Sony A7r and Canon EF600/4L IS - Observations of a bird photographer

[Frank Kolwicz]

Executive summary: nice camera for landscape photography!

Being a bird photographer and so always lusting for more resolution to make useful images from distant birds and wishing I had something like Nikon's 36 meg sensor in my 5dII or 70d, the Sony A7r with an adapter for Canon EF lenses looks like a sure bet, BUT here's my take on it.

I've had a rental camera for 4 days and finally have given up on it as being too slow, inaccurate and just plain unsuited to moving subjects – it's like using a field camera for sports – by the time you're ready, the play is over.

I missed out on the first day of shooting because the Sony stopped working after only a dozen or so images and required a call to Sony support to find out why. I must have bumped or twisted a couple of the controls and caused the LCD to turn off; a single thing couldn't have done it. So, that's weird, but unlikely to be repeated (I hope). The second day, having gotten what I think was a good selection of images for comparison, I got an error message about the status of the SD card and the camera wouldn't let me continue shooting without "recovering" some files, which I allowed, but then when I tried to read the images on my home computer, it wouldn't even recognize that the card existed, so all of them were lost. I reformatted the card and tried again. Apparently, mixing different company's file formats is a no-no for the Sony; maybe it is for Canons, too, but I haven't ever tried that.

Things I've found out in use (or non-use): AF sucks, totally; with Canon 600/4 lens and Metabones III adapter only Single Shot AF is possible – none of the more sophisticated focusing schemes, like continuous focus, that make wildlife photography so much more successful are available. Single shot AF locks the focus at the point when the shutter button is half-pressed, so, if the subject moves out of the plane of focus, you have to try to get a new focus point and so on. If the AF were really fast that might be a workable technique for some slower-moving birds, but when the AF takes a couple of seconds to regain focus, it's a total failure.

A big part of the reason why AF is very slow is that it goes through all kinds of focus hunting gyrations before selecting something to focus on and then it may not be the subject I want, so, I have to give it at least one more try, sometimes a lot more than one, before I can click the shutter (if the bird is still there). This is with the smallest AF sensor area in use (presumably the most selective) and even so it seemed to find things well outside the indicated focus area to glom on to. This happens even when there are few obstacles near the subject bird, like one somewhat isolated on a twig or on water.

Since continuous (tracking) focus and other possibly useful focus settings are not available with this lens combination, do I want to spend $2200 just for sleeping birds? Mmmmmmaybeeee, if the image quality blows me away, but more likely, NOT! And the image quality did blow me away on the very few images I made that were sharp.

Manual focus using peaking is faster than Sony's AF, but not nearly as fast as Canon's AF (and is not as accurate). It's hard to tell just where the best plane of focus is amid the hash that's shown with the peaking set to a brightly visible yellow. For example, with a bird on the ground you can see the yellow band sweep back and forth as you rotate the focus ring, but only somewhere in the middle of that band is really in sharp focus and it's pretty hard to tell when you've got it on the bird's head – somewhere in the vicinity isn't good enough. And, if you don't have the ground plane under the bird to show the peaked focus area, good luck with your guess.

Also, the peaking level has to be adjusted for lighting, as in bright light a low level is needed to avoid having way too much yellow showing, but in dim light a high peaking level works best. And changing the level of peaking requires diving 3 clicks deep into menuland to find the adjustment item, change it, and OK it, IF you already have the menu set to the peaking level adjustment.

Getting used to the Sony's menus and controls is not trivial. After about 7 hours of use I still can't get to some frequently used adjustments as fast I need them, like the magnifier, which I had hoped would be useful for focussing, but only works on reviewing previous images. Usefulness? Hello? While it's nice to have magnification for chimping, it is so much more useful for focussing perfectly.

As to the electronic viewfinder, I find that it frequently changes brightness in use, depending on the brightness of part of the screen, despite having set it to manual. And it is slow to turn on when I need it. I'm used to an optical viewfinder that is on all the time, not black when I put it to my eye and only comes on after a pause when I touch the shutter button. Maybe I would get used to it. Maybe not. It still makes it hard to get the subject in the viewfinder while the system is coming on line. Maybe "getting up steam" is more like it.

Battery life isn't as bad as I thought it would be on the first day, when the battery may have lost power and shut the camera down with no warning after only about an hour's use and a couple of dozen frames. Today I shot 127 frames in an hour and still had enough power for perhaps as many more.

By the way, if you happen to need a paper manual because you lost the original, the web PDF download wastes huge amounts of space printed on letter-size paper and there are 448 pages of it!

Detailed summary: lenses on adapters are severely crippled and the camera only limps along attempting any kind of action shots. It seems like the designers and marketing people only intended this camera for the broadest and most common uses: street, casual portrait, travel, etc. and discounted the niche and technically challenging kinds of photography that the quality of the sensor would be exceptionally well suited for.

I admit that I don't get it; how many photographers need this kind of image quality for the uses to which the camera is best suited? And why isn't it better suited for those of us who really can use it's image quality?

