RS-MaxxMudd Experiments - Page 3

I agree. Something looks 'off' in the last mirror shot with color bars titled "Full Coating, Off Axis". If you look at previous mirror shots with initial coating - off axis - the image looks fine sans mirror. But if you look at the above said picture, it appears to be a dark bar overlayed down the middle of the photo, including both mirror and sans mirror. Look at the bottom of the bottom mirror, you can see the curve but only a very slight change in image.

mech

PS. After reading my post it sounded accusatory. I apologize. I didn't mean it that way. I guess what I'm asking is does it look that bad in person? And the only reason I'm asking is because I was contemplating a mirror up until this point.

I think he probably is, those are the ones I was referring to as well, but we discussed it in chat, I should have posted that in here as well too when you asked.

I finally got all my samples and films too. Some of the films look very interesting, but I'm thinking there may be the same viewing cone problem that we saw with your frosting tests. It's worth checking though and should be fun. I'm also looking around for a broken RP HDTV so I can tear it apart and look at the screen. One of these films when placed over platinum looks exactly like my brother's JVC HDTV, the difference though is his projects from the rear and the dark smoked plexi is on the opposite side of the projected image. Anyway, my samples are in though. I even have gray films (one matte silver gray) that allow 25% of the light hitting it to pass through.

Tiddler you are covering the paint end, I'll continue with the nonpaint tests (now that I have samples to test with that is) Mine will probably be in a different thread though to keep the topics separate and not confuse people

And who said DIY wasn't fun? lol

Some interesting experiments coming up. Yes the laminate topic needs it's own thread as does any of the film testing. The 'Anything over..' thread was a search for a substrate over 4x8 in my area, and laminate turned out to be it, so the thread went in that direction. The original thread should be retired now and a dedicated one started.

As far as your testing, any chance of making some small color swatches of some of these mixes to send to Prof? That way we can get them analyzed and added to the chart. When all the chart data is done with the inital colors I'll probably make a flash presentation that you can click through, less scrolling that way... anyway this is getting off topic.

Talk to Clarence too about his mirror testing and see what he tried...

I have just been rereading some of this and some of the conclusions drawn and speculations also. And I'll quote something Tiddler said a few days ago and is basically my belief also.

Having shown that somewhere around 4 coats of these hybrid mixes the remaining light is close to nill and that the paints do draw light into their depths and in such mixtures there are reflective materials buried in the paints.

What if

There was a 5 coat paint solution and each coat contained the same ingredients but in different proportions. The first coat being the greatest percent of reflectance and the lowest percent of pigment. And as the layers came forward they gradually converted to something in the range of the mud mix you have been using.

Each layer softening the effect of the one below and the top layer widening the viewing cone. Any takers.

Not exactly.

What I'm suggesting is a paint mix or rather 4 different mixes they would all be made from the same stuff but the mix rates would be different.

I haven't had any experience with these metallic paints but what I'm saying is the first coat would have say 4 times the normal; silver the second 3 times the third 2 times and the final coat the normal silver amount. Also the poly rates might do the same thing with each coat. The point I'm making is as the light goes thru each layer or depth of the paint it weakens and the extra reflectance would give it the needed kick back out. we know if we load the very top surface to high in metallic what the problems would be.

Keep in mind I'm just throwing out a concept I haven't spent any great amount of time thinking about. More of a what if question.

What I'm trying to come up with is a progressive LF with the current rolled on LF we have determined the remaining light is not enough to show any good results and doing something like frosting is such a extreme jump we get a viewing cone approaching zero. so why not LF within the layers of paint. And do it gradually thru the thickness of the total paint coating. We'll call it PLF progressive light fusion

I've been following this with interest, as I want to improve my painted screen myself. But I am holding off doing a mix version just at the moment until a few more tests like the light loss idea is done.

May I suggest a couple of things, within the aim of trying to be a little more scientific, but without adding to much complexity to throw the followers off.

Firstly the glass panel with the mix upon it, although a great test, you need to add a measurement, as what you see via eyes and camera can lead to perception rather than actual amount.
I suggest using a simple Lums meter.
With it placed before the screen you can measure the lums from the PJ directly. Remember you lose lums over distance, so this is your starting value.
Then place the meter behind the glass panel. I would note that even pure glass will have some loss.
Then paint layers across the panel of glass, add layers in stripes and you have a paint thickness test panel.
If you use straight colours(color), white, Red, Blue, Green, Black, each one will have a different value from the PJ and thus will have a different exit lums value aswell.
Knowing this you could calculate a possible reflected value. Not discounting what is purely absorbed by the paint.

