Offical JVC DLA-RS4810 Owners Thread - Page 29

Do you use different color difference formulas?
CP use CIE94 while CM seems to use dE2000, Different color difference formula will result in different dE.

Btw, I run i1d3pro profiled against i1 pro and they were calibrated by the manufacturer a year ago. I don't think it has no such huge errors.
Edited by freebits - 1/20/13 at 5:40pm

dE2000 - I use what CalMAN is using. Having not seen the actual formulas I don't know how much of a difference CIE94 vs dE2000 actually makes, but CalMAN's targeted to produce dE's less than three, so I imagine the different dE formulas are roughly comparable or there would've been more mentioned about it on the forums.

I have no idea what you mean by this or if it was even directed at me. I haven't claimed to have any huge errors so maybe this comment is meant for someone else.

Help!

Remote has stopped operating. So I put in batteries and it is communicating with the unit as the green light flasshes 2 times when I press a button and then nothing happens. Cannot turn on or off or use any remote function.

PLEASE tell me this is an easy fix as I don't feel like taking projector down from ceiling and sending in for repair!

S

Oh, it's not for you. sorry.

Chromapure can be set to use dE2000 if you wish in one of the options.

Yeah but I prefer CIE94. I think Calman also change it to CIE94.

SOWK, Geof, Kelvin, Mark, 5mark, etc........Thanks again guys. All these posts and info that you are putting out are a big help and I am learning a lot.


So just to be clear, if we want to make tweaks, run the auto cal for greyscale/gamma FIRST and then do any tweaks if you wish to greyscale and/or gamma (gamma tweaks would just be to the low end ~5%, so it sounds like any errors as a result of tweaking wont have any significant impact in general, right?). Once you have any tweaks in place and are satisfied with both greyscale and gamma, then run the 125 point color calibration, correct?

Very interesting. I was using Gamma A before doing my calibration to 2.22 since by eye I noticed it revealed more shadow detail vs the other gamma options I tried (I never tried 1.8 and 1.9). Of course Gamma A overall is very low as you mention which was interesting to see when I actually measured it the other day. I am looking forward to watching more material now with my 2.22 gamma to see what differences I notice in general vs what I was using (A). I wonder why the JVCs are having issues revealing shadow detail though when other displays are not, some of which have MUCH lower contrast.........
Edited by Toe - 1/21/13 at 8:32am

Sorry to interrupt the endless calibration discussion, but on a different topic....I am coming from an RS-20 and noticed from pics and diagrams that the geometry of the lamp assembly in the 4810 appears to be at a right angle to the former lamp design. Before, with the RS-20, et al, one could remove the lamp assembly and easily inspect and clean the back glass of the optical block for accumulated haze and film deposits. Judging from the diagrams, it looks like it would be difficult to do so on the current design. Has anyone attempted to inspect or clean the back glass on this model or perhaps on previous models with a similar lamp geometry? Routinely removing the film deposit accumulations, before, did wonders for my RS-20.

I don't think that's true. I've been using the very latest version of CalMAN and all of the dE charts are very clearly marked "dE2000."

@Toe, yes I thnk you've got it. Tweak 5% after the first greyscale autocal, then continue with the 125 point colour gamut cal.

@ Jedi, I used to clean this glass on my previous HD350 (RS10) to good effect, so I would have expected to do this as well on myX35, but I haven't attempted to remove the lamp to check this (barely at 100 hours yet and no dimming so far). If I check this soon before anyone else, I will post back to let you know how easy or not it is.

@ Freebits I just leave it on CIE94 in Chromapure as well. You also have the debate as to whether you select rec709 or SMPTE-C but I may do one of each and just save two different memories in the Lumagen as I have 5 spare at the moment.

Actually I looked at this last evening and one can adjust gamma and grayscale in 1/2% (0.5%) luminance increments. even I'm not that anal....

I looked again too at CalMAN's DCC and it's 0.1% there. Does the Lumagen just round off to 0.5%?

As Kelvin states I do the tweaking first but in reality it may not matter much. The 125pt Autocal routine calculates its luminance targets based on what gamma you have selected in the pull down menu (i.e., it does not measure gamma while running the 125 pt cal -- it uses the gamma value you've selected in the pull down menu). So you could do the tweaking before or after as long as you do not change the gamma value you selected. Please note that it's very important that you select the same gamma value when you run grayscale/gamma autocal and run the 125 pt auto cal.

After I run a grayscale and gamma auto cal I use the Gamma module in Chromapure to make manual tweaks. Start by taking a 100% reading and then choose the 5% steps (if you desire) and also select continuous. Work your way down from 90% (or 95% if you selected 5% increments) to 10% (or 5%). As you progress thru this Chromapure will automatically setup the Lumagen for the proper grayscale level. Next, enter the service mode on the Lumagen (this lets you edit gamma and grayscale values). Then at the Lumagen Top menu select Output -> CMS -> Gray/Gamma and select 11 pt or 21 pt depending on what you selected in CP (10% or 5%). After that you'll see a banner come up on the top of the screen. You'll also notice that the pattern is no longer showing...press 4 (I think but try 1 if not) on the Lumagen remote and the pattern will come up. Now comes the "tricky" part.....do not let Chromapure and the banner get out of sync with luminance value. Both have to be on the same setting (i.e., 80% or 60% etc). If you get out of sync just change the first value (I think it's the step number) in the banner so the luminance value in the banner matches the luminance value selected in Chromapure. When both are in sync you can tweak Luma, R, G, B values. Luma changes luminance and use this if the gamma needs tweaking and use R, G, or B if grayscale needs tweaking. There is some interaction so you may end up tweaking several of them. Adjust so both gamma and grayscale are good. When you get to the lower luminance's give it some time to make sure you get stable readings....if you make any changes let it settle out again - what you want is for the readings to be fairly stable. When you're done exit and save -- this saves the changes you just made but they are still not permanently saved after a Power Down/Power Up unless you also select Save in the Lumagen Top menu. And if you've screwed the pooch just exit without saving. This sounds far more complicated that it is because a) I'm not a writer and b) I'm going by memory and c) after a few minutes you'll get the hang of it. The first time thru may take some time but enjoy it as you'll never have another first time!!!
Edited by Geof - 1/21/13 at 12:05pm

I don't know....again I am referring to luminance step increments (not 10% or 5% but 0.5%) not luminance resolution (I don't know what Calmans DDC is).

