PMW-350 kit lens iris noisy at DVinfo.net

Paul Gale · January 30th, 2010, 03:58 AM

Anyone else have a noisy iris ring?

Mine makes a kind of rattling noise when under auto control - not sure if it's a physical rattling or the motor or gearing.

I'm pretty sure it's duff but wanted to check it's not an inherent fault.

Paul Gale · January 30th, 2010, 04:13 AM

the other thing i've noticed is that the iris doesn't close down when the camera powers off - IIRC all my other cameras and lenses do this. By design???

Paul Cronin · January 30th, 2010, 12:23 PM

Paul I will have to look at that since I have only used manual iris.

Paul Gale · January 30th, 2010, 12:30 PM

thanks.

I know at least one other user doesn't have this issue.

Paul Cronin · January 30th, 2010, 01:30 PM

Mine seems fine Paul. How loud is it? Do you hear it when recording in a quiet room?

Thierry Humeau · February 1st, 2010, 05:37 AM

Yep, I noticed this on my camera too. It would definetely be picked up by the camera mic in a silent room and the faint grinding noise seems to be a bit more pronounced when the lens is on its longest focal length. That said, I very rarely use auto iris and if I did, it would most likely be in an uncontrolled and noisy environment so I don't think it would be an issue but it is a bit puzzling indeed.

T.

Paul Gale · February 1st, 2010, 05:54 AM

Hmmm, odd then.

I've got a replacement coming - so will see if it's any different or whether it's a 'feature' across all of them.

Paul Cronin · February 1st, 2010, 07:00 AM

Paul I agree with Teierry,

I noticed noise yesterday in a quite studio but agree I would never use auto iris in such a controlled environment. So I don't see it as a problem at all.

Paul Gale · February 1st, 2010, 07:06 AM

Thanks Paul.

Sure - I wouldn't use auto iris either in that environment.

BUT, my concern is whether there's actually anything wrong with the lens or if this is the same on all of them. If it is faultly, why put up with it, whether or not it's going to make a difference shooting.

Cheers,

Paul.

Paul Cronin · February 1st, 2010, 07:16 AM

My thought is it is a cheap lens and I expect this type of problem. It seems to have very nice optics but servo motors could be lower grade and this could cause the problem. Either way for me I am just going to move forward and not worry since other lens I have looked at don't have the problem., and they will be the main lens I use on the camera.

Alister Chapman · February 1st, 2010, 11:24 AM

The one I have is noisy too. I would not call it loud, but there is more noise than I would like. It's most noticeable when the Iris is making big changes across several f stops, smaller adjustments are much less noticeable. I hadn't picked up on it before as for most shots I don't use auto iris. The only time I do use it is following aircraft across cloudy skies at airshows and then any noise is drowned out by the aircraft.

It's there, I don't like it, but at the same time for me it's not an issue. If I had spent $10k on the lens... then that would be a different story.

Tom Roper · February 1st, 2010, 12:38 PM

Sure it isn't the auto focus? Mines dead silent spinning the iris ring, but I can hear the servo motor when auto-focus is switched on.

Alister Chapman · February 1st, 2010, 12:45 PM

No, it's the iris ring, no doubt. It makes a kind of mechanical noise like gears meshing as you do big auto iris swings.

Alister Chapman · February 1st, 2010, 04:13 PM

OK I spent some time looking at this and I think what is happening is that the drive servo is either a stepper motor or driven using PWM which makes the motor "step", stopping and starting very quickly and this is creating the rattle during fast iris changes. During normal everyday iris adjustments mine makes no noise, it's only really when the iris is going from fully open to fully closed etc. Turning the Iris speed down in the Iris 2 menu also makes the noise go away.

David Hart · February 2nd, 2010, 03:41 AM

I'm also finding the noise that you are hearing is down to the motor vibrating on the gears and maybe lack of noise damping maybe due to cheaper parts? if you touch the ring lightly with you finger the noise is greatly reduced, at the end of the day its a good cheap lens. if this became a problem for me I would have an external mic plugged in.
I'm using A13x4.5 and A22x7.8 lenes from my SD cameras that i'm testing on the 350 to see if I need to upgrade to HD glass, this obviously is a costly move.

On a different subject, does anyone find the camera LCD display a little too bright? Maybe it could do with a lower setting?

January 30th, 2010, 03:58 AM	#1
Paul Gale Major Player Join Date: Feb 2004 Location: Oxfordshire, UK Posts: 425	PMW-350 kit lens iris noisy Anyone else have a noisy iris ring? Mine makes a kind of rattling noise when under auto control - not sure if it's a physical rattling or the motor or gearing. I'm pretty sure it's duff but wanted to check it's not an inherent fault.