Now using this you could test variable mix layers as you could place an actual value on it rather than just perception.

Next suggestion, is use grey scales and color bar tests from the DVE calibration disks or similar as the base references. Adding the personal favourite movie pics or the like at the end.
I mention this as most movies have filters of some discription over the whole movie to create the mood. These colour shift skin tone references all over the place. Again if skin tones are to be reference as a guide i suggest using one of the calibration disks for reference.

Regards
<^..^>

I had an idea tonight while jogging. We know a mirror provides gain thanks to tiddler. And alot of it under the right conditions. We know that viewing cone is compromised because of that gain. We paint with a translucent gray mix on top of the mirror and think it looks great. I personally don't because viewing cone is still compromised because it is gray and has gain. We need a diffusive layer in between the mirror and gray paint. This is how CGII and CGIII work. Flat white substrate to increase viewing cone and transluscent reflective silver/gray topcoat to provide gain and deeper blacks without crushing whites.

What if...we coat a mirror with a transluscent white basecoat. Then put our translucent reflective silver topcoat on top of that. We should get improved viewing cone. We should get gain from the topcoat. We should get deeper blacks and maintain whites for improved perceived contrast. And, if there is such a thing as fusion which I still need to prove to myself, we would get that benefit also.

Does this make sense?

I may just try this approach. And maybe even with the interference powders.

Actually I think any experiment that yields additional questions was a good experiment. Otherwise it was just proving the original thought behind the experiment. It's the questions that yield more information than the experiment itself. Answer the questions and some real progress is made. Without them, experiments are usually ended and conclusions written up, but they pretty much support what was thought in the first place.

We all have some interesting questions left


I think Tiddler needs a sabbatical right about now!

A very thin White undercoating on top of a reflective surface is not a new idea. It was/is intended to collect the reflected light and do exactly as you suggest, more evenly distribute the reflected light. The "Gap"in a 2nd Surface Mirror does this more than adequately, when combined with "White"MMud, or MMud-SE. More "Silver & Pearl" intensive mixes that by nature are more Retro reflective gain a wider viewing cone by the introduction of such a white undercoat.

But as pointed out, the more variables there are in the necessary coatings, as well as the number of coating applied, the more difficult it becomes to "nail it". That has never been in dispute or ventured as being any easier than it is.

As for why we/I/anyone has not done the degree of testing and comparisons that Tiddler has managed, suffice it to say that coming from a distant realm, such testing carries more weight, and is subject to less rebuttal....for rebuttal's sake alone. All that, and an admission that if one was to wait for me to have the time to do such extensive examples, they would still be waiting.

Tiddler is effecting a service to all, and in so doing, is presenting several concepts, not just LF or RS_Maxxxmudd, in a manner easily understood and appreciated by those with an interest in such trivial matters. Trivial. That's a jest, ya know.

Yes, a white coating is not new. What's new is the translucent, reflective silver topcoat on the white base. And, from I've seen, the gap in a second surface mirror, does not do a good enough job. If this works we'll have to come up with a new catchy name for it.

Smokey Joe

Everything you say is correct and the proper way to conduct a scientific test. I believe I was the originator of many of these concepts Tiddler used in doing this great body of work. I have posted many times as to approaches to take in doing testing and one of the last was over in the BF explained thread. There are several problems with doing quantitative testing here at AVS DIY first being almost no one has the equipment required to take the accurate measurements. Secondly of the members that would have equipment it's hard to get standardization between members. And lastly at these early steps of testing I don't know if most members would relate well to numeric data compared to visual. As wbassett said the great part of what tiddler's experiments do is raise interest in the subject and forms new questions.
All your observations are more than valid and I do hope someone will take it that next step as it seems Tiddler is going to need a rest when this is done. The use of the color bars hes been using like you said is a big step in the right direction also and once again I like the combination of the color bars with real world images only because I believe when selected carefully they relate much closer to how many of the members do testing.

Tiddlers observations that he is sure his cam in auto mode is adding variability into his studies has always been a concern of mine and I have cautioned many times not to compare to strongly picture to picture but rather within picture. Thus the idea behind the two and three sample comparison testing, and as tiddler has done and been asked several times can you put up this with this and this together each time we view different combinations together we gain new insight. Once again raising more questions to be answered thru some later quantitative tests.

Thoughts on mirrors and some conclusions on my part:

A mirror by its very nature is a screen surface with the very tightest viewing cone possible. It reflects all light striking it off at a angle equal to the angle coming in. that's a known fact.

