DIY Lens Questions

[mmmkam]

I have 2 of the Massillon Plaque wedges that I will be using for a DIY lens, but have a couple questions before I start playing around with it.

1) Do I need to have the projector mounted in its permanent position (ceiling mount) to get the wedges arranged correctly or can I put it on a table, test the wedge positioning, build the case and mount it all on the ceiling? Didnt know if the wedges would have to have a diffent positioning if the projector was moved slightly.

2) Should the long sides of the wedges be on the inside together, both outside, or both wedges oriented the same way? (I know that one has to point left and one right to stretch the image properly).

3) With the above type of DIY lens if a slide is used to move the lens will the position of the 16:9 image have to be manually adjusted for placement on the screen when the lens is moved out of the way.

Thanks all.

[klemsaba]

I have 2 of the Massillon Plaque wedges that I will be using for a DIY lens, but have a couple questions before I start playing around with it.

1) Do I need to have the projector mounted in its permanent position (ceiling mount) to get the wedges arranged correctly or can I put it on a table, test the wedge positioning, build the case and mount it all on the ceiling? Didnt know if the wedges would have to have a diffent positioning if the projector was moved slightly.

2) Should the long sides of the wedges be on the inside together, both outside, or both wedges oriented the same way? (I know that one has to point left and one right to stretch the image properly).

3) With the above type of DIY lens if a slide is used to move the lens will the position of the 16:9 image have to be manually adjusted for placement on the screen when the lens is moved out of the way.

Thanks all.

1 - You can adjust the wedges on a table. The stretch won't change once mounted on the ceiling.

2 - I have mine setup like this...

http://members.cox.net/klemsaba/prism/prismsketch.jpg

3 - My image shifts slightly, but not enough to need adjustment. This probably depends on the setup.

[mmmkam]

Great thanks for the feedback! Thats exactly what I was looking for. Anyone have any tips on minimizing the image shift?

[JDLIVE]

My image shifts quite a bit vertically when I have my lens in place. I didn't notice this when I was first testing, my guess is that my enclosure does not allow the prisms to be perfectly parallel to each other? I'm able to compensate for it by shifting the image in my scaling settings (on my HTPC), someday when I get some initiative I may build a new enclosure and see if that's really the cause. :D