Max projector screen size for 21ft wide room?

[Yongchai]

Hi guys,

I am building a golf sim room using a GC2 and I have a space of width 21ft, lenght 32ft, height 19ft.

Conditions
1) I want to make best possible use of the full 21ft width,
2) but i only want to use 1 projector
3) and have no image distortion (ie. retain life size proportions).

Questions
1) So what is the max size screen i can use?
2) What resolution/ratio do i need for my projector (compatible with GC2 software)?
3) how far away must i set up my projector to my screen?
4) minimum lumens/contrast required

Answers/opinions appreciated

Thanks
Chai

[Yongchai]

After researching some more, I feel like i need to add another critera and that is
4) screen must be seamless.

With this, calculating max size is much easier since the nettings without seams that i can find from par2pro and westcoastnetting are 126' and 100' respectively.

http://www.par2pro.com/shop/product_...products_id=98
http://www.westcoastnetting.com/nett...-18-4-205.html

Using 100' as a start since WCN is smaller (and cheaper), i started looking for a projector and one that caught my eye was the Optoma GT 760
Price $630
Brightness : 3400
Contrast : 20,000 : 1
Throw Dist : 0.4 -3.5m
Res: 1280 x 720

http://www.projectorcentral.com/Optoma-GT760.htm

So now using max height and res ratio, i can come up with max width for 1 projector, and thats 177.8' (100 / 9 x 16 = 177.8),

Kinda sad to only be using 15ft when i have a full 21ft....

So now for a few more questions:
1) Does anybody know if this size 15ft x 9 ft will give a distorted image? (Ie. I don't want to think i'm hitting over a massive trees when its actually a small sapling)
2) i found another interesting projector with higher resolution (but noting else going for it) and am wondering which is more important. "Brightness and Contrast" or "Resolution"?

BenQ W1080st
Price $1099
Brightness : 2000
Contrast : 10,000 : 1
Throw Dist : 0.6 -4.6m
Res: 1920 x 1080

http://www.projectorcentral.com/BenQ-W1080ST.htm

I'm leaning towards Optoma because its cheaper, and i figure a golf sim room would require a higher brightness rating but am wondering what u guys think.

Answers and opinions appreciated

[Dax]

How bright is your room? At that size image, you will want something that puts out some good light and also has good resolution. I remember watching a youtube posting for an Epson G Series EB-G5950 that seemed to put out a good image in a very bright room. Only problem is that this was a European model I believe. Also, I suspect the price was higher than what you are looking for and it still likely was not 1080p.

I went with the Benq, but suspect that I will be pushing its brightness limits when I get it into my sim room which I am currently consrtucting. Likely to be finished at the end of the month. I believe someone else just purchased the Benq around the same time as me and has it up and running in their sim now, you might want to check out some of the other posts as they may have reviewed the projector.

[syhlif32]

15 feet is a big screen. Where you will need a good deal of lumen to light that up.
+3000 lumen would serve you better.
If you only want 1 projector 1920 X 1080 would be much better than 1280 X 720.

I got a 11 feet wide screen. Was 12 feet but felt the picture wasn't that great even with a 1920 x 1080 projector. 2500 lumen which is fine with light control.
We also use the screen for Home Theater. Had it just been Golf sim I would have kept the 12 feet wide screen.
If you can look away from the pixelation with such a large screen and have complete light control then a 15 feet wide screen will be very impressive.

You got a prefect size room for a 2 or even 3 projector setup but that will add quite a bit extra cost.

[Yongchai]

The room is an old squash court, so it has pretty high solid walls with ventilations/light gaps near the top and windows behind. I am not planning on doing much light control, as it is already pretty dim with lights off and i don't want to practice golf in the dark.

So which should i go for? The optoma with higher lumens or the Benq with higher resolution for a big screen?

Right now with the optoma gt760, it says that the projector needs to be 7-8ft away from screen to cast full size. Is this 7-8ft specific to this short throw model or can i use this number to search for other projectors? (Because right now my projector options are limited by short throw model, but with 7ft throw, i can search for models not listed as short throw)

And does anybody know how to calculate what the height should be if i don't want to cast a shadow? (I'm around 5'8 and projector will be ceiling mounted)

And does anybody have any answers on how a life-sized projection should be set up? (Ie. screen size/resolution limits)

Thanks

[Libbing]

The best measure of brightness is to use the projectorcentral.com calculator

example: http://www.projectorcentral.com/Pana...ulator-pro.htm

important setting: select video games as the use, screen gain of 1 (better screens that an impact screen would improve performance)
if the projector has zoom, you can get better brightness by placing the projector closer and adjusting the zoom

I have this Panasonic AR100u projector that is set about 20' back from the screen, projects to 15 x 9 or so.

