Improving Black Level

[Nathan Arizona]

I've owned the EPSON Powerlite 720p for just over a year now and for the most part have been extremely happy with this projector; however, this weekend I watched Harry Potter HBP and the limitations of the black levels became obvious. This is a very dark film, and I'm usually not so picky but it did hinder the viewing experience. Other films with a better balance of brighter and darker scenes look fantastic for the most part. I watch movies on the Theatre option and have about 500hrs on the bulb.

I project on a painted light grey screen (a formula I got on an AV forum) and have painted the wall around it a dark colour. Outside light is not a problem as I have a blackout blind on the one small window.

I'm looking for some ideas to improve the black level with my existing projector as upgrading is not an option at this time.

Would a proper projector screen improve black level or contrast and fool my eye into thinking it's darker?

Part of the problem is my dark wall around it; I can tell I'm not getting an inky black when I look over at it. Maybe this should be lighter? I also have a white stucco ceiling.

I’ve gone through all the options on the projector and no matter what option I’m on or any amount of trying to customize it, I have not been able to affect the base black level at all.

Any ideas for improving the black level are appreciated.

[Suntory_Times]

Use a white screen and mask the image with black borders (the larger the border, the better). Also run a calibration (using something like DVE basics) if you havn't already. Also consider running the projector in the high power mode.

[Termdj]

The white ceiling is also not a good idea. A lot of the light is being reflected from the ceiling. Try and change the ceiling to a non glossy darker colour

[Beta Man]

If a new screen isn't in the budget, perhaps get a "new formula" to paint a new one...... there are multiple paint formulas out there because many people have experimented with different ones...... just pick one that was designed to give better black levels.

Also, I second the "Black Border" make it velvet or something that will absorb the light.... and paint everything you can with flat paint to reduce reflections..... Especially the ceiling if the projector is ceiling mounted.

[bhampton]

I don't have that pj but I bet there's a whole thread about it on AVS.

You're much more likely to find someone there who's gone though the same experience.

Projector settings can have a big effect. And using something like DVE may not help you enhance the black level but by setting the brightness precisely the image may be improved even with an inflated black level.

Edit - If it's the Epson HC 720 .. Here's the 51 page owner's thread.

http://www.avsforum.com/avs-vb/showthread.php?t=917897

-Brian

[Nathan Arizona]

I will indeed paint my white ceiling as it is low; the top of my screen is only about a foot from it -- I'm thinking this is my biggest issue.

I will try the DVE basics and run the projector at a brighter setting, but the projector seems to have a set black level that does not change with adjustments; however, a brighter and better balanced image may fool my eye.

I may try a different formula or go with something better suited like Screen Goo. I have the screen boarded with a flat black tape.

Thanks for the replies.

[BarkingGhost]

Originally Posted by Nathan Arizona

I watched Harry Potter HBP and the limitations of the black levels became obvious. This is a very dark film, and I'm usually not so picky but it did hinder the viewing experience.

This is one of the biggest reasons why I have followed digital projection for years and have not yet moved into that arena. Instead, I am still firmly planted in CRT projection (ahem, the three-eyed monsters).

One of my favorite movies in Dirty Harry. imagine trying to watch the back alley scene that takes place at night. No way to see what is going on during this "pie hawker" scene. Or, in the Kill Bill 2 coffin scene when the flashlight isn't on.

I do have a rather crazy pair of eyes and can see in the dark. This means even in my bat cave with complete control over ambient lighting I can still see. With digital projection based on blocking light that is on all the time the rather high black level is difficult to live with.

In the case of digital projection from an owners perspective you may need to ask yourself if you can like with a lower peak light output, and if you can then consider color-correct filters to increase the contrast ratio, and ND filtration to lower the black level.

I tried this a few years ago with some success on a LCD-based projector marketed toward HT use, but even with color correction and neutral density filtration the black level was still higher than my worse CRT projector.

I had hopes for SED/FED making it to a consumer market (vs a niche market) and on a large display size, but economics and poor decision-making conditions have seen to crush those hopes--and those technologies were based on producing light only when called for.

If you are looking to make the best of what you have I would consider buying a calibration kit (or renting a professional kit) and filter the output. Of course, any rewards you achieve will be limited by the environment in which you use the projector in.

[Swede]

I'm not sure which projector you have, but if you can adjust iris settings, I would suggest lowering it as much as you can while still getting a bright enough image otherwise, also setting the bulb to low-lamp mode usually increase black levels, especially on older lcd projectors. I can also recommend using DVE essentials to calibrate your projector, especially to get the brightness/contrast levels down to get the best blacks you can without crushing the blacks too much.

Setting the projector to higher brightness wouldn't help you at all in darker scenes (which is where you mostly notice the bad black levels to begin with, like you said) so I wouldn't recommend doing that.

I can also recommend masking off the black borders with black velvet, so if you have a 16:9 screen, you would mask the left/right borders, that should help quite a lot with increasing black level and get a more contrasty image. Since you already have a darker wall color you may not need to repaint your walls black, but like others said if you can get that ceiling darker that's also highly recommended.

[Deciazulado]

All surfaces black except where noted ,
this is how the ideal would look:

room_diagram_far_sitting_distance.jpg
Sitting farther that 2PH maybe you might need to bias light the back wall behind your screen if your projector doesn't have deep enough blacks.
If needed, increase the bias light from 0 up till the blacks on the image are perceived as dark and the image looks good or the back wall looks like a medium grey from a test disc

The little guy enjoing his mixer is sitting at 2.75 PH (Picture Heights) from his UltraPanavision 2.75 wide screen.


room_diagram_close sitting_distance.jpg
At around 2PH you might not need to bias light the back wall (the screen image itself becomes your bias light) specially if your projector has high enough contrast/blacks

The little guy enjoing his mixer is sitting at 2 PH from his UltraPanavision 2.75 wide screen.

He's probably enjoying Ben-Hur like never before.


I did this rather quick by eye so please excuse any scale errors or drawing horrors