Oh well yes adjusting one or two or even a half dozen that's one thing (and I am that anal too)....but no way I'm going thru the entire range in 0.5% increments.....

It's Direct Device Control. But I get what you are saying now. That would be very useful! I'm having a little trouble with shadow detail too.

Yes I see what you mean, though having a 2.35:1 screen and an A lens I have no black bars to compare against. At least with the Lumagen you can change memories without anyone knowing so long as the output type, resolution and frame rate is the same then the change is imperceptible (apart from the desired change by using a different CMS memory ). To be honest though I've not really found many discs that need the adjustment that you mention and I don't watch cartoons myself. For me the whole point of calibration is that I don't have to keep fiddling with the settings so if a disc has raised black levels, then I just run with it and I usually find that a fade to black seems to go to 16 (or maybe below) anyway.

However, in the light of the comments about what percentage relates to which flashing bars, I think I might be tempted to use the JVC's 5% control and move the Lumagen's 5% control down to 1% to adjust the lowest points I can next time I run a calibration, so thanks for this information.

FWIW I never touch the RGB offsets on a JVC: Raising any of them above 0 will raise the black floor and lowering any may tend to cause the low level detail issues that have been talked about. I've not used the X35's offsets so I don't know if this is still valid however (especially since it has the black level adjust control that my HD350 didn't have).

Actually I take this back...I think it may make a difference.

It is true that Chromapure calculates the correct 125 pt levels based on the gamma that is selected in the pull down menu (I have verified this with Tom). But if the readings that it takes are incorrect because of erroneous gamma value (ie, one that you would normally tweak) it may be making corrections that it would not have to make if the actual gamma value was correct. So, do the gamma and grayscale tweaks before running the 125 pt autocal.

You did great explaining it. I printed out your post and will experiment with this next time I pull out the calibration gear. Thanks again!

Still a bit confused on this. So you would actually adjust the JVCs 5% control, but change the Lumagen from 5% down to 1% before you adjust in the JVC? How would this be different vs just leaving the Lumagen in 5% mode and still adjusting in the JVC at 5% (in other words you would still adjust in the JVC in both cases at 5% but in the first scenario the Lumagen would be set at 1% and the second scenario the Lumagen would be set at 5%)?

Gotcha. So do all tweaks before the 125 point and then do the 125 pt autocal and after that, dont touch it! In that case, I might just hang with my straight 2.22 for now and not even mess with tweaking it, but next time I run an auto cal use a seperate CMS setting in the Lumagen with the tweaked gamma/greyscale so I can have both my original untweaked and my new tweaked and experiment with both depending on the material.

Yeah part of the beauty of the Lumagen is having 8 CMS memories to play with. I do my Gamma/grayscale and after I get all the tweaks done I copy it to another CMS memory. For two reasons: First it's nice to compare a gamma grayscale calibrated picture to a gamma, grayscale, 125 point calibrated picture. Secondly, if I play around with the cal gear a day or two later it's far easier to tweak any drifting manually without re-running the gamma and grayscale auto cal (I once forgot to copy and stupidly started a gamma-grayscale autocal which zero's all all those tweaks )


I trust you know to adjust the white balance (grayscale) at 100% using the gains in the JVC user menu (or in the service menu if you prefer.....the service menu is global, the user menu is not). I do it in the SM but others do it in the UM....either works.

But as Kelvin explains don't dork with the cuts (again some folks do but we have a Lumagen so we don't have to ). There can be side effects as Kelvin so aptly explains:

As per your comment now in bold:

The autocal greyscale will adjust the Lumagen at 5%. I want to then use the Lumagen's control to adjust 1% so I have to move this control down to 1% in the Lumagen menu and then tweak the very low end. This then may leave the 5% reading off from target (gamma/whitebalance) so my plan is to then use the JVC 5% adjustment to make any correction if needed to put gamma where I want it (2.1 probably).

Makes sense in my head, but might not be very clear I guess. It might even be that in practice it doesn't make enough difference to worry about.

I'm completely ignorant of how the gamma works in these new JVC's. But if it's anything like the old, it drags neighboring points around with it. It was very frustrating. Can these new pj's gamma points be adjusted without effecting neighboring points?

Nope...that was the exact problem I ran into when trying to use the internal custom gamma controls on my 4810. It was a total PITA.

I love the 8 CMS memories. I am using 2 projectors right now so it will be great to be able to easily switch between the CMS memories for the different displays and for other various reasons as you mention.

I did adjust the 100% white balance before running the auto cal using only the JVC gains and did not touch the offsets.

Gotcha. That makes sense to me now and I will experiment with this next time I break out the gear. If you try it before I do, be sure to let us know how it goes as I am curious.

Will do but sounds like there is still the interaction between different levels using the JVC gamma, so it might end up being a frustrating exercise.