Sony A7SII Focus Problems

nocturnalphotoguy

nocturnalphotoguy

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I have recently acquired a Sony A7SII. Does anyone have any experience with the camera body? I seem to be having problems with the autofucus system prodominantly in the AF-C mode; where the focus just seems to pulsate without locking on to anything. I only have one lens a Samyang 135mm 1.8 AF I shouldn't see why a third party lens would affect this, though any input or suggestions would be much appreciated.

I have updated to the latest firmware and reset the menu settings.

Thanks.
 
I think this is likely to be down to the lens but how does it perform in AF-S?
 
It seems okay in AF-S, maybe does a slight defocus before fowarding into focus but confirms with the beep. I am quite shocked really especially when it is a fairly expensive lens. Went into WEX the other day and we tried a native cropped lens and still did the same thing, thats why I am not totally convinced that its the lens. But wanted to see what other sony users experienced. Reason why I bought a Sony in the first place was for the ability to mix and match a few lens manufacturers using metabones mounts.
 
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What's the easiest way to recreate this issue? I think I've only used C-AF in video on the A7SII and I've not had any issues I can recall apart from it not being very speedy.
 
I guess finding someone with the exact same model camera and mounting the lens onto it John. Shame as I was hoping to use it with back-button af. Yea I am not too bothered with it in the video mode and yes as you say its not the fastest by any means. Here is an example of the problem focusing, I recorded the screen whilst using the AF-C mode;

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And here is an example of how it should be behaving (nothing new or groundbreaking);
View: https://www.youtube.com/watch?v=EuDaEUyH9SU
 
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AF-C. As long as you half press the shutter it’ll keep re-acquiring focus. It will not “lock on”. I expect this is the pulsing you’re experiencing.
NB. There will be no beep.
 
IIRC A7Sii used contrast detection AF only.
That's the reason you get the pulsating effect, same as on most Panasonic bodies for example when used in video or AF-C.
But Panasonic's CDAF is super optimised because that's basically all they used for like two decades. So the pulsating while annoying was minimal. On Sony apart from A7S and A7SII, rest of the bodies use PDAF. So unlikely it's as well implemented as Panasonic which is probably why you see a stronger pulsation.
In AF-C the camera is trying to constantly keep the subject in focus and hence the constant pulsating versus AF-S where it just focuses once.
And as mentioned above there won't be a focus confirmation in AF-C unlike AF-S.

I imagine something like samyang lenses are even less optimised for a body like A7SII. So that probably doesn't help either.

The video above is on A7riii which has phase detect AF hence no pulsating.

Edit:
Just looked at you video, looks normal to me for this body and CDAF.
 
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I agree with nandbytes that this is normal on the A7SII as it's CDAF only whereas the A7R3 has both CDAF and PDAF, with only CDAF the camera cannot identify how out of focus the image is and whether the lens is front or rear focused. This means the cameras has to move through the focus range and it measures the image getting sharper and then when it moves past the in focus position, the image will get softer again so it knows where the focus point is. With the C-AF this means the camera has to move the focus slightly back and forth to check where the image is in sharp focus.

PDAF can identify if the image is front or back focused and how out of focus the image is so the camera can quickly jump to the right position. CDAF systems have improved considerably but now mirrorless cameras mix PDAF and CDAF since PDAF can quickly identify where the focus point is and CDAF can get accurate focus.

I've recorded my A7SII with the Sony 28mm F2 lens and in the C-AF mode I see similar pulsing to your video:

View: https://www.youtube.com/watch?v=r33SemKQolk
 
Thanks for taking the time to upload, yes John your camera/lens is working perfectly. I notice you were using "Lock-on AF - expand flexible spot" never used that mode, tried that out too but still just continues to to pulse may as well be shooting in pitch black. Mine just continually pulses for eternity so I know this is not normal now, and contrast based detection is same technology used in my 7D if i am correct it's older tech but still works.
trevorbray said:
AF-C. As long as you half press the shutter it’ll keep re-acquiring focus. It will not “lock on”. I expect this is the pulsing you’re experiencing.
NB. There will be no beep.
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Thanks Trevor, I know there is no confirmed beep in AF-C haha. It just never goes into focus did you watch the we-transfer attachment?
 
