Black Widow Help

[swesse]

Hi
New to the forum I wanted to contribute.
I am from sweden and has tried to create a BW screen. Though I can not get the results shown here and elsewhere.
When painting I first used some leftoverpaint to test with and then bought some correctly mixed 231 211 199 flat latex. The most interesting stuff is that the flat mix got me no way near these results, but the leftoverpaint with quite much sheen in it gave me better results. It also improved the visibility of the aluminumflakes. But sheen is not a very good performer when it comes to viewing angle and ambientlight performans...

Do you have any idea on how to proceede?

[swesse]

Rather new to this forum I have tagged along from AVS. I've tested BW mix using AAA. Different latex paints and acrylics. I am not saying sheen is the key or anything as I have'nt seen your originals.

What I can say is that in Sweden, a flat paint hides most of the aluminum and more sheen added reveals more flakes. In my case as I have'nt found a good base yet, I've added some sheen, I think I may have found a balance which leaves no hotspotting but really nice whites and blacks. In my case I tried for the BW-EW or Munsell N8-8,5. Have an old Toshiba Mt200 which is'nt a light canon...

So, if sheen do not give the screen it's properties it definately brings forward the aluminum.

If you have any other suggestions on how to get myself a nice BW screen I am all ears.

[swesse]

Just some info, according to paintshop, something is added to paint to reduce sheen, not the opposite.
Could this inflict the aluminum?

[mechman]

Welcome to the Shack!

More sheen equals less TiO2. Less TiO2 is not what anyone really wants. You'll have to experiment some with the paints available to you in Sweden to find the happy medium. We did it here in the US and it's been done in Australia and the UK as well so I don't doubt you can figure it out there in Sweden.

How exactly are you adding your sheen? Are you adding polyurethane? Or are you just buying a paint with a higher sheen value.

Flat paint works fine here. Harpmaker has used flat paint in all of his tests.

Keep in mind we don't check on AVS anymore. Last I checked though the view count surpassed all of the 'advanced mixes' within a month and a half or so! And we didn't even have to keep going back and pimping our own threads like some do!

[cynical2]

swesse wrote:

Just some info, according to paintshop, something is added to paint to reduce sheen, not the opposite.
Could this inflict the aluminum?

Welcome to the Shack, swesse!

Hmmm...I think I would take mech's advice and experiment with other paint manufacturers in Sweden. If too much sheen is used to brighten an image, it may begin to hotspot if used with a powerful projector. That being said, some people don't recognize hot-spotting for what it is and actually think it's a good thing...I've seen screenshots of images with hot-spotting, and the poster described it as having "an added pop". If you can find a base that works well with the aluminum additive, then IMO it's a better way to achieve whiter whites while maintaining black levels.

That being said, it's all about what you (the viewer) are happy with. If you are quite pleased with your screen that uses a paint with sheen, then you also have the option to sit back and enjoy it. My opinion is that you could do significantly better with an appropriate BW mix...but I wouldn't let that spoil your viewing if you're happy with what you've got.

And again...WELCOME!

[swesse]

Finalised my screen today, but as I painted over my old neutral grey (Munsell 8,5) I lost my comparison.
I also do recognize the problem you had taking pictures. Pics just seem light gray.

To answer how sheen is added, I just used a higher gloss(sheen) paint, I never used glossy paint for PJ's before but the difference is vast and without issues, instead the opposite. According to personal at my local paintshop, sheen is not added as I believed, instead they add something to lower it. Maybe it's so that TiO2 is there, but is "destroyed" by the added ingredient?

I have made some experiments and it seems more sheen makes the aluminum go to surface. I also added maybe 3:1 or so to get what is now a really good screen. So it's nothing wrong with the mix as such, but some sheen was necessary to achieve it. I do though emphasis it's not the sheen that makes it good ( sheen destroyed blacks...), though mix in total definately has some sheen to it.

Any european readers may try sheen of 7 or higher. for a NCS 0907-Y70R.

And thanks for welcome.

[wbassett]

swesse wrote:

Rather new to this forum I have tagged along from AVS. I've tested BW mix using AAA. Different latex paints and acrylics. I am not saying sheen is the key or anything as I have'nt seen your originals.

What I can say is that in Sweden, a flat paint hides most of the aluminum and more sheen added reveals more flakes. In my case as I have'nt found a good base yet, I've added some sheen, I think I may have found a balance which leaves no hotspotting but really nice whites and blacks. In my case I tried for the BW-EW or Munsell N8-8,5. Have an old Toshiba Mt200 which is'nt a light canon...

So, if sheen do not give the screen it's properties it definately brings forward the aluminum.

If you have any other suggestions on how to get myself a nice BW screen I am all ears.

Another welcome to the Shack!

A couple of quick questions if you don't mind. That might help some with determining what's going on with your situation.

What size is your screen and how far back is the projector?

