Axiom Home Page Forums General Discussion Home Theater Screen Door Effect...what is this?

I am about to pull the trigger on my first projector and I keep reading posts about Screen Door Effect. Could somebody quickly educate me on what this actually is? Does this occur in certain projectors and not in others?

I apologize if this is a stupid question, but I just want to be informed.

Thanks,

....pixelation, also known as the "screen door" effect. This means you can see the empty spaces between all the projected LCD pixels, so it can appear like you are looking through a screen door.

Here is an exageration:



It gets worse the closer you get to the screen. Some notice it more than others.

Coach,

Make sure that you don't think about everything you read. If you can demo the projector and you like it then buy it. Don't spend all of your time worrying about flaws when you like the picture. Most of the things I read on AVS I can't see or if I do it doesn't bother me one bit.

Hey Coach I know I posted this on one of your other threads, but I'll mention it again......

The screendoor effect is caused by the space between the pixels, known as the inter-pixel gap. In older LCD's from a few years ago, the screendoor effect and pixelation were much more of an issue.

However, in today's LCD projectors, the inter-pixel gaps on LCD panels have been reduced and physical resolution--the number of pixels on the screen--has been increased. Many of today's LCD widescreen format projectors use either 1280x720 or 1366x768 resolution displays. So, visible pixelation and the screendoor effect is really a none issue. At these new pixel densities, visible pixelation is usually eliminated at normal viewing distances.

In addition, the Inter-Pixel gaps have also been reduced a lot in SVGA and above resolutions, so screendoor is not really an issue anymore. For my Sanyo Z2, with a 110" diag. screen, you have to get within a few ft. to even see a hint of screendoor, and I have 20/15 vision, not that that makes a difference.

DLP technology creates a pixel by reflecting light from a tiny mirror, its edge definition is softer and less well-defined than LCD. So for the most part, at any given resolution, DLP still holds a slight advantage over LCD in visible pixelation, however, LCD is narrowing the gap.

I do agree that if you can demo a projector that is great, however, it sometimes is hard to demo a projector in a real life situation that will match your home. Just like my Axiom's, I researched projectors online, read hundreds of reviews, and lived over at AVSforum.com. ScreenDoor is not an issue with the newer LCD's, as long as you get one with a higher resolution. My Sanyo Z2 is a native 16x9 projector which is WXGA resolution. Screendoor is not an issue unless your a few feet away, who in the heck stands that close anyway. Rule of thumb is that you want to be back about 1.5 times the width of the screen, so for a 9' wide screen, your talking about 13' or so. There are a lot of other factors, including your room environment, lighting, etc...

Personally, I would be worrying less about screendoor and making sure your not one of the few people that suffer from the "Rainbow Effect" that is common with DLP projectors. The majority of people do not have this problem, but if your one of the few that does, you will hate DLP.

I would also get a projector that is 720p or above resolution. High Def is jaw dropping on my Z2.

Good Luck

Coach,

By all means check a demo of the projector you are considering. Individual sensitivity varys significantly. A small percentage (less than 10%) of viewers are sensitive to DLP's rainbow effects. I taught myself to see them and they don't bother me, however, I've spoken to one Axiom customer whose wife could not abide the rainbow effects of a DLP, which he exchanged for a plasma.

None of my friends have ever noticed or complained of rainbow effects on my DLP.

On the other hand, I've always been sensitive to LCD projectors' screen-door effect, and I always see it. DLP does not have any inherent visible pixelation, but of course you can sit too close to any projection system and the picture starts to lose cohesiveness. It's important to view a good demo of the unit. I recently viewed a demo of a new Panasonic LCD front projector that retails for $3,000 (the 700) and I was disappointed by the screen-door pixelation that was quite apparent to me. It might not bother others, but it would drive me crazy.

Regards,

I, too, am a little sensitive to the screen door effect. I have tried and failed to find rainbows on a couple of DLPs. I suppose that is a good thing.

The screen door is a near deal breaker for me. I considered some of the Sony models (and will take another look again, now that they've changed the cabinet design for the newer models to look more like the Samsungs), but always found the SDE to be too distracting, especially when dealing with straight lines that were slightly diagonal (making the line break up or shimmer a bit).

For now, it's just the old tube for me. Maybe at the end of the year or next January I'll get a new set. And it'll probably not be an LCD rear pro.

Oh - another thought. This is supposed to work well with non-HD sources with an LCD front projector - if you make the image slightly out of focus, the pixel structure will nearly disappear, as the lines between each pixel are slightly blurred. Of course, there is an obvious downside to this - blurry pixels. But, this blurring is supposed to help fill in the gaps between the pixels, and can "smooth out" standard def programming and a provide a "film like" image with DVDs.

What is funny, is that I am very very picky when it comes to the overall picture that I am watching, I am constantly tweaking menu settings to get the most out of my projector. At recommended viewing distances I find it hard to believe people still say they see screen door. Everyone's jaw's hit the floor when they see the performance of my Sanyo Z2 LCD WXGA projector, especially with HD material. Screen Door is a none issue unless your very close to the screen. With 110" + diag. I can't see why people would be that close, I guess there are still a few people that like the front row.....

Just my 2 cents but SDE is no longer an issue for most LCD's, as Rainbow is no longer an issue for most DLP's with faster wheels.

I have to agree with the above. I have a Z2 projector and my viewing distance is about 10 feet from the screen which is 100" diagonal. There is no screen door effect until I move about two feet in front of the screen, then I see it. So I know what it is and and don't deny its existence.
However, I doubt anyone would be sitting two feet in front of a 100" screen and would be affected by this. We watch digital TV and DVD on this unit all the time. My biggest complaint isn't the projector, but the crappy signal from the cable company. HDTV on this projector is absolutely great!
Also no complaints from anyone else that has viewed the setup, including all the teenagers on the X-box when they sit on the floor at about 5 feet.
My advise would be to see both technologies in action (LCD and DLP), find out if you are affected by either quirks of technology (the screen door for LCD or rainbows for DLP). If not - just go for the best deal (with my z2 I got an extra bulb thrown in $300+ retail value)

Living here in Cincinnati, I can not find any retailers that have front projectors on display. We have HHGregg(which doesn't sell projectors), Best Buy, Circuit City and Ovations. I believe Ovations only handles Runco projectors. If anybody is in the Cincinnati area that knows of retailers that have Front projectors on display, please let me know.

Thanks