Do I have a flaky Chroma5?

[tony22]

Hi guys. I've noticed a couple f things over the past few days of calibrating that have me worried. Using my Chroma5 on a Pioneer 111FD, looking at an HDMI input displaying Tom Huffman's free patterns. Display and meter are both warmed up in all cases.

The first problem is that in the 40%, 50%, and 60% intensity windows I will often see the blue channel "drop out" on the CalMAN curves and bar charts. Doesn't matter if it's the grayscale curve or the RGB tracking bars, etc. I will often have to re-read these stimulus windows to get a reading consistent with the points on either side.

The second thing is that I see progressively more unstable readings as I continue to take them (across the range). For example, I was just doing 9 point gamma and was on the 70% point. Now, after I was done with the first part of my cal yesterday (grayscale + RGB) I was reading a gamma of 2.18 at 70%. Without having made any additional adjustments, the first time I read it tonight it was 3.34! And it just bounced around and was very unstable the whole time. How am I supposed to count on such an expensive (to me) meter if I can't predict from day to day what it's going to do? Is this an indication of a bad meter?

[Bob Walters]

Tony,
I'm really hoping for an answer.............mine's doing the same!!!!!

[Turbe]

Derek is taking a look at his logs.. I'll update or perhaps Derek will post here

[tony22]

Yeah. I had to check all the boxes in the Logging options and do a run, and then email it over. Went last night (East Coast Time). Hoping to hear something soon.

[tony22]

BTW Bob, does your Chroma5 do this only at certain intensities like mine (40%-60%)?

[Bob Walters]

Tony,
Same thing.................everything's looking all right & then some # is just not right. It's the "confidence in your equipment" that bothers me. You've been there.............there's always that one client that watches your face for 4 hours and KNOWS you're NOT happy about something!!!!! A poker face I DO NOT have!!!!!!!!

[tony22]

Well, here's hoping Derek finds something soon. :please:

[tony22]

Just wanted to update anyone who's interested: no word back yet from Spectracal. They apparently are swamped getting the new Spyder3 combo ready to go. Understandable, but I have to admit to feeling a little left on the sidelines, wondering how bad a problem I really do have.

[bodosom]

I have problems reading 40-70% AVSHD ControlCAL windows but I've not seen one of the primary channels drop out. I just thought it was a C5 thing although I've been meaning to ask Spectracal about it.

My meter was certified on 28-May-09.

[tony22]

Update: I called X-Rite while waiting for Derek and the boys to get back to me (which they did today while I was at work, but I'll get to that in a second).

I explained what was happening to the X-Rite guy and he suggested that maybe my problem was not getting enough power from the embedded USB port on my Dell laptop. I had actually had this happen before for another device, so as soon as he said that I smacked my head and said "Of course!". So I went to Best Buy on the way home from work and bought two different powered hubs (I would have tried the one I already have at home but that's in heavy use). Long story short it did not make the problem go away - however, it did seem to stablize the readings some. But I was still getting the Blue Channel dropout. So based on that I might advise that anyone getting inconsistent readings with a Chroma5 running from a laptop might want to try a powered hub.

Now, like I said the SpectraCal gang did get back to me. After looking at the data I sent they could not identify a root cause for my problem. So right now I've got another one on the way for me to try. We're all hoping it will work as it should.

I want to give a shout out to the SpectraCal gang for their response. Like I said earlier, I knew they were busy with the Spyder3s but I was feeling a little lost in the mix. Once they got on the case they did seem to get back to me right quick. So I'm happy about that.

[tony22]

Today's news.

The new Chroma5 was waiting for me when I got home from work. I let it warm up on my panel and then ran the usual grayscale patterns, just like I did with the previous meter. Unfortunately I still get Blue Channel dropouts, but it seems with this meter not quite as often and only at 40% and 50% (not also at 60% like the other one). Tried with and without the hubs.

Bob, are you using a Dell laptop for your calibrations?

I'm still hoping this is a sensor issue as I noticed both were calibrated on the same date, so maybe it's a batch probelm. But Chris at SpectraCal tested this one before sending it out and it apparently had no problems at his end.

Bodosom, these sensors are also both from 28-May-09. What sort of measurement problems are you seeing? What sort of computer are you using?

So I figured I'd have to wind up just keeping one or the other of these. I ran the grayscale twice for each sensor to see if there was any issues with repeatability or anything. Well, I don't know how repeatable these things are supposed to be, but I was surprised and a little put back by what would seem to be sample to sample variation. I am attaching two outputs to demonstrate. The first is from the old sensor, the second from the new. Now don't get thrown off by the old sensor looking better - that's the one I had been using to test the calibration settings on my Elite. What's more important is the channel to channel balance between the two. I'd have though since they each have their own cal matrices that the channel balance would match a bit better. I guess I'm wondering how different the picture would wind up looking if I used one versus the other?

