Kit lens auto focus

[DKK]

Hello,

I have purchased a brand new A7 II and, being a novice user of interchangeable lenses, I have a couple of questions about the 28-70mm kit lens:

- Is it safe to turn the manual focus ring while on auto focus or will it damage the lens? I have found some relevant information about this in the following links, but not specific to sony lenses: https://photo.stackexchange.com/q/39705 and https://www.dpreview.com/forums/thread/2304898

- Is it normal for the lens to make a short, almost inaudible mechanical sound (like a whir) when auto-focusing? Or does it indicate there is a problem with the motor or gears?

Thanks.

Edited February 16 by DKK

[XKAES]

You need to get a user manual for your camera.  It will tell you not to try to manually focus the lens while it is in auto-focus mode.  That will damage the camera and or the lens.  If you want to manually focus, you switch to manual-focus mode.

Lenses and cameras make noise while auto-focusing.  You describe it as "almost inaudible".  That's normal.

You need to get a user manual for your camera. 

[FunWithCameras]

There isn't a "manual" for that lens. Just a large piece of paper folded many times - that's normal for lenses, though.

Here's a link to it if you don't still have it: https://www.sony.com/electronics/support/res/manuals/4479/dd872ea359967bb6142f930eddb0cf8f/44791220M.pdf

There are two ways to use this lens in manual focus:

• set the camera to MF focus mode - that means all of the responsibility for focusing the lens falls on the user
• set the camera to DMF focus mode - that means the camera will do a single auto-focus (hopefully getting the lens close to focused), then the user can turn the focus ring to touch it up, if necessary.

Many lenses have an AF/MF switch - looking at the diagrams on the instructions page, this lens does not appear to have an AF/MF switch.

Here is the help guide for the A7 II: https://helpguide.sony.net/ilc/1450/v1/en/index.html 

and the information about choosing a focus mode: https://helpguide.sony.net/ilc/1450/v1/en/contents/TP0000386486.html 

[DKK]

Thank you both for your answers.

11 hours ago, XKAES said:

You need to get a user manual for your camera.

Unfortunately, the manual that came in the box did not provide this information.

 

11 hours ago, XKAES said:

It will tell you not to try to manually focus the lens while it is in auto-focus mode.  That will damage the camera and or the lens.  If you want to manually focus, you switch to manual-focus mode.

That was my assumption, but I read that apparently most E mount lenses are "focus-by-wire" and thus can not damaged by that. Is this not the case?

 

6 hours ago, FunWithCameras said:

Many lenses have an AF/MF switch - looking at the diagrams on the instructions page, this lens does not appear to have an AF/MF switch.

Correct, the lens does not have a physical switch on it, only a zoom ring and a focus ring.

 

6 hours ago, FunWithCameras said:

Here is the help guide for the A7 II: https://helpguide.sony.net/ilc/1450/v1/en/index.html 

This guide is more detailed than the one included in the box so it will be useful.

[Pieter]

31 minutes ago, DKK said:

I read that apparently most E mount lenses are "focus-by-wire" and thus can not damaged by that. Is this not the case?

@XKAES extensive experience with cameras and lenses dates back to the analogue age, so his advice is colored by that experience 😉

You are correct: turning the focus ring while autofocussing with this lens is no problem at all. There is no physical connection between the focus ring and the focussing mechanism.

[Thwyllo]

On 2/17/2024 at 2:59 AM, XKAES said:

You need to get a user manual for your camera.  It will tell you not to try to manually focus the lens while it is in auto-focus mode.  That will damage the camera and or the lens.  If you want to manually focus, you switch to manual-focus mode.

Lenses and cameras make noise while auto-focusing.  You describe it as "almost inaudible".  That's normal.

You need to get a user manual for your camera. 

I hate to burst your bubble but that's complete nonsense. I have DSLR and mirrorless cameras with umpteen lenses from Sony Nikon Canon and Pentax and not a single lens or camera in that collection operates in that way.

 

Typically turning the focus ring either does nothing or adjusts the focus which the autofocus will then reset with a half press of the shutter button. There is no resistance to the focus ring and it doesn't do any damage.

 

In fact there are lenses and camera systems where it's perfectly normal to be able to half-tap the shutter button for autofocus and then fine adjust that manually with the focus ring... I've never bothered with that myself so I'm not sure whether you have to keep the shutter button half pressed; I assume so otherwise autofocus would just readjust to its original setting wouldn't it.

 

But the OP can safely operate the focus ring during autofocus without fear of causing a problem, although the only reason I can imagine you would want to is if you're focus point settings were too wide or inappropriate for the scene you were photographing. So I offer the OP this piece of advice since he's new to this camera.... As with most other DSLR or mirrorless systems the best way to get accurate focus on any particular object is to select the single central point of focus in the focus options menu... Or you then need to do is put that focus point on the item you want crisp and sharp, half pressed the shutter button and KEEP it in that position while you recompose your photograph if, for example, you want some specific thing in the scene to be in focus at a rule of thirds point away from the centre of the frame.

For landscapes you can obviously use a different setting but it's perfectly feasible to use that single point for pretty much everything.

[XKAES]

Just a follow-up.

Although DKK's main concern deals with one lens and one camera, s/he asks the question, "Is it safe to turn the manual focus ring while on auto focus or will it damage the lens?"

I was looking at one of my user manuals for a Sigma lens, and it specifically states that if using a camera set for auto-focusing mode, make sure that the lens is also set for auto-focusing mode before it is attached.  If the lens is set for manual mode, on some (unspecified) a-mount cameras, the camera motor can be damaged.

It goes on to state that to use the lens in manual-focusing mode, to switch both the camera and the lens to manual mode, although it does not specifically state that the camera or lens can be damaged by turning the manual focusing ring with the lens or camera or both are set for auto-focusing.  In any event, I'm going to err on the side of safety.

So there are exceptions to the "do whatever you want" rule.  With any lens and any camera, it's a good idea to read the manual because every camera and lens is different -- but that would dramatically reduce the amount of discussion on this BOARD.

Edited March 26 by XKAES

[Pieter]

18 hours ago, XKAES said:

it's a good idea to read the manual because every camera and lens is different -- but that would dramatically reduce the amount of discussion on this BOARD.

Lol yea, this would be a boring place if everyone read their manuals 😂

On-topic: all (autofocussing) E-mount lenses have focus-by-wire systems (unlike many A-mount lenses). So yes, within the scope of the question (related to the E-mount system), it's safe to say you may turn the focus ring whenever to your hearts content.

Edited March 27 by Pieter

[XKAES]

The question was posted in the "ALPHA FULL-FRAME LENSES" category, and to all the a-mount users out there -- be careful.  Don't assume you can manually focus your lens, SAFELY, while your camera or lens are in auto-focus mode.  Blanket statements about it being safe should be taken for what they are.  In short, it depends.  Here's a warning from one of my a-mount lens' user manuals:

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited March 27 by XKAES

[Pieter]

6 hours ago, XKAES said:

The question was posted in the "ALPHA FULL-FRAME LENSES" category, and to all the a-mount users out there -- be careful.

Yes, the wondrous contemplations by Sony to call both A-mount and E-mount 'the Alpha-system'...

They shoulda called E-mount the Epsilon-system or something...

Edited March 27 by Pieter