TH2G Edge Blend Discolorization

[hoosierman]

Looking for some advice on an edge blend problem that we've had for quite some time. We're doing a two projector edge blend and we're seeing a yellowing of the projected image at the point of the edge blend. Our process of elimination has found that we don't see the yellowing on the QLab created edge blend straight out of our iMac, sent to a monitor and local screen (iMac). But when we connect up our TripleHead2Go Digital SE that's when it surfaces. Anyone have any insight as to what might be going on?

 

[DanH]

What happens when you swap the signals between the projectors - does it follow the signal or the projector?
(I suspect the yellowing is caused by something failing in one of the projectors, either chip or mirror or....)

 

[josh88]

Any chance you could post a picture? Its just happening in the area were the blend is occurring? And the preview doesn't show anything, its just when you actually set up projectors? My first guess is that the lamps are just different ages and thats causing the noticeable difference in color between the two images.

 

[hoosierman]

What happens when you swap the signals between the projectors - does it follow the signal or the projector?
(I suspect the yellowing is caused by something failing in one of the projectors, either chip or mirror or....)

We started at the projectors and worked our way backward. The edge blend is what you would expect straight out of the iMac. Then it surfaces when we connect the TripleHead2G Digital SE, and look at the edge blend via a monitor direct out of the TH2G. I'm hearing no complaints from TH2G users and none are claiming to have seen this...so I'm wondering if there is some other set-up that we may have missed with the TH2G. So far, I'm not finding anything.

Now attempting to find another TH2G to test.

Thanks for responding!

 

[hoosierman]

Any chance you could post a picture? Its just happening in the area were the blend is occurring? And the preview doesn't show anything, its just when you actually set up projectors? My first guess is that the lamps are just different ages and thats causing the noticeable difference in color between the two images.

Here is the best that I've been able to come up with. We played around with the gamma adjustment and the yellowish tint never goes away. As mentioned in the other reply, we traced this down to the output of the TripleHead2Go Digital SE, and are working at obtaining another unit to test. Also, working through the possibility that a step in the configuration of the TH2G was missed. But I don't believe we did.

Thanks for your response!

 

[josh88]

Yeah thats odd, the left and right certainly appear to be the same color. You've turned each projector off and checked? the yellowing only appears when they are both physically on and the blend is happening? I mean it seems obvious but sometimes you have to ask, its not just one triple head/projector is throwing yellow in the blend and the other is totally clean, it would at least trace it back to one of the units or signal paths.

 

[hoosierman]

Yeah thats odd, the left and right certainly appear to be the same color. You've turned each projector off and checked? the yellowing only appears when they are both physically on and the blend is happening? I mean it seems obvious but sometimes you have to ask, its not just one triple head/projector is throwing yellow in the blend and the other is totally clean, it would at least trace it back to one of the units or signal paths.

When you look at each side of the edge blend independently, the yellowing is evident as it starts to feather down to black on the blended edge of each image.

So the tests made recently were done to take the TripleHead out of the equation, taking the dual thunderbolt outputs of the iMac out to the projectors via a thunderbolt to VGA adapter > 3' Extron VGA > ConnectPro EOC-VA1-A-T transmitter> 275' of Cat6 > ConnectPro EOC-VA1-A-R receiver > 3' Extron VGA > Christie DWU1050-Q Projectors. The result... No yellowing of the edge blend. Now trying to get another TH2G Digital SE in to test.

After numerous conversations, without exception, no one I've encountered has experienced this kind of thing coming out of a TripleHead. But we will see what the replacement does.

Anyone ever have issues with thunderbolt to displayport cables? That's the one item that I haven't replaced between the iMac and the TripleHead. I didn't have a spare.

 

[josh88]

We don't use triple heads in our shops I cant comment to that but we haven't encountered any issues with adaptors or thunderbolt, but for edge blending we're generally using an ascender to handle it all. so the scenarios are a bit different.