Aerial image telecine techniques at DVinfo.net

Bob Hart · July 18th, 2011, 06:25 AM

Has anyone done this with a HD camera and a sync film camera used as a projector and can pass on any hints?

I have done a still-frame optical test with a piece of 16mm workprint with a CP16R, SI2K, each with an 85mm Nikon lens and it looks sharp enough. The Nikons yield about 70 or so sharpness points on the SI2K. The CP Ultras were sharper at about 120. Inverting a low contrast negative is another matter.

My imagining is that a very slow slip of sync may occur. The CP16R is the last model with the 1500rpm mirror shutter at 25fps ( originally a PAL TV news film camera ). The CP16R and a Nagra IV were good for slip of one frame or less in 400 ft of film.

I have a fair chunk of archived 16mm neg film to transfer. I don't have the budget for HD telecine and definitely not for scanning. The film would have to be shipped across the country to Melbourne or Sydney for telecine and shipped back.

If anyone has any clues, advice would be appreciated.

Brian Drysdale · July 18th, 2011, 09:25 AM

Never done it that way around, but when shooting a CRT with a CP16R the TV sync bar looked pretty solid, although that's not to say it wouldn't do a slow drift over a sustained length of time. However I'm not sure how the phasing would work iif you got an overlap between the CP16R shutter and the video camera exposure. Usually it's a matter of WYSIWYG, but you may have to do a phasing exercise between the two cameras.

How are you illuminating the film in the CP16R gate? The pressure plate is thick and held down from behind by a sprung metal arm.

Bob Hart · July 18th, 2011, 06:10 PM

Thanks for your reply.

I am hoping that there may be a shutter setting in the SI2K which will expose for the whole CP16R shutter cycle which will mean maybe some weird motion artifacts as the SI2K is a CMOS sensor.

I have previosuly remade a CP16R pressure plate so will make another one with a larger frame aperture in it and remake the spring retainer flap wide to do the same thing. To collimate the lens and harmonise the viewfinder, I made up a small groundglass pressure plate replacement with marks to rest in the gate and used a small prism to view from the side and later to direct light through the small hole in the spring flap.

Brian Drysdale · July 19th, 2011, 08:10 AM

I suppose it should be OK if the SI 2K exposure is complete between the CP16R shutter opening and closing, so you lose the wiping effect of the shutter across the frame.

One area of concern could be having even illumination across the 16 mm frame

Bob Hart · July 19th, 2011, 10:32 AM

I have tried the shutter running with back illumination. A few starts of the CP16R are required before a full frame is imaged by the SI2K. Once it is established, it holds for at least 4 minutes, which is as long as I left the film camera running without pulling film.

My initial enthusiasm has waned somewhat. The two Nikon lenses I have used seem to be a stumbling block. Obviously, any softness introduced by the lenses is additive. A two lenses together seem to yield a sharpness reading of only 34 at best of either the film plane or the viewfinder screen. Two good 16mm prime lenses would likely work better.

Any furthur suggestions will be much appreciated, especially when it comes to inverting neg film mage.

Brian Drysdale · July 19th, 2011, 04:59 PM

I think you can get away with only one lens, since you've basically got an optical printer with the CP16R as the projector. You may need to use bellows or extension tubes on the camera lens.

Bob Hart · July 21st, 2011, 07:57 AM

Brian.

Yes. That's the next trick to try. I have a fair few bits and pieces left over from building Agus35s to try something out. The lens-to-lens solutiopn was attracting since two zooms if used might allow for easier optical reframing for standard and Super16 which the CP16R is gated for. I might just give the Angenieux zoom pair a try anyway. - The advantages of doing 3D.

Brian Drysdale · July 22nd, 2011, 12:52 AM

Could be a case of running some tests, although using zooms wouldn't be the optimum for image quality.

