JVC RS40/X3 Calibration Thread - Page 10

Hi,

I think it's not a peak but the average of nine measures on the screen, as square : left, center, right and up, center and down on the screen.

It could be an average of multiple projector, but I think, in most of case, measurements are for a single projector (I'm not sure but it seems logical to me).

If you are a CalMan pro user, you can download the latest CalMan beta that does direct control of the RS40.

Check the SpectraCal forums for the beta download link.

By "pro" do you mean expert or commercial? This seems really cool.

JVC workflow is currently only supported by the Commercial license.
But you can use the manual DDC control with the interactive add on

Hi everyone,

Apologies if the subject has already been discussed, I did a search and couldn't find any relevant post in this thread.

I have a question for those who have calibrated gamma on the x3/rs40 using the internal controls.

There is a problem with the gamma controls of the rs50 which is that when you adjust white at one level, it disrupts the greyscale at that level, which means you have to spend ages to correct both white gamma and RGB balance, going back and forth betwen the two.

I would really appreciate if someone could confirm whether the rs40 has the same issue or not.

If you are not sure, there is a very simple way to check for this. After you have set your gains for the color temp (say at 80 IRE) so that the RGB balance is perfect at that IRE level and the pattern looks grey/white with no tint, if you keep the 80IRE pattern on the screen and move the gamma white control at 80% (either up or down, please try both), does the white pattern change to something reddish, blueish or greenish, or does it stay white? If it stays white, the gamma controls work as expected.

I would really appreciate if someone could check this quickly next time the meter is out...

Thanks,

Manni

Th JVC workflow is included in the Commercial license but there might be a JVC add-on available for the Expert license, it's worth checking with Spectracal if you have an Expert license and are interested in the JVC workflow (which only works for gamma/greyscale as far as autocalibration is concerned, not for gamut calibration by the way).

Try the following:

1. Adjust contrast and brightness. Look for the values near 235. I had to reduce the contrast (-4), otherwise I got a color error.
2. Display a 100% IRE pattern. Use the GAIN controlers to adjust RGB to 100%. That's very important because it sets the white point correctly. You can also go to the service menu to do this.
3. Check brightness and contrast again.
4. Use the gamma equalizer to adjust the greyscale points from 10 till 90 IRE and the gamma. Yes, it is possible to calibrate the greyscale points (use RGB in the gamma equalizer) AND the gamma (use WHITE in the gamma equalizer) only via using the gamma equalizer.

Important:

- Do not use the offset controlers ! That destroys the black level
- Do not use the 100% RGBW-controlers of the gamma equalizer !

At the moment you can use the JVC workflow only with the commercial license. That info comes directly from Spectracal. Maybe there will be a add-on in the near future but that's not for sure.

Thanks for the 101 in gamma calibration - I agree was all this by the way - but I was not asking for the theory, I was asking whether moving the white gamma controls on the rs40 disrupts the rgb balance or not, as it does on the rs50. I only suggested 80IRE because that's what most people use for settings the gains and I wanted to keep it as simple as possible. I do calibrate the gains at 100 IRE, but thats not relevant here as there is no gamma control at 100IRE, the highest being 95. I don't have an rs40, only an rs50, so I can't try myself on the 40.

So, anyone has noticed this on the rs40, or are the controls working as expected, i.e. moving gamma white doesn't disturb the RGB balance at that control point, whether it is 80 or 90IRE?

I use the internal GAIN controlers for setting the 100 IRE white point; gamma and grayscale are done via my Lumagen Radiance. That does function very well.

But I asked a good friend of mine who owns a RS40 too. He calibrated his RS40 like the way I told you before. And no, there was no problem with the RGB balance vs. gamma: you can adjust the RGB balance with the RGB controlers of the gamma equalizer and the gamma itself with the W controler of the gamma equalizer. The W controler does not interact with the RGB controlers --> the deltaE values don't change after using the W controler.

Thanks, that's the information I was after.

This is good news for rs40 owners.

I am a little bit confused. The RS50/60 are using the same CMS for gamma / grayscale. But I have never heard anything about problems with the internal controlers. I know that there is still a problem with the gamut controlers of the RS50/60: if you use the internal gamut controlers of the RS50/60 "too much", you will loose the linearity of the gamut. The only solution at the moment is to use the CMS of an external video processor like the Radiance.

Thanks, but I am VERY familiar with all these informations. I am running the calibration thread for the rs50/60 on AV Forums and investigated these in details very early.

The rs50/60 do not have the same CMS as the rs40, as it is very limited on the rs40 and is only accessible in the service menu. The rs50/60 have a full internal CMs which doesn't track saturation properly, but it is possible to get excellent results with it if you know what you are doing and are NOT targetting rec-709 in order to get it. It is true that it is less easy than using an external processor like the lumagen. You need to aim for a slightly oversaturated gamut at 100% Sat in order to compensate for the undersaturation at 75% sat, which is not easy to do but again gives very satisfying results visually, which explains why rs50/60 users can be happy in this area when the unit has been calibrated by a competent calibrator.

The issues with the cms and gamma controls have been confirmed by Phil Hinton in his review of the x7 on av forums and aknowledged by JVC, who promised a fix a while ago, so it's pretty common knowledge.

The issue with the gamma controls on the rs50/60 are probably due to the fact that they are handled by the genessa chip in charge of the cms, 3d and gamma, which is not present on the rs40.

You should read the calibration thread on av-forums and the multi-part review of the x series from Ekkeheart at cine4home if you are interested in this.

In any case, I'm glad to hear that the rs40 doesn't have the gamma issues of its older siblings, thanks for the information.