In Tiddlers experiment with a mirror and a diffusive frosting the frosting itself offered very little in the way of a screen surface in and of itself. The vast majority of light striking it went thru it in a straight line. Low diffusion and like wise the returning light passed thru strongly and in a straight path with only a small secondary diffusion. The combined two diffusions were enough though to produce the bright clear color bar image with the very narrow viewing cone. If the desired effect of a screen was to totally maximize the brightness and provide a viewing experience that could only be viewed from a very selective area then this type screen would fill that bill.

Now if that mirror wasn't a flat single surface in plane but rather millions of mirrors set at millions of angles. It would be what I have been calling lately an (optical texture) or it could be thought of as a (mirror diffuser). Light passing thru a illuminating layer like the frosting would reflect a little light and pass most the returning light wouldn't follow the narrow tight viewing cone the flat mirror provides but rather be diffused / scattered and then re-illuminating the frosting. The intensity of the image would be lessened to the viewer at that previously perfect viewing location but in exchange there would now be many viewing locations / wider cone. What would be better then with a screen made this way than one that just reflects off say a white / gray surface. There is just one word that explains it and it is. efficiency.
Now if in the process of doing this the frosting can appear dark under low light levels and still offer little resistance to light passing thru in both directions and still have a illuminating / diffusing effect. That would be the highest of efficiency.

That's what Light Fusion strives to do IMHO.

Its also my belief now after pondering both Tiddlers work and all the offerings I have seen of LF screens painted over both optical mirrors and also just plain bright painted surfaces, is that the mirror itself has a minimal effect on the outcome over another bright substrate using the paint blends commonly used for these screens. I believe the majority of the Light Fusion going on is taking place within the paints themselves. The smooth surface of the mirror combined with the low cost still provides a great surface to paint on and still could most likely be the best cost effective method of doing this for those without walls suitable to paint without costly prep work.

I know some are going to think me quite bold making these statements without ever actually painting a LF screen or undertaking the experiments on my own. And once again like always I submit the above as only IMO. I'm not viewing or analyzing anything on this forum with any preconceived reasoning or agenda. Just calling it as I see it.

I welcome comments and rebuttal based in a factual manner from anyone that wants to offer some. And like always my mind is open to facts and will defiantly change my position on this if I can see new information that leads me that way.

Get some (comet cleaner ) and a small piece of glass. Put the comet on the front of the mirror and add a little water and use the other piece of glass by hand to frost the front surface of the mirror by polishing.

I made a diffusion lens for an enlarger this way years ago. Sandblasting also will work.

Doing it this way will produce a true diffusive surface because remember the light coming back off the mirror will be striking the back side of any paint you put on the glass. With the front surface of the mirror being very smooth normally no mater what paint luster you put on it the back side luster will be gloss due to the smoothness of the glass.

Also remember there is only lumens, gain, viewing cone and efficiency of the system.

Couldn't you just use some of the glass etching cream that they sell?

Tiddler and Boomer

Yes the light will bounce back and forth between the sheet. Glass like water requires light to enter it at a steep angle or it will glance off. That's the theory behind how fiber optics work.

Yes acid etching is another approach that could be tested.

You should be able to get etching cream at any crafts store. I am sure Michaels would have it.

Yes. Those are the pics that seem a bit odd. Do the pics represent what you saw with your eyes? What was the thickness of the mirror? What was the back drop in these pics and why does the image vary from the first to the rest? Did you highlight the mirrors image in the first pic? Or was the gain (?) that much so as to darken the sides? I guess what I'm trying to say is that in the first pic the sides are darkened but not in the rest. As I stated previously, I was planning on using a mirror for my screen - 1/8" acylic - and that is why I'm asking. From what I've seen from your pics, I might as well paint the polywall I'm using as a temp as opposed to going through the trouble of acquiring and spraying a mirror.

I really appreciate the time you're taking to conduct these experiments!! It's helping me alot! Any chance of doing a bunch of test panels, ie a shootout? j/k

mech

Thanks for the quick reply! I think that's what I'll do first. Test with the polywall and see what happens. I just wish I had as much time as you folks to spend on this stuff!

Also, as I see you are near the end in this endeavor, I wish you luck in the future and many thanks for all you've done in an incredibly short time here!

mech

Thanks bud. But, I'm having a hard time understanding what you stated. The light will bounce back from the mirror and hit the back of the paint layer. The paint layer on the glass will have a gloss lustre to it. I can sorta rationalize this in my brain. So in stating that how does RS MAxx or BF react on the glass. I would assume much in the same way. And if they do, viewing cone would be affected.