nandbytes said:
IIRC A7Sii used contrast detection AF only.
That's the reason you get the pulsating effect, same as on most Panasonic bodies for example when used in video or AF-C.
But Panasonic's CDAF is super optimised because that's basically all they used for like two decades. So the pulsating while annoying was minimal. On Sony apart from A7S and A7SII, rest of the bodies use PDAF. So unlikely it's as well implemented as Panasonic which is probably why you see a stronger pulsation.
In AF-C the camera is trying to constantly keep the subject in focus and hence the constant pulsating versus AF-S where it just focuses once.
And as mentioned above there won't be a focus confirmation in AF-C unlike AF-S.

I imagine something like samyang lenses are even less optimised for a body like A7SII. So that probably doesn't help either.

The video above is on A7riii which has phase detect AF hence no pulsating.

Edit:
Just looked at you video, looks normal to me for this body and CDAF.
Click to expand...
Thank you nandbytes I see what you are saying, I will go to another camera store Friday, did I mention I already tried a Sony lens in WEX the other day? They said it was the body, same problem this guy is having presumably;
he replys on the comments saying the service centre replaced the focus board.
https://www.reddit.com/r/SonyAlpha/comments/bou6uo
View: https://www.reddit.com/r/SonyAlpha/comments/bou6uo/help_wanted_my_a7iii_has_started_focus_pulsing_on/
 
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nocturnalphotoguy said:
Thanks for taking the time to upload, yes John your camera/lens is working perfectly. I notice you were using "Lock-on AF - expand flexible spot" never used that mode, tried that out too but still just continues to to pulse may as well be shooting in pitch black. Mine just continually pulses for eternity so I know this is not normal now, and contrast based detection is same technology used in my 7D if i am correct it's older tech but still works.

Thanks Trevor, I know there is no confirmed beep in AF-C haha. It just never goes into focus did you watch the we-transfer attachment?
Click to expand...
It's been a while since I used my A7SII so it's lost its memory, the only change I made was from AF-S to C-AF. The video is maybe not showing it properly but it does keep pulsing the focus.

The 7D uses PDAF as do all DSLRs with the mirror down, mirrorless cameras cannot have the same dedicated PDAF setup since they're using the main sensors so they used a mix of PDAF detection on the main sensor and CDAF.
 
JohnMcL7 said:
It's been a while since I used my A7SII so it's lost its memory, the only change I made was from AF-S to C-AF. The video is maybe not showing it properly but it does keep pulsing the focus.

The 7D uses PDAF as do all DSLRs with the mirror down, mirrorless cameras cannot have the same dedicated PDAF setup since they're using the main sensors so they used a mix of PDAF detection on the main sensor and CDAF.
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Yes you are correct it is CDAF. I was confusing the 7d in live view mode.

You mean you were half holding the shutter button through the whole video? I can see you pressed it about 6-7 times. Indeed I can see a bit of hesitant jittering on your video (looking at the left window), imo its no way as bad. I have a feeling if you change your focus mode to small or medium spot only it would improve focusing on subjuects you point it to, I could be wrong though. :oops: :$
 
nocturnalphotoguy said:
Yes you are correct it is CDAF. I was confusing the 7d in live view mode.

You mean you were half holding the shutter button through the whole video? I can see you pressed it about 6-7 times. Indeed I can see a bit of hesitant jittering on your video (looking at the left window), imo its no way as bad. I have a feeling if you change your focus mode to small or medium spot only it would improve focusing on subjuects you point it to, I could be wrong though. :oops: :$
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I never let my finger off the shutter button, it was on the half focus position the entire time. I think the video doesn't show the pulsing that clearly as I was definitely seeing it each time the camera moved slightly.

I guess ultimately the question is what do you want to do with the camera? Even putting aside these issues you're having, it's not a camera I would use in C-AF due to the poor performance it has.
 
