?? Projector Central's FL ambient light contradiction for Optoma GT1080HDR vs EH412ST

[GolfLikeItsaPandemic]

I'm comparing Optoma's EH412ST vs Optoma GT1080HDR. Plugging in my 10'6" screen width at 4:3 aspect ratio gets me 36FLs for the EH412ST and 23FLs for the GT1080HDR (see attached screen grabs). Thats all well and good BUT then projector central mentions that:

36FLs of the EH412ST are "recommended image brightness for rooms with *LOW* ambient light" and that the
23FLs of the GT1080HDR are "recommended image brightness for rooms with *HIGH* ambient light".

I was certain that higher FLs should be equating to overcoming more ambient light. Is there something you and ProjectorCentral know about the differences in these projectors that I'm not seeing/grasping? Trying to compare apples to apples here.

[Adam Prince]

Something is off there, I agree. I have the gt1080hdr, and it's plenty bright for my needs in moderate ambient light. The thing is, too much ambient light in any sort of setup is going to be terrible because it will wash out even the brightest projector. The screen itself, in presence of ambient light is as BLACK/DARK as anything will ever appear, and that's before turning the projector on, so if you want good contrast and good black levels(even with the most expensive proj), you need to minimize direct ambient light on your screen. I actually turned the brightness of my Optoma down to make it optimal. Shade the light sources from your screen, and the 1080 will work great.

[Adam Prince]

The only way a super high lumen proj would really be worth your time is in extreme ambient light, where you'd be using a dark grey screen to get your black levels back.

[Dax]

It appears that one has gone through projector central’s testing and the other has not. This, projector central was amble to test the actual brightness of the screen when they did their testing. The other is just what they estimate based off of manufacturers specs.

[GolfLikeItsaPandemic]

Thanks all. Looks like Dax has nailed it. If I do the manufacturer's spec they're much closer in FLs.

I think I'll go with the Optoma even though its fixed offset means I'll have to do a vertical keystone of about 10 degrees.

Edit:
Looks like there is still something odd going on though. My main concern was the qualitative description of ambient light levels that Projector Central is attributing to each projector. Its use of "Low" and "High" seem to be used depending on where in that projector's range those FL's fall. So if a projector is capable or hitting 150 FLs at one end of its range then when its setup is at 25 FLs it proclaims that isn't good enough for High ambient light but another projector that maxes out at 45 FLs at one end of its range then when its setup is at 25 FLs it proclaims that is good enough for High ambient light.

That seems misleading to me. Shouldn't equivalent FLs mean equivalent handling of ambient light. I'm not an AV guru, hopefully there is one on here thats willing to school me on this.

[3on3putt]

Thanks all. Looks like Dax has nailed it. If I do the manufacturer's spec they're much closer in FLs.

I think I'll go with the Optoma even though its fixed offset means I'll have to do a vertical keystone of about 10 degrees.

Edit:
Looks like there is still something odd going on though. My main concern was the qualitative description of ambient light levels that Projector Central is attributing to each projector. Its use of "Low" and "High" seem to be used depending on where in that projector's range those FL's fall. So if a projector is capable or hitting 150 FLs at one end of its range then when its setup is at 25 FLs it proclaims that isn't good enough for High ambient light but another projector that maxes out at 45 FLs at one end of its range then when its setup is at 25 FLs it proclaims that is good enough for High ambient light.

That seems misleading to me. Shouldn't equivalent FLs mean equivalent handling of ambient light. I'm not an AV guru, hopefully there is one on here thats willing to school me on this.

Careful with keystone, as it can eat away at your picture quality. I would be more concerned about the 10 degrees of keystone than the difference of 200 lumens.

(It looks like the vertical offset is actually the same for those 2 projectors though?)

[GolfLikeItsaPandemic]

Yeah, I'd really like to avoid using keystone correction. I'm setting up in a small room (9' ceilings and 14' long wall to wall). My max throw ratio is 0.5 to avoid shadows which has the projector sitting directly overhead. This seemed ideal at first but then the search began... I can't seem to find a projector that has a lesser vertical offset AND has a short throw like 0.5 or less. I'm close to giving up the search and just falling back on a 10 degree keystone with the 1080HDR Optoma. Seems like I'd have to pay big bucks for a projector with a vertical lens shift. Perhaps there's a reasonably priced way to achieve what I'm looking for using a projector with interchangeable lenses but at first glance those options seem to be very expensive as well.

