I’m close to being done with the a7S review. In this post, I’ll depart from my usual objective reporting and give you an impression of what operating the camera was like.
When I first got the camera, I thought of it as sort of like a Nikon D3 or D3s, both of which I loved enough to buy multiple copies. Same resolution. Full Frame. Great in dim light. Makes sense, in a superficial way.
It turns out that what the a7S is good for and what the D3s was good for are miles apart. Oh, there’s one aspect that’s the same: they are both great low-light performers, the a7S more than the D3s — sensors are getting better. The D3s is a run-and-gun camera, with really rapid auto focus. I remember taking pictures with the D3s and a Nikon 400mm f/2.8 lens of a row of musicians during a Carmel Bach Festival rehearsal a few years ago. I was sighting down the row, shooting wide open, so that the musician in front and the one in badk were pretty far out of focus. It was a nice look. Then the player I was lined up on leaned back and the lens snapped into focus on the one behind so fast it was shocking. That’s not going to happen with the a7S. First off, it focuses only by contrast detection, like the a7R but unlike the a7. Not only is that inherently slower, since the AF system can’t take a reading and jump immediately to something close to the in-focus position, it means that the camera can’t do very effective predictive focusing of a moving subject.
Sure, there are advantages of contrast autofocus over phase detect — no forward or back focus (unless it focuses on the wrong thing), more choice of focus points, choice of the size of focus points — and there are reasons to include both like the a7 does, but alone, it’s just not as good a system, in my quasi-humble opinion. It was never a problem with the a7R, because I used that camera very deliberately, but when I used the a7S and the Zony 55 or the Sony 70-200 f/4 G lens in fast moving situations, it was frustrating. I kept comparing it to the D3s, and it kept coming up short.
To give you an idea how much the a7S AF slows things down, when I pressed one of the focus-lock buttons on the 70-210 in bright light, the frame rate in continuous mode would double.
This is not really saying that there’s anything wrong with the a7S’s autofocus; it’s more that I had the wrong idea of what camera to compare it to. If I’d thought more clearly at the outset, I wouldn’t have been so disappointed. The AF works pretty well in really dim light, probably a bit better than the AF on the D3s in similar darkness. It’s only the difference between “terrible “and “pretty darned slow,” though.
A lot of the handling of a camera is the user interface, and the a7 user interface is one I know and don’t love. It’s pretty much the same as that on the a7 and a7R. Perfectly serviceable, but no fun to use, Not enough direct access, controls too light, too easy to change something without knowing it, and way too many menu items. I do like the fact that it’s so configuable, including the two memory settings on the control wheel on the top of the camera, and the assignable function buttons. Sony’s user interface has been making progress with each generation since the NEX-7, and I think they’ll get there eventually. But here’s a hint to the Sony engineers working on the next camera: get yourself a Nikon D4 and use it for a while.
The a7S silent shutter opens up new picture taking possibilities, and could be reason enough to buy the camera for some. It would have changed my photographic life to have had this feature when I was taking pictures for the Carmel Bach Festival. I imagine that this camera is a godsend to still photographers working on movie sets who can finally say goodbye to cumbersome, heavy sound blimps,
Then there’s video. That’s really the reason I got the camera; I want to do some synthetic slit scan work with 4K video and the camera in the portrait position. For that I’ll need an external recorder, and the Sony-recommended one isn’t yet available. I’ll report on that at a (much) later date.
I 100% agree with you!
Handling of the A7whatever is way different than any serious D-SLR (I own the Canon 1DX, that Sony engineers could use as a reference for ergonomics too).
There are some benefits and serious drawbacks.
The electronic viewfinder is, overall, a benefit.
You can zoom in the viewfinder and when, like me, you need reading glasses, there is no other way to use manual focus lenses with good focus accuracy. When you go back to a ‘normal’ D-SLR, you miss it.
The AF speed and accuracy (which is linked mainly to the ability to tell the camera accurately and without too much effort what you want to focus on) are clearly lacking.
Unless you have plenty of time.
So you have two choice with A7x : Take your time to focus (typically : you’re shooting static subjects) or pre-focus manually and shoot when the subject is where you expected it to be (the old way). Both work.
But then you have situations where it doesn’t work.
And then you have those ugly menus and so on. And this ‘non consistent’ behavior.
You can customize buttons. Sure. But why the hell can’t I select just the one function I needed (like the zoom on replay images in the center dial button) ???
Understand me well : I like the A7R a lot. And I ultimately shoot more with it than with the 1DX. But why is it so difficult to use ?
I usually get used to a camera quite fast. With the Sonys I just can’t. I dropped the Nex 7 for that very reason.
Well, the fact I can use manual focus lenses in their native focal length makes me stick to the A7R. Just.
Thanks for all your reviews !
Hi Jim. First of all, this is one of the best review I am finding, at least from the A7s autofocusing. But some thing were just a bit confusing for me:
“Sure, there are advantages of contrast autofocus over phase detect — no forward or back focus”.
As far as I know, the contrast detection has to exceed the focus point in order to recognize it. And that its for me a system that is based on hunting unlike the Phase detect that knows in which direction has to go. Just wonted to know, why did you said that and please correct me if I am wrong.
Then you said that the “A7s AF works pretty well in really dim light, probably a bit better than the AF on the D3s in similar darkness”.
So this means that can focus in the same darkness as the D3s but forget about focusing over fast moving objects? What about slow moving objects like a cat, a child or people walking in the street in same dark conditions?
Thanks a lot!
WRT the back- or forward- focus issue on phase detect AF systems, I was talking about the systematic errors that can occur with that system, depending on the position of the ground glass assembly, the lens design, the subject distance, and — for all I know — the phase of the moon. Cameras that have phase-detect alone usually have micro-adjustments to tune the AF for each lens, but that’s a hassle and results in incomplete correction.
I suppose any system using negative feedback can be characterized as being off some of the time, but increase the loop gain and you can drive the error signal nearly to zero. Ideally, you want both kinds of AF, and the a7 fills that bill.
The a7S AF is not very good for medium-speed moving objects like the ones cited in your example when it’s light. It will be worse when it’s dark.