Projector & Lens Setup - AVS Forum
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post #1 of 9 Old 08-17-2014, 04:53 AM - Thread Starter
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Projector & Lens Setup

Greetings All

I managed to get a Isco III lens and cineslide to go with my JVC RS55(X70) projector and 110'' wide 2.37 flatscreen. The Distance from the projector lens and the screen is 15 feet. The 16:9 picture is 82.5 inches wide so I work that out roughly as 2:1 throw ratio (correct me if I'm wrong).

I will be setting the projector and lens up at the back of the room preferably on or hanging from a shelf which can easily handle the weight . My question is what is the best place to position the projector? I have read that the projector should be lined up with the top of the screen and the lens is usually angled to point the projected picture to the center of the screen.

Any advice would be welcome.
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post #2 of 9 Old 08-18-2014, 02:40 AM
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Nice A-Lens and sled

Your TR is actually closer to 2.2:1.

Ideally (lens shift pending) you want to have the projectors lens inside the vertical height of the screen frame.

As for tilt of the A-Lens, you are best to see what the image looks like first, then tilt to even out pincushion. I have a curved screen that was custom curved for the set up.

In my case, the A-Lens actually sits quite straight and if I tilt, offsets the amount of pincushion top to bottom. I would suggest some will be needed on a flat screen.


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post #3 of 9 Old 08-20-2014, 06:56 AM
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Optimal PJ position depends on your screen material. Retroreflective, beam close to your eye level. Generally, angular reflective, beam to eyes 2x angle of incidence with your eyes. One works like a reflector, one works like a mirror.

The lens isn't "angled" if you mean point the PJ body; you use the PJ's lens shift to adjust the image position. The former would result in keystone distortion, the later will not. With your lens, I'd stay close to the top of the screen as a upper limit. Although a little above won't hurt if your PJ has that much shift. Typically, PJ's shift limit is top of screen or slightly above. Yours will allow a good bit above.

Last edited by GetGray; 08-20-2014 at 06:59 AM.
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post #4 of 9 Old 08-20-2014, 03:04 PM - Thread Starter
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Thanks to both of you for your response and advice. I am tempted to use lens shift to avoid installation headaches but read somewhere that it's best avoided when using a lens. If I choose to do so I could have everything sitting on the shelf as opposed to hanging which obviously has more work involved. But sitting on the shelf would take the projector just above screen height and I would definitely have to use the lens shift.

In regards to the screen I'm using, it's a Seymour center stage XD Acoustic transparent screen so I don't imagine it's too reflective but I'm more than happy with it.
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post #5 of 9 Old 08-20-2014, 03:26 PM
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Welcome. You can consider that screen as angular reflective, not retro. You are using lens shift anytime you are above center of screen. Slightly above top of screen won't be a big deal if that helps otherwise in your room. Won't be a problem with your lens. Curious where you got your lens and slide (I made it).
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post #6 of 9 Old 08-20-2014, 04:00 PM - Thread Starter
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You made a great product so thank you. I thought it was you and I was going to send you an email from London out of courtesy. I wanted to let you know I managed to get a lens and a cineslide off one of your old customers here in London as it came up when I was conversing with you about your stock and products and it was within 3 miles. I think he got it back in 2009 using it with a Meridian MF10 projector.

I also wanted to thank you for all of the advice you gave me and efforts you made. I'm grateful to you and the countless others who share their experience and expertise so that others such as myself can enjoy the wonders of home theater.
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post #7 of 9 Old 08-21-2014, 09:02 AM
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Welcome and no worries, I didn't recognize you from your userid. Glad you found a local deal.
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post #8 of 9 Old 08-25-2014, 03:38 AM
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Quote:
Originally Posted by GetGray View Post
Welcome. You can consider that screen as angular reflective, not retro. You are using lens shift anytime you are above center of screen. Slightly above top of screen won't be a big deal if that helps otherwise in your room. Won't be a problem with your lens. Curious where you got your lens and slide (I made it).
hello is every cineslide made by you?
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post #9 of 9 Old 08-25-2014, 07:18 AM
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Quote:
Originally Posted by knsy View Post
hello is every cineslide made by you?
Yes, every one.
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