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#### wlum

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I need help calculating the min, max, and optimum throw distance for a G15, ISCO II, and 87" x 49" screen. Thanks in advance.

Wayne

#### jnissen

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Wayne,

I have Dukane 9015 (G15) and an ISCO I. The ISCO does very little to screen height. From tables of your manual, get height for min and max throw distances then

Width = (H x 16)/9

For optimum I believe you will find maximum throw is best for minimum distortion from ISCO.

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Jim Nissen

#### wlum

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Jim,

Thanks for the help that didn't help http://www.avsforum.com/ubb/smile.gif

I don't know if Dukane has a different manual than JVC or I'm just not getting it. In the JVC manual, it shows two tables -- one for 4:3 screens and the other for 16:9 screens. I have a 16:9 screen, so do I use that table or the 4:3 table?

Also, the tables list projection distance vs. min and max diagonal lengths of the screen. There is no width or height although it can be derived, I guess, from the diagonal lengths. Also, the projection distances jump in 3 to 4 foot increments on the tables -- not enough granularity for my small theater room.

Anyways, if anyone knows the formula for calculating what I asked for -- I'd be mighty gratelful. An example calculation (using my numbers) would even be better..

How much closer is the throw distance using the ISCO -- 33% shorter?

Thanks,

Wayne

#### Michael Grant

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Wayne,

JVC's 16:9 tables are likely based on the assumption that you're using a 1365x768 pixel area. In other words, for the same throw distance, the 16:9 screen width will be the same as a 4:3; but the height of the 4:3 screen will be 33% larger.

The ISCO, on the other hand, will leave the height the same, but increase the width by 33%.

So to use JVC's tables properly in your situation, ignore the 16:9 table completely. Instead, use the 4:3 table to compute the optimum throw distances for a 65" x 49" screen.

Michael

#### wlum

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Michael,

Thanks for the simplified answer to my question. I found and used the "Projection Calculator" at the Projector Central Website -- plugged in 49" for height a got the following answer:

81.7 inches Diagonal

49 inches High

65.3 Inches Wide

Throw distance 10.3 to 15.9 feet.

From what Jim states, I should try to get it as close to 15.9 feet (or less) as possible for optimal picture. The way my room is set up, it will probably be around 13 feet.

Anyone care to confirm these numbers??

I'll most likely be looking for an ISCO 2. Thanks,

Wayne

#### jnissen

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Wayne,

With an ISCO I, you are pretty much limited to max throw. I am at 18 feet for my 60" x 107" screen. I understand that you can use more of the zoom with the ISCO II. You may get more pincushion as you move closer to the screen.

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Jim Nissen

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