I see you're rated at 700 Lumens. If that is video optimized Lumens then you're fine. If that is max Lumen on off brightness, then yes you are a bit low there. Depending on your screen size and setup could be why you are not seeing the same results.

Black Widow doesn't require a light cannon, but it also isn't something I'd recommend to someone that is a bit low on Lumen power. Same as I wouldn't recommend a gray screen in the N8 range to someone that is a bit Lumen deficient. Even if it looks okay now, as the bulb starts to age you'll quickly lose brightness and the image will become unacceptable before you are actually at the end of the bulb's life.

Based on your comments about sheen, I will take a guess that we're talking about a lower Lumen output. Sheen can get out of control very fast, especially with bright projectors. Hot spotting is the biggest issue.

One thing I often see is people forget about Lumens and recommended fL. 12fL is the recommended minimum for a dedicated theater with a white screen. I've seen some people question that or say 10fL or other numbers. I can assure you that 12fL is the industry recommendation. Can a person get away with less than that? Sure, nothing is totally cast in stone, but the image won't be as bright or vibrant as it would be at the recommended level.

Gain is a tool, not the ultimate answer. Say you have 10fL with a particular setup, then some gain to bring you up to the recommended 12fL is advisable. So in this example (and that's all it is at this time) you'd need a gain of 1.2 in order to bring you to the brightness recommended for a white screen in a dedicated setting. Darker screens typically have less gain than that.

One way in DIY to achieve some gain is with sheen. Like I mentioned though, that is not my favorite way to go about things because of the tradeoffs that can quickly come into play.

I see far too many people jump on one type of screen as their recommendations to others. It really needs to be a balance between a few variables in order to make a good recommendation to a person. Here is something quite a few people may disagree with, and I am not saying this because I am a screen person, it happens to be a solid approach- Ideally a person should start with their screen first, or more appropriately stated, evaluate their setup and viewing habits and decide what type of screen best suits that profile.

For instance if you do a lot of viewing with lights on, it will dictate a different type of screen and setup than if you only use the projector with all the lights off in a dedicated 'theater' type setup. More and more people are integrating projectors into their family rooms or multipurpose rooms, and do not have control over lighting conditions that others do. Then there is the scenario of someone that actually watches their projector during the day and has sunlight to contend with. Hopefully now my statement about starting with the screen first makes a little more sense. I would recommend different screens to people in each of these scenarios.

Once you have your viewing habits and room setting, then you can properly match a projector to the type of screen and environment. Notice that not once did I mention a specific screen... DIY or commercial. At this point we're just determining whether a person is better suited for a gray screen or a white screen, and if gray, a light gray or can they benefit from a darker gray.

This is why you often see people ask about the screen size, projector, and setting. So they can help with a proper recommendation. Sometimes though things are limited because the projector was already purchased and from there you have to work with what its capabilities are.

There really are no magic screens... but the right projector with the right type of screen will look spectacular.

Again... Welcome to the Shack!

[Harpmaker]

Bill, I've seen fl mentioned numerous times, but never an explanation of how to measure fl (foot lamberts). I have a light meter that measures in Lux, which are easy to convert to fl, and would like to know what to do to obtain a valid reading. I would assume I should use the 100% white field from the DVE DVD, but I'm not sure. Any pointers?

[wbassett]

Smokey can probably give the best answer to that.

[swesse]

Thanks for reply and info, much appreciated responses.

First off, PJ is Toshiba MT200, about 15" from screen of 92".
Should equal to my calculations about 14fL, as mt200 usually outputs around 350 calibrated.

Regarding screen made and sheen I would'nt say it's matte as I couldn't get Al punch with it. Though it's definately not shiny.

I will try to upload a few pics, disregard the mess and my little kid playing. Last pic shows (edited contrast and brightness to highlight Al flakes) a close shot maybe 2"x3". As you can follow on the Pioneer pics, were background is "BW" front a matte white. Other pics are different shades of BW on background of OTS grey about N8,5.

[mechman]

swesse,

It appears that the BW panels have blacks as dark as the background screen and whites that are much better. Is that correct?

The comparison to a matte white is as expected as well. What's the last picture of?

[swesse]

That observation is definately correct, though I did paint over the previous "screen" and lost my comparison. One thing I have noticed is that blacks during bright scenes looks a bit washed out not as before (not easy when I lost comparison), but this might be the result for more light being scaqttered through the room and therefore brightens the whole room. Something that is not easily noticed when only viewed on a sample. Still though I think the image still have better CR then before.

As you can see in the pics this setup is only temporary, with some old curtains to improve CR. Hopefully a "cave" will improve quite alot.

Last shot is a try to show the amount of Al seen in paint, but hey, Im not a professional photographer am I.

I must say that I really dig your swift answers and devotion to this, may be in future a more international approach towards products e.g. is possible.??