I agree with your determination as far as the White over Silver looking better than the reverse in your specific instance. Having a Silver undercoating beneath a White surface was always the best of the DIY paint applications for a controlled to semi-controlled lighting situation produced Black levels that were superior to White alone, and that surely shows up in your images.
The problem back then was that what with most people Rolling on paint (2003-2005) that it was very difficult for people to get just the right amount of paint over the Silver to have it be thin enough to let a decent amount of light pass through to react to the Silver, and then be able to intermingle with the topmost image.
No issues in that regard using a far more porous Spandex.
It is obvious to me however that in fact, although the images on the White alone look "brighter", they are blown out as far as color saturation and a natural look of depth as opposed to the Silver/White combo. Bright isn't all it's cracked up to be, and obviously your White / Silver example shows that to be true as one can see that the darkened returned light beneath the White serves to curtail the overly bright, almost washed out appearance of the White Spandex alone. But there is a distinct difference in image quality in the first Silver over White example shown, where there is ambient light present. The White side is decidedly washed out.
Besides all that, since the Silver Spandex is not in fact a "reflective-oriented" material, the darker color serves to attenuate light a bit. Not much....but enough to be obvious in any direct comparison with a pure White material.
Such is why .....for the most part, we resist the practice of making such obviously weighted comparisons between a White and a Gray, as the end results will always be slanted toward the White surface if sheer brightness is what is being considered as being most desirable.
And it's fur shur that brightness plays a strong part in self-determinations made by many, especially those who are new to the Front PJ genre. It's only when an obvious difference is shown that pre-set ideas and preferences tend to get reversed.
I think that if you had a more proficient PJ with at least 1800-2000+ lumens (...or the 8100 w/new Bulb) that the initial showing by the Silver over White combo would have been much more impressive. One thing that would have, or rather obviously did benefit the 8100's performance with Silver over White was the increased appearance of having deeper contrast. Fir those who have much newer PJs such as the Beamers from Epson / Optoma / Viewsonic and the like, I really do think that your results do not give enough emphasis as to the benefit of having the Silver on top.
But even so, for those with a dedicated and light controlled Theater, and who are especially are looking for a viable alternative to the far more expensive Acoustically Transparent Mfg Screen materials, what you've shown is of almost immeasurable value. The White over Silver does in fact look splendid.
I've taken the liberty of cut & pasting excerpts of the two identical scenes that are both shown with the varying Silver/ white combos.
The bottom image is of course White over Silver
As seen, the depth of shadows, and the richness in color saturation is very apparent in both the Silver over White and the White over Silver combos, but lacking in the "White only" representation. Brightness is the only real advantage the "White only" has over the other two. The White over Silver does show a slight uptick as far as brightness as compared to the Silver over White, but not a whole lot.. Really, it's the presence of enhanced contrast that spells the difference over "White only."Memphisanid
, we all owe you a well deserved thank you for the effort you put out! So now comes the caveat. Using the same chosen scene (...how about the Night shot of the Joker looking through the Armored Truck's windshield...) can you put up a shot of the Silver over White that shows the Silver completely covering the White, the reverse as far as White over Silver, and one each of both alone? and take at least one shot of each in ambient light? If you can do that, such a complete dossier of examples for comparison would be well nigh invaluable to those considering a Spandex solution, and it will most assuredly find it's way into the "Advanced DIY Screens" compilation I'm making for potential "Sticky Status".
No matter what else, ya dun gud.