Film-Tech Forum ARCHIVE: White Balance video projector help

This is topic White Balance video projector help in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Martin McCaffery (Member # 37) on 10-13-2008, 10:44 PM:

Any tips on adjusting the white balance of a non-DLP video projector (Sanyo plc-xf40)? Is it even possible without spending a few grand on a proper meter?

Posted by Steve Guttag (Member # 268) on 10-13-2008, 11:41 PM:

Martin....it is virtually impossible for most anyone to get white balance correct (or much of anything else) without a proper meter and test images. When using one's eyes it becomes too subjective and everyone's eyes are different with differing degrees of color sensitivity (and I'm sure luminance too). At an Extron class...the let some experts tune just gain and peaking by eye and the results always favored setting the gain too high (too bright) and peaking was never right either. Do it with an O'Scope or waveform monitor and you'll get it consistantly right every time.

With color, you have to make sure you adjust it properly over the luminance range too. I cant tell you how many times I've seen redish tinged brighter images with something like blueish tinged darker images. Those of the CRT era will know of this as setting "screen" and "drive" controls...similar controls exist in the digital world too.

If you obtain the Sanyo service manual, that will let you know the Service menu to set the levels...note...it often will vary based on input (or input type) as well.

Steve

Posted by Martin McCaffery (Member # 37) on 10-14-2008, 09:13 AM:

Thanks Steve, it was pretty much what I was afraid of. Our picture has taken a decidedly blue shift in the last few months. Not sure if it corresponded with changing the lamps or not.

I'll see what I can get from Sanyo