The important brightness rating to look at is the "lf" factor (that is small L, small F). It shows up just to the right of the throw range slider. The Panasonic AR100u I am linking to (with video game setting, from 20' to a ~15x9 image) gives an lf of 11. It is a great brightness in my room, but I have heavy lighting control (no natural light at all, blacked out walls & ceiling from the screen to about 17' back, only two ~75 watt spot lights shining down on the hitting area; room is well lit starting 18' back from the screen and it carries into the hitting area). Light is the massive enemy of these projectors. The brighter the room, the better the lf rating you are going to want. There is a local indoor range near me that has a simulator with poor lighting control. I stopped going there because the image was so terrible from the projector (in combination with an endurance screen that didn't reflect very well either)

Note that a higher lumens number doesn't always result in a better lf factor, so it's only directional

Most guys are hanging a projector on 9.5 - 10.5 foot ceiling. In my application, I stand about 10' from the screen and shadowing doesn't occur (I'm 5'11"). There is a small shadow when using the Protee putting sensor, which is a couple of feet closer to the screen, but it really isn't that big of a deal since you have your head down to putt. My screen picture projection starts a foot or two off the ground - so that will reduce shadow impacts as well. If your image goes all the way to the ground, the shadowing may be more. If very concerned with shadowing, note that any projector without a zoom will have more limited places where you can mount it (can't move it around and just adjust zoom to get rid of a shadow - you have to move it back and forth to adjust the picture size)

In terms of your life-size question, I think you'll find that getting the brightness is way more important than any other factor. Also more important, in my opinion, than the resolution. The screens you are playing on are not great screens for video quality so they only get so much benefit from high res. They are good (we watch movies on it and really like it), but keep in mind that it will get scuffed up and warp a bit from impacts; hard or impossible to avoid that. Sure, high res is better, but I'd likely swap better brightness for higher res if we're talking about a beaten up low-gain impact screen with low-light control environment. After playing for a bit you'll get a sense for how high you can hit your shots (whether to make it over a tree or not). You won't likely mistake some small tree for a big one - the tree proportions are pretty easy to figure out rough size (e.g. based on how skinny they are, size of branch spread, etc.). As stated in an earlier post, it's hard to get a sense for life-size proportion because you'd have to have a great ability to translate a 2-D picture (not knowing how tall anything is and not likely taking time to figure out how far away the tree is) into 3-D image in your head. You'll eventually just get a sense for height after having cleared a few trees (or hit into them)

[Dax]

I don't understand why you say the projector will be 7 to 8 feet away, in order to get a 21' wide image with this projector in 16:9 format it appears that you need to have it just under 11 feet away. 4:3 would be even further and both seem to be pretty dim at this width and distance. Also, the projector will need to be a little over 12 feet 4 approximately off of the ground and given you would likely hit around 10 or so feet from the screen, I cannot see shadowing being an issue. As an alternative, given your width, you could go for a couple of projectors and consider a curved screen, that would be a very immersive experience.

To be honest, while the optoma gets some really good reviews, I think for the width you are planning that you may want to choose a different projector based on how you have described your room.

[Yongchai]

It sure would be nice to go for curved screen, but there's the budget to consider... And for a first timer, i think its best to start small, and then slowly upgrade once i'm in better position to know better what i want.

The room has width 21 ft, but using conditions specified above, screen size will 'only' be 100' x 178' ( h x w ). For this size and the optoma Gt 760, projectorcentral calculator states throw distance of 7'8".

It also states an image brightness of 14fL

Libbing, is this what u mean by the "If" factor? If not, i can't find this factor anywhere. Your projector gives off 6fl on same screensize. But thanks for writing about your experience, i think i will prioritize brightness over resolution, and with your experience that ST projectors are not necessary, i will start looking for other projectors and see if i can get a better one than the optoma GT 760.

But i'm worried that the further the screen is, the more lumens it needs to show the same brightness. Ie. If i have the gt 760 -3,400 lumens set up at 8ft, does that mean that if another non-short throw projector is set up at 16ft (double the distance away), it would need double the lumens (6,800 lumens) to have comparable brightness? Those projectors would be in the pricey range....($5,000+)

Also, if we were to theorize about multiple screens, i'm guessing projectors at 4:3 scale? Height will still be fixed at 100' because of seam issues, so width at that ratio would be 133', 2 projectors would be 266' (22.1ft - which would be just about right for my 21ft room). Is that how it works? Then why do i see some set up with 3 projectors (max 399' width), but the room doesn't seem that wide? (even after taking into account curvature)

Is theres any other benefits other than width size (+88') when going with two 4:3 projectors at 100' x 266', compared to 1 projector at 100' x178'?

