Optoma 8200 Review - Page 2

I am sure it's nice to know that Mark is taking the ball and running with it. You guys seem to have a great team over at AVS..might have to change the name to Audio Video Superheros

Can you advise your screen type and fabric used in your review please. thx

Great review. The one place that we differ on is the lumens. When I get to work I will post my calibration results but my lumens reading was allot higher. Your meter is better than mine though as I am using a i1Pro.

I am using a Stewart Studiotek 130G3. Projector is 15ft back and Ceiling Mounted. Disregard below 30 as the i1Pro does not read correctly under 30.

Mode - User
Contrast - 41
Brightness - 41
Color - 57
Tint - 47
Sharpness - 2
Noise Reduction - 0
Gamma - Standard *Curve type 4, offset -1*
Color Temp - Warm
Red Gain 5
Green Gain -3
Blue Gain -5

Red Bias 0
Green Bias 1
Blue Bias -1

Pure color Off
Pure Detail Off

Mark,

Thanks for a great review. Your observations match my brief demo of the 8200. I believe my HD81-LV to be a bit sharper edge to edge and brighter. It has a manual iris that I run pretty closed down(11) for my 100" wide Stewart Studiotek 2:35 screen.

It was great to read your comparison to the RS20. I have never found LCOS or LCD or SXRD as seductive as DLP, no matter the black and CR advantage.

I look forward to your comparing other DLP models, such as Planar 8150, InFocus IN83 and BenQ W20000 in the future. My concerns about Optoma QC and reliability make me hesitant in going that route again.

Wing said you should tune blacks and whites with DB on to avoid the crushing.

"I can see that he said 7% on each side or ~14% total. Thanks for catching that and I'll update my post to reflect the change."

That's good, but Optoma is still on the hook for their misleading picture.

so is it 5% and 7% per side?

For a total of 10% of the Vertical and 14% of the Horizontal?

He told me crushed blacks or whites is a pet peave of his and the PJ wouldn't be designed with the problem. Also mentioned you could try different Cinema user choice - gamma's, I think there's five of them. But in the end simple contrast and brightness adjust ments should do the trick. Like when you engaged DB and saw the crushing in the high end you should just lower the contrast till the detail comes back.

I think you probably were, except that Optoma adds lamp modulation on top of it. Put another way, looks like the Optoma uses dynamic gamma to me (like the Planar does) and the suggestion to lower the Contrast setting would probably lower the native on/off CR, much like people could lower the Contrast setting on the Sony's to get rid of brightness compression, but at the expense of native/static and dynamic on/off CRs.

While the Optoma looks like it could use the lamp to avoid brightness compression, it still looks like it was doing dynamic gamma in your case. Maybe the TI part is doing the dynamic gamma and the Optoma part is doing the bulb, causing the compression. Either way I think your measurements show that gamma was changed dynamically, any way you look at it.

In this case it looks like the Optoma projector could have used the lamp to get more peak lumens for the same CR without using dynamic gamma, but TI's part may include dynamic gamma and need something to be done to avoid having it do that (like telling it different iris positions than you actually have because the lamp is compensating).

I agree that it is impressive, but looks like another case of a DLP manufacturer using DB to deliver more lumens, instead of to deliver more CR. What I mean is it looks like they could have given just as much CR natively, but with lower lumens. That is useful for people looking for high lumens and still caring about CR, but for those who were fine with less lumens (like those using a high gain screen) it doesn't necessarily give them more on/off CR that they could have achieved just by leaving 2 irises closed down (like the Marantz 11S2 and Sharp 20k). And without the DB artifacts.

If it is used for higher lumens when you have high CR and they start at a low static on/off CR iris position and end at a much higher static on/off CR iris position. If it was used for even higher CR at lower lumens that generally come with fairly closed down irises then I'm not sure it would still have the above advantage. It looks to me like they are using the fact that static on/off CR can go up significantly when going from a very open iris to closed down with DLP and that isn't likely to apply as much if they started with the irises closed down a fair amount for higher native or static on/off CR.

