HELP: Aperture goes wide open when camera just turned on, but aperture read out is different (F11)

This is really a question for the Sony forum, but sounds like a lens-body communication issue.

Do you see the problem with other lenses? Have you tried dismounting and remounting the lens?

If you go to the Sony forums there may be other people having the problem and someone may have a solution.

Gato

I reattached lens yes. Don't have other lens to test.

Domantas said:

Before anything, I use Sony A7S III with samyang/rokiron f2.8 24 mm. I use manual or "movie" mode which is essentially also manual just for video.

So as I stated in the title, when I turn on my camera, aperture instaltly goes wide open, which is not what is showed on the screen (either I have it set on f4 or f11, it goes wide open (F2.8) no matter what). It happens almost every time. It "fixes" when I adjust aperture by one stop, which is kinda annnoying, missed some shots because of that. What is the problem? Please help I am really stressed, should I go to warranty or what? And is it lens or body or something else issue? Maybe its something with settings? I was filming an awesome video and this happening almost all the time really annoyed me. Thank you!

Click to expand...

Not a Sony ILC shooter myself.

Just read from a member recently that his Sony camera will stop down the lens @ the set value always, which is quite different to my understanding that modern day AF camera will wide open the lens for easier AF (allow more light for the AF module/system to work with) and will only stop down to the set value on the moment of capturing...

Your finding is more in line with my expectation, but is contrary to the earlier confirmation from the aforementioned member...

Might be better to post this on Sony forum for confirmation. And will appreciate if you could update the result here to expand my knowledge. Thank you in advance.

OP double posted:

https://www.dpreview.com/forums/thread/4599648#forum-post-65484233

To be quite clear, am I correct in thinking that your problem is as follows: when shooting video, the lens doesn't stop down when you first start shooting. It does stop down if you change the aperture setting during the video (?). The problem recurs when you stop shooting and then restart.

As Albert has said, most cameras keep the lens diaphragm wide open when not shooting to collect the maximum amount of light for AF and, in a DSLR, to get the maximum light to the viewfinder. They only stop down if the Depth of Field preview button is pressed or if you start shooting. So the f/ number displayed in the viewfinder or on the rear LCD is the aperture it will stop down to when you start shooting.

Sony may be different - I know that they use stopped down focusing at higher shutter speeds, and video is probably different anyway. The A7Sii is also a new, highly specialised camera so that may be different again. So, I think that you need to ask your questions on the Sony Alpha Full Frame E Mount forum, not here on the Open Talk forum or the Sony Lens forum. You need to find other Sony A7Sii owners.

I can think of the following possible causes:

1. A setting on the A7Sii.
2. Some incompatibility between the A7Sii and this particular Samyang lens.
3. A faulty lens.
4. A faulty body.
5. A communication issue between the lens and the body

To help eliminate some of these, please carry out some tests, if you haven't already done so before posting on the Sony FF forum.

• Does the same problem occur with both video and still shooting?
• Does the lens work correctly on another body?
• Does the body work correctly with another lens?
• Try cleaning both the lens and body contacts and see if that solves the problem.

Best of luck and please let us know if you find the solution. Somebody else in the future may have the same problem and find this thread.
--
Chris R

Actually treble - he started two threads on the Sony lens forum but got no replies to the first. I think that he needs to post on the Sony FF e Mount forum in case this is a peculiarity of the A7Sii. That is a very new, specialised camera and there may not be many owners around.

alcelc said:

Just read from a member recently that his Sony camera will stop down the lens @ the set value always, which is quite different to my understanding that modern day AF camera will wide open the lens for easier AF (allow more light for the AF module/system to work with) and will only stop down to the set value on the moment of capturing...

Click to expand...

There can be more to it than that, too. The Canon R5 does not like looking at very bright light for metering and/or AF, and will stop down lenses to f/5.6 or maybe a little more, if a fast lens is pointed at a bright scene when a fast shutter speed and/or a lot of negative EC is dialled in, until shooting actually happens, even though with lower light, it normally keeps the aperture wide open until shooting needs for it to stop down for the capture exposures.

