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Thread: Autofocus A7 vs A7R

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    Autofocus A7 vs A7R

    I recently rented the A7 from LensRentals to gage whether it had all the requirements to replace my A850. Well, I was pleasantly surprised with the autofocus using the 35 f2.8. Even in low light I would describe it as reasonably good. However recently I have seen a number of descriptions stating that the A7R actually has more accurate low light AF than the A7. If that were the case I would probably prefer the A7R. If anyone has personally had both cameras in hand and tested the autofocus with the native lenses and has an opinion on low light capability I'd love to hear about it before putting in my order.

    Regards,
    John

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    Re: Autofocus A7 vs A7R

    Okay, so Christmas Eve, the A7R arrived from Amazon. I've used it for the last few days and tried out a few things. My strategy was shooting indoors in low light situations that required ISO 6400 to allow hand held speeds. The autofocus time did not seem any slower than the A7 (maybe slightly slower but I can't swear to it, so close enough as not to matter). So then I wanted to check whether the focus was actually real. I would autofocus a shot and expose then manual focus with magnification and take that same shot. I compared them and and found them to be almost all in focus. So now it seems that the low light autofocus for the A7R is at least as good as the A7 (maybe a little bit slower but maybe a little bit more accurate). So my dilemma is whether the A7 is a better fit than the A7R for my photography. The extra megapixels and the more powerful shutter shake are not exactly needed. So I'll have to evaluate the appearnce of the photos from both cameras. If the A7R doesn't bowl me over with extra pop I'll probably send it back and get the A7. But either way I think both cameras are what I am looking for in an upgrade so I can't go wrong.

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    Re: Autofocus A7 vs A7R

    I tried out both cameras. In low light, the A7R was a little faster and more accurate. In better light, the A7 was faster. I tested with both the kit zoom and the 35mm f2.8 FE lens. I later tried the 55mm f1.8 lens on the A7R and it was slower than the 35mm f2.8 lens. I didn't have the A7 to test it with but others have reported that the 55mm performed better with the A7 due to the PDF. The other difference was shutter lag and shutter blackout. Both longer with the A7R.
    V/r John

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    Re: Autofocus A7 vs A7R

    John:
    Your report seems to jibe with what I found. Of course if low light image quality and low light autofocus capability are important (as indeed they are for me) then A7R has an advantage despite a couple of drawbacks (too many megabytes and a too powerful shutter). But life is a series of trade-offs. I've just got to analyze the options and pick one.

    Regards,
    John

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    Re: Autofocus A7 vs A7R

    John's experience echoes my own with the 2 cameras. I think it would boil down to wanting

    A7R
    -- Detail beyond all else in files
    -- Slightly better low light focus
    -- Large files to print or crop down, while preserving detail

    A7
    -- Faster daylight AF
    -- Plays better with most M lenses (if you already have these)
    -- Quieter shutter
    -- "manageable file sizes". I have a mac pro that handles A7 and A7R files readily, but 24 mp is still faster to handle

    There are other pros and cons. I went with the A7. I find it to be the best compromise, given my kit and my "street" photography sensibilities

    If I were a landscape or portrait/studio photographer, where I could exert more control over photographic circumstances, and if I didn't own a host of M lenses, I would go for the A7R, no doubt....
    Ashwin Rao
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    My Photography

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    Re: Autofocus A7 vs A7R

    Quote Originally Posted by ashwinrao1 View Post
    John's experience echoes my own with the 2 cameras. I think it would boil down to wanting

    A7R
    -- Detail beyond all else in files
    -- Slightly better low light focus
    -- Large files to print or crop down, while preserving detail

    A7
    -- Faster daylight AF
    -- Plays better with most M lenses (if you already have these)
    -- Quieter shutter
    -- "manageable file sizes". I have a mac pro that handles A7 and A7R files readily, but 24 mp is still faster to handle

    There are other pros and cons. I went with the A7. I find it to be the best compromise, given my kit and my "street" photography sensibilities

    If I were a landscape or portrait/studio photographer, where I could exert more control over photographic circumstances, and if I didn't own a host of M lenses, I would go for the A7R, no doubt....
    Ashwin:
    I agree with your analysis. And I assumed I would be going with the A7 also. And if I were reasonable I probably will. But there is one complication. I am a Minolta/Sony shooter. So because the Sony A850 didn't have particularly good low light capability I decided to try the Sony e-mount NEX-5N. Well the 5N wasn't any better at low light IQ but worse still, the low light autofocus was really bad. So because of this I'm determined to get the best low light autofocus that Sony can offer. Now granted the difference between A7 and A7R low light autofocus isn't huge. But I'm on a mission so rationality is difficult for me.

