[Jeff Smith]

I have a 107x60" 1.3 gain screen up now, and am leaning strongly to 9" CRT. How hard is it to set it up and roughly converge it then move it closer to the screen and reconverge (ie rolling cart) and if I find its too dim at 107" move it to say 96-100" width just to try it before I decide to mount it on the ceiling or buy a new screen?

 

[bryan_chow]

Closer = Better, as long as geometry is still acceptable. So just put it as close as you can while straight lines are still straight at the edges. I don't see why you should move it back and forth.


Bryan

 

[bpdski]

Exactly. If you're already set on the screen size, which it sounds like you are, then get it as close as possible. The idea is to use as much of the CRT as possible to get a brighter and clearer picture. The farther back you place the CRT, the less of the tube you'll be using to fill the screen. Less tube = less light.


- Brian

 

[Jeff Smith]

I didn't ask this very well. What I want to do is try the unit with my 107" wide screen...then move the PJ forward to only light up a 96-100" portion of the same screen. If I don't see that much difference, I'll stick with the larger screen...if I do, I will sell that one and buy a new one.


I just wondered how long it took to set up the PJ "enough" to adequately judge b/w the 2. Eventually, when I pick a final screen size, I'll have a pro do the ISF/convergance/etc. I just don't want to do a full (ie $$$) setup until I decide how much I gain or lose with the larger vs smaller screen sizes.


I have seen a well setup G70 at 107" wide and it looked good, I just haven't seen how much better it would look at 96" wide. I may value the size over the quality.


Is this (semi)easily done?

 

[bpdski]

Ahhh. Well, it depends on the projector I think. I've heard that some are much harder than others. I have a Sony, which are supposed to be easier than most, and I know I can do a basic focus and convergence on it in about 1 hour.


- Brian

 

[CaspianM]

I would go with manufacturer throw distance as a rough guide.

Get roughly 85% of raster covered then find your distance based on that to fill the screen. You may use your current screen but raster coverage should be constant with resolution desired. If dim then move to PJ forward for desired combined result. You do not have to set the PJ 100% inorder to get a reference though. I will tell you 107" should be on the too much side once your PJ has a couple of thousand hours on it. Good luck

 

[Gertjan]

Jeff -


I was in a similar situation when i first got my Marquee 8501LC. I had it set up on the floor and moved it back and forth several times to see what looked better.


It's fairly easy to do it once you get the hang of it. The time spent depends on how perfect you want to get the picture. I went all the way with each move, doing a mechanical and electrical setup from scratch each time. It turned out i could easily do one each night, it would take me maybe 1 1/2 hour i think.


It's farily easy, depending on which projector you have. The Marquee has a lot of the setup related stuff available through menus, so it's fairly easy to do that. I read that with some of the other projectors some of the settings that you can do with the remote with the Marquee, you need to do mechanically, which would take longer i would think.


Gertjan

 

[wm]

No, don't use the manufacturer's throw distance, it's too conservative, especially for a 16x9 screen.


If you set it up properly for the widest image you want to evaluate, including red/blue toe-in, scheimpflug focus, etc. then you should be able to move it closer and evaluate a smaller image size with minimal changes. Just leave the lens toe-in bolts loose and recenter red/blue with this, and refocus optically, then touch up convergence and you should be close enough to see the difference. Leave the size adjustments alone; if you resize the image on the crt this will not be the comparison you want to make as this will affect the light output.


You don't say which 9" projector... For a G90 (measured at 350 ANSI lumens) a 107" wide image would be about 10 foot lamberts on a 1.3 gain screen - not over bright but you might find this acceptable. If you drop to a 96" wide screen this goes up to 12.6 foot lamberts, a significant increase.


William

 

[Curt Palme]

you simply will not notice a difference in only 7-10" change in width. go say from a 107' wide screen to an 84", then you'll notice quite a difference in brightness and clarity difference.


Curt