Forgot to say, please note that on the jvcs, gamma is usually not controlled by the cms, as models without a cms (like the rs10, 15 or 40) have always had gamma controls.

Oh, I have read your thread at AVF And I also know Ekki from cinema4home ... he calibrated my RS40 6 month ago and I personally talked to him for many hours at the home cinema trade show in Karlsruhe / germany

Because of "CMS": IMHO a complete CMS consists of controlers for grayscale, gamma and gamut. And, of course, I know about the fact, that the RS40 lacks of a "complete" CMS: there are no controlers for the primaries / secondaries available. That's one reason I use a Lumagen Radiance.

Chromapure + VideoEQ + RS40

Until now, I have been dependent on the generosity of a friend to calibrate my projectors (previously an RS1 and now an RS40). Unfortunately, my friend has moved out of the area, so I have taken it upon myself to learn how to perform calibrations. My RS40 was exchanged for a replacement, so now I need to calibrate it. I had been using a VideoEQ and I have just purchased the Chromapure Software with the Chroma 5 meter.

After reading all the documentation and this thread plus spending a few hours performing various calibration steps, I am still having some difficulty trying to figure out how to use them together. If any of you are using these with the rs40 and are willing to answer some questions, please respond here or pm me. Thanks in advance.

I will be doing a CalMAN + VideoEQ + RS40 calibration in 3-4 weeks. Just waiting to get enough hours on the bulb. I'm pretty happy with everything after doing some basic adjustments, so a full calibration should make it exceptional.

RE: Custom Gamma RGB question

I have adjusted the "white" gamma to get a fairly flat line around 2.3 with Chromapure. I do not understand what pattern(s) I use to adjust the red, green & blue gamma within the custom gamma menu.

Don't you just put up the gray fields and adjust red, green, and blue so they are all 100% at each IRE level? Make sure you set your white level properly first.

Thanks.

I have been getting varying measurement results (luminance, gamma, grayscale) from one day to the next with the same settings on the RS40. As this is my first experience with calibration (Chromapure software with Chroma 5 meter) I thought it might be something I was doing wrong so I documented the results over 3 days with 3 different picture modes with no change in the RS40 settings. I sent the data to Tom Huffman (Chromapure) and after he reviewed the data, he attributed the variance to the instability of the RS40 bulb. Now that I know that it is not an operator issue, I will move on to the VideoEq to further improve the results.

Instability of the RS40 bulb ? How long have you calibrated your RS40 ? I did many calibrations on my RS40 within 60 hours. There was NO difference between the measurements ! BUT: you should ALWAYS wait for about 1 hour, BEFORE you start calibrating !

With the recommend settings for measuring lumens in this thread (Natural,standard,open iris,high lamp mode, etc.) and using the AVS disk to set contrast and brightness, I measured single center lux at 335 which using the calculator comes out to 1037 lumens bulb at 132hrs. JVC X3 is 14ft away from 106" screen. Hope it does not drop too much with more hours but happy I have a little headroom.

I know that it is really too early to be doing a calibration, but I couldn't wait any longer, so I did a "quick" calibration. For this calibration I adjusted the projector settings to get 100IRE as close to D65 and Gamma 2.3 first and then further dialed in the settings and adjusted the CMS with the VideoEQ. I should be able to leave the projector settings alone from now on and just change the VideoEQ as needed over time. I plan on doing a full calibration again at 50H, 100H and then every 100H after that. My hope is that I will be able to maintain a lumanance of 12fL in Normal Mode as the bulb ages by adjusting the Lens Aperture.

Calibration Equipment
Colorimeter: Spectracal X2
Software: CalMAN 4.2.2
Lux Meter: LX1010B

Screen: 106" Grandview White 1.0
Lamp: 30 hours
Throw: 12'
Seating: 13'
Lumanance(D65): 12fL
Zoom Ratio: ~1.9
Lux: 130
Room: Dark walls, white ceiling, medium carpet, black velvet on screen wall, no windows.

Lens Aperture: -12
Lamp Power: Normal
HDMI: Standard
Black Level: 0


Comments:

- Very happy with the results.
- The VideoEQ is really an exceptional device that makes adjusting any display very easy.
- I will continue to monitor my calibrated lux.
- Next step will be lowering the ambient light and reflections in the room.


CalMAN After AVFoundry VideoEQ Adjustments:

From Kris Deering's review of the X3:


Hi,

The reason that many of us rookies use the Normal gamma setting is because it is what JVC recommends, both in the owner's manual and in their FAQ.

I would be interested in hearing from others on the pros and cons of using the a Custom Gamma Correction value of 2.3 versus the default Normal Gamma.

Thanks.

Larry

I am curious about this as well. I started out using the 2.2 custom setting (which it seems is closer to 2.1 from what I am reading here) then moved over to the "A" setting which is what I am still using. Guess I should try out the 2.3 setting since it is closest to 2.2.

You should use the custom gamma 2.3. But also this gamma equals to a power gamma of 1.9 till 2.2 - much too low in most parts of the 2.2 power gamma curve.

Hi Guys,

Here's a rookie question for you folks.

When we are comparing various preset gamma settings using normal content, without test equipment, what are we looking for? Improved shadow detail, more resolved highlights? What movie scenes are useful for comparison purposes?

Thanks.

Larry

Those are stellar results. Congrats!

Did you check how the VideoEQ tracks color saturation using the saturation window patterns on the AVSHD disc? Curious how well the CMS in the VideoEQ tracks lower saturations of the primaries and secondaries. They look excellent at 100% color saturation, but are you able to show how they do at 25%, 50% and 75% saturation? I'm assuming the VideoEQ will handle these patterns just fine, but I'm just curious. Hmm....
Dan