Thoughts/comments?

[Dax]

Sorry, I did not see you changed your dimensions from 21 feet and thought you were still wanting to fill your room width.

Have you looked at the projector help and hd projector threads here? A few people have added comments on some pretty good projector choices that they have used with a lot of success. Given how big your room is, you should have lots of choices for different projectors.

Please know that the lumen number for each projector can be misleading, but in a room with ambient light and for the larger screen size that you are going for you will need a projector that has a good light output.

[Libbing]

Libbing, is this what u mean by the "If" factor? If not, i can't find this factor anywhere. Your projector gives off 6fl on same screensize. But thanks for writing about your experience, i think i will prioritize brightness over resolution, and with your experience that ST projectors are not necessary, i will start looking for other projectors and see if i can get a better one than the optoma GT 760.

Yes, it is fL (got that mixed up). For the projector I use, you set the screen size first, then change the zoom to 2x (in the throw range box) - this changes the fL to 11 rather than 6 (it's 6 when it is set back a lot farther at neutral zoom). Not all projectors have that zoom (the GT 760 doesn't) so you have to watch that. Zooming in and setting closer gives beth fL.

My projector is fine / perfectly happy with it. I only show that as an example for that calculator. I had a 1080 criteria (using it as a movie theatre) - not sure how much that was really needed. Could be tough to beat that 760 without spending a lot more, but worth looking.

[Dax]

When I was considering which projector to go with, the 760 was near the top of my list and I could have picked one up for a little over $600 on a Amozon Thanksgiving day sale. The reasons for not going with it were due to the lack of zoom, the fact that it would have been in front of my hitting position by about two or three feet and most importantly was that it did not do 1080. I think it was a great bang for the dollar based off of all the reviews that I had read and the other plus was lamp replacement prices were very good (and lamp life was also very good). The Benq is definately not as bright, but I will be able to control my lighting and will have no lights between the projector and the screen that could further wash away my image. While I am building my sim, I have set the benq up in my theatre room and must say that I am very pleased with the image quality and brightness (I have full lighting control in the room and while my walls are still a light colour, I believe that the picture brightness will be good enough for me. I will put a review up once I get my screen installed, which I hope will be close to the end of the month.

I note that the prior version of the 760 (it may have been the 750) was also highly rated on other posts here, handled a 16:10 ratio and could likely be picked up used for a very good price as well.

[Yongchai]

Well i managed to exchange a few emails with one of Foresight's "in-house experts on space solutions" ( their title, not mine) and he managed to answer a few questions

1) max screen size is 16ft x 9ft
2) use a projector of 16:9 ratio that supports 1920x1080 resolution
3) min lumens of 3,500 and 2,500:1 contrast
4) lumens more important than resolution and contrast

So based on this information, i bought the GT760 as it has the highest lumens in its price category and for a 16x9 screen (thinking of getting a seamed vinyl tarp to go full size), i think i'm going to need all the lumens i can get. Will see how it turns out.

[Jsgregg]

I have the GT760 and one thing that you should know is that it's native aspect ratio is 16:10, so it displays at 1280x800.

[Dax]

Jsgregg, are you sure on the aspect ratio of the new GT760? I had thought they changed the aspect ratio on the latest version to 16:9 and that 16:10 was no longer an option?

[Jsgregg]

I am positive...it is 16:10 native. I was surprised too, but it is. It's really wierd, you look at the specs on their site and it says 720p native, but look at the aspect ratio and it is 16:10 native. I hooked it up and it is 1280x800.

[Dax]

Very strange, but good information for someone to know. Thanks for the update!

[Jsgregg]

This article explains:

http://www.pcmag.com/article2/0,2817,2429748,00.asp

[Yongchai]

Regarding the 2 ratios 16:10 and 16:9, if 16:9 is the software's native resolution, and we set computer at 16:10, what happens? Does it stretch the image so a 9ft tree is now 10ft, or does it retain the size of a 9ft tree and add in 1ft of sky?