    Regards,
    John

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    Re: Autofocus A7 vs A7R

    Okay, so my one month return window from Amazon ends Friday (boy, already a month since Christmas) and I finally got a day with enough sunshine to make some comparisons to the A7 shots I took in early December. And after all the hemming and hawing it's basically a case of the differences being so minor that it's not worth returning the A7R to get the A7. And I also think if it were reversed I wouldn't send back the A7 to get the A7R.

    So the A7R has marginally better low light AF and marginally better high ISO IQ which I want.

    But the A7 has a smoother and quieter shutter, smaller files and requires much less care with respect to technique which are all good things. I'd add the vibration problem as a plus for the A7 except that I usually don't use anything longer than a 200mm macro lens so I haven't seen much in the way of blur with the A7R (let's just add that to the lack of finicky technique advantage of the A7).

    So if I were the kind who used emoticons I'd probably use the one that reflected grudgingly amused acceptance of the slight advantage of the A7R over the A7 (FOR ME!).

    But one thing that I am sure of is I'm really starting to like this little camera. I hope that Sony makes a few more high quality lenses for it cause it's actually a pleasure walking around with a small camera that's this capable. I had a NEX5N that I hoped would replace my A-850 for walk-around use but the menus and ergonomics were so annoying that I never really learned to love it. I think the A7R (and equally the A7) is that camera.

    Don't know if this helps anyone, but my two cents.

    Regards,
    John
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    Re: Autofocus A7 vs A7R

    I would like to add one question to this thread and that is why can't Sony get faster AF with the PDAF sensor in the A7? It seems to me, that Sony hasn't really taken full advantage of the sensor based PDAF and that the extra pixels available in teh A7r for CDAF are enough to almost offset the speed advantage of the PDAF in good light and actually allow for slightly better performance in low light. Another observation is that the 55mm FE lens is much slower AF than the 35mm on the A7r. I don't know about the A7 as I no longer had it when I had the 55mm lens.
    V/r John

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    Re: Autofocus A7 vs A7R

    Quote Originally Posted by barjohn View Post
    I would like to add one question to this thread and that is why can't Sony get faster AF with the PDAF sensor in the A7? It seems to me, that Sony hasn't really taken full advantage of the sensor based PDAF and that the extra pixels available in teh A7r for CDAF are enough to almost offset the speed advantage of the PDAF in good light and actually allow for slightly better performance in low light. Another observation is that the 55mm FE lens is much slower AF than the 35mm on the A7r. I don't know about the A7 as I no longer had it when I had the 55mm lens.
    John:
    I'm gonna guess (based on my short experience with the A7) that in good light, the A7's PDAF actually does result in more accurate and faster AF than the A7R. But it's still not up to SLR standards. I've heard that Canon has an on-sensor PDAF based on using the whole sensor for auto-focusing that is up to SLR standards but I'm not gonna wait for Sony to get there. In low light both A7 and A7R are using CDAF so the extra pixels in the A7R may be the difference as you say. If I really needed highly capable tracking AF I probably wouldn't be in the mirrorless market yet. So I guess the acceptability of these cameras is very much an individual calculation of needs vs capabilities.

    Regards,
    John

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    Re: Autofocus A7 vs A7R

    For me, the decisive point isn't autofocus, it's Ashwin's, that A7 "-- Plays better with most M lenses (if you already have these)."

    I've experimented with quite a few M-mount lenses in the 28-50 range. Many produce smeared corners at wider apertures and are unacceptable. With A7, when corners are tinted, the tint is all in the blue channel and is often too gentle to need PP repair. From what I've gathered, this is the part where A7 'plays better' with M-mount lenses.

    If you use DSLR / retrofocus lenses with the rear element farther from the sensor, or if you plan to acquire Sony's lenses as they appear from behind the magic curtain, A7r would be the wiser choice?
    Last edited by thompsonkirk; 21st January 2014 at 15:30.

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    Re: Autofocus A7 vs A7R

    I don't have an A7r to compare, but have to say that the A7 compares favorably with my GH3 in low light (using the 24-70 kit lens). GH3 is maybe a tad quicker but nothing that affects my use. And with video the A7 has less of a tendency to start hunting "just because."

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