A1 having Gain/WB Problem ( Not AGC) Under Multiple Lights
 

Hi All,

I'm currently in the process of filming a training video for a hair salon. I'm using two A1s. Both have gain L set to -3db. When I went to review the first days footage there seems to be a large amount of "fluxing" gain or grain in the image. The salon we're filming in has lots of lights, some flouresent, some halogen spots and some normal Tungsten incandencents so I did try to manually set the WB with a 100 IRE card. The image I'm getting is washed out, the blacks look gray and everything is grainy. Does anybody have any ideas of CPs to try and combat this?
I've uploaded a 4 second clip ( shot at 25F and imported to FCP at 1080p25, exported to 720p H264). If you look at the black in it you should see what Im talking about.

http://fyp.ie/declan/XH-A1%20Grain%2...20p%20H264.mov

Any help would be greatly appreciated

Declan

Clip doesn't work; I go this:

The requested URL /declan/XH-A1 Grain%2...20p H264.mov was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache/1.3.37 Server at fyp.ie Port 80


If things look grainy that's usually an indication of shooting on a higher gain. Are you sure all the auto stuff is off and you're in the manual mode, not one of the auto ones?

Hi Declan..............
 

That link won't even persuade Explorer to get out of bed.


CS

try this link:

http://fyp.ie/declan/XH-A1%20Grain%2...20p%20H264.mov

Link Fixed
 

Links is fixed now, sorry about that

Declan

yeah, i see it in the dark areas. that's actually pretty typical for HD.
turn on any hdtv channel and you will see it. reds and dark browns will do it.

you will need to magnify and check those types of colors for noise before you shoot. sometimes you can correct the exposure and tone it down.

the shot is a little underexposed on the subjects and you have that light in the back shining right through them. i think that might be the reason too.

if you are using auto exposure, it's going to underexpose the subjects and properly expose the light.

regardless, i find it acceptable. with those two girls in the front, nobody is looking at the wall.

i'd set the gain to 0 for indoor shooting, -3 is really for outdoor shooting with the HMI in the sky. adding gain seems counter-intuitive to solving a noise issue, but it might help smooth things out a bit...

Well, at least no red-blooded guy will look at the wall.

I would suggest that you address the bright back light from the window(?) and the overhead lights, unless you are trying to obtain that effect.