Originally Posted by sandcam
What screen and what gain are you currently using? I'm planning on a 16x9 non AT 130 stewart grayhawk screen with about a 20ft throw distance. I have considered maybe moving to a 120inch if that would allow the LS-5 to light it up with all the lights off and with ambient lighting. Again, I am stressing that I am not looking for a perfect picture with the lights on or dimmed, I'm looking for a functional picture that you can still see decent. Then when the lights are off, I want to have a good picture that makes me very happy. I was looking at the Q-750 and it just couldn't quote get enough brightness IMO to the 130 and as soon as there was some abient lighting it became very difficult to see. NOTE: all ambient lighting i am talking about is recessed lighthing that is dimmable in a basement.
Sandcam - My apologies for the slow reply. I have never seen the grayhawk in action, but I know Stewart makes some fantastic surfaces. My screen is a 120" wide 2.37:1 SmX Cineweave HD and I do use an A lens rather than zooming. Their website says the gain is 1.16 but I have never taken any measurements and honestly don't know a whole lot about it. However, I'm pretty sure I have read here on AVS that the measured gain is actually closer to 1.0.
Are you thinking about 120/130" wide or diagonal? Either way, you're looking at a big screen and a relatively long throw distance. Of course this is a matter of personal taste, but when you couple a screen that size with a long throw distance, some ambient lighting and factor in an aging bulb, you might not be 100% happy. The LS-5 is certainly brighter than the Q-750 on day one, but you have to factor in dimming of the bulb as it ages with the LS-5. I don't know - I think that if it were me, I would probably be happy with the LS-5 in your environment. If I have some lights on, I'm not "really" watching and I understand that the picture isn't going to be outstanding. If it's something I really care to watch, I will sit down and give it my attention, which means I don't mind dimming the lights. With the lights dimmed down pretty low in my theater, I have never been unsatisfied with the brightness of the LS-5. The picture is in my opinion ridiculously good, and if it were any brighter I think I would get headaches!
Just some food for thought - you're talking about a decent amount of money here between the projector and screen. I would suggest that you take a step back and clearly define your priorities. Are you sure that the Grayhawk screen meets your goals? Sounds like you're essentially looking for a "watchable" picture with some lights on, and an image that makes you "very happy" when the lights are off. I don't know much about Grayhawk, but it sounds like you might be better off searching for something that will blow you away with the lights off. In my experience, when you try to find a happy medium with this stuff, you can at times find yourself underwhelmed in all categories. Maybe it's best to focus on just one area and get a setup that will really impress in that area. That's a call you have to make...
Finally, if you think you need more light, I would consider the LS-HB or the DPI M-Vision Cine-260 HC. I don't have experience with the DPI, but that was my #2 choice when I bought my projector. Similar pricing, and while you'll have to accept lower contrast, you'll get noticeably more light output.