D-Nice, you out there anywhere? I wouldn't mind getting your take on this.

[bodosom]

Bodosom, these sensors are also both from 28-May-09. What sort of measurement problems are you seeing? What sort of computer are you using?

The meter takes much longer to read 40-60% windows than the others. I use a MacBook+Bootcamp.

[Bob Walters]

Tony,

Yes,
I'm using a Dell laptop...........and coincidentally enough, I was "tweaking" my Panasonic TH-50PHD8UK last night...just to play with v3.4 and again I got a spike between 40 & 60 IRE.....it's happened before...erase it and start again.....goes away?! How often should these be calibrated???

[tony22]

Bodosom, the longer than what seems to be normal read times are present on my sensor as well in the same range. Except in my case the dropout occurs at the end of these reads at a frequent rate. Then I noticed that when I see an even longer reading (!) that tells me that this one will come back looking normal.

Bob, I don't think this is a calibration issue. I'm not sure I believe it's a USB issue either, as I've hooked a bunch of stuff in to my laptop and have never seen any problems with anything else. It's either a hardware problem (maybe with the batch) that may only show up with certain sensor/computer combinations, or it may be a software problem. But then the SpectraCal guys should have been able to see this.

Bob, what date is on the X-Rite certification document that came with your Chroma5?

Can either of you try your sensor on another computer? I have only one laptop, and my desktop computer at home really can't be moved into the living room without serious pain.

[Bob Walters]

Tony,
The date I can check..........another computer might be a little more difficult but I'll see what I can do!!!!!!!!!!!!!!!!!!!!

[Chad B]

I'm having the same problems with blue dropout and random long readings at middle stims. I didn't have the problem with the first two tv's I used it on, a direct view CRT and a direct view LCD (at least not the dropouts). Yesterday I tried it on 2 plasmas and got the dropouts. I was using an active USB extension cable yesterday on both the plasmas, but I wasn't using it on the 1st two. Maybe it had something to do with it, but I'm not sure. I also have a short 3' non powered extension. I'm doing another plasma tonight and I plan on not using the powered extension if I can get close enough. I use a Lenovo Thinkpad SL300 notebook. I have tried changing the exposure time in CalMAN to anything from .5 to 2 seconds. I thought it was a little disappointing that even when I had the exposure to .5 sec the readings seemed to take closer to 2 seconds.

[tony22]

Hmm, I'll be very interested in finding out whether eliminating the USB hub does anything.

[Bob Walters]

Tony,
The CalMAN # is C5-0023792. Got 0 thru 100 below deltaE "2" but MORE anomalies!!!! 50 IRE spiked, exit, start again OK??? In order to get back to greyscale had to hit "back" twice in order to go forward. I'm almost tempted to erase all existing software, reboot and start from scratch............also tempted to try Sencore's version of CalMAN!!!! Got a calibration Saturday so I WON'T rock the boat!!!!!!!!!

[tony22]

Bob, I can appreciate your frustration. I can only tell you that for the moment the second Chroma5 that I got does seem to be more stable. Definitely drops out less than the old one, and recovers within one or two re-reads.

Hmm, both of my sensors are 26xxx, so I'd have to think yours was from an earlier run. When you get another chance also check the cal certification date; it should be just below the serial number on the lower left of the sheet that came with the sensor.

Not sure Senecore's version would be any different. I think they're just resellers for SpectraCal, just like SpectraCal itself is a reseller for the Chroma5.

[Bob Walters]

Tony,
I'm having a hard time finding that sheet.............I KNOW it's somewhere!!!!!!

[Chad B]

I didn't use the active USB extension on the plasma last night and still had the dropouts and speed irregularities. I still had to use my 3' non powered extension because the C5's USB cable is pretty short, but that 3' cable is hefty and it doesn't look like it would cause any significant loss. I'm not exactly happy with my recent Chroma 5 purchase. With the C5 speed issues, the CalMAN enhanced Spyder3 probably would be just as fast.
Have the issues shown up on other display types besides plasmas? The 1st 2 cals I did with the C5 were not plasmas and I sure don't remember anything like this happening in those 1st 2 cals.

[Chad B]

I think my next experiment will be to tell CalMAN that I'm calibrating a CRT direct view instead of a plasma (even though I am calibrating a plasma) and see if I still have the issues. Has any one tried that?

[tony22]

I haven't tried that Chad, but it sounds like an interesting idea. I wonder if that changes any of the internal algorithms in the CalMAN program?