Also, for the projector, because there is no zoom, i guess its size needs to be adjusted by its distance from the screen (for a 9x16 screen, distance is 8'4") can i build the frame now with this distance in mind or should i wait for the projector to come and build the frame only after projecting in realtime and getting its actual distance from screen?

Also can anyone confirm that this model has to be flipped upside down for mounting? Or can we build a shelve and set it right side up and have it project down?

And just to clarify, projector central shows that to mount the GT760 on the ceiling, the image shows that the lens needs to be higher than top of the screen but it states a numerical value of -1'1". I'm correct in assuming that lens needs to be higher right? (the negative value is confusing me)

And is this 1'1" value absolute or can i move it higher and tilt projector down so i reduce the chance of my ball bouncing back and hitting the projector?

[flydigital]

Regarding the 2 ratios 16:10 and 16:9, if 16:9 is the software's native resolution, and we set computer at 16:10, what happens? Does it stretch the image so a 9ft tree is now 10ft, or does it retain the size of a 9ft tree and add in 1ft of sky?

Also, for the projector, because there is no zoom, i guess its size needs to be adjusted by its distance from the screen (for a 9x16 screen, distance is 8'4") can i build the frame now with this distance in mind or should i wait for the projector to come and build the frame only after projecting in realtime and getting its actual distance from screen?

Also can anyone confirm that this model has to be flipped upside down for mounting? Or can we build a shelve and set it right side up and have it project down?

And just to clarify, projector central shows that to mount the GT760 on the ceiling, the image shows that the lens needs to be higher than top of the screen but it states a numerical value of -1'1". I'm correct in assuming that lens needs to be higher right? (the negative value is confusing me)

And is this 1'1" value absolute or can i move it higher and tilt projector down so i reduce the chance of my ball bouncing back and hitting the projector?

Scaling/stretching or larger view area is software-dependent... Hopefully the software is smart enough to add view area for a given resolution and not scale/stretch from default/native.

I just got a GT760. No zoom and yes the size depends purely on distance from screen so you should wait and test this before deciding the actual position of the projector.

The projector has various projection modes including standard, flipped, reverse, and reversed + flipped so you can mount this any way you want to. The up/down angle required and keystone adjustment will change and you may run into the limits here, so it is worth testing it out at various temporary positions/modes. I have mine mounted upside down with universal projector mount, flipped image, and the projector is about 2' above the projected image top border. The projector points upwards about 10 degrees. Yes I think the lens needs to be higher (and pointed slightly upwards) than the top of the screen, when upside down.

You should be fine moving the projector higher than 1'1" than screen top, using tilt angle and keystone accordingly. Not sure what the limit is, but my estimation is about 3' (keystone limit).

Thank goodness I'm using foam balls right now, because my son has already sent balls straight up into the projector... I don't think any height will be out of range completely. Best to put some kind of barrier under the projector. I'm considering mounting a 1/2" thick 1x1' square lexan piece for protection (so the remote still works).

[Jsgregg]

The projector has some vertical lens shift also. So you do have the ability to raise or lower the image somewhat before having to engage the keystone adjustment.

[golfsimxpert]

The largest screen I have ever put in without seams is about 18' wide and 10' high in a room 22' wide by 30' deep by 12' high.

No seam required. Do suggest at least 18" to back wall as it flexes more from shots the wider it goes. check out "the Golfer's Academy" in Burlington, ON to see pic's.

The projectors were Optoma's and mounted about 22' from screen. No Shadows at all. When you flip them and mount with bracket the projection angle changes and shadowing disappears. Especially up at 10'. Lighting was wide open net tops at 12' in a 25' high ceiling. Images looked great. Screens can be built in all aspect ratio's but for that width the 16:9 gives the widest screen with a 10' image height.

The Panasonic VX 440U has been a great projector for me and I have put in probably 50 of them with great success. 4000 Lumens and looks good. If you build in a top skin over top the hitting area you eliminate most ambient light.

[Yongchai]

Couldn't find a Panasonic VX440U, but there is a VW440U

http://www.projectorcentral.com/Panasonic-PT-VW440U.htm

But at 4000 lumens, u probably mean a VX400U?

http://www.projectorcentral.com/Panasonic-PT-VX400U.htm

However, both projectors never crossed my screening process probably beacause i was looking for short throw projectors to eliminate shadows (which i guess i need not have worried about) and even if it did, i would probably not have picked it because of price!

Will wait for my GT 760 to arrive and do some trial and error, but not sure how much fiddling i can do with no support structure up at 10'1". A ladder in the middle of the room holding a pricey projector up, sound like a disaster story waiting to unfold...