Sony 24mm 1.4 GM Focus Noise: Just received this lens and it is amazing....but....as it auto focuses I can actually feel a slight "clunk" as the optics inside move. There is an almost...

tinplater Loc: Scottsdale, AZ

Just received this lens and it is amazing....but....as it auto focuses I can actually feel a slight "clunk" as the optics inside move. There is an almost inaudible noise associated with focus change. I am trying to determine if this is normal function or should I exchange lens? Appreciate other owners of the lens' input.

Architect1776 Loc: In my mind

tinplater wrote:

Just received this lens and it is amazing....but....as it auto focuses I can actually feel a slight "clunk" as the optics inside move. There is an almost inaudible noise associated with focus change. I am trying to determine if this is normal function or should I exchange lens? Appreciate other owners of the lens' input.

Most lenses without the Nano-USM or the STM will have noise when focusing. USM is very quiet and is good except for in camera video sound recording as the camera mike can pick up the slight noise.
Can't tell what the supersonic motor is but it appears to not be on the level of the STM or Nano-USM.

tinplater Loc: Scottsdale, AZ

Architect1776 wrote:

Most lenses without the Nano-USM or the STM will have noise when focusing. USM is very quiet and is good except for in camera video sound recording as the camera mike can pick up the slight noise.
Can't tell what the supersonic motor is but it appears to not be on the level of the STM or Nano-USM.

Thanks...my other GM lens, 100-400 is totally silent and I can't "feel" the focus changing as I can with the 24mm.

Architect1776 Loc: In my mind

tinplater wrote:

Thanks...my other GM lens, 100-400 is totally silent and I can't "feel" the focus changing as I can with the 24mm.

Then that appears to be something wrong.
I would send it back.

tinplater Loc: Scottsdale, AZ

Architect1776 wrote:

Then that appears to be something wrong.
I would send it back.

Thanks again...Sony Customer Support advised (after a long hold while they tried to find an answer) that it was not normal to hear or feel the focus change. However on DPreview an owner of the lens says his functions in the same way! B&H Photo promptly authorized free shipping return and replacement so I will go ahead and try a second lens unless I hear from some other owners that this is normal function. It is barely noticeable, but there.

Architect1776 Loc: In my mind

tinplater wrote:

Thanks again...Sony Customer Support advised (after a long hold while they tried to find an answer) that it was not normal to hear or feel the focus change. However on DPreview an owner of the lens says his functions in the same way! B&H Photo promptly authorized free shipping return and replacement so I will go ahead and try a second lens unless I hear from some other owners that this is normal function. It is barely noticeable, but there.

Again most USM type lenses do have barely audible noise when operating.
You need to go to Nano-USM or STM to get absolute video quality quiet in a lens.
But yours sounds like it is quite audible and that is not good for that lens as it is a premium top level pro lens.
Likely something is wrong.

tinplater Loc: Scottsdale, AZ

Architect1776 wrote:

Again most USM type lenses do have barely audible noise when operating.
You need to go to Nano-USM or STM to get absolute video quality quiet in a lens.
But yours sounds like it is quite audible and that is not good for that lens as it is a premium top level pro lens.
Likely something is wrong.

Thanks...it is not so much hearing the focus (I believe below threshold for interfering with video) but the fact that I can FEEL it change focus that catches my attention.

Architect1776 Loc: In my mind

tinplater wrote:

Thanks...it is not so much hearing the focus (I believe below threshold for interfering with video) but the fact that I can FEEL it change focus that catches my attention.

Remember it is moving a lot of glass and doing it quickly, called inertia. Hard to change physics.

tinplater Loc: Scottsdale, AZ

Architect1776 wrote:

Remember it is moving a lot of glass and doing it quickly, called inertia. Hard to change physics.

except my 100-400 (which seems about three times the size and weight) focuses in total silence without any discernible click or sense of something moving and coming to a halt. My 70-200, on the other hand, is a real "clunker" it actually rattles when shaken.

Architect1776 Loc: In my mind

tinplater wrote:

except my 100-400 (which seems about three times the size and weight) focuses in total silence without any discernible click or sense of something moving and coming to a halt. My 70-200, on the other hand, is a real "clunker" it actually rattles when shaken.

I really can only conjecture at this point. But it does seem like you have a very valid concern that should be addressed as normal or there is something wrong.
I wish you luck and would love to hear the results so as to increase my knowledge base on such things.
I am just an Architect and not a lens technician but just trying to throw out ideas but I believe your instinct is right and it needs to be checked out or returned for another sample. There are times something with a defect slips through. I had this happen on a very expensive camera. The manufacturer fixed and calibrated it and it worked for years just fine until I traded it for a different camera.

tinplater Loc: Scottsdale, AZ

And thanks for your input and help. Again I hope to hear from others who actually have the lens...right now it is one with the same noise, one without noise!

Architect1776 Loc: In my mind

tinplater wrote:

And thanks for your input and help. Again I hope to hear from others who actually have the lens...right now it is one with the same noise, one without noise!

I hope you hear too, interesting none yet have chimed in.

chapjohn Loc: Tigard, Oregon

When it first came out I got the Sony FE 50 f1.8. It was loud and slow to focus. Sony issued a firmware update for that lens and now it is quiet and faster to focus. My thought is Sony should correct your issue with the 24mm GM by a firmware update.