Official JVC RS20 / HD750 Calibration and CMS thread (NEW FIRMWARE V1.1) - Page 10

I did some rigorous calibration and side-by-side comparisons of photos between my calibration and THX mode.

THX measures very nicely on my RS20. My calibration measures even better. Comparisons of pictures when switching back and forth between THX and User 3 show very little, if any, differences in colors.

Based on this, I trust that my i1 is measuring consistently.

My calibrated numbers are very different than Manni's. Manni's yields a green that looks far too oversaturated.

I am very tempted now to get a better meter and see where the problem lies.

Incredible results Tom. Thanks for sharing. Wish I could see one of these in person, well calibrated.

Dan

I just wanted to thank everyone involved that helped get where we are today as well as JVC for understanding their customers needs kudos to everyone.

Manni I tried both of your settings the 1st & 3rd and all I can say is wow! Absolutely amazing colors, depth to the image etc..

Can't ask for a better picture PERIOD..the RS20 officially kicks major butt! Even the Lumis I saw at CES does NOT provide the depth this RS20 does TODAY. Tom Huffman confirms its the best display HE has seen and whether or not he has seen a Lumis I can assure you I have and the image of the Lumis at the show was NOT as striking as the image on the RS20 before me today with this new firmware.

Now I know I probably started something I shouldn't by mentioning the Lumis in the same sentence as the RS20 and will get slammed for it by a couple of individuals you know who but the truth sometimes hurts especially when the competition costs 7 times more than this JVC. And did I forget to mention JVC's extremely quick response to solve this problem unlike the others?

There are still some interactions. For example, lowering saturation also lowers brightness, which it shouldn't. But then you just restore the brightness using the brightness control and it is fine. So saturation affects brightness, but brightness doesn't affect saturation, at least not much.

The Orb Optronics SP-100 spectroradiometer. With it I measured a THX green that was undersaturated a little (x0.307, y0.583), but the rest of the gamut was very close to accurate.

Tom,

If you could recommend one meter in the roughly $1k or better price range, what would it be?

The thing is that THX uses the 6500K preset color temp, which cannot be adjusted. That's still the same. What is different is that the 6500K preset is now more accurate than before. When I did it in Jan. I got x0.317, y0.337. That is blue deficient, and a CIELAB dE of 4.3, which is slightly over SMPTE's error tolerance of 4.0. Last night I got x0.309, y0.324, which is somewhat excessively blue (the opposite of before), but more importantly it is a dE of only 2.7. You could use the service menu trick to get it even better, but it is hardly worth it. Also, that removes the whole advatange of a simple preset selection.

At that price range I'd use a Display 2 corrected by the i1Pro. You can get both meters for under $1K.

Thanks.

Tom - great to hear things went so well once you got the firmware installed.

I installed the firmware and spent a good 6+ hours just on the custom gamma tweaks. So I wanted to ask you about this...

With a custom gamma curve set to all the default values except the gamma correction number at 2.3, I still was measuring 2.1. To get close to a 2.2 measurement I had to choose a gamma correction of 2.4. Still even from there I had to make a lot of adjustments to "white" - and even then I was still coming out with an average of about 2.15. Any idea what was going on here?

Its really a PITA with the custom gammas as tweaking the white up/down in the 5-10% range throws off the color balance significantly. Then fixing the 5% level throws off 10%. Then fixing 10% throws off 5%, and around and around we go. And yes I am quite certain I am getting good readings as low as 5% - the meter backs up what I can see with my eyes.

Well the good news is that, as has been reported, the CMS issues are certainly fixed. It only took me 35 minutes to dial into Rec 709 with a dE of 1 or less for all 6 colors at 75%, which then measured with a dE of 2 or less for all colors using 100% levels. The CMS controls are now EXTREMELY easy to use. What a turn around, and major kudo to JVC which I'll have more to say about later. I'll post my settings shortly along with HCFR chc files. I will also post some slightly over saturated settings for those that like things a bit more souped up.

I don't know how much an EyeOne Pro goes for these days, but I use a Spyder 2 meter trained to an EyeOne Pro. This provides the color accuracy of the EyeOne along with the low level readings of the Spyder 2 and the ability to read directly out of the lens with no dark readings and so forth. Highly, highly recommended. You can even calibrated down to 5% with consistency.

The grayscale below 20% is way off, and I can't tell you how important it is to use the custom gamma controls to dial in a truly flat grayscale all the way down to 5% if you can. And with these meters (and a GREAT deal of patience) you can!

Does HCFR allow you to do that?

Does that work for greyscale as well or is there a separate meter calibraton for grey scale?

Thanks.

The unit I worked on was a little different. At the 2.3 setting, the gamma measured from 2.25 - 2.15. As I said, I made some small changes at a few points to get everything a little flatter. Also, its grayscale was pretty good down to 10%.

I agree with Tom. I measured all of the Custom (1.8-2.6) gammas and they tend to be on the number at 10% and then gradually drop off and flatten about 0.1 lower at 40% and above. The factory grayscale on my unit also tended to be quite good down to 10%, but I'm sure there will be unit to unit variation in the grayscale.

Thanks again Manni. I found the prtsc key and was able to save as jpeg as you said. After I tweak my RS20 a little more, I willl be able to post some of the charts and data now.