[Chad B]

Well, I couldn't use CRT selection because it has to sync with it, but I tried the SXRD rear projection. Still had the issues, so I changed it back to plasma. Plus, now I'm noticing repeatability is terrible. It had me spinning my wheels trying to get the grayscale refined, and it turns out it was just giving me slightly different readings with each run. My i1's don't do this. I can't trust this meter. :(

[tony22]

Sigh. Read this

http://www.avsforum.com/avs-vb/showthread.php?t=1165606

I'm not sure what we should do about this. :confused:

[Bob Walters]

Guys,
I spent HOURS trying to get the grayscale right on a Panasonic TH-42PH10UK......................a complete horror show. 30 & 70 right on the button, go to check the entire grayscale, 40 @ 5Delta E, go back with one click in the service menu & the whole grayscale gets "skewed"! I'm done.....can you guys recommend another meter???? I never had these problems with Sencore's ColorPro III & IV! What to do?

PS Tony, mine was originally calibrated 9-23-08???!!!
PPS I just read the AVS forum thread...............that's EXACTLY what was happening to me yesterday
PPPS this was the exact question I had on the CalMAN forum under "color bounce"

WHAT GIVES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[tony22]

There may be some clarity forthcoming.

http://www.avsforum.com/avs-vb/showthread.php?t=1165606

Read especially posts 14 and 24.

[tony22]

Gentlemen, another update. Derek asked me to run Histograms for Plasma, LCD, and CRT selections at 50%. I did so and discovered a couple of interesting things.

1) The dropouts occur also for LCD but not for CRT.

2) The dropouts do not occur for Plasma or LCD when the read time is set to 1 second! (I was using the default 2 seconds this whole time.)

Of course the downside is that the readings are a bit more unstable at 1 second, but NO DROPOUTS!

BTW, just for laughs I tried readings at 2.5 seconds and they also generate dropouts for LCD and Plasma (but again not for CRT).

Update 10:15PM - From Derek

"From this preliminary data I would use CalMAN in CRT mode for now. It looks like even if I tell the C5 to not auto sync it still does something at this level. BTW, the only difference between CRT and Plasma mode is auto sync on/off they both use the same calibration table."

He went on to say that it does not appear at the moment to be something that suggests a general fix, and that the user may need to try CRT mode in their situation to see if it works better than Plasma mode. He thinks it's related to the C5, although he's not sure why it's showing up.

I am attaching the 2 second Histograms for both Plasma and CRT so you can see for yourselves.

[LBDiver]

Tony,

I'm happy to see the dialog has resulted in a serious look at the issues you guys are experiencing with this meter. Hopefully a proper solution will be found shortly.

I have a question, when you ran those greyscale readings you posted on AVS, what settings had you manipulated prior to that. Based on the fact Bob found the same issue on a different make plasma, I figure it is a meter/software issue. However, I am trying to judge whether some adjustment you made on your Pio may have exacerbated the problem, which D-Nice seemed to imply when asking about your workflow. Though I don't see how it could explain the drastic drop-out and channel separation, unless some setting was really out of whack.

Thanks for the update, keep us posted.

[Bob Walters]

Tony,
To add to this catastrophe!!!!

1. If read time is the same as exposure time my default is 1 second already!!!

Derek suggested the CRT direct view for plasma which I will try TONIGHT!

[tony22]

LBD, I was having randomness and channel dropouts from the get-go, with whatever the default settings are for ISF Day and Night. I was a bit alarmed when D-Nice let on that leaving the CMS controls at zero is not ideal, but I'm not sure if that would have made anything any better. When I did try to go through a full cal (including CMS and Saturation) it really didn't seem to get any better. Now that he posted his revised workflow what he said makes more sense to me.

Bob, you should be able to select a 2 second read time at the start of CalMAN (at the screen where you pick the meter) and then select the CRT profile. When I did that I got 2 second reads as expected.

[Bob Walters]

Tony,
I'm going to leave the 1 second default as is and try the CRT input select just to see what happens...I'll let you [and Derek] know what happens tomorrow!

[Bob Walters]

Tony et als.,
Here's the response I sent to Derek last night:

As we speak, I am calibrating!! I had to push the sync button or I couldn't proceed! NO fluctuations on 50IRE!!! 60 & 90 were within deltaE3 but a click in the SM got EVERYTHING below deltaE2 except for 60, 90 & 100 which are a tad over deltaE2. I'm NOT going to push since things look good! Now a 2nd series of readings with NO changes to the SM & now only 100IRE is a tad over deltaE2. This is my main bitch...why a change, insignificant as it is in the grand scheme of grayscale tracking, but IT'S THERE!! Now, 3rd reading...NO changes....60 & 80 over deltaE2....not a lot [and it makes no difference as far as the grayscale is concerned] but it's there!!! But not-for,-nuthin',NO fluctuation at 50 or anywhere else!!!!