--
Beware of correct answers to wrong questions.
John
http://www.pbase.com/image/55384958.jpg

I have that lens and its works on my a7r2 as it should, maybe theres a setting on your a7s3 that needs changing , go on the sony forums and post there.

Don

alcelc said:

Domantas said:

Before anything, I use Sony A7S III with samyang/rokiron f2.8 24 mm. I use manual or "movie" mode which is essentially also manual just for video.

So as I stated in the title, when I turn on my camera, aperture instaltly goes wide open, which is not what is showed on the screen (either I have it set on f4 or f11, it goes wide open (F2.8) no matter what). It happens almost every time. It "fixes" when I adjust aperture by one stop, which is kinda annnoying, missed some shots because of that. What is the problem? Please help I am really stressed, should I go to warranty or what? And is it lens or body or something else issue? Maybe its something with settings? I was filming an awesome video and this happening almost all the time really annoyed me. Thank you!

Click to expand...

Not a Sony ILC shooter myself.

Just read from a member recently that his Sony camera will stop down the lens @ the set value always, which is quite different to my understanding that modern day AF camera will wide open the lens for easier AF (allow more light for the AF module/system to work with) and will only stop down to the set value on the moment of capturing...

Your finding is more in line with my expectation, but is contrary to the earlier confirmation from the aforementioned member...

Might be better to post this on Sony forum for confirmation. And will appreciate if you could update the result here to expand my knowledge. Thank you in advance.

Click to expand...

It is still wide open when I start to film. I posted on Sony forum, but here got quicker response. Now got some responses there two, but still no obvious solution.

Chris R-UK said:

To be quite clear, am I correct in thinking that your problem is as follows: when shooting video, the lens doesn't stop down when you first start shooting. It does stop down if you change the aperture setting during the video (?). The problem recurs when you stop shooting and then restart.

As Albert has said, most cameras keep the lens diaphragm wide open when not shooting to collect the maximum amount of light for AF and, in a DSLR, to get the maximum light to the viewfinder. They only stop down if the Depth of Field preview button is pressed or if you start shooting. So the f/ number displayed in the viewfinder or on the rear LCD is the aperture it will stop down to when you start shooting.

Sony may be different - I know that they use stopped down focusing at higher shutter speeds, and video is probably different anyway. The A7Sii is also a new, highly specialised camera so that may be different again. So, I think that you need to ask your questions on the Sony Alpha Full Frame E Mount forum, not here on the Open Talk forum or the Sony Lens forum. You need to find other Sony A7Sii owners.

I can think of the following possible causes:

1. A setting on the A7Sii.
2. Some incompatibility between the A7Sii and this particular Samyang lens.
3. A faulty lens.
4. A faulty body.
5. A communication issue between the lens and the body

To help eliminate some of these, please carry out some tests, if you haven't already done so before posting on the Sony FF forum.

• Does the same problem occur with both video and still shooting?
• Does the lens work correctly on another body?
• Does the body work correctly with another lens?
• Try cleaning both the lens and body contacts and see if that solves the problem.

Best of luck and please let us know if you find the solution. Somebody else in the future may have the same problem and find this thread.
--
Chris R

Click to expand...

Thanks for your in-depth response!

Yes, you are correct when i turn on camera, lens doesn't stop down ("stuck") until I change aperture. The story repeats again after turning it off, then on.

"is the aperture it will stop down to when you start shooting"

the problem is it is still filming wide open as it turned on like that and showing incorrect aperture. It looks terrible, especially obviously on bright day.

"1. a setting on the A7SIII"

I think I checked every setting and it should be fine. Tried with manual mode, still same issue.

Other causes are not checked. I am probably bringing lens to warranty because I don't have a lot of ways to test. It would be cool if there be a way to fix it, but it seems like some "not so often" problem. I think lens is somehow not sending any data to camera for it to correct the aperture accordingly. When camera send data to it, its somehow "activates" and works good.

John Sheehy said:

alcelc said:

Just read from a member recently that his Sony camera will stop down the lens @ the set value always, which is quite different to my understanding that modern day AF camera will wide open the lens for easier AF (allow more light for the AF module/system to work with) and will only stop down to the set value on the moment of capturing...

