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Discussion Starter · #1 ·
I have a room that I am making into a home theatre. It is 14-1/2 feet wide by about 19 feet deep. I will be using a JVC RS-35 and plan on using a Studiotek ST-130, roll down screen. My primary seating area will be about 13 to 14 feet from the screen and the projector lens will be about 16-17 feet from the screen. I want to do CIH, but most of the info I find refers to 16:9. So, while I know that there is some personal preference on this subject, I felt it would be useful to get feedback, suggestions, or personal experience from this group of people. Also, would you suggest 2.35, or 2.4? While I amy not use it at first, I will probably end up with an anamorphic lens.


Your input is appreciated.

Rich
 

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Rich,


If you intend to do Constant Image Height with an A-Lens, then you need to be aware of the Throw Ratio and how that will impact your image quality. The TR is found by dividing the distance between the screen and the projector's lens (you've given a possible 17 feet). I will suggest that your TR be above 2.0:1 with 2.1 or even 2.2 preferred as some A-Lenses just won't work if the throw is too short.


So looking at the figures you've provided, you might be able to have an 11 foot wide Scope screen.


I like to use math to check that this will work before you spend ca$h.


Your TR for the 11 foot screen would be 2.06:1. 17 /(11 x 0.75) = 2.06

An 11 foot Scope screen is about 4.6 feet hight and 4.6 x 3 = 13.9 so your seating distance is good too.
 

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Discussion Starter · #3 ·
Thanks for the reply Mark. I am not quite sure I follow how to calculate throw distance. You said that you divide the distance from the lens to the screen by ? I see that you divided it by the screen width x .75, but I am not sure that I know what the .75 is. Can you explain that to me? I know quite a bit about audio, but the home theatre is just a fun project for me. Also, I see that you are in Brisbane. I was just there last week as part of an "around the world" speaking tour I was doing (on professional audio, I am pretty well known in that world). It really is a beautiful place. I went up to the Sunshine coast as well. Wonderful. Thanks for the help. Rich
 

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When finding the TR, we always work off the native 16:9 image width. The (Scope) screen width x 0.75 will be the native 16:9 width.
 

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Isn't the JVC RS series projectors really flexible on the placement? Although our room size is virtually the same, the projector that you're using are way more flexible than mine, so if I can make mine work, so can you. I'm putting up a 4 feet high CIH, and about 9.5 ft wide scope image at about 11 feet away. If you're going to be sitting about 13-14 feet away with 1080p, I think you can go much bigger than my setup. Think 10 ft to 11 ft wide scope. There are plenty of people that have the new JVCs and were able to find a compatible A lens, so look around to get ideas.
 

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He just needs to keep his beam "small" or his choice of lenses is cut right back to a very select few and they tend to cost more than the projector he wants to use it with.
 

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Very useful as my room size is very similar and I am consdering the new JVC's. Mark, how would the calculation work out if one were to want to go scope without an anamorphic lens (simply "zooming" the image allowing the black bars to overscan the top & bottom of the screen, properly masked of course).


Reading the spec's of the JVC's it appears the projector would handle that width within the confines of a 17-19' throw, however brightness and "screen door" comes to mind as possible pitfalls.


Thank you,


Paul
 

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The JVCs have a 2x zoom, so pretty flexible for either lens or zooming.
 

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Quote:
Originally Posted by CAVX /forum/post/18313206


The JVCs have a 2x zoom, so pretty flexible for either lens or zooming.

Sure, but does anyone have experience with the JVC 15/25/35 zoomed to 11 or 12 feet wide? I'm looking for comments related to brightness and any visible pixel structure from 10' - 14' back.


Thanks,

Paul
 

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Quote:
Originally Posted by pkarmouche /forum/post/18319015


Sure, but does anyone have experience with the JVC 15/25/35 zoomed to 11 or 12 feet wide? I'm looking for comments related to brightness and any visible pixel structure from 10' - 14' back.


Thanks,

Paul

Yes I've zoomed a HD350 (RS10?) to 3300mm (approx 11 feet). The image seemed fairly bright and there was no visible pixel structure at my viewing distance. However when comparing the same size image to one using an anamorphic lens...well we know the outcome there
 

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Quote:
Originally Posted by pkarmouche /forum/post/18319015


Sure, but does anyone have experience with the JVC 15/25/35 zoomed to 11 or 12 feet wide? I'm looking for comments related to brightness and any visible pixel structure from 10' - 14' back.

I have an RS20 zoomed to 10' wide on an AT scope screen. I sit 13' back and there is no visible pixel structure. No problems with brightness - although I've got a relatively new bulb (~200 hours) and complete control over lighting.


Very happy with it


Quote:
Originally Posted by richcolorado /forum/post/0


I have a room that I am making into a home theatre. It is 14-1/2 feet wide by about 19 feet deep. I will be using a JVC RS-35 and plan on using a Studiotek ST-130, roll down screen. My primary seating area will be about 13 to 14 feet from the screen and the projector lens will be about 16-17 feet from the screen.

That's about the same size as my room and setup. Mine is 13.5' x 18'. Details are here


Jay
 

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Sooming RS10 to 10' wide and still very dense, sharp pic at first row of 12'. Mostly bluray but HD sports looks very sharp as well.
 
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