Originally Posted by cpc
I see online in the manual the 8" measurement from the back to a wall or surface refers to the projector being enclosed in a space with the dimensions as shown in the diagram, 12" to the sides, 6" above and 8" to the back. If in this small of a space you need air conditioning. My guess is that if the projector is ceiling mounted you can place the projector closer to a back wall than 8". I will probably go with 5-6".
If I have to use the widest zoom when viewing 2.35:1 films, what do I end up with? Will I have the dimmest image at the widest setting? Telephoto vs wide what are the trade-offs? Contrast vs brightness?
I guess at that point you're answering your own question
. They actually say in the manual those are minimum dimensions without further qualification, and additionally that if you did make a box to just those minimum dimensions that it wouldn't be sufficient and you'd need an air conditioner too. As I say there are undoubtedly folk using them closer without them catching fire, but whether there is a long term longevity impact or operational impact (such as fans operating faster) is anyone's guess, a couple of inches less at the rear is perhaps unlikely to be significant so long as it isn't close to side walls as well.
I will say as someone who has been involved in these kind of things in manuals before that if they were just sandbagging the numbers you'd expect them all to be identical, and they're not identical, which implies there is some engineering behind them.
Out of interest, is this a projector you already own or one you're looking to get? If you are that tight on the throw, just be mindful that JVC have specified tolerance of +/- 5% on the throw distances in the tables in the manual (they don't quote this figure in the manual, but have in several other places), so if your calcs are showing you needing to be right back against the back wall and you've not allowed for the potential of 5% throw tolerance you might not manage to fill your screen.
As you increase the amount of zoom you are using (ie getting closer to the minimum throw distance for the given screen size) you can expect a reduction in on/off contrast, an increase in ANSI contrast, and an increase in overall light output. I don't think any of the above are earth shattering differences, and if you're constrained in your location (which it sounds like you are) then it doesn't much matter really...! You've got what you've got.
Mine's about 8-10 inches away from the back wall. I don't see any reason to go closer unless you are really short of throw.