Click to expand...

There can be more to it than that, too. The Canon R5 does not like looking at very bright light for metering and/or AF, and will stop down lenses to f/5.6 or maybe a little more, if a fast lens is pointed at a bright scene when a fast shutter speed and/or a lot of negative EC is dialled in, until shooting actually happens, even though with lower light, it normally keeps the aperture wide open until shooting needs for it to stop down for the capture exposures.

Click to expand...

Sadly nothing else fixes it expect changing aperture one stop down and bringing it back to which I wanted fixes it. It stays like that for a very long time till battery drains.

Donald B said:

I have that lens and its works on my a7r2 as it should, maybe theres a setting on your a7s3 that needs changing , go on the sony forums and post there.

Don

Click to expand...

If it works fine, I would wild guess is probably faulty lens. I would doubt body is faulty because everything else is working so perfectly on it. Lens is not super expensive and maybe it is faulty copy (probably on contacts, because besides aperture problem it is working not bad).

Our camera does what it is designed to do, one way or another. I wish you can find out how your camera works.

Domantas said:

...

Other causes are not checked. I am probably bringing lens to warranty because I don't have a lot of ways to test. It would be cool if there be a way to fix it, but it seems like some "not so often" problem. I think lens is somehow not sending any data to camera for it to correct the aperture accordingly. When camera send data to it, its somehow "activates" and works good.

Click to expand...

I think you are on the right track here -- either the lens is not communicating properly with the camera or something is sticking inside the lens. Hopefully a warranty claim will solve your problem.

Good luck

Gato

Domantas said:

Chris R-UK said:

To be quite clear, am I correct in thinking that your problem is as follows: when shooting video, the lens doesn't stop down when you first start shooting. It does stop down if you change the aperture setting during the video (?). The problem recurs when you stop shooting and then restart.

As Albert has said, most cameras keep the lens diaphragm wide open when not shooting to collect the maximum amount of light for AF and, in a DSLR, to get the maximum light to the viewfinder. They only stop down if the Depth of Field preview button is pressed or if you start shooting. So the f/ number displayed in the viewfinder or on the rear LCD is the aperture it will stop down to when you start shooting.

Sony may be different - I know that they use stopped down focusing at higher shutter speeds, and video is probably different anyway. The A7Sii is also a new, highly specialised camera so that may be different again. So, I think that you need to ask your questions on the Sony Alpha Full Frame E Mount forum, not here on the Open Talk forum or the Sony Lens forum. You need to find other Sony A7Sii owners.

I can think of the following possible causes:

1. A setting on the A7Sii.
2. Some incompatibility between the A7Sii and this particular Samyang lens.
3. A faulty lens.
4. A faulty body.
5. A communication issue between the lens and the body

To help eliminate some of these, please carry out some tests, if you haven't already done so before posting on the Sony FF forum.

• Does the same problem occur with both video and still shooting?
• Does the lens work correctly on another body?
• Does the body work correctly with another lens?
• Try cleaning both the lens and body contacts and see if that solves the problem.

Best of luck and please let us know if you find the solution. Somebody else in the future may have the same problem and find this thread.
--
Chris R

Click to expand...

Thanks for your in-depth response!

Yes, you are correct when i turn on camera, lens doesn't stop down ("stuck") until I change aperture. The story repeats again after turning it off, then on.

"is the aperture it will stop down to when you start shooting"

the problem is it is still filming wide open as it turned on like that and showing incorrect aperture. It looks terrible, especially obviously on bright day.

"1. a setting on the A7SIII"

I think I checked every setting and it should be fine. Tried with manual mode, still same issue.

Other causes are not checked. I am probably bringing lens to warranty because I don't have a lot of ways to test. It would be cool if there be a way to fix it, but it seems like some "not so often" problem. I think lens is somehow not sending any data to camera for it to correct the aperture accordingly. When camera send data to it, its somehow "activates" and works good.

Click to expand...

I don't know if this will help but have you reset your camera back to the factory setting or is that possible?