First... Welcome to The Shack!
Okay screens and gain- Gain is a spec used to gage how bright a screen is
as compared to a unity gain white screen. It is just one aspect of a screen but often is mistaken as the most important attribute. It is a tool to achieve the needed brightness for a theater setting.
I'm not trying to be negative, but I'd be careful. Not all companies are totally forthcoming when it comes to gain. Some use industry standards for measuring gain, others have their own methods. I do question a 1.8 gain with a 120 degree viewing cone. That seems awful wide for that high of a gain. As a comparison DaLite has a Pearlescent screen with a 1.5 gain and a viewing cone of 80 degrees. That does seem realistic since we know as gain increases viewing cone decreases.
To have a similar type of screen material with a higher gain, that means that the reflectiveness and sheen has to be higher so the viewing would be lower. Gain due to higher sheen also indicates an inscreased chance of hot spotting. That's the laws of light and physics. Unless Elite Screens has a different way of measuring screen gain and viewing cone we have a disparity here.
Most screens 1.8 gain and over also start to get into the retro-reflective type of screen, meaning they reflect light back at the source like a traffic sign. This requires the projector to be mounted low, like on a table. Mounting a projector on the ceiling for a retro-reflective screen not only negates the reason for getting the higher gain, it could even look dimmer and have a poor image as compared to a lower gain angular reflective screen. Whether the Elite Screens PowerGain is retro-reflective or angular reflective I can't say. I couldn't determin that from their web site but it appears that are implying an angular type screen.
What concerns me about the Elite Power Gain screen is I can't seem to find much of any information about the screen on their site. I was looking for some information on viewing cone, or a gain chart and couldn't find anything like if it is angular or retro-reflective... I couldn't find anything on their site. From what I see the average price for a 100" SilverFrame PowerGain screen is around the $400 mark. That's not bad for a commercial screen, but also not cheap when not knowing all the specs. It could be fantastic, or it could be mediocre. Do yourself a favor and make sure to ask lots of questions on this one. Ask yourself this- Would you buy a car without knowing anything about it? Probably not.
Now... I want to be clear on this, I am not bashing Elite Screens. I am just saying I couldn't get a lot of information from their site.
What kind of price are you being quoted?
This is what concerns me
onebigdoor said:
...snip i use my projector mostly in cinema mode and i'm trying to squeeze life out of an old bulb. ...snip
all signs seemed to point to a 1.8 gain screen.
I need to know some more information before I can try to assist you. What size screen do you currently have and what brand is it?
My other concern is the comment that you're trying to squeeze life out of an old bulb. The HD70, while not the brightest projector out there, turns in a respectable 15fL of brightness in max setting on a 104" screen (according to company specs). The HD70 with a new bulb (after the breakin period) will produce a screen brightness on a 104" diag screen of max 31fL (which is unrealistic because actual brightness is rarely what the max specs are) to 12.3fL in Cinema mode, and 23fL in Bright mode. Knowing this projector is a bit lower than manufacturer specs the actual image will be less bright than those numbers.
That's a lot to digest I know. The main point is you mentioned an aging bulb. You really don't want to compensate for that by spending money on a screen, you probably should take that money and buy a new bulb.
Again I would need to know your current screen size to be able to make a screen recommendation, but based on a new bulb after it's been broken in, and assuming a 100"-106" diagonal screen size in a dedicated setting with occasional lights on, I would recommend a screen running in either Cinema mode with the brightness calibrated and adjusted for the room setting (meaning brightness would be increased) or run in Bright mode with the contrast and brightness lowered just a bit for the best calibrated image. For that setup which would be be the estimated 15fL of brightness I mentioned earlier, I'd go with a screen between an N8 and N9 shade of gray, meaning a medium to light gray screen.
Notice something though- gain was missing in that discussion. It doesn't mean gain isn't important, just that it is not as important as most people think. You have to take everything into consideration when building a Home Theater. This is what professional installers do, but once we know what they do we can also do the same and fore-go the expense, right?