Guys, if I want to recalibrate with the new firmware with a view to getting the gamut, grayscale and gamma correct as well as optimising for maximum brightness, what order should I calibrate in and what things should I look out for to ensure that the calibration does not unduly reduce brightness?

I'm guessing the calibration steps should be:
1) Set all settings to factory defaults (the firmware update will do that)
2) Adjust grayscale (adjusting down the primary colors that are higher than the lowest primary - dont reduce the lowest primary too much if possible)
3) set contrast & brightness (using the visual differential of near black to black, and near white to white of the grayscale bars)
4) recheck & adjust grayscale
5) check gamma and do a custom adjustment if needed to get the grayscale spot on
6) check contrast again
7) Adjust the CMS in HCFR to reach Rec709 for xy hue & saturation sliders, try not to go too negative on the brightness sliders if possible. Then using Dan's spreadsheet adjust for correct Y values using the color brightness control.
8) Do a last check of gamma, contrast/brightness and grayscale.

I have a D2 probe and it only measures about 6fL on the screen (I have a large screen), should I reduce the size of the picture so that the lumens the meter sees increases (ie. am I risking a poor calibration as there is not enough light on the screen for the sensors?)? I know that adjusting iris does have some affect on the calibration but I'm assuming that reducing the zoom does not.

Anything I have missed out?

I just finished my gamut tweaking with my i1LT. I don't know what kind of measurement drift others are experiencing, but in one day I got a max difference of only 0.001 for delta xy and 1% for Y. This does not seem like much to me. Obviously I do not know how correct the absolute values are to begin with.

I am little bit curious still about Y calculation spreadsheet. I tweaked x and y and then adjusted Y using luma delta values from HCFR visible after I scroll down in 'primaries and secondaries' table. Now, what am I missing here?

This was generally what I found too. Except when I looked at the gamma histogram curve the line was visibly separated from the reference, and it said my avg gamma was 2.12. This was with the gamma correction set to 2.3. Odd. Previously (when the bulb was rather new and with the old firmware) setting the correction # to 2.3 yielded an avg gamma 2.2. So I bumped it to 2.4 but that wasn't much better.

When looking at a gamma graph (the graph that should show straight horizontal line along the reference line if correct) it is clear that gamma is indeed higher at the lower %s, like you found. How important is it for me to flatten these out?

For instance it is possible to use the "white" adjustment within the custom gamma curve to raise/lower the overall brightness at a given % in order to try and flatten this line.

However I have to wonder whether this is worth it. I spend 6+ hours messing with this last night trying to get it flat. It is very tricky because a change to white at 5% impacts its RGB, then you fix that and it has an impact on 10%, then you fix that and find that 5% is off again and around in circles. Typically you can work at say 30% and above without the white adjustment affecting surrounding % level of brightness or rgb, but its nearly darn impossible. I can get the dE <3 from 5-100 but trying to do that while also keeping the gamma graph flat - this is where it is extremely challenging. What is the impact of not flatting out the gamma line and is it worth it??

Thanks!

Thanks Manny.

I use a HTPC and just leave the source contrast / brightness settings alone, as I think the tuning is best done in one location and at the end of the chain (projector) and I only have 1 source that matters, the HTPC. I use the standard (16-235) setting on the HTPC and PJ so I can't see BTW/WTW but I tune so that I can just differenciate level 16 from level 17 (the last 2 black bars on grayscale bars) and similarly 234 and 235 for white.

Also, any recommended lumen level for a decent calibration? 12fL? I don't have any choice but to shrink the picture to get that lumen measurement on the screen. I'm fairly sure zoom will not affect the calibration but happy to be told otherwise. BTW - at measuring 6fL the image does not look dull or lifelike, it has pop and in transitions to bright scenes lights up the whole room (even with dark walls/ceilings) and hurts the eyes. So I fugure the D2 is either reading low or my setup of the D2 to measure off the screen is sub optimal (but I do adjust its position to maximise the lumens).

Hi,

As said, I did yesterday a first (quick) CMS calibration with the Minolta CS-200, I didn't had time yet for color temperature and gamma calibration. I will not publish my numbers yet, since I'm planning tomorrow for some finetuning.

Instead yesterday evening and this evening I have been watching some movies, for example the last Batman "Dark Knight" and an older one, being "Hard Candy".

I'm amazed about the picture I get now, the colors are very good, nice!

However, when watching "Hard Candy" this evening I noticed in some scenes some color contouring (difficult movie in this respect), first on the girl her churgery clothes on her shoulder, later when the man was standing in the sun on the roof on his face. This started me thinking about the CMS, so I switched it off, gone is the color contouring!

Then I switched for the first time after weeks again to THX, first I was amazed that I don't see color differences with my own calibration, indicating my CMS settings are not that bad ;-). However, I don't see the color contouring in THX mode on both scenes! It looks like this THX mode does something special! Also when I switch to the built-in blue bar test pattern of the JVC I notice in my calibrated mode a shift in hue on the brightest blue, in THX this is not the case.

Did somebody experience the same phenomenon? OK, my calibration needs maybe some finetuning, but contouring can not result from this.

Contouring is unacceptable to me, and I would rather prefer to use a color gammut that is a bit off rec.709 instead!

Please note that I used "User1" as the picture mode for calibration, is "Cinema2" a better choice? By the way, why does "Natural" look so different?

Thanks,
Ignace.