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Holy screen door effect batman!

1098 Views 8 Replies 5 Participants Last post by  armystud0911
I just got my new outdoor projector in the mail today (indicus IN3128HD) and while going through slides, I found that I could easily.identify a sde up to about 1/3 the image width away. I figured that since it was dlp and 1080p, I wouldn't have much sde but it is showing up in a big way. I can't really see it in movies but it is very much an issue with stills. I know many people here claim they can't see a pixel structure up to 1foot away but I have always been able to pick it up, maybe some models have improved it a lot.

The last.projectors I watched were LCD's and even though they were decent quality ht models, I could always see the sde, this dlp doesn't seem to be any better.

The overall image quality is decent on this unit, I wouldn't put it in your ht but for what it is, I am really impressed. The brightness is insane, a true light cannon, I threw a 160".image up on boc in video mode with eco mode and it was extremely.bright. The image lit up the entire room way more than I was expecting, it definitely belongs outside or in a bright office.
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Just to show the brightness, here is a shot from my phone of a 45" diagonal image on a sheet of black mattboard. The camera couldn't resolve the color because it was so bright compared to the rest of the room and I had all of our lights on in the first floor.

IMAG0842_1.jpg 1017k .jpg file


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SDE is always a visible artifact from projectors. Most people with typical 20/20 vision should be able to recognize visible pixel structure under 1.5x the screen width, so the fact that you can recognize SDE is not at all a surprise to me. Certainly some people can't see SDE with their particular projector, but that's them. Also keep in mind, using a business class projector may exacerbate this issue depending on the DLP chip that is in use. But, at 1/3 image distance you are far closer than basically anyone would recommend viewing from, so it just doesn't surprise me in the least.
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Thanks, thats good to know, the more I looked at it the more apparent it became, I started noticing it near my seat with still images, with movies its not much of an issue though.
You will also notice that the max screen size used for 1080p projectors is about 120" the bigger the image the bigger the pixels and the farther you need to be away from the screen not to see them.
There's a difference between the ability to see pixel structure and screen-door-effect. At 1/3 screen width, pixel structure will likely be visible on even a 4K display - though I've never actually paid attention to how far away I was standing at the point pixels become visible. On a sharply focused 1080p projector I can't see pixel structure at 1x (better than 20/20 vision according to my last eye exam) but the effects sometimes can be recognizeable, thought not distracting.

SDE on the other hand is a motion artifact that should not be visible looking at stills. If you're seeing some form of moire, whether it be stills or motion, assuming it's not in the source, the signal is likely losing something somewhere, possibly from duplicate processing, inefficient scaling or color sampling. To eliminate it, you need to check your settings to make sure source output is set to best match the resolution of the panel and any extraneous signal processing is disabled (not always possible depending on the device design without going into the service menu). General rule: use as little processing as is necessary. For 1080p sources no processing should be required. For non-1080p material, let the device that does it the best handle everything, whether that be a player, computer, AVR it's routed through, or the display.
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Originally Posted by airscapes  /t/1517723/holy-screen-door-effect-batman#post_24374080

...max screen size ...about 120"
Screen size, resolution, and quality, are all relative to viewing distance.

Visual acuity generally finds that just beyond 1.5x screen width, most people can't possibly see visible pixel structure on a 1080p image. It will look as sharp as it possibly can. But, there is no specific size associated with any of it. Just resolution then a formula to determine screen size vs. viewing distance.

Increase the resolution, and you can be closer and not see visible pixel structure.

That said, resolution of a projector is not necessarily tied to inter-pixel gap (SDE). So, it is possible for some people with sharp eyesight to notice SDE at ranges where they may not be able to see pixel structure.

Typically though, I would expect at about 1x screen width most people would not see SDE with a 1080p projector.

Still, all about distance vs. resolution vs. screen size. Nothing really 'fixed' in any of it.
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Originally Posted by armystud0911  /t/1517723/holy-screen-door-effect-batman#post_24355370

Just to show the brightness, here is a shot from my phone of a 45" diagonal image on a sheet of black mattboard. The camera couldn't resolve the color because it was so bright compared to the rest of the room and I had all of our lights on in the first floor.

IMAG0842_1.jpg 1017k .jpg file
Hard to tell from a photograph but it looks like the projector is too bright, over emphasizing the whites. I would tone it down a little. The best way to check for SDE is to set the PJ on its white test setting. If its really bad it will really show up there. Also this is just a 3000:1 contrast so you will end up with more SDE than you would with a higher contrast PJ. The picture looked pretty good though.
The photo was taken from my phone and very washed out, this is from the camera and is not apparent in person. Since this was taken on black matte, I do not intent to actually use this as a screen but. To have a look at what is possible in broad daylight.
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