I took advantage of the last of the really bright sunny days in New York for this year and got some shots of the black-screen in action with an eye on further opportunities to improve the design.
I never get tired of seeing this
Here is a pic of my screen with the lights on and the blinds open during the afternoon with bright sun. My living room is a projectors nightmare with white walls, white carpets, white ceiling and a large window right next to the screen. Room lights are one thing but with sunlight pouring in, that is a different challenge:
While comparisons to other screens are fun, the performance in challenging conditions is what counts here. Here is the same pic with the blinds closed and lights off. With white walls etc and marginally effective blinds, the room never gets very dark during the afternoon. This is the darkest I could make it though:
The screen is set to 110 inches. With my lens, I can zoom it all the way to 170 inches without moving the device. Under my black screen, is a 150 inch white screen which I used to use before I built the black one. I zoomed the image until it came off the edge onto the white surface for a side by side:
Now, it's no news that the white surface is inferior with sunlight pouring in. The extent to which it is washed out though, shows the level of brightness it is contending with. For the shot, I adjusted the settings to try to optimize them for the white surface but it didn't make much difference. You can barely even see that an image is projected on the white screen. Here is a slightly closer look:
Here is the same shot with the lights off. Note how the reflection off the white walls makes the room brighter You can see why nerds paint their walls black:
I criticize reviewers who compare a black diamond or Supernova to their reference white 1.0 gain screen and state the revelation that the black screen is better with the lights on. A grey screen would be better than the white screen too while we are stating the obvious. In this test, I was looking for opportunities to improve the design.The comparison to white is only to give some idea of the conditions that the screen is dealing with. It is hard to tell room brightness in a pic . With bright room lights, my projector will give a good image, even on white. It is only against sunlight that this level of wash-out occurs.
As much as I love my screen, I identified a few areas with opportunities for improvement. The primary one is surface glare. I noticed a fair amount of glare on the black diamond screen at best buy and that was without any sunlight. Mine has less glare (in my opinion) but, in really bright conditions, I can still see some glare off the translucent layer. It is reasonable to assume that increasing ambient light will increase glare until you reach a point where the image is no longer watchable and that this should be true with any screen.
On my setup, It isn't easy to see the impact of glare until it gets brighter than I would ever have it in a real world setting but still.... It is the difference between the crisp sharp image that is full of Pop that I get with room lights on and the watchable but not optimal image I get under super high levels of light. Its nothing I can't live with but while I'm in DIY mode, why not explore all opportunities to enhance it.
I decided that I want to test a 5th layer which would be an anti-glare / anti reflective transparent surface and possibly even a scratch resistant finish.. This is different to the diffuser layer. The diffuser film takes care of hot spots from the projector but not all of the glare from the sunlight. . I think it would make watching in super bright conditions comparable to watching with just room lights in an evening (we'll see). I also think that it will increase the viewing angle (in high ambient light). Less important to some, a glass front would also present a more professional display finish like you see in high end commercial set-ups as well as protecting the fabric from scratches, kids and cleaning ladies who are all enemies of screen surfaces.
The problem with high ambient light is that projectors rely on darkness to produce blacks (we have solved for this by using a black screen), and glare off the surface that blocks our view. The latter is rarely addressed in a major way because most screen / projector combos would fail way before the room got bright enough for glare to be the reason the image fails. Using a black surface address the major barrier so it seems like a logical leap to look at ways of reducing glare for further improvement (selective reflectivity is another but that's another thread).
I did some research and have ordered around $300 worth of samples that include:
- Anti reflective glass
- Anti glare film
- Anti reflective / anti glare plexiglass
- Anti glare diffuser glass
- Custom LED display glass with embedded optical lenses
- Tinted matte reflective plexiglass
Scratch resistant anti reflective plexiglass
My theory is that it will offer greater benefits than micro louvers without affecting image clarity and viewing angle (as the louvers do). The louvers were ineffective at stopping glare in my opinion on both the black diamond or the louver film I tested at home (I know louver film is not intended as a glare control method directly - they just attempt to block the light all together from a direction). Blocking light from above sounds better on paper than it looks in reality. Again, just my opinion / observation, but it added little that I didn't already have from using a black screen surface.
I am not sure why SI opted not to add a separate anti glare surface. It defiantly wasn't because they are trying to save on cost. I think it is more likely that they didn't consider it because the potential benefits only become obvious once you reach a certain level of ambient light performance ( ie in conditions bright enough for glare to be an issue). Perhaps it is easier to say, most screen set-ups don't let you get bright enough for glare to be the major issue. Washed out images normally make the set-up not viable first (before surface glare).
I can't wait for the samples to arrive so I can start testing them. This is the last phase of the black screen project - getting the build quality and design to a level that is comparable or better than the high-end commercial offerings. Preferably in a way that doesn't require me to become a carpenter. An anti-reflective/ Anti glare / scratch resistant glass layer at the front would add to that high end plasma look and make it look like a commercial screen.
There is a question around the point at which the cost of extra layers stops it being viable as a DIY offering. Finishing a large screen with a piece of anti-reflective / anti glare plexiglass will add $100 -$250 to the project costs. While this still leaves it way below high end commercial offerings, some would rightly point out that it is firmly within the territory of low end commercial grey screens. The extra layer certainly isn't necessary as the black-screen looks great without it. Even some of the $5000 commercial options don't have it but I want it to be the best that it possibly could be and I think this layer will make a small but noticeable improvement in higher ambient light conditions.
As an FYI, I have seen options for anti glare / anti reflective plexiglass for $5 - $9 per square foot. Testing will identify if they can double as diffuser or tint layers. One of the samples I ordered is a tinted charcoal plexiglass diffuser with a 25% light transmission which is perfect. It could potentially act as the rigid flat layer, the tinted layer and the diffuser in one. If it works, it would reduce the number of individual layers and take the cost back down to where it was before.
If anyone has any experience of anti-glare / anti reflective films or glass for use in screen surfaces, I would love to hear about it. Assuming we are talking about the appropriate matte finish transparent options that have a chance of working. When I say transparent, I do not mean like the diffuser films which are color transparent but hazy overall. The glass and film options I ordered claim 97% light transmission and glass like transparency (albeit with a matte but very much see-through appearance). When fixed to the front of the screen, the image should go straight through with no reflection, hot spots or glare. They should also block glare from other sources (like the sun) from reaching the screen layers underneath.
I will post results when the samples arrive and will report back on the claims that glare can be reduced by 97% without sacrificing optical clarity. We'll see!