NEX 7 autofocus

[bezier1955]

Hi Everyone,

Newbie here with my first post/question.

I just got a NEX7 with 18-55 kit lens this week and getting to grips with it. One thing I find puzzling is that the camera focuses even without half pressing the shutter, so as I point the camera at different things, it re-focuses. This happens regardless of the focus mode I'm using (barring MF of course!) If I do half press the shutter then the focus locks like you would expect. The manual says you should half press the shutter to invoke focus.

The half press has been the functionality on all other cameras I've had so I wonder if it's just me being a bit thick!

Bezier

 

[d__b]

I played around a little bit with my NEX 5 and it seems, that this only happens, when the AF-Area is set to "Multi". When I just use the "Flexible Spot", which I like best anyway, the focus doesn't change. Hope that helps...

 

[bezier1955]

Thanks d__b,

Not sure if the NEX5 is different but the NEX7 still focuses on it's own whether the AF area is multi, centre or flexible spot. It also does it whether in AF or DMF modes too....

 

[Ken Ford]

What exposure mode are you in? I seem to recall hearing the iAuto (or whatever it's called) and scene modes do this.

 

[bezier1955]

Hi Ken,

Doesn't matter what mode, it does it in iAuto, Scene, as well as the PASM modes too.

 

[Ken Ford]

Hmmm. I know I've seen this mentioned in other forums, but I don't experience it and I don't recall the solution. I do believe it was due to a menu setting or a combination of settings.

 

[bezier1955]

Thanks Ken,

Been through all the menu options and nothing jumps out at me. I've posted the question on the Sony forum too so I'll see what happens.

 

[zb3]

My NEX3 does that as well. Just one of the quirks.

 

[CK Dexter Haven]

Is it set in a 'continuous' AF mode?
Coincidentally, i am watching/listening to a video about the NEX7 right now, as i find your question, and the person being interviewed mentions having this problem when he was initially setting up the camera.

See the early part of this:
http://www.sonyalpharumors.com/sony-nex-7-with-canon-fd-and-contax-g-lens-test/

 

[zeezea]

Hello. I've not used a NEX yet, but had used a Panny G1 for a while. IIRC, there is
a setting on that camera called "Pre AF". I think it focused constantly (even without
pressing the shutter button). This was an attempt to minimize the lag time between
pressing the button, focus lock and the shutter actually firing.

Regards,
Al

 

[bezier1955]

Thanks Al,

I suspect that is exactly what's happening here. As the NEX uses contrast based AF it makes sense to 'pre AF' as you describe.

I'd like to turn it off if that's possible but I'm beginning to suspect that might not be possible.

Bez

 

[douglasf13]

Yep, it's a common complaint about the NEX-7 AF that I'd imagine will be fixed in a firmware update. The good news is that the NEX-7 has the rear AF/MF button. What I personally do is leave the camera in manual focus, and press the AF/MF button to autofocus. Make sure you set AF/MF control to "hold," and map the AF/MF button to "AF/MF control" in the setup menu.

Doing the above will stop the constant pre-focus and save you battery life. A lot of DSLR shooters shoot this way, because it decouples metering from AF, which is nice, IMO.

 

[bezier1955]

Thanks Douglasf13,

That's the solution! Ken Ford mentioned in this thread he thought there was a combination that turned it off. I do agree it's good to separate AF from metering, so thanks again.

Bez

 

[bezier1955]

Many thanks to all respondents...

 

[Jim Evidon]

I've been using my NEX5N for a couple of months and I thought I was doing all the focusing with a half press on the shutter button. So when I saw this thread, I figured there was something wrong with your menu settings. So, I just took it off the shelf and checked it out. You're right. The little sucker focuses on its own no matter what I point to and no matter what distance it is from the subject. It makes you wonder what else it does when your out of the room. Frankly, I don't see this as a disadvantage except it does seem to be a shameful waste of battery power. My GF1 has better manners and focuses only when I want it to. I wonder what Sony had in mind with this neat little feature of questionable value.

 

[Hatch]

Maybe I'm thick, but my 7 focusses with a half press.
(With the 16 mm) And it locks focus until released.

I think it's under settings.

I'll have look tonight when i'm home.
I can take a few test shots to see if it refocusses when taking the shot.

 

[bezier1955]

Thanks Hatch,

My NEX 7 does focus with the half press, but it will focus anyway without pressing. Try pointing yours at something without half pressing and I think (if it's the same as mine) that it will focus anyway.

 

[Hatch]

Yup, I'm thick.

Never noticed it because the only AF lens I have is the 16 mm.

iIt's probably a feature.
It does reduce time when snatching the decisive moment.
But it would indeed be nice to be able to switch it off.

 

[Speedfreak]

Interesting. I am using manual lenses only with my NEX. Constant AF would annoy the hell out of me.

 

[Peter^]

Thanks Hatch,

My NEX 7 does focus with the half press, but it will focus anyway without pressing. Try pointing yours at something without half pressing and I think (if it's the same as mine) that it will focus anyway.

Yes, but the trick is: once you've pressed half down and the system has focused, it will not refocus as long as you keep the button pressed. At least mine works like that.