Okay interesting, I was looking at the green confirmation focus on your screen John, but I see now it was just confirming when it achieved focus or it interpretation of it. :) Did C-AF improve a lot more in the mk3 and mk4s in the a7models? I know this body was more aimed towards film makers but the high iso performance attracted me most and thought the focusing system would have been better being mirrorless too. Modeling portraits in blue hour/twilight/long exposures is what I wanted it for. I can return it but I have the lens too now which I purchased separately.
 
nocturnalphotoguy said:
Okay interesting, I was looking at the green confirmation focus on your screen John, but I see now it was just confirming when it achieved focus or it interpretation of it. :) Did C-AF improve a lot more in the mk3 and mk4s in the a7models? I know this body was more aimed towards film makers but the high iso performance attracted me most and thought the focusing system would have been better being mirrorless too. Modeling portraits in blue hour/twilight/long exposures is what I wanted it for. I can return it but I have the lens too now which I purchased separately.
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A7R, A7S & A7SIII all have CDAF and basically useless at AF-C for all intents and purposes.

A7 & A7ii have the first gen PDAF which mostly is only good for getting rid of the pulsating you are experiencing but basically not of much use for tracking anything challenging. You could probably track a snail with it :p

A7Rii is the first body that had usable AF-C IMO.

Then A9 came along and changed the whole landscape for mirrorless cameras in terms of AF-C & tracking.

A7RIII/A7iii borrow a lot from the A9 and probably the first mirrorless bodies that really gave DSLRs a run for their money in terms of AF-C/tracking

A7RIV/A7SIII/A7C have further refinements and improvements with first full implementations what Sony calls real time tracking. Though original Sony A9 got this via. Firmware updates I believe.

A9ii is an incremental update with mostly similar performance to A9 but with newer processor, faster write speeds etc.

A1/A7IV use similar set of algorithms and added useable eyeAF for animals and birds along with the updates we already saw in above bodies.

A7v goes one step further adds more subject detection and has new processor with "AI recognition" for tracking.

A7S/ii/iii aren't much better than say A7R series for low light performance

View: https://youtu.be/gAYXFwBsKQ0
 
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nocturnalphotoguy said:
Okay interesting, I was looking at the green confirmation focus on your screen John, but I see now it was just confirming when it achieved focus or it interpretation of it. :) Did C-AF improve a lot more in the mk3 and mk4s in the a7models? I know this body was more aimed towards film makers but the high iso performance attracted me most and thought the focusing system would have been better being mirrorless too. Modeling portraits in blue hour/twilight/long exposures is what I wanted it for. I can return it but I have the lens too now which I purchased separately.
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If you're wanting it for stills performance then I wouldn't use this camera, its low light advantage was in video not stills (as Nandbytes has posted above) and mirrorless cameras for a while did lag behind the mature PDAF systems DSLRs had.

FE-mount though gives you access to a fantastic range of cameras so I'm sure you can find something better suited to your use, there's a big thread on Sony cameras here:

www.talkphotography.co.uk

The Amazing Sony A1/A7/A9/APS-C & Anything else welcome Mega Thread!

I'm not sure we're all talking about the same thing tbh as the effect is far less pronounced the smaller the aperture, I've never seen it at f5.6 for example. Only at long focal lengths or large sensors (ie MF film or large format)
www.talkphotography.co.uk www.talkphotography.co.uk

Or you could start another topic asking for advice if you can give a budget and what you're looking to do with the camera.

I bought an A7SII as I was blown away by its low light video capabilities and I had only planned to use it for video, I did use it for some photography when I didn't have another camera with me which worked fine but the sluggish AF-S performance felt more like an older mirrorless model. The camera was a mistake and I hardly ever used it because there's just so few times I actually needed or wanted super low light video performance plus I suck at video, with a gimbal the A7SII is an enormous package and other cameras I have that are much better for photos.

I've not used any of the other A7 series cameras so can't comment on them, it's an A9mk1 I use at the moment as my FE-mount camera.
 
Lol track a snail, definately agree with that! Thanks for the detailed information you have posted nandbytes. If it wasn't for the poor C-AF I would have been estatic but then I guess there is no perfect camera out there, but just have to make do with what you are willing to trade off.
 
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