AVS › AVS Forum › Display Devices › Digital Hi-End Projectors - $3,000+ USD MSRP › Do projectors have overscan?
New Posts  All Forums:Forum Nav:

Do projectors have overscan?

post #1 of 8
10/5/09 at 5:10pm
Thread Starter 
I own a Pro8100 and have slight black bars on the sides of some DVD's. Both SD DVD and Blu ray. It's about 1 inch on average. Most titles don't but some do. For Bram Stokers Dracula(SD) I have a 1 inch bar on the right side throughout the movie. Not on the previews or main menu though. On X-Men(SD) I have a black bar on the left of the movie, doesn't appear in the menu either. Crouching Tiger Hidden Dragon I get about 1/2 an inch that varies from side to side and most times isn't there. On The Machinist(Blu-Ray) I get a 1 inch bar on the right side in the opening sequence and then it's gone.

Now I would think there is an issue with my pj, except it occurs at the same point each time I run the movie, it never changes. Also, running the DVD's through my comp onto my monitor, I can see the same amount of "dead space" that I see using the pj.

Does anyone have this issue? I was reading that many projectors have 0.5-1.0% overscan. Is it possible that the Pro8100 has 0% and is showing the full frame and(I'd guess) about 0.5% more than others? Setting overscan to 2.5% on the pj is way too much..these blacks bars are very thin.

Help?
Reply
Reply

AVS Top Picks

post #2 of 8
10/5/09 at 5:22pm
"overscan" refers to the amount of image you make bigger than the screen you are projecting on. So all projectors have overscan IE: make image bigger than screen.

unless you want to see the artifacts of the various source images that exist around the image you are trying to project.
Reply
Reply
post #3 of 8
10/5/09 at 5:42pm
Thread Starter 
Quote:
Originally Posted by Tryg View Post

"overscan" refers to the amount of image you make bigger than the screen you are projecting on. So all projectors have overscan IE: make image bigger than screen.

unless you want to see the artifacts of the various source images that exist around the image you are trying to project.

That doesn't make sense to me...if I enable 2.5% overscan the image doesn't get bigger, it crops it to fit within the 92" screen.

Also why would you make your projected image larger than the screen, you're losing part of the image in all four directions then?
Reply
Reply
post #4 of 8
10/5/09 at 5:44pm
Quote:
Originally Posted by novasol View Post

Overscannign by 2.5% on the pj is way too much..

i think your projector has a Manual Overscan mode that you can adjust. are you saying that the minimum it will go to is 2.5%?

it's weird that the black bars move around side to side. i haven't noticed this on any movies i've watched on my SP7205, though this may get me to watch Crouching Tiger again sooner rather than later
Reply
Reply
post #5 of 8
10/5/09 at 5:46pm
Quote:
Originally Posted by novasol View Post

Does anyone have this issue? I was reading that many projectors have 0.5-1.0% overscan. Is it possible that the Pro8100 has 0% and is showing the full frame and(I'd guess) about 0.5% more than others? Setting overscan to 2.5% on the pj is way too much..these blacks bars are very thin.

Help?

Sadly some disks are just badly framed. All or just parts of them so you might see thin black bars on one or more sides. Even more annoying is when you get a green or grey bar down the side. Best to avoid using overscan though as you're adding another scaling factor, and yes 2.5% is way too much anyway.
Reply
Reply
post #6 of 8
10/5/09 at 5:48pm
Quote:
Originally Posted by novasol View Post

That doesn't make sense to me...if I enable 2.5% overscan the image doesn't get bigger, it crops it to fit within the 92" screen.

Also why would you make your projected image larger than the screen, you're losing part of the image in all four directions then?

In my old SP7205, there are two "Overscan" modes. Crop and Zoom. Crop is what you are seeing with black bars around the entire image. Zoom is traditionally what is called "Overscan" because the image is being shown larger than the viewable area so you lose some detail around the edges.

My new RS2 these are separated into 2 different settings Overscan (aka Zoom on the 7205) and Mask (aka Crop on the 7205)

Why? Because sometime there are noise artifacts on the edges of images (especially SD sources) so enabling Overscan for those sources and turning it off for sources with no issues lets you deal with this without having to change the PJ zoom settings.
Reply
Reply
post #7 of 8
10/5/09 at 6:15pm
Thread Starter 
Quote:
Originally Posted by drewski11 View Post

i think your projector has a Manual Overscan mode that you can adjust. are you saying that the minimum it will go to is 2.5%?

it's weird that the black bars move around side to side. i haven't noticed this on any movies i've watched on my SP7205, though this may get me to watch Crouching Tiger again sooner rather than later

It's very,very slight and very thin on Crouching Tiger, the bar moves from the left to right and always in the same scene. In fact if I pause it I can get the exact frame it changes.

Quote:
Originally Posted by Ken Tripp View Post

Sadly some disks are just badly framed. All or just parts of them so you might see thin black bars on one or more sides. Even more annoying is when you get a green or grey bar down the side. Best to avoid using overscan though as you're adding another scaling factor, and yes 2.5% is way too much anyway.

This must be it. Reading more, I found projector reviews that mention pj's default overscanning to be up to 1%. My Epson 720 cuts off just enough it seems, to not see the bad framing. So just live with it I guess..centering and zooming the image is probably the best method? I do have manual overscan but won't use it if it's degrading the image
Reply
Reply
post #8 of 8
10/5/09 at 6:27pm
Zooming the image is definitely prefered if you want to preserve the maximum resolution of the image. Using electronic overscan will compromise your resolution and soften the image. This is easily seen on a test pattern that shows single pixel lines at your projector's native resolution, such as a multiburst pattern. Display the pattern and toggle between full scan and overscan modes while watching the single pixel section of the pattern.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants Affiliate

"Advancing the art and science of electronic imaging"
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home

AVS Top Picks

AVS › AVS Forum › Display Devices › Digital Hi-End Projectors - $3,000+ USD MSRP › Do projectors have overscan?