Offical JVC DLA-RS4810 Owners Thread - Page 28

the lumagen will allow for much more advanced color controls than the built in CMS.

click on the link in my signature for a close up look at the darbee. In short, it enhances perceived sharpness and contrast for a relatively low cost. definitely a worthy investment for any projector.

That's an excellent approach. Given that I have a Lumagen and don't care for this years eshift I would have opted for the RS46 if I had known then what I know now. That said the PQ on the RS54810 is excellent and it comes with an extra year of warranty.

Everybody has a Darbee because it improves their sex life. They just don't want to say.


Seriously, I saw the Darbee in prototyoe form years ago and have been plugging it ever since. I started the original thread years ago Most perceive it as an inline device that makes contrast detail in picture more visable in a way a higher quality lens might let one see more fine detail. It does have some negatives but most conclude that used in moderation 9it is settable) there is a net improvement in PQ. I like it a lot but even i would say the improvement in PQ is in the neighborhood of a few percent, maybe 5. Worth it in my opinion at its current price. Give Mike a call at AV Science, he will set you up and there like most things AV Science sells is a trial period.

Here's my calibration report...as you can see, green is under 3. In my case it did take some farting around with the two effective green controls because adjusting brightness would affect hue and saturation and adjusting hue would affect brightness and saturation. Adjusting saturation, in my case, did nothing.

I used the Natural color mode and Standard color profile.

Oooh yeah from the screenshots on their site I am definitly ordering that, the price is a bargain in the A/V world. Can someone who knows the AVS price PM me? I know they don't like disclosing their prices on the forums. Because I can get it on Amazon for $320 with a return policy, and on credit(which sad to say is necissary at this moment).

I was watching some end credits last night and I suddenly thought that I must have accidently put CMD on low as it seemed so smooth. I checked and CMD was off, so it's just that I do find the motion smoother on the X35 compared to the HD350, but then I've missed quite a few generations out (the best way to upgrade IMHO).


That's interesting to hear. I thought long and hard about the choice, but I've seen an X55 since and wasn't overly troubled that I made the choice for an X35. I'm also going to calibrate an X55 for a UK forum member (in return for a chance to listen to some high end PMC speakers) so that will give me chance to have a bit more in depth viewing of the X55.

Thanks for posting this, as per my above comment, it helps to know a good starting point when I calibrate the X55 mentioned above. I would however recommend that you revisit the low end gamma as it looks like it's well above 2.3 at the low end (maybe even 2.4) which will ruin any shadow detail. If it isn't too difficult I'd even suggest lowering the gamma on the 5% adjustment perhaps to 0.1 or even 0.2 below your target.

@ Plissken99 The Darbee is a great little device, but IMHO if you haven't got the cash I wouldn't sweat it: Not worth getting into debt over (as is any of the gear we talk about on here, it's a luxury after all).

Sorry......no mocking intended.....that question just struck me funny

I didn't calibrate gamma...I think I set the "Custom Gamma" adjustment value to 2.4 or 2.5 in the 4810's menu and left it at that. As you suggest, I'd prefer that the gamma curve "swing" the other way (low at the low end, high at the high end), but CalMAN recommends a gamma between 2.4 and 2.6 for a darkened room so I figured that a low-end gamma of under 2.4 would be fine. I'll fiddle with it the next time I get my meter out.

There's no standard workflow for calibrating gamma in the CalMAN 5 Basic software that I have and I got into a real mess trying to do it with HFCR so I decided to save myself the frustration this go around. I suppose I can simply bump up the custom gamma curve at the low end to achieve the results you suggest.

The problem with a set accross the board gamma number is that the on/off at the screen will not be high enough to support a high gamma at the very low end. Its a fact. If the on/off is not high enough, you will experience black crush or in other words a loss of low end detail as the blacks merge into nothingness. It is imperative that to avoid this, a non linear hign number gamma be used. An S curve gamma must be employed with the gamma number being lowered t the low end. at the high end a higher number can be supported, even higher than the supportable gammma at mid levels.

gamma depends on viewer preference. How contrasty a image do you like but then once again, your preference may bot be obtainable given the limitations of your projector and how you set it up, high lamp/low lamp, iris setting and throw.

I laugh at people who thing there is somethig magic about 2.2 and paying a calibrator set set you a straight line gamma at 2.2 (really a curve, just calling it a straight line). Most calibrators do not understand gamma and want you to think you have bettered your projetor by giving you a nice graph showing a perfect 2.2. What a joke. They have given you black crush at the low end and not the magic of movies which are often displayed at their best at higher mid and high end gammas. but once again the exact gamma at any point is a metter of preference avoiding choices that crush the blacks and/or clip the whites.

Your gamma curve looks very much like the gamma presets when my RS55 was new. It gives the impression of lots of very deep blacks but loses shadow detail. The best way to get the detail back without calibrating is to raise the Dark Level control which tweaks the low level gamma. But at some point I would highly recommend using the custom gamma controls to get it perfectly flat. And as Kelvin mentioned, tweaking 5% for that last bit of shadow detail.

