HTS-X2 - an experimental N8 reflective screen mix

42568 Views 107 Replies 12 Participants Last post by roads, Mar 4, 2013

Harpmaker

Discussion Starter · Nov 22, 2009

We have a number of experimental mixes in development; one that has been designated HTS-X2 has recently been tested by 1canuck2 and he will be adding info and photos to this thread.

HTS-X2 is part of a family of mixes that will run from N9 to ~N7.6. The paints used in these mixes are readily available in many, if not most, areas of the U.S. and Canada. Basically, a N6 gray paint is added to regular Cream&Sugar™ to get darker shades.

HTS-X2 is a N8 reflective screen mix.

Addendum:
This is the mix that will be called Elektra™ N8.

1 - 16 of 108 Posts

mechman

· #9 · Nov 29, 2009

Gonna take a look at it 1C2. Have to load HCFR though.

mechman

· #10 · Nov 29, 2009

1C2,

Get readings directly from the pj - the 11 grayscales and the primaries and secondaries. Then get me a second set from the screen. :T

mechman

· #19 · Dec 1, 2009

It should be a tad bit quicker getting them from the projector! Last night I did a quick comparison fo HCFR and CalMAN. The numbers are pretty much the same with regards to xyY. For the dE, they were close to the same for gray scale but different for gamut. I think that was due to on e or the other using a different formula and me hurrying through the readings while not paying close enough attention. Regardless, HCFR did very well. :T

mechman

· #21 · Dec 5, 2009

1C2,

Basically, all we're doing is comparing the two. The readings from the pj is what is hitting your screen. And the reading from the screen is what is reflected back. If there's a difference between the two, the screen is affecting the image. If it's a big difference, as I've seen with some things, it may be detrimental to the effect of not being a viable solution.

My initial look at the numbers shows me very little difference between the two readings. I see a very slight drop in blue, but nothing significant. Looks good so far! :T

Also, I disregard all of the readings below 30IRE. I'll have more for you later this evening when I have a bit more time to look at these files. :nerd:

mechman

· #23 · Dec 5, 2009

I just look at the numbers in HCFR, not the graphs. Believe it or not, after a couple years of Bill pounding this stuff into my head, some of it actually stuck! :dumbcrazy: Let us know which graphs your curious about and we can help you out. :T

Is that that simply because the Spyder3 is not good at low IRE? I assume the super-spendy colorimeters do better at low light.

Yes. And as for the super spendy colorimeters, we may find out in the not so distant future. :T

Slightly OT: Generally speaking, total neutrality is the ideal goal, but also exceedingly difficult to get perfect. So how big a deal is it? Is not the purpose of a calibration to correct for such differences? I understand a big push in one colour may be too big to correct for, but little ones should be no big deal. Could you actually have a screen surface that is a better overall performer in other respects but exhibits push in one colour. A good calibration can correct for the push, leaving you with a better screen than one that was perfectly neutral but less well performing in other respects?

It is not that big of a deal when everything is close. However, when everything is not close and you're dealing with a projector that does not have a CMS, it's a big deal. Most of the pj's we're dealing with in the diy world are ones without a CMS. Even my BenQ W5000 doesn't have a real CMS. It's kind of a hybrid watered down CMS.

I understand as screen formula developers that the holy grail is totally neutral, but is there a risk that goal is followed to the detriment of other goals? For example, on other forums it seems that gain or reflectivity is the goal, to the detriment of neutrality. I'm not claiming to understand the complexities of the art/science, just curious...

Gain is so yesterday. lol It may be needed in certain cases, such as the house of worship thread, but rarely does any projector need a screen with gain. BW has a tad bit of gain - probably along the lines of a .15 or a .2 gain advantage over a matching neutral gray. That's not bad. The bad is the haphazard dumping of polyurethane and micas in a cauldron of screen goo and calling the result 'pop'. It's more like fizzle. Gain introduces a lot of issues. And those issues are usually coined as 'pop' from the maligned troller of customers (MississippiMan). If you know what I mean...

Check out the Silver Fire thread. Check out the readings there. That can tell what gain from heavy doses of mica and polyurethane will get you.

Is Maurice still over at avs? Do they even still have a diy screen forum?

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mechman

· #26 · Dec 6, 2009

Well my assessment hasn't changed much.

Mainly because I haven't had enough time to look at them. :hide:

The big thing I would try and work on, since you have a CMS, is getting the primaries and secondaries adjusted better. Specifically Red, Blue and Magenta. Try and get the dE to less than 10 - red is but you can probably get it a bit lower than 9. I wouldn't worry about anything else until you have more hours on the bulb. When you have more hours on the bulb I'd go back and adjust some things to get it closer to D65 and see if you can get the primaries/secondaries dE a little lower.

I will get a more thorough look at it sooner or later. :hide:

mechman

· #28 · Dec 6, 2009

What kind of things can you adjust in the CMS? On my BenQ I can enter a measured value for primaries/secondaries and then a desired value. That's how I get them to be what they should be. Do you have something similar.

