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On the ISCO website, the stretch factors for the ISCO and ISCO II are given as 1.44 and 1.33 respectively. Can I simply use the projectorcentral.com calculator, plug in a throw distance, and multiply the resultant screen width by the above coefficients?


I have a fixed throw distance and want to use the LT150 which has no zoom, so would very much like to know what the final screen size would be with either the Panamorh or ISCO lenses.


Thanks,

Kelly
 

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I have the lt150 and ISCO II. At a throw distance of about 10.5 feet, the lt150 projects an image of about 80-81" wide, 61" height, without the ISCO. With the ISCO II, multiplying by 1.33, I should get about 107-108" width, with same vertical height. For some reason, however, I actually get about 111-112" width and 62" height. Thus, I don't think the 1.33 is entirely accurate.


Sitting from only ten feet away, the combination produces an authentic theatrical experience (assuming you're someone who sits toward the front of a movie theater rather than in the back). I don't notice any pixelation. Thus, if you're looking to substantially increase the size of your image, utilize a 16:9 aspect ratio, and only have a limited distance between your projector and screen, the ISCO II is an ideal solution.


Note, however, that the ISCO II introduces considerable (i.e. noticeable) pincushion distortion to the image. The only way to reduce the distortion is to overproject the image and mask off the perimeter of the screen. You will have to use masking as well for 2:35:1 images. I find that the distortion is an annoying aspect of the ISCO II, but you learn to live with it.


I also believe that, despite reports of increased resolution and brightness, the ISCO II softens the image and slightly decreases brightness, at least with the lt150. This observation was confirmed by another AVS forum member who visited my apartment. Notwithstanding, the overall impact of the image with the ISCO II in place is superior to the lt150 image alone.
 

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Jfreeman,


How much pincushion did you end up with?


As far as brightness, if you don't change the projector distance, you're spreading out the light by 33% and will reduce brightness accordingly. But you're getting an image with 1.78 (1.33 x 1.33) times the area.


If you moved the projector 1/3 closer to maintain the same image width, you'd have 33% greater brightness.


------------------

Noah
 
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