For 1:1 pixel mapping, you want the SHORTEST (wide)distance b/t PJ and screen, right? - AVS Forum
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post #1 of 5 Old 03-20-2012, 04:20 PM - Thread Starter
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I apologize if this is in the wrong forum. Wasn't sure where to put it. Mods: Please move to wherever this should go.

It's been awhile since I've setup a PJ and I forgot how to do this. In order to get the best picture quality (AKA 1:1 pixel mapping?) you want the PJ's zoom to be all the way open, right? So, that would mean your PJ should be as close to the screen as possible while still filling the screen area.

In other words, looking at this picture of my setup, for the best picture quality, I want my PJ to be 108" from the screen.




Am I correct on this? Thank you.
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post #2 of 5 Old 03-20-2012, 05:03 PM
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1-to-1 pixel mapping has nothing to do with how you set the zoom lens (optical zoom). Acheiving such 1-to-1 pixel mapping means you are feeding an input signal with the same resolution as is the native resolution of the projector (1080 x 1920 in the case of your HC4000) and also you are not applying any scaling or video processing, such as using the projector's keystone correction adjustment or digital zoom or stretch functions, which would alter the original image size or shape. Moving the projector to the shortest allowed projector-to-screen throw distance for your size screen means you will be setting the optical zoom to maxium (i.e., to produce the largest image). This setting will give you the brightest image since the zoom lens will have less light loss at this setting as compared to mid or minimum zoom. However, depending on the specific lens and projector, the image might be a little sharper or with a somewhat higher contrast by moving the projector back further from the screen and change the zoom setting accordingly. However, some projectors are capable of fully resolving all of the the pixels throughout the full zoom range of the lens (such is the case with both the Epson and JVC projectors that I currently own and I think you will find this to the case with your Mits HC4000).

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post #3 of 5 Old 03-20-2012, 06:15 PM - Thread Starter
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Hi Ron,

Thank you for the detailed explanation of pixel mapping and for clearing up my confusion. I had pixel mapping and screen throw confused. Now that I know what it is, I will be pixel-mapping; 1080P BRP to the HC4000.

I already have a 90" diagonal, 16x9 screen. The room I'm putting it in will allow me to have the PJ up to roughly 150" away (give or take an inch or two) from the screen. I'm trying to decide where exactly to mount it.

Thanks again.
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post #4 of 5 Old 03-20-2012, 06:51 PM
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Use the calculator at projector central and it will tell you exactly how far away you can mount it based off zoom and throw for that model.
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post #5 of 5 Old 03-21-2012, 08:00 AM - Thread Starter
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Yep, I've used both the Mitsu and PJ Central calculators and I know the min/max range for my screen size. I was just wanting to know what distance from the screen would net me the OPTIMAL image/picture quality. I'm shooting for the shortest throw (108") but may go up to another 18" or so further back, depending on where the best place for the ceiling mount is. It's not easy creating a theater from a pre-existing room. Ceiling fans, lights, etc....all conspiring against you!
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