Yes, I read your comments about cal'ing his x55. I'll be most interested in hearing about how well it calibrates and your impressions of the unit compared to your X35.

I went with the x55 because I really liked eshift1 on my RS55 (which ended up with a very significant purple-ish cast in blue skys which is why I no longer have it). But I should have acted on my first impressions of eshift2 and returned it for the RS46. With all the adjustment options I thought I could dial it in but I have yet to get there. Zombies eshift1/eshift2 comparison photo clearly shows eshift2 is adding artifacts that eshift1 did not so I have given up trying. I wish they would have given us a mode that simulates/emulates eshift1.

Interesting gamma discussion guys and thanks for all the info. I just did my auto cal with the Mini/CP a few days ago and right now I have a flat 2.22 gamma. My question is what is the best way to tweak the low end back down a bit to reduce black crush and can I do this without getting out the meter and calibration gear AND will this screw up the rest of my calibration? Can I simply put on some sort of reference type shadow detail scene (any suggestions?), pause it and tweak the low end (5%?) up a few clicks or so? Next time I pull out the meter and calibrate I assume I can either tweak this in the Mini or JVC (does it matter which place I tweak it?), but I was hoping I could just tweak the low end by eye until then without damaging the rest of my calibration. Any tips/advice would be appreciated! Hoping I can just tweak this in the JVC by eye at the low end without getting out the meter.........

EDIT: I just read 5Marks post. I dont have a dark level control in my 45 so this is not an option unfortunately. What is the next best attack to improve low level detail?
Edited by Toe - 1/20/13 at 10:50am

In fact I used picture mode User1 with color profile STAGE (X55´s Manual page 38).

I guess I'm too used to the Lumagen, because I don't have a problem with low level gamma causing crushing. On this occasion I'm going to disagree with Mark as don't find that a measured 2.2 crushes black at the low end as I can see the 17 bar flashing on the AVS disc whereas if it were crushed I wouldn't be able (16 is as dark as 15, 14, etc, so black level can't go any lower).I find that a gamma of perhaps 2.3 that drops to 2.2 at 10% looks good to me (when I had a temporary black room treatment up anyway). If you slightly raise up the 5% in custom gamma it may well help without raising the absolute black level unless perhaps the RGB offsets have been adjusted away from 0.

IMHVO getting the gamma response right is paramount to seeing a good image: No good having a perfect greyscale and gamut if the gamma means shadows are hidden and brighter parts look washed out. Putting the projector in 2.4 or whatever and leaving the other settings alone is only doing half the job. In fact I'd argue that colour temp could be a little way off and you may not even notice since our eyes will tend to compensate, but poor gamma stands out (or it does to me anyway).

It is possible to move the 21 point greyscale around on the Lumagen so that you could have a 1% setting should you wish, but not sure how this effects the autocal result (perhaps you could just move the 5% on down in the Lumagen and use the JVC's 5% control if necessary).

The 21 point merely divides 0 to 100 in 20 equal steps. i believe you could measure and customize gamma at 1% increments if you wanted to but certainly not using an auto cal function. I have never done more than a 20 step, twenty onepoint but I think it is possible.

Yes!!! Getting a good gamma curve on my pj was the biggest eye-opener (pun intended) I've ever had in home theater. It made a huge difference! More than grayscale or gamut.

I'm with you that having a good gamma response makes a huge difference. Then I'd rate grayscale and then gamut.

As Mark states, one can adjust Lumagen greyscale and gamma in 1% increments but that is of course limited to doing it manually. Have fun financing a meter that can do this accurately below 5% though.....

SOWK: Have you tried a BT1886 gamma curve? I'm sure you also realize that jumping up higher in the JVC food chain (higher contrast ratio machines) would yield more luminance separation between level 16 and 17.

You couldn't adjust at 1% increments unless you only wanted to adjust from 0 to 20% as the 100% and 0% can't be moved and you only have 19 points that can be moved around where you feel they would work best.

Using a Lumagen you could adjust the greyscale and gamma manually and move the 19 points where you see fit (and use the JVC's custom gamma too if you really had nothing better to do with your time), then run the autocal for the colour gamut. However, I find it's quicker to let the autocal do it all, maybe check the greyscale (make any slight tweaks if you wish) then do the colour gamut separately. Anything away from the target gamma will produce errors due to the way the cube works, but from those who have measured these errors they don't seem to be too major and we are talking about low % levels anyway, so you could argue that the gamma is more important here than absolute spot on colour temp at very low %.

