PMW F3 sensor cleaning

Brian Drysdale · December 28th, 2010, 03:19 AM

Quote:

Originally Posted by Thierry Humeau

The thing to keep in mind when using ND is to always use enough ND filtering so you are a stop or two away from your lens's smalest aperture setting.

I'd assume that there will always be some optical glass in this position (regardless of using ND), otherwise you could run into back focus problems.

Jim Tittle · December 28th, 2010, 07:18 AM

Old photographer's rule of thumb--most lenses look best 2 stops down from wide open. I break that rule sometimes, for various reasons, but I understand what you're saying, Thierry.

When I made that comment about an "actual ND filter" causing "trouble", I was overstating things. Sitting here at the keyboard, I tend to get a little to get hypothetical. The ND filter on my 2/3" camera does visibly degrade the image when the lens is at 1.8. Now, I know I shouldn't be using that lens wide open, but sometimes I'll do it to get the limited DOF. I can't get away with that if I use ND.

Andy Shipsides · January 1st, 2011, 09:54 PM

When we had the cameras in last month we cleaned the sensor easily. Not the actual sensor of course, but the glass protecting it. Once the PL adapter is off, it is easy to get to.

The way the ND filters role in is pretty impressive. We also liked the manual flange adjustment option, which we will learn more about in the future. It should be a very handy feature though.

Jim Tittle · January 2nd, 2011, 10:09 PM

"Manual flange adjustment"? I'm curious about that. Can anyone give a few more details?

Dave Sperling · January 3rd, 2011, 12:29 AM

As I understand it, since Cine lenses typically do not feature back focus adjustment other than removing their mount and re-shimming the lens (something that I always sent my film lenses in to the shop to have done when required), this provides a way of fine tuning the flange distance of the mount. Obviously this is not something to be done casually in the field, but it does add a potentially needed capability to the camera (especially when using rental PL lenses or sharing a lens set between more than one camera.

Brian Drysdale · January 3rd, 2011, 03:05 AM

Hopefully the manual adjustment will be a more a check before a shoot begins operation, rather than a between lens changes. The lenses should (in theory) be set up to a standard, rather than each camera.

Of course, if the mount is prone to thermal expansion, you may need the manual adjustment.

Jim Tittle · January 3rd, 2011, 07:15 AM

Thanks, but I was just wondering about the particulars. Guess I'll have to wait for that.

January 1st, 2011, 09:54 PM	#18
Andy Shipsides Sponsor: Abel CineTech Join Date: Feb 2009 Location: New York, NY Posts: 361	When we had the cameras in last month we cleaned the sensor easily. Not the actual sensor of course, but the glass protecting it. Once the PL adapter is off, it is easy to get to. The way the ND filters role in is pretty impressive. We also liked the manual flange adjustment option, which we will learn more about in the future. It should be a very handy feature though. __________________ Andy Shipsides -Camera Technology Specialist AbelCineTech, New York - Visit our Blog - http://blog.abelcine.com

December 28th, 2010, 07:18 AM	#17
Jim Tittle Regular Crew Join Date: Dec 2010 Location: Saint Paul, MN Posts: 114	Old photographer's rule of thumb--most lenses look best 2 stops down from wide open. I break that rule sometimes, for various reasons, but I understand what you're saying, Thierry. When I made that comment about an "actual ND filter" causing "trouble", I was overstating things. Sitting here at the keyboard, I tend to get a little to get hypothetical. The ND filter on my 2/3" camera does visibly degrade the image when the lens is at 1.8. Now, I know I shouldn't be using that lens wide open, but sometimes I'll do it to get the limited DOF. I can't get away with that if I use ND.

January 2nd, 2011, 10:09 PM	#19
Jim Tittle Regular Crew Join Date: Dec 2010 Location: Saint Paul, MN Posts: 114	"Manual flange adjustment"? I'm curious about that. Can anyone give a few more details?

January 3rd, 2011, 12:29 AM	#20
Dave Sperling Major Player Join Date: Jan 2010 Location: Tinton Falls, NJ Posts: 780	As I understand it, since Cine lenses typically do not feature back focus adjustment other than removing their mount and re-shimming the lens (something that I always sent my film lenses in to the shop to have done when required), this provides a way of fine tuning the flange distance of the mount. Obviously this is not something to be done casually in the field, but it does add a potentially needed capability to the camera (especially when using rental PL lenses or sharing a lens set between more than one camera.

January 3rd, 2011, 03:05 AM	#21
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Hopefully the manual adjustment will be a more a check before a shoot begins operation, rather than a between lens changes. The lenses should (in theory) be set up to a standard, rather than each camera. Of course, if the mount is prone to thermal expansion, you may need the manual adjustment.

January 3rd, 2011, 07:15 AM	#22
Jim Tittle Regular Crew Join Date: Dec 2010 Location: Saint Paul, MN Posts: 114	Thanks, but I was just wondering about the particulars. Guess I'll have to wait for that.