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-   -   so close... have a strange image question (https://www.dvinfo.net/forum/panasonic-dvx-dvc-assistant/39398-so-close-have-strange-image-question.html)

Wing Gee February 13th, 2005 05:37 PM

so close... have a strange image question
So me and a friend got busy the past few days...
this has also been posted on dvx user


hey guys - well over the last three days I decided it was time to make some changes to my panny. Started with taking the thing apart and ended with a little hack-saw action.

I will post more info on my manual conversion, but I ran into a strange problem that I am hoping you all might be able to help me solve so i can start doing some benchmark/comparision tests.

As the pictures make fairly evident, the camera has been pretty re-worked. All circuits are connected besides lens control and feedback.

Basically the camera works completely fine in 30i and 30p mode.. however when I switch it over to 24p or 24pa suddenly the image becomes dark, and the blacks just completely take over. Almost reminded me of an exaggerated black-level raise as seen in LP mode compression. Why the image is fine in 30p and crappy in 24p is beyond me. It doesnt seem to be a hardware issue, because during the processing "flicker" I can see the camera operating in 24p with normal levels for a split second, and then the camera kicks in this funky effect.

Is there some sort of master reset I should try? I see what looks like a diagnostics port on the back of the camera, maybe a panasonic tech can help me out. Other than that all settings are at 0, with cine gamma and cine-like matrix, step-up is 0%

here is a link to a test video I quickly shot this morning showing the effect. No camera settings were changed, aperture was riding a f16. It is really drastic, all shadow detail is completely lost. Sorry for the fuzzy image - so rushed I havent even cleaned the lens yet!





John Hudson February 13th, 2005 06:26 PM

That is wild; what in gods name have you done?

I have no clue what is causing this; but I dropped into my NLE (Vegas) and attempting to adjust the 'dark' frames and the levels are jumping from 40 IRE to 0 IRE with ZERO control between them.

It appears the blacks are down at 7.5 IRE and can't be brought up. When I tried it gave me some weird imagery. I also tried simply boosting the gamma up and instead of normal 'feedback' I was given:


This even before it peaked at 100 IRE. Maybe check your IRE Setup?

Also lots of Interlacing in the footage of 24p.

Sean Porter February 13th, 2005 07:31 PM

more info
hey this is sean, the crazy responsible for the idea... anyways all camera settings are at factory reset value, 0, with 0% setup. It may be tied to the white balance mechanism since 30p worked fine until I attempted to white balance and then it took on the dark image effect as well. In addition the progressive modes will not white balance correctly. 30i can be whitebalanced and looks totally fine.

the 24p stuff might be converted to interlaced - since I imported to avid in 30i - its probably not true pro-scan, but it should have both fields in the stills..

thanks for the suggestions


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