Hi all,

So I found the zuggsoft prism guide which got me interested in the idea of playing with prisms and I went ahead and ordered some from xpress (though it would have been nice to not have to order like 8 of them, the minimum order is £50).

Anyway, the question I have is in regards to aligning the prisms and the throw distance.

I have my projector (IN76) mounted on the ceiling and it's at the very back of the room since it's only 15ft long. Now I can take the projector down to play with the alignment but I can't do this at the back of the room as there is no surface to do so.

My question is, if I am going to play with the projector in the middle of the room to align the prisms, will I then run into problems when I mount it back up on the ceiling?

Any help would be appreciated!

-Joel

I actually just had a thought, if I were to add the ability to adjust the rotation of the prisms and the angle of the final lens assembly, would that make this irrelevant, or would the distance between the prisms still be a problem? :confused:

-Joel

Joel,

I noticed you got no replies so let me try and help you. As long a the projector is centered horzontally relative to the screen the placement of the projector to the top of the screen will have only a minor effect on the picture. The prisms should be mounted such you can tilt them downward to align to the project beam. It is only the downward tilt to consider when ceiling mounting the projector. I purchased a prism lens and if you don't tilt the lens assembly down any resulting pincushion distortion will not be balanced evenly between the top and bottom of the picture. Near perfect alignment of the projector to the screen is necessary for optimum results. Make sure before installing the lens assembly that there is no vertical or horzontal keystoning from the projector alignment. Since the horzontal is being stretched any missalignment is magnified with the addition of the lens.
Hope this helps,
Charles
CRGINC

My question is, if I am going to play with the projector in the middle of the room to align the prisms, will I then run into problems when I mount it back up on the ceiling?

Any help would be appreciated!

-Joel

Hi Joel,

You may find that alignment for one TR (centre of the room) may not work as the same once the projector is installed at the rear of the room as the TR has now increased and therefore the amount of prisms displacement muct also increase. I certainly found this when going from an extremely short throw to the mid/long throw I am at now.