Do I need a VGA amp?

[ddsnodgrass]

I have 3 projectors, 1 is right above my media booth which projects on the back wall for the stage. I have 2 projectors for the congregation. Of my two in the front, 1 has a significant different in image quality...on most backgrounds or video you can tell this one is a little darker than the other. I assumed it was the bulb, but it has been replaced not too long ago. The VGA cable that feeds the two projectors makes close to a 150 ft. run. Also, the company who installed the projectors made a joint in the ceiling near the projectors so that there is only one VGA cable running back to the media booth where the splitter is?

Would it make a difference if I took out the joint, made up ends for those cables and installed a VGA amp in the ceiling near the projectors?

So I guess my main question is this... How long of a run can you make with VGA before having a significant signal drop in which case you would need to install an amp.

Does this make sense?

[[Admin] osborn4]

I'd put an amp before the 150' send and at the splitter point.

But if I could only do one, I guess I'd try the splitter point first.

Does your rear projector use the same feed, or is it using a separate VGA out on your computer?

[daver2]

I would avoid a direct joint (if that is what your installers have done). Like Joel I would install and amplifier before the long run and a proper splitter where the cable forks to go to the two projectors. That's what we have and our cable runs sound similar to yours. We have no problem with our VGA install. A lot will depend on the quality of VGA cable you have installed as to how long the run can be.

150 ft sounds too long - even with decent VGA cable - to me without amps and splitters.

Dave

[six5tring]

Just a quick agreement that 150ft is a long way for a vga to run even at say 1024x768.. I was running a length similar the other day and had no end of problems with noise. Installing a vga amp did not help. Hum bugs no good.. it was just too far! If at half way they have properly slipt the cable drop a DA in to re drive the signal. I sadly dropped fibre in instead!

six

[ddsnodgrass]

Yes, my rear projector is getting the same feed...

Thanks guys...your input has been most helpful. I really think I need some kind of amp and/or splitter. But, also in the back of mind I am curious if the one projector has a bad bulb or something. I guess I'll just have to find out for myself and see what it takes to brigten the projector up.

The contrast and brightness settings on the two projectors are identical...but that left projector is sligtly darker than the other...

[[Admin] osborn4]

Then I would definitely put a Distribution Amplifier at the computer, to send to the front pair and rear projector (as well as a monitor by your setup, if you have one). And another where the signal is split to the two front projectors.

[Stever]

I agree 150' way to far especially when split.

If the projectors are the same model you can swap the lamps to see if the problem follows the lamp. What is the age of the units? How have they been maintained? Many reasons can cause 1 unit to look different than the other over time.

[ddsnodgrass]

yeah the projectors of the same model, Hitachi CPX3500 I believe. I thought about swapping the bulbs, but then about the risk in moving the bulbs around since projector bulbs are kind of sensetive. I still may try this though. I am hoping that next weekend I'll be able to get up there and check things out. I'm a bivocational pastor so I've got to plan for things like this...