July 18th, 2011, 06:25 AM	#1
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Aerial image telecine techniques Has anyone done this with a HD camera and a sync film camera used as a projector and can pass on any hints? I have done a still-frame optical test with a piece of 16mm workprint with a CP16R, SI2K, each with an 85mm Nikon lens and it looks sharp enough. The Nikons yield about 70 or so sharpness points on the SI2K. The CP Ultras were sharper at about 120. Inverting a low contrast negative is another matter. My imagining is that a very slow slip of sync may occur. The CP16R is the last model with the 1500rpm mirror shutter at 25fps ( originally a PAL TV news film camera ). The CP16R and a Nagra IV were good for slip of one frame or less in 400 ft of film. I have a fair chunk of archived 16mm neg film to transfer. I don't have the budget for HD telecine and definitely not for scanning. The film would have to be shipped across the country to Melbourne or Sydney for telecine and shipped back. If anyone has any clues, advice would be appreciated.

July 18th, 2011, 09:25 AM	#2
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Aerial image telecine techniques Never done it that way around, but when shooting a CRT with a CP16R the TV sync bar looked pretty solid, although that's not to say it wouldn't do a slow drift over a sustained length of time. However I'm not sure how the phasing would work iif you got an overlap between the CP16R shutter and the video camera exposure. Usually it's a matter of WYSIWYG, but you may have to do a phasing exercise between the two cameras. How are you illuminating the film in the CP16R gate? The pressure plate is thick and held down from behind by a sprung metal arm.

July 18th, 2011, 06:10 PM	#3
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Re: Aerial image telecine techniques Thanks for your reply. I am hoping that there may be a shutter setting in the SI2K which will expose for the whole CP16R shutter cycle which will mean maybe some weird motion artifacts as the SI2K is a CMOS sensor. I have previosuly remade a CP16R pressure plate so will make another one with a larger frame aperture in it and remake the spring retainer flap wide to do the same thing. To collimate the lens and harmonise the viewfinder, I made up a small groundglass pressure plate replacement with marks to rest in the gate and used a small prism to view from the side and later to direct light through the small hole in the spring flap. Last edited by Bob Hart; July 18th, 2011 at 06:11 PM. Reason: error

July 19th, 2011, 08:10 AM	#4
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Aerial image telecine techniques I suppose it should be OK if the SI 2K exposure is complete between the CP16R shutter opening and closing, so you lose the wiping effect of the shutter across the frame. One area of concern could be having even illumination across the 16 mm frame

July 19th, 2011, 10:32 AM	#5
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Re: Aerial image telecine techniques I have tried the shutter running with back illumination. A few starts of the CP16R are required before a full frame is imaged by the SI2K. Once it is established, it holds for at least 4 minutes, which is as long as I left the film camera running without pulling film. My initial enthusiasm has waned somewhat. The two Nikon lenses I have used seem to be a stumbling block. Obviously, any softness introduced by the lenses is additive. A two lenses together seem to yield a sharpness reading of only 34 at best of either the film plane or the viewfinder screen. Two good 16mm prime lenses would likely work better. Any furthur suggestions will be much appreciated, especially when it comes to inverting neg film mage.

July 19th, 2011, 04:59 PM	#6
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Aerial image telecine techniques I think you can get away with only one lens, since you've basically got an optical printer with the CP16R as the projector. You may need to use bellows or extension tubes on the camera lens.

July 21st, 2011, 07:57 AM	#7
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Re: Aerial image telecine techniques Brian. Yes. That's the next trick to try. I have a fair few bits and pieces left over from building Agus35s to try something out. The lens-to-lens solutiopn was attracting since two zooms if used might allow for easier optical reframing for standard and Super16 which the CP16R is gated for. I might just give the Angenieux zoom pair a try anyway. - The advantages of doing 3D.

July 22nd, 2011, 12:52 AM	#8
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	Re: Aerial image telecine techniques Could be a case of running some tests, although using zooms wouldn't be the optimum for image quality.