Anyway, I guess what you are trying to tell me is that even white matte paint layer would not diffuse the light enough. Therefore, any paint layer, thin enough, would have the same result?

Try not to step on any toes....

mech

Benven

I think we are pretty much on the same page here. First the light has to pass thru something paint or films etc. and become diffused in two direction some being reflected back instantly as in a normal screen some being diffused and sent into the mirror on passing thru the glass of the mirror being as how the glass is fairly thin the light cant be dispersed to far off target before striking the silver the angle it strikes the silver will be the opposite of the angle it leaves the silver. Now the return trip starts. Back thru the glass and this time it contacts the back side of the paint finish. This finish will not be governed by the flattening agents in the paint but the smoothness of the glass the paint dried to. And glass is very smooth in order to be transparent.

What tiddler was saying is that it could possibly act as another partial mirror again and thus the bouncing back and forth within the glass. That's one way light can be lost another is what happens in fiber optics. In thin layers of glass light that comes in on a very slight angle can never exit the fiber / sheet the light will take a zig zag path down the length and exit on the other end every material has a different angle that this takes place at. So in theory if some of the light diffused the first time into the glass at a slight enough angle it would likewise be trapped. All this bouncing around will also soften the focus if the mirror glass is two thick and could be the reason we hear of a halo or plasma glow. (don't really know)

The idea I had of etching / sandblasting the front face would take the place of the first layer diffusing paint. And along with doing that it would make the second light path reflected out an equally textured light scattering path. And that equates to viewing angle / cone. But as viewing cone widens gain has to drop. There is only so much light to go around the wider you spread it the less there is for each viewer to see. The screen cant make light so no mater what kind of screen you have it's a matter of what you do with the lumens you have. Ideally you adjust the viewing cone to match the seating and then make a screen that has a high efficiency. And by that I'm saying a screen that converts the most amount of light it can to watch able image and returns it to the viewing area. Less wasted light is another way to state it. Gray screens / trapped light / light passing thru a screen are all wasters of light. Thus lowering the overall efficiency of the system.

I took a totally different approach to the problem. Somewhat by design and somewhat by luck. But realizing luck when you see can be a form of science. First off my projector it delivers close to two times the light I would normally need for the image size I'm shooting. Second my screen material is canvas with a texture that acts as a natural reflective diffuser when painted. Then I went down the neutral gray road and found the shade that killed enough of the lumens to get me in a good ft Lambert range and in doing so pushed the perceived CR of the dark end. At that point I was happy but lacking hot whites and pb maxx answered my request into adding poly's to gain sheen to boost gain. My experiments lead me to a poly level I now know is way to high for a smooth screen. (see tiddler's testing thread of poly) the reason I could go so high of a level I now believe is because of the texture / diffusion of the canvas without hot spotting.
I had at this point an inefficient screen still that because of the high starting lumens produced a very bright image with great CR and excellent blacks.

I had the chance last week to test my screen against a Da-lite sample of there silver gray high contrast material. The first thing I noticed was the sample had a textured surface and a sheen similar to mine only a slightly darker gray / silver in room light than mine and mine the texture was more pronounced. They were so close in side by side testing during a movie I almost forgot there was a sample across the screen.

I know no light makes it thru my screen and the first 3 coats of paint had no poly so I'm assuming the image is taking place against that top coat of the base and in the two coats of the poly paint I top coated with. Because it's possibly going thru some of the paint a slight depth and coming back out can I call this light fusion? I don't know about that.
Would someone with a less bright projector be able to get away with just neutral gray poly screen? I don't know about that ether. Tiddlers test show a fair improvement side by side between gray poly and gray poly metallic and he did a much better job of matching the gray levels as compared to first comparison using SS as the gray poly. But I have to point out even the gray poly he used in the above test started at a darker value and because of his flat substrate the poly level was lower, thus a wider viewing cone than the gray, poly, metallic. It was a fair test in all as are all his tests. I'm not quite ready yet to throw in the neutral gray poly towel. But I am considering posting the above thought process concerning extra lumens into my thread as a edit.

Proponents of metallic LF and all the rest will point out to me that with them combined with my lumens I even have more to gain. I don't know about that ether. MM just did a contract for a screen using these latest advancements for a XR10X projector and I have been following that story closely. The screen he did was a good 30% smaller than mine and with the lumen output I was expecting a screen that looked almost black under room lighting. I figured with the efficiency of the better screen the base shade could be dropped more and super high black CR could be had along with amazing ambient light rejection. So far only a few pictures were posted and I was surprised the mix he used was close in room lit gray to mine. When more screen shots become available maybe the towel will fly in the ring. We'll have to wait and see.