and with an optical viewfinder, it’s even worse).

      I think I’ll keep using my E-PL5 which gives me far better (and more consistent) results. Maybe some day when something like a 645D gets cheaper – in that case, I would carry a tripod even during daytime 😉

      1. My experience is that in general good lenses give better results on A7 than on Nex or mFT. But to see the difference I had to update my monitor. On the other hand, after some experience in adapting different lenses to A7 I have to agree with Ming Thein: the picture quality is really easy to spoil with bad adapters. In fact, with 50mm f1.4 lens unless you get a perfect copy of both lens and adapter, you have a DIY tilt lens with the sharpest area of picture lying on a line somewhere in stead of having a roundish sharpest area in the middle! I think peoples “reviews” of lenses based on a few pictures on cheap untested adapters are funny to read after measuring a bunch of adapters with mauser and micrometer only to see they have 0,3mm differences in thickness from side to side. -mfG, Osmo

        1. Right – I’d also get a good adapter with one of these. Tho you can be lucky and/or try and measure them in a shop if you have one around. Thanks for your comment Osmo!

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