DOF adapter / HVX200 problems at DVinfo.net

Tony Relph · November 2nd, 2006, 09:03 PM

Whilst using my new HVX200 with the P2 cards I have noticed digital artifacts appearing on the footage. I would consider this a serious problem for independent film makers who use it with DOF adapters. Anyone else had the same problems?

I transfer the files via the P2 slot drive. Is it the transfer that causes this or is it the recording? I will contact Panasonic about this as I spent £4k on the camera and if its going to do this then it might as well become a very expensive paperweight as there is no way I can film with this appearing on screen.

Thanks,

Bob Hart · November 2nd, 2006, 11:52 PM

Tony.

You might like to try shooting a rather savage test on the camera / P2 combination without the adaptor, by shooting in low light conditions, maximum video gain to hopefully provoke video gain noise.

The subject should be something finer textured like twilight moving leaves backlit or you could shake a fine high contrast pattern tablecloth on a clothes line in the same conditions, anything to stress the ability of the system to process detail.

There is an unholy combination in some groundglass based imaging systems, of some light loss, high moving detail load in the image from the groundglass texture and sometimes a very slight movement of the entire image due to vibrations or run-out of disks on some home grown versions.

With an adaptor in the chain, these all conspire to add a baseline processing load on the system. If you then add (due to low light) some gain noise and/or a lot of finer detail and motion, there is less - I think the term used is "headroom" - for the image to be processed within, than if the camera is aquiring the image directly.

With the FX!, I have found the sharpness goes off in low light. The lenses of course go off at their widest apertures also. It is hard to distinguish between optical softness and softness from the in-camera processing and it would be unfair to ascribe blame to the camera which was never intended to be abused in this fashion.

The "gain noise" test may give you a indication of the means within which you have to live and the likely limitation of the camera / adaptor combination.

The FX1 HDV codec seems to sacrifice image sharpness when challenged with lots of gain noise and GG artifacts. The MiniDV codec in the Sony PD150 flavour seems to simply pass the gain noise on as a grain effect.

What the Panasonic does with its higher data rate and I assume more tolerant compression system, I can't even guess. I would expect it should do better, but there may be a wall there that even it cannot overcome.

I'm really only guessing here so don't pay too much heed to my comments. If you can take video directly to a HD monitor via the highest quality conection and do an identical test it would be interesting to see if the artifacts turn up.

November 2nd, 2006, 09:03 PM	#1
Tony Relph Regular Crew Join Date: Jun 2006 Location: Canary Wharf, London E14 Posts: 166	DOF adapter / HVX200 problems Whilst using my new HVX200 with the P2 cards I have noticed digital artifacts appearing on the footage. I would consider this a serious problem for independent film makers who use it with DOF adapters. Anyone else had the same problems? I transfer the files via the P2 slot drive. Is it the transfer that causes this or is it the recording? I will contact Panasonic about this as I spent £4k on the camera and if its going to do this then it might as well become a very expensive paperweight as there is no way I can film with this appearing on screen. Thanks, __________________ Tony Relph. anthonyjohnrelph@hotmail.com

November 2nd, 2006, 11:52 PM	#2
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Tony. You might like to try shooting a rather savage test on the camera / P2 combination without the adaptor, by shooting in low light conditions, maximum video gain to hopefully provoke video gain noise. The subject should be something finer textured like twilight moving leaves backlit or you could shake a fine high contrast pattern tablecloth on a clothes line in the same conditions, anything to stress the ability of the system to process detail. There is an unholy combination in some groundglass based imaging systems, of some light loss, high moving detail load in the image from the groundglass texture and sometimes a very slight movement of the entire image due to vibrations or run-out of disks on some home grown versions. With an adaptor in the chain, these all conspire to add a baseline processing load on the system. If you then add (due to low light) some gain noise and/or a lot of finer detail and motion, there is less - I think the term used is "headroom" - for the image to be processed within, than if the camera is aquiring the image directly. With the FX!, I have found the sharpness goes off in low light. The lenses of course go off at their widest apertures also. It is hard to distinguish between optical softness and softness from the in-camera processing and it would be unfair to ascribe blame to the camera which was never intended to be abused in this fashion. The "gain noise" test may give you a indication of the means within which you have to live and the likely limitation of the camera / adaptor combination. The FX1 HDV codec seems to sacrifice image sharpness when challenged with lots of gain noise and GG artifacts. The MiniDV codec in the Sony PD150 flavour seems to simply pass the gain noise on as a grain effect. What the Panasonic does with its higher data rate and I assume more tolerant compression system, I can't even guess. I would expect it should do better, but there may be a wall there that even it cannot overcome. I'm really only guessing here so don't pay too much heed to my comments. If you can take video directly to a HD monitor via the highest quality conection and do an identical test it would be interesting to see if the artifacts turn up.