We'll get it all figured out. :T In the mean time I'll go read that thread you pointed me to. Take a look at Tom Huffman's guide in the display calibration forum there as well. Kal has a very good guide here as well.

mechman

· #32 · Dec 10, 2009

1c2,

Remember that I am an amateur at this. I have no training and only go by what others have taught me or what I have read. :T

For gray scale tracking I would adjust both the blue gain and offset up a notch while adjusting the red gain and offset down a notch. Ideally what you would want to do is adjust your offsets real time while displaying a 30 or 20IRE window and your gains while displaying a 80IRE window. Generally if you get those two in line the rest fall right into place.

The luminance for each of the primaries and secondaries is also low. Generally anywhere from .5-1. The ones I would be concerned with though would be red, magenta and blue. Those dE's are well above ten and I would try to get them lower. They also fall outside of the triangle which generally means they are over saturated - the y value being low on red/blue and high on green.

These are the numbers you should be shooting for:
x y Y
R 0.6400 0.3300 3.5094 (0.2126)
G 0.3000 0.6000 11.806 (0.7152)
B 0.1500 0.0600 1.1918 (0.0722)
Y 0.4193 0.5053 13.315 (0.9311)
C 0.2246 0.3287 12.998 (0.7905)
M 0.3209 0.1542 4.7012 (.2848)
W 0.3127 0.3290 16.507 (1.0)

Try and get the dE as low as possible. I'd shoot for less than 5.

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mechman

· #34 · Dec 10, 2009

1canuck2 said:
The only diff is the card was not primed with Kilz2, but it was a white card from a frozen food box. Given I put three coats on, I'd guess the primer (or lack thereof) would make a minimal difference.

After three coats the primer is having no effect upon the image.

Very little light gets through even two coats of paint. And what little does get through, virtually none of it would make it's way back.

mechman

· #69 · Jan 4, 2010

1canuck2 said:
Wouldn't you also require two different calibrations? One done for the white BOC and a different one done for the grey?

This is one of the things that has always confused me about the side-by-side shots that get posted. The PJ is calibrated (hopefully) for one of the screen surfaces being displayed, so naturally, all the others will not looks as good as they *could* were the PJ calibrated for them.

I'd rather see a shot of screen 1, displaying picture X, with the PJ calibrated for screen 1.
Then take a second picture of screen 2, displaying picture X, with the PJ calibrated for screen 2.

Change as few other variables as possible, then compare the results...

My general thought process has always been that re-adjusting black and white levels would suffice.

mechman

· #79 · Jan 7, 2010

Yeah if you want to send something out to me to take a look at that would be great. If you could send something the size of a sheet of paper that would be best. Not a big rush as my i1pro is going back to X-Rite tomorrow for it's yearly re-certification. I'm a couple months late on that this year.

mechman

· #82 · Jan 9, 2010

If mech or anyone else who has a full BW screen interested in doing this let me know.

I no longer have a full BW screen. My screen was damaged and has been replaced by a Elite EZFrame CineGrey.

But I still have several panels and I'm sure one of them has BW on it. :T And I can get pretty much everything I need from the 11X8" piece.

As for Jeff's (umr) test, I wanted to take a run down to Missouri to see how he does things but my (actually my kids) schedule doesn't allow me to. And then I figured why bother. :dontknow: We've already accomplished most everything that he's done and the readings he has done up to this point confirmed ours so there's really no point. :huh: He's not doing anything that we haven't already done before him. It's nice to have our numbers and our data backed up by a more expensive spectro. :nerd:

If you want to send something out to him though feel free. :T

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mechman

· #84 · Jan 9, 2010

pyro2 said:
mechman: What panels do you paint your test samples on?

I've used various panels over time - 1/8" pressed hardboard, 1/4" pressed hardboard, 1/8" foam poster board, etc. They all have their faults and advantages. I think I like working with the foam the best though. But they're not as durable as the hardboard. Plus you have to paint both sides to get them to lay flat. The 1/4" hardboard is probably the sturdiest material. And it stays flat after painting and after a long time in storage.

As for the gain readings, who knows. I admit that I haven't delved into Jeff's pdf as to how he got to those numbers. But I do know this, I followed and applied the industry standard. Someone mentioned that he may have gotten a bad sample as well - the wrong finish or something. I tend to agree with that because about the only thing I could disagree with him about was his DW conclusions. But I've never compared DW to the Studiotek. But I have large samples of each so I may in the future. :nerd: I do need to get grayscale and gamut readings from each of them...

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mechman

· #87 · Jan 20, 2010

P2 - It may be a couple weeks or so until I can get any readings. My i1pro is at X-Rite being re-certified.

mechman

· #96 · Jan 31, 2010

jmuir said:
I'm hoping two coats will do the job.

If you rolled it you should be fine. :T

mechman

· #102 · Feb 6, 2010

pyro2 said:
Sounds good. I'm hoping to paint a 24" x 54" piece of BOC and ship it to someone who would like to do photo side by side comparisons. If mech or anyone else who has a full BW screen interested in doing this let me know. Either way I'll ship a 11"x8" piece to you, Harp and umr. Should even be interesting to see how umr and your results compare.

P2 - I don't think I ever told you that I received your sample. I did. I'll be getting some readings from it tomorrow or early next week. :T

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