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Where have the rainbows gone


Distinguished Member
On my DLP projector I use to have it on a coffee table and was shooting up. I had to put a number of cup mats under the front leg to get a height I needed and correspondingly had to have the key stone quite aggerssive.
I would see rainbows quite requently, espectialy when i was tired.
I now have a stand so the projector is now head on (well pointing slightly down) and I haven't seen a single rainbow since doing this. Non of the people I live with have either, although they rerely saw any unless I reminded them that they exist.

So does the angle of the projector/keystone make a big difference or have I just become imune to rainbows over time?


Component input would be the deciding factor, by using the component signal you are utilising the progressive scan, something that you wouldn't have done using the S-Video connection. This would be the deciding factor in clearing up the rainbows rather than ceiling mounting it!


Distinguished Member
The projector has a faruja(sp) chip, so would the component connection utalise this were as the s-vid and composite wouldn't. The signal i'm passing is not progressive, but the chips is ment to do some stuff which turns the signal progressive anyway.

Bristol Pete

Well-known Member
I suspect that the rainbows were caused by the cup mats :D

There is a big feature on this over at avsforums :lesson:

Cup matts and projectors = big trouble :suicide:

Cap :)


Distinguished Member
Yes you might have a point cap.
Good job i didn't use mug mats or else ...

It's all good though as now there are no rainbows, the only fault i can say is that the black lvl is not as good as it could be, always a white/grey border. I think I would have to upgrade to a CRT to be of a big enough improvement and i can't be bothered with the scaling and all the other crap that would be needed, aswell as the gurder for cieling mounting.

Bristol Pete

Well-known Member
What are you using to drive the image.

My Denon 2900 has a mode to change the black level. Changing it to dark ramps up the black massively :lesson:

Just an idea.

Cap :)

Ps , sounds like you struck lucky over the cup/mug differences. Phew :rolleyes:


Active Member
gazbarber said:
I use to have it on a coffee table and was shooting up.

I suspect this sort of activiity would make you see rainbows whether the projector was on or not ! :D

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