Just for the sake of trying to figure out how they achieve this, let's go with your 2000:1 without the DB on. If the lamp is turned down low (I'll say 60% of max for this example, although I'm not sure they could go that low) and they could shut 1 or 2 irises down in a way that would lower lumens by 30% and increase static on/off CR by 2.3x (to 4600:1) then they could have 1/2 the black level and 15% higher white level in a dark image with a little bit of white and the lamp at max with the iris(es) shut down.

In the above case what they largely would have achieved is higher lumens at around 5k:1 on/off as opposed to higher on/off CR.

Sorry if I missed it, but did you notice any difference in how loud the projector was between low lamp and high lamp? Is so, then how about between DB on with the lamp on low and DB off with the same? If they are pushing the lamp up to and maybe even beyond what it does for high lamp then some extra cooling might be necessary, especially for very dark movies where the iris might remain shut down a lot.

It would be interesting to see graphs like yours for the Lumis and see if they did things similarly.

--Darin

"the suggestion to lower the Contrast setting would probably lower the native on/off CR"

Darin no that's off because if they tune whites with DB on then blacks should be tuned with db on lowering the black level and keeping the CR intact.

I get the projector tomorrow can't wait to see what's going on.

I'll ask if when DB is set to off if the Iris is in wide open mode, maybe it's closed down a little for more CR.

No, that is not the way it would work unless Optoma messed things up. If you set the Brightness so that the mirrors are just off for video 16 with the DB off they should still be just off when DB is enabled.

Put a different way, Optoma and TI's job with the DB was to lower the blacks appropriately as the iris is closed down. That is how a proper DI works. A user in a dark room shouldn't need to set the Brightness with the DI enabled. Your statement above seems to have an assumption that they aren't doing the right thing for video black.

You can try setting the Brightness with the DB enabled and set it with the DB disabled and see if you come up with different values for this Brightness setting. If they are different by more than one click then Optoma should probably fix their implementation.

--Darin

Mark the light pulsing is the same item Alan started a thread on a while back.

http://www.avsforum.com/avs-vb/showt...743&highlight=

Both should be tuned with DB on which is the first thing I'll do tomorrow to keep the CR at it's best. You wouldn't tune blacks with DB off and whites with DB on, that would lower the CR. We don't want to leave the machine crushing whites for sure.

What a superb in depth review Mark! Aside from being so technically thorough, the review benefits from your being so in tune with what we AVS readers want to know about a display.

Thanks,

Rich

It seems like you are sticking with your previous claim that adjusting the Brightness while DB is on will give you a different black level than adjusting the Brightness with the DB off and then turning the DB on. I don't mean this to offend, but it doesn't seem like you understand what the Brightness does with a DLP projector. If you think I am wrong, please explain why you think you would end up with a different Brightness setting if you calibrated it with the DB off than with the DB on.

I don't agree. Some people may feel that way, but then why even using the DB? That is a serious question. What benefit do you or Wing think the DB brings if there is never any crushing? And I wonder if it is Wing's position that this projector doesn't do any dynamic gamma.

A DB brings some positive, but there is some negative that comes along with it if you use it to its full or very large advantage. If you want to make a rule that there will be no crushing near white ever or no brightness compression near white then that is also going to be very limiting as far as how much benefit can be applied to the on/off CR or total CR range. Put another way, there are benefits that most would like from a DI that they won't get if there is never any compression or crushing, even with that extreme image that Mark used (almost all black with a small gray step area).

I would like to see some actual numbers, like what native and dynamic on/off CRs you get after setting the white levels so that there is never any crushing near white, even and extreme image that is almost all black with just a little bit of stuff near white. We could then compare those to what people would get if they just turned the DB stuff off and set the white point for that way.