January 30th, 2010, 12:23 PM	#3
Paul Cronin Inner Circle Join Date: Dec 2005 Location: Rhode Island Posts: 4,048	Paul I will have to look at that since I have only used manual iris. __________________ Paul Cronin www.paulcroninstudios.com

January 30th, 2010, 01:30 PM	#5
Paul Cronin Inner Circle Join Date: Dec 2005 Location: Rhode Island Posts: 4,048	Mine seems fine Paul. How loud is it? Do you hear it when recording in a quiet room? __________________ Paul Cronin www.paulcroninstudios.com

February 1st, 2010, 05:37 AM	#6
Thierry Humeau Telecam Films Join Date: Apr 2006 Location: Washington DC Posts: 723	Yep, I noticed this on my camera too. It would definetely be picked up by the camera mic in a silent room and the faint grinding noise seems to be a bit more pronounced when the lens is on its longest focal length. That said, I very rarely use auto iris and if I did, it would most likely be in an uncontrolled and noisy environment so I don't think it would be an issue but it is a bit puzzling indeed. T. __________________ Thierry Humeau, DoP Télécam Films www.telecamfilms.com

February 1st, 2010, 07:00 AM	#8
Paul Cronin Inner Circle Join Date: Dec 2005 Location: Rhode Island Posts: 4,048	Paul I agree with Teierry, I noticed noise yesterday in a quite studio but agree I would never use auto iris in such a controlled environment. So I don't see it as a problem at all. __________________ Paul Cronin www.paulcroninstudios.com

January 30th, 2010, 04:13 AM	#2
Paul Gale Major Player Join Date: Feb 2004 Location: Oxfordshire, UK Posts: 425	the other thing i've noticed is that the iris doesn't close down when the camera powers off - IIRC all my other cameras and lenses do this. By design???

January 30th, 2010, 12:30 PM	#4
Paul Gale Major Player Join Date: Feb 2004 Location: Oxfordshire, UK Posts: 425	thanks. I know at least one other user doesn't have this issue.

February 1st, 2010, 05:54 AM	#7
Paul Gale Major Player Join Date: Feb 2004 Location: Oxfordshire, UK Posts: 425	Hmmm, odd then. I've got a replacement coming - so will see if it's any different or whether it's a 'feature' across all of them.

February 1st, 2010, 07:06 AM	#9
Paul Gale Major Player Join Date: Feb 2004 Location: Oxfordshire, UK Posts: 425	Thanks Paul. Sure - I wouldn't use auto iris either in that environment. BUT, my concern is whether there's actually anything wrong with the lens or if this is the same on all of them. If it is faultly, why put up with it, whether or not it's going to make a difference shooting. Cheers, Paul.

February 1st, 2010, 07:16 AM	#10
Paul Cronin Inner Circle Join Date: Dec 2005 Location: Rhode Island Posts: 4,048	My thought is it is a cheap lens and I expect this type of problem. It seems to have very nice optics but servo motors could be lower grade and this could cause the problem. Either way for me I am just going to move forward and not worry since other lens I have looked at don't have the problem., and they will be the main lens I use on the camera. __________________ Paul Cronin www.paulcroninstudios.com

February 1st, 2010, 11:24 AM	#11
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	The one I have is noisy too. I would not call it loud, but there is more noise than I would like. It's most noticeable when the Iris is making big changes across several f stops, smaller adjustments are much less noticeable. I hadn't picked up on it before as for most shots I don't use auto iris. The only time I do use it is following aircraft across cloudy skies at airshows and then any noise is drowned out by the aircraft. It's there, I don't like it, but at the same time for me it's not an issue. If I had spent $10k on the lens... then that would be a different story. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

February 1st, 2010, 12:38 PM	#12
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	Sure it isn't the auto focus? Mines dead silent spinning the iris ring, but I can hear the servo motor when auto-focus is switched on.

February 1st, 2010, 12:45 PM	#13
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	No, it's the iris ring, no doubt. It makes a kind of mechanical noise like gears meshing as you do big auto iris swings. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

February 1st, 2010, 04:13 PM	#14
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	OK I spent some time looking at this and I think what is happening is that the drive servo is either a stepper motor or driven using PWM which makes the motor "step", stopping and starting very quickly and this is creating the rattle during fast iris changes. During normal everyday iris adjustments mine makes no noise, it's only really when the iris is going from fully open to fully closed etc. Turning the Iris speed down in the Iris 2 menu also makes the noise go away. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

February 2nd, 2010, 03:41 AM	#15
David Hart Regular Crew Join Date: Jan 2010 Location: Bristol UK Posts: 29	I'm also finding the noise that you are hearing is down to the motor vibrating on the gears and maybe lack of noise damping maybe due to cheaper parts? if you touch the ring lightly with you finger the noise is greatly reduced, at the end of the day its a good cheap lens. if this became a problem for me I would have an external mic plugged in. I'm using A13x4.5 and A22x7.8 lenes from my SD cameras that i'm testing on the 350 to see if I need to upgrade to HD glass, this obviously is a costly move. On a different subject, does anyone find the camera LCD display a little too bright? Maybe it could do with a lower setting? __________________ www.iceboxvideo.co.uk