[Bob Atkins]

I'm not surprised that AF wasn't very good. You are never going to get AF that's as good as a Canon lens on a Canon body like the 5D MkIII. The Af adpaters for Sony NEX don't work well. They'll give you some AF, but nothing like the AF you get with a 5D MkIII or EOS-1D X. I've yet to see any report that the AF via any adapter is anywhere near as good as going Canon all the way.

Do you really need 30+ MP? You have enough trouble getting spot on AF with a 20MP sensor. With a 30MP+ sensor AF would be even more critical, plus for long range shots atmospheric turbulance or any subject motion will probably wipe out any visible difference.

Personally I don't see the point of the Sony mirrorless full frame camera. Why make it mirrorless? You have to put full frame lenses on it, so the size of the body is a minor issue. Stick a mirror in it and make a DSLR!

If you wait long enough you'll probably see a Canon 35MP sensor without an anti-aliasing filter, though I don't see it coming very soon. I guess if you want that now your only option is to switch to Nikon. However I don't see nature photographers generally abandoning their Canon gear to get the extra resolution of the Nikon sensor. Under field conditions I'm really not sure you're going to see much difference. You can certainly measure resolution differences with the best lenses working under lab or studio conditions, but out in the field there are far more variables to deal with. I don't think there's much practical difference between a 20+ MP Canon and a 35 MP or so Nikon or Sony sensor once you get out of the lab.

[Frank Kolwicz]

Thanks, Bob, for the reply, but I have to say that my experience contradicts your assumptions.

As a matter of fact, I found the difference quite worth the cost for the higher resolution sensor under all significant ambient conditions and distances. I would have traded-in my 5dII immediately, if the Sony was even in the ballpark for AF or if MF with peaking was really accurate and easily usable.

Your remark that the AF "wasn't very good" is way too generous; the Sony's AF is abominable under these circumstances for anything more mobile than a statue.

But, comparing the best image of a B-C Chickadee that I got from the Sony to one from a Canon 70d with all the same settings and in the same light, with both birds viewed the same size on screen, the A7r produced very superior resolution. I did a survey of my archive Chickadee images looking for the best one in full sun and there were no great differences among them, so the one I selected was representative of the Canon 70d camera's ability with this lens and extender. Naturally, the bird was pretty close, in each case it filled about the same portion of the frame and atmospheric distortion didn't play a part, both birds were within about 30 feet. I also compared larger birds at greater distances, Red-tailed Hawks at about 150 feet and Pintail Ducks at about 75 feet, and came to the same conclusion. There are definite differences in favor of the Sony's sensor.

Atmospheric distortion almost never causes problems with my photography, as I only photograph at such distances for a record or for identification purposes, so I'm not concerned about its effect on image quality.

I didn't mention it in my original observations above, but I think the Sony also has better dynamic range.

As to the question of mirrorless or not, I doubt a mirrored version would accommodate Canon lenses without an optical adapter and consequent loss or image quality. What I do have to question is why the shutter is so damn noisy; when I do Live View or MLU photos with either of my Canon cameras they are much quieter than the Sony, which sounds a lot like a 1970s film camera shutter.

In the absence of a 36Mpix camera from Canon or a 600mm lens from Sony, maybe some firmware hacker will figure out where the problems are for using adapted lenses on the A7r. Maybe someone like Metabones, who could make out pretty well with such a device, is even working on it.

[Bob Atkins]

I really doubt anyone will (and possibly even could) develop an AF adapter that will come anywhere near the quality of Canon AF. It's a tuned system. I doubt anyone is going to invest the kind of time and money to try to duplicate that, even assuming it would be possible. The firmware for AF is in the Sony body, not the adapter, so they'd probably have to hack the Sony firmware. Plus the A7(r) just doesn't have the high speed, high precision phase sensitive hardware of the 5D3.

As for MILC vs DSLR, I was thinking of Sony using Sony lenses. They're not making a MILC so that people can put Canon lenses on them! I don't see any advantage of a FF MILC over a FF DSLR when used as intended (i.e. with manufacturer's FF lenses).

I'm surprised you see a big difference in image quality, but I haven't done that direct test using your gear. I have compared the D800 with the 5D3 using similar quality lenses. Indeed, on the optical bench, I saw maybe 25% higher resolution from the D800, though unless you are filling the frame with the subject, you'll get even higher resolution from a 7D or 70D shot from the same position. Higher pixel count certainly doesn't hurt (as long as noise stays low). On real world shots with the 5D3 and D800 (using 24-70/2.8 lenses) I really didn't see a great deal of difference (on distant subjects), but maybe that was my technique rather then the camera's fault.

As I said, if you want it all now, your only option is to switch to Nikon. If Canon are working on a high pixel count sensor it could be a while before we see it in a camera. Thay can certainly do it if they want. They made a 120MP APS-H sensor back in 2010, though they've never used it in a production camera. See http://www.bobatkins.com/photography/digital/canon_150MP_apsh_sensor.html