From what I am reading my doubts about Optoma knowing what they are doing with respect to DIs are increasing. This is the same company that finished dead last in the DI rankings by the Cine4home guys with the HD80. The Planar projector hadn't been reviewed by them at that point, but when they did review it they liked the DI very much from what I recall. And I think Bob Williams is one of the most respected engineers around here. I hope he won't mind me saying that I know his recommendation is to set Contrast and Brightness with the DB off and then turn the DB on with the Planar. And he has spent a ton of time optimizing their DI. I am sure that he would disagree with claims that you want to set things up to avoid any white crushing under any circumstances. That would be very limiting. Making the DI work the best possible includes some tradeoff when getting more benefit.

BTW: Just to add one example with respect to wanting no white crushing, what do you (or Wing) think the projector should do if there is an extended fairly dark scene where there is all of a sudden a very small glint off of something that then goes away? Do you think the projector should make the whole image brighter when that glint is there to avoid any crushing, not give much CR for the extended fairly dark scene because there might be a small glint of bright stuff coming up, go ahead and give that dark scene high CR and then deal with the small glint by doing some crushing or compression to keep the rest of the image from showing a bad pumping effect, or something else? I'm thinking of a scene in Johnny English like that and I think there is one in Donnie Darko that is somewhat like that, although it doesn't start as dark. There is also one near the beginning of There Will Be Blood as Daniel Day-Lewis takes a swing at the wall and sparks fly, but they might be bright enough that pumping would be noticeable.

--Darin

How would they get crushing like you showed in that one image if there wasn't a component that was raising 80%stim up to be equal (or close to equal) to 100%stim? The lamp wouldn't do that and the iris wouldn't do that. They may use dynamic gamma much less than Sony and others, but I don't see what else would cause 80% and 100% to be at the same levels in that one fairly extreme image.

It will be interesting to see. One nice thing about using LEDs like a DI is that they could still have manual irises like the Marantz 11S2 and Sharp 20k so a person could choose to start with less lumens, but higher native on/off CR. And I would expect that it would be easy to know how much the images had been dimmed when the LEDs were reduced, where a system with something like one manual iris and one dynamic iris with a DLP could have problems with the projector not knowing how much the light had been reduced by the dynamic iris (although this likely depends on the particular design).

I wonder if they have a similar thing to what this Optoma does, where some of the intra-image CRs are higher than the measured dynamic on/off CR would normally indicate, even for a projector with as much native on/off CR as that.

I may have missed it, but did you measure full screen white with the DB enabled? I saw that you got around 15% more for a small amount of white on black with DB on than DB off, but was wondering if full screen white was that much brighter or even more than that.

--Darin

Mark,

I just noticed something that seems a little odd. I noticed that you said the on/off CR was about 2000:1 with the DB off. But your chart of intra-image CRs as gray is swept from 0 to 100%stim shows less than 1000:1. I had been thinking that you were using just a little bit of non-black in that image, so that with a high ANSI CR compared to native on/off CR projector like this you would get close to the native on/off CR for your measurements in that image when you used 100%stim. Do the images for that one contain just a little bit of non-black? Do you do your measurements for black near those non-black parts? I'm trying to understand how you got so much less intra-image CR than on/off CR there without DB on and then what that means for the almost 2k:1 intra-image CR you got with DB on.

--Darin

The problem, though, is that lowering the contrast to eliminate crush reduces picture quality on brighter scenes where DB had no crush in the first place. Its the achilles heel of these DI algorigthms IMO.


Any scene that has near peak bright areas but is overall dark so that the DI clamps down will show it I would imagine...at least thats how it worked on my W5000. On Wall-e you can spot it during the 'space flight' scene when the AXIOM first comes into view. The bright edge of the ship is totally crushed. Its also easy to spot in side by sides with the JVC PJs...you can spot it more frequently if you look for it.

Once you spot it, you can use those scenes as a reference and tweak the settings to see the difference.