IMAG is blown out

[alleyman]

Howdy,
Our IMAG camera look "blown out" when ran through our scaler/switcher to our projector. The camera is also ran to tvs throughout the building. The signal on the tvs looks great. I'm usings s-video from the camera to a kramer distubution amplifier - to tvs and scaler/switcher. The scaler/switcher is a kramer vp-725ds. The s-video is scaled to dvi, for projector, and vga for control monitor. The projector is a panasonic pt-d5500u. I sent my kramer scaler to kramer to have it tested. They found no problems. BTW. Other data sent to through the kramer looks good, computer, dvd. Camera is a sony vx-2100. The bright spots, pastor's head, look washed out or compressed. His flesh tones get to a certain brightness and looses all gradience. It becomes one flat color. It's like a photo being overexposed but instead of all white it maintains a color. It's like when audio hits a limiter. I turn the brightness down on the projector and/or the kramer. It looks the same but darker. Any ideas would be greatly appreciated.

Chris Alley
Minister of Music & Media
FBC Marshalltown

[Paris MkVI]

Hi Chris, and welcome to CMN!

Front or rear projection?

You say other sources like good, correct?

How many hours on projector lamp(s)?

Distance to screens?

Size/type of screens?

[petereit]

Let's eliminate everything else and focus on the projector. Press the TEST PATTERN button on the remote control, or select “TEST PATTERN” in the MAIN MENU and search through the various types of test patterns by using the < and > buttons.

Every test screen should look perfect. If anything's amiss there, then you'll know your projector is at fault.

If everything looks fine in the test screens, then I would try connecting a video source directly to the projector.

[six5tring]

What your describing almost sounds like a termination issue to me. Often common on composite sources.. although never come across s-video termination issues. Do you have a loop through cable attached but not connected?

six

[alleyman]

It's a front projection system. We shoot it 70' to 12' screen. I thought about the termination thingy. I still does it when I plug it directly into the scaler. I'll try the test patterns and direct connection to projector. The projector's contrast ratio isn't the best. If I remember right, it's 1600:1. However, the video playback is good.

[petereit]

Do you have a way to measure the ambient light at the screen under normal conditions without the projector on?

[waynehoskins]

Maybe you're running your iris too wide?

Have you put a waveform monitor on the camera's output?

[alleyman]

Help me understand. If it is a iris problem or ambient noise problem, why does the picture look good on tvs and other videos, computer/dvd, look good on the projection system?

[jcwu]

Originally Posted by alleyman

BTW. Other data sent to through the kramer looks good, computer, dvd.

This is what's throwing me off.

We also have projectors that are blown out - turns out it was the VGA over CAT5 baluns. We were using IOGear units, and had assumed that things looked that way just because the projectors couldn't handle the range of colors. Then in our new sanctuary we had two screens set up, and for whatever reason, one was run with a Gefen balun and another was with an IOGear balun. The projector that used the IOGear balun had blow out and a lot of brighter details are lost.

But your assessment that other data besides the camera looks ok throws me off, because that means it should eliminate the signal path from the scaler to the projector as the culprit (I had just naturally assumed you were using DVI or VGA over Cat5 baluns).

[Paris MkVI]

If the issue is the camera exposure setting (iris or boost), The camera image could be poor while other sources look fine.

[dmot]

Originally Posted by Paris MkVI

If the issue is the camera exposure setting (iris or boost), The camera image could be poor while other sources look fine.

If I understand him correctly, he is running the camera signal through a Kramer distribution amp. From there the signal goes to some TVs where the the signal looks fine. He is also coming out of the DA to the kramer vp-725ds and on to the projector. The camera signal looks fine on the tvs but not on the projector. Also, other sources that run through the kramer vp-725ds also look fine.

If it was a problem with the camera why would the signal look good on the TVs?

[waynehoskins]

CRTs seem to be more forgiving of blowout than LCDs, from what I've seen. A waveform monitor would show you if your whites were going over 100 IRE and if your skintones were sitting around 70 where they should.

Excessive DA gain or lack of termination would do it as well.