SEL 70200 AutoFocus

[ypnoz]

Hi everybody,

 

This is my first post here. Nice to meet you all!

I have an A7II and bought a SEL70200. After a few hours of use, AF stopped to work entirely.

It worked randomly once in a while...So I took it to the shop and after a few tests they came to the conclusion that the lens had an issue (was afraid they would tell me it was my A7II) and replaced it.

 

Everything worked fine since then and really enjoying it. It's my first 70200 range zoom so I can't really compare it to others.

It's obviously a bit slower and less 'creamier' than those fancier 2.8 zooms but overall, a great lens.

 

Something has been bothering me though. In AF-S mode, I half-press the shutter and very fast (as it should), I hear the little sound and see the square turning green: Focus should have been acquired by now...yet the image is completely out of focus.

 

I see it happens quite a lot and maybe it's my imagination but feels like it happens more recently.

 

Did anybody experience such thing?

 

Thanks

[Guest all8]

Post one of these out of focus pictures, it may simply be that you need to change the Autofocus Selector. Also, if the problem does not happen in AF-C ... then is it possible the subject has moved after the AF lock?

 

In this photo (a crop), distance around 1.5 meters @ f4, was first autofocused with "Small Square" and then I had to switch to Manual Focus to get the focus point where I wanted it. The DOF under those circumstances was too small for the AF to get focus "right". The other shots in this sequence done with AF were in focus, just not in the right place.

[Austerror]

Indeed, critical focus is much more important on a telephoto lens.

[ypnoz]

Hi 

 

Thanks for the answer. I didn't take such pictures. I simply retried to get focus until it worked.

It might be a problem of selector. I am using Small spot. I'll try to see if it happens to me while using medium.

 

Which one do you guys use?

 

I generally use:

- Small Spot in AF-S

- Small Flexible Spot Lock on

[Guest all8]

depends, post one of the pictures ...

 

 

I'm going to use Large Spot for a while, because I'm curious if it work better then Small Spot for me (I'm wondering if it will give a little more DOF than Small Spot does). And for fast moving people I get the feeling that "Center Region" + Lock On is working a little better, especially with Face Detect ... and there is the Eye Focus to experiment with too for not moving people.

 

Not really auto focus .... 

[foto-fanatic]

Just as a heads up there is a firmware update to ver .20 for this lens [in australia anyway].

I just installed on mine.

Also there is a minimum close focus distance you may already be aware.

[Karlitos]

On an object like the one shown by timde and an open aperture, it is better to use small focal spots and decide on what you are interested in/want to focus on. 

[foto-fanatic]

Well i feel compelled to say im very happy with the image quality and focus speed and accuracy of my new 70-200 f4 lens, the dof blur is pretty nice very nice for a zoom i like the compressed nature of zoom boquet lol.

Its a very nice lens so far, havent had that much opportunity to shoot in good light atm due to weather conditions but so far yay great score.i got it for a great price too here in aus/

[ypnoz]

hi sorry for the delay

 

actually, as foto-freak said, i also thought i may have been at the limit of minimum focus distance.

because since then, i didn't have any issues. 

 

on the other hand, i switched to Back Button Focus, like i was used on Nikon and loves it but very often, not getting face/eyes in focus

 

any recommandation on that?

 

thanks

[ypnoz]

Forgot to say i use Lock On Flexible spot (M in general)

I try to initially focus around the eye, then the big Green square takes over and surrounds the whole face.

So im not sure i understand what it focuses on...

[foto-fanatic]

Have you tried switching between phase detect and contrast etc?

 

I get the feeling its a matter of configuring to optimise to your liking.

 

I have been reading about sel70-200g and there are 2 modes for image stabilisation [oss]  mode 1 for normal use and mode 2 for panning moving subject so i believe.

 

P.s have you tried the updated firmware v 2.0 for 70-200g?

Mine came with v 1.0. i updated straight away and focus is pretty good for me.

[ypnoz]

i didn't try that, i will, thanks

 

about firmware i did, but wasnt it only for quicker start?

[foto-fanatic]

Im not sure but updated anyway, is your camera running the latest firmware too just wondering?

[Karlitos]

The big green square sounds like face detect. You can turn it off if you don't like it, but it is also using the eyes for focusing.