While on the subject: I've seen the arguements about only aiming for 3dE, but my opinion is that it is better to aim for as low as is possible. Then any error of the sensor might still fall within limits:if only 1-2 dE meter error it might mean that the actual dE is still within 3dE if you hit near 0dE with your measurements. However, I don't spend so much time calibrating these days...I did lots and lots of experiments when I first got my old i1LT and Chromapure: I tried different gamma responses (flat and curved) and saved them in different memories. I would then pause different scenes (light, middle and dark) to try to understand which settings effected which parts of the image. Now that I know I personally prefer 2.3 that drops to 2.2 (maybe even 2.1 at 5% on my older HD350 with less contrast) then that's what I aim for...it doesn't take long these days either manually with Chromapure and the Lumagen or autocal with a few tweaks, so all the more time to watch films.

When I go into CalMAN's DCC I find resolution to 0.1%. What am I missing? Do you mean 1% relative to the current point's level or 1% relative to 100IRE? The DCC shows 0.1% relative to 100IRE, right?

I was referring to 1% luminance steps (Autocal does 5% or 10% increments) but I think you may be right that you can go finer than that....I just don't recall at the moment.

And Kelvin, to be clear, I also try to get ∆E lower than 3 (lower than 1 if I'm in the mood) but if the meter is accurate a gamut ∆E error of 3 really isn't an issue.

That's the point Geoff, we don't know for sure how accurate our meters are: I have the i1 display Pro enhanced, which is supposedly pretty accurate, but without a $$$$ spectro to compare it to, I don't really know how accurate it is. So if it's 1-2dE out and I manage to hit below 1dE on my readings then I'm still good as my max dE is still under 3. If I hit just under 3dE and my meter is out by 2dE then I could be at 1dE or just under 5dE actual error depending which way the error is. Of course I don't even know if my meter is within 2dE, but all I can do is make it as accurate as I can in the light of the above.

Yes, I understand. Lower is fine but if you can't get there then you can't get there. I didn't mean to imply (though I realize I probably did) that one should stop trying at ∆E of 3. That said, if one is using a profiled meter (by Chromapure or Calman) I don't think meter error is going to be a big deal.

Might still have it,but my son is 13 now and I think we got rid of most of the old discs now (he says they are too babyish for him to watch ). I've got the Bond discs for sure though, so I'llhave a look at that scene if I can find it. However, my X35 is calibrated with the Lumagen, so it's cheating really, though I could bypass it and see if I can still see the detail in person, I can't take good photos as I only have a basic point and shoot 5mp Pentax.

@ Geoff I agre: I get as close as I can without spending hours over it, but if there is a greyscale point that is at 2.9dE I'll maybe try to tweak it down manually before running the colour gamut autocal. I'm really pleased with the D3 as it seems much more consistent as I can remeasure my TV the next day and get pretty much the same results. Of course projectors drift more quickly anyway, so in some ways it's a bit moot, but these days I just do a calibration at 100 hours, then maybe not until 400 hours (I did a calibration at 15 hours on the X35, but I fully expect it has drifted now that I'm near 100 hours).

Yeah, Kelvin with Grayscale I aim for a ∆E ≤ 1. My routine is to run just a grayscale/gamma auto cal then use Chromapure's Gamma module to manually tweak all 5% point to less than 1 ∆E...this usually goes pretty fast. I've found that the gamma/grayscale autocal gets things close but there are two things that fool it....first off, my projectors luminance is bouncing around at 100% (I'm hoping that next tiem I calibrate the lamp has settled down a bit). That results in "bouncy" gamma from about 75 to 95% -- Chromapure can't average the bouncing as well as I can by eye so I set it such that the average gamma is at my target (say 2.2). IOW....I adjust it so it's bouncing higher and lower then 2.2 by an equal amount. Likewise at lower stimulus levels (below 25% or so) it takes time to settle out (it takes progressively longer as the level is reduced). So I just watch and wait for things to stabilize...at 5% it may take minutes to get a consistently stable reading. When doing the manual tweaking I adjust both gamma and grayscale using the Lumagen remote so it usually takes but one pass to get both where i want them to be (if I had to do a lot a tweaking I'll take a 2nd pass). But I have found that by waiting for things to stabilize I get very consistent and repeatable results using my i1D3 Pro (it's a very nice meter) and my grayscale ramps look clean with no hint of tint.....Only then will I do a 125 pt auto cal.

Sounds a good process to follow and not too disimilar to mine. I also find that 100% 'bounce' but I was only at 15 hours so it'll be interesting to see if it's better when I do my 100 hours calibration anytime soon. I hope the X55 I'm calibrating will have a good few hours on it too otherwise it could be a long one. I'm going to have a play with the JVC controls for custom gamma since he doesn't have the Lumagen so I'll have to have a practice first...

Yeah, 15 hours on mine as well. I'm probably close to a 100hrs now but I haven't looked at it recently. I have looked at the gray ramps (I just love having the Lumagen in the chain....no muss, no fuss.....anyway the gray ramps still looked excellent. I'm sure that gray ramps my RS55 would have not looked that nice after 100 hours...

have fun with the X55.....I'm glad I don't have to go the custom gamma route....

This worked great; thanks for the tip. Three clicks up on the Dark White Level setting got my gamma to 2.2 on the very low end -- just what I was looking to do without screwing around with custom gamma curves.