Edit: to tag 3on3putt

[3on3putt]

Yeah, I'd really like to avoid using keystone correction. I'm setting up in a small room (9' ceilings and 14' long wall to wall). My max throw ratio is 0.5 to avoid shadows which has the projector sitting directly overhead. This seemed ideal at first but then the search began... I can't seem to find a projector that has a lesser vertical offset AND has a short throw like 0.5 or less. I'm close to giving up the search and just falling back on a 10 degree keystone with the 1080HDR Optoma. Seems like I'd have to pay big bucks for a projector with a vertical lens shift. Perhaps there's a reasonably priced way to achieve what I'm looking for using a projector with interchangeable lenses but at first glance those options seem to be very expensive as well.

Edit: to tag 3on3putt

You're trying to hit from 7 feet away from the screen?

And your screen is 126 inches wide?

[Lucas MacEwan]

I have the EH412 st. Estimated at 7-8 feet from the screen. Ceiling mount. Pretty happy with it, although its in my garage and I blacked out the windows. Best image quality is with all the lights off except for a small table lamp. If I have one of the ceiling lights on which is behind the screen the image is not as crisp. 5 minutes ago I just finished hanging a blackout sheet used for photography behind the screen. Now with the ceiling light on the image is better. When the ceiling light is off, the image appears the same.

[Lucas MacEwan]

Here is a pic as the black sheet was hung partially covering the back. You can see on the right side.

[3on3putt]

What's your screen size and resolution?

[GolfLikeItsaPandemic]

You're trying to hit from 7 feet away from the screen?

And your screen is 126 inches wide?

3on3putt Yes. I took some more measurements just now and I can get as far back as 8.5ft from the front wall before my driver starts to tickle the back wall. If I'm leaving 1ft for my future Par2Pro SQ screen to sit from the front wall then there's 7.5 ft between the middle of my stance and the screen (meaning a little bit less for the ball when I'm using driver and have it up at my front foot. My room is 11'10" wide. I have been intending to make a screen thats 8.5 tall by 10.5 wide and padding the walls/ceiling directly vs having an enclosure.

Do you advise against having such a large viewing area from so close? Are you thinking its too risky to be hitting that close?

[GolfLikeItsaPandemic]

Lucas MacEwan Thanks for sharing your setup. Do you have a short ceiling that required you to use a keystone to bring the image up?

I have excellent control of ambient light in the room with setups in place to completely black out the room and for only new golf-simulator-installation-specific lighting on dimmers to be added as needed. Also, I'm planning on blacking out the entire walls/ceiling/front-wall with padding that will be black already. Maybe a blackout photography sheet will make it into the mix as well, I'll see how it goes.

[3on3putt]

3on3putt Yes. I took some more measurements just now and I can get as far back as 8.5ft from the front wall before my driver starts to tickle the back wall. If I'm leaving 1ft for my future Par2Pro SQ screen to sit from the front wall then there's 7.5 ft between the middle of my stance and the screen (meaning a little bit less for the ball when I'm using driver and have it up at my front foot. My room is 11'10" wide. I have been intending to make a screen thats 8.5 tall by 10.5 wide and padding the walls/ceiling directly vs having an enclosure.

Do you advise against having such a large viewing area from so close? Are you thinking its too risky to be hitting that close?

Nope not at all. I hit from about 7.5 feet. The reason I was asking is you could check out some BenQ projectors like the TH671ST. It would need to be mounted 10 feet, 7 inches away to fill a screen 126 inches wide, which would put it behind your hitting zone. However, the vertical offset is only 2 inches, which means you could mount it flush to the ceiling. It will not be in the way of your swing and I think there's a good chance it won't cast any shadows. I can't be 100% sure of that and I'd hate to give you bad information, but if it's only about 2 feet behind you and the lens is almost 9 feet high, you might be okay from a shadow perspective.

BenQ has a number of models with short vertical offsets which make them good for people with low ceilings. You may be able to find one with a slightly shorter throw distance that could put it even more over your hitting spot. BenQ's tend to be a little bit lower on the lumens count, but if you have control over the room light it should be just fine.