PS The default on my software IS 2 seconds!!!!!

[Turbe]

more...
What we have found is not as much as a "real problem" as Tony puts it but just a odd way the C5 works on some Plasmas not all.

The Chroma5 has a sync sensor so when reading off a direct view CRT it can time the readings so the other sensors get the same amount of exposure time. Which with the C5 is a bit tricky because the C5 has it's sensors arranged in two rows and those two rows could be on different scan lines on the CRT.

Anyhow when reading from a Plasma you don't need the sync because of how Plasma works but when turning the sync sensor off at some point usually 40-60% stim the C5 really gets confused because a Plasma does energize the phosphor just not the same way as a scan line CRT but as pulse width modulation kind of like Morris code. It's at this point the C5 thinks it's reading a CRT and wants to try and sync even with the sync sensor off and is when it can’t sync you get odd results.

So the current work around if you are getting erratic readings that being the RGB’s are jumping around a lot for no good reason is to tell CalMAN the display type is a direct view CRT and just ignore the sync step. The only difference to CalMAN from Plasma vs CRT is we turn on/off the sync sensor.
It's not clear from this what's fixing the problem.
Are you saying the C5 + CalMAN can be in three states?


Unsynced.
Synced.
Synced but not setup.


And that being in state 3 will stop the extended (and sometimes failed) reads that happen starting around 40%?
For the most part yes. For Plasma's that cause the C5 is be erratic using CRT direct view tells CalMAN to turn the sync sensor on but we don't require a sync to happen to be able to read.

[tony22]

Tony et als.,
Here's the response I sent to Derek last night:

As we speak, I am calibrating!! I had to push the sync button or I couldn't proceed! NO fluctuations on 50IRE!!! 60 & 90 were within deltaE3 but a click in the SM got EVERYTHING below deltaE2 except for 60, 90 & 100 which are a tad over deltaE2. I'm NOT going to push since things look good! Now a 2nd series of readings with NO changes to the SM & now only 100IRE is a tad over deltaE2. This is my main bitch...why a change, insignificant as it is in the grand scheme of grayscale tracking, but IT'S THERE!! Now, 3rd reading...NO changes....60 & 80 over deltaE2....not a lot [and it makes no difference as far as the grayscale is concerned] but it's there!!! But not-for,-nuthin',NO fluctuation at 50 or anywhere else!!!!

PS The default on my software IS 2 seconds!!!!!

Bob, that sounds great. Regarding the 100IRE point: I was experimenting last night and got further experience in what happens when pushing the 100IRE point too far. (BTW, what was the fL for this point?) I did a repetitive read on 100IRE and gradually raised the Contrast 1 notch at a time. Not only did the RGB bars start skewing (they started dead even), but the skew changed as I went further up the line in Contrast, and it seemed to get more erratic at various points. The details...

I ran the range from about 36 fL to 49 fL (ISF Day). The RGB bars were even at 36 fL. As I went up, first the Red channel started lagging, followed by the Green channel. But as I kept going up the Green channel recovered to be close to the Blue Channel. However, during this transitional range the readings seemed to fluctuate more. Now here's the funny part. By the time I got to 49 fL all three bars were back in line! And they were stable again. If I moved the Contrast setting even one click off that mark the channel imbalance and more erratic behaviour started up.

It seems like there's a "safe" range (at least on my set) up to about 36 or 37 fL where everything behaves very linearly. Then there's this range of non-linear behaviour up to about 49 fL. Maybe each set has this odd "Twighlight Zone" range where trying to get a calibration becomes tough. I suppose it could be done by someone who really knows their stuff, but I suspect it's a lot harder than setting Contrast and Brightness so that either end is still operating in a predictable, linear manner.

I could be completely off the mark, so take all this with a very large grain of salt.

[Bob Walters]

Shawn,
The software WON'T let you proceed UNLESS you hit the sync button unless I'm doing something wrong?

Tony,
I got 38ftL on my display?!

[tony22]

Shawn,
The software WON'T let you proceed UNLESS you hit the sync button unless I'm doing something wrong?

That is correct. You are not doing anything wrong. Just point it at a 100IRE window and hit the Sync button.

I got 38ftL on my display?!

Well, I don't want to take my experience and generalize. But you may wish to try the same ramping test I did with the Contrast. See what happens to the RGB bars as you progress above and below 38 fL, and see if there appears to be any differences in stability of the bars.

[Bob Walters]

Tony,
Is v3.4.1 usable................I'd just like to get rid of the plasma problem............only for MY own peace of mind!!!!!!!

[bodosom]

Is v3.4.1 usable

What's the definition of usable? The current beta fixes some problems in 3.4 but issues remain. You can check your workflow and see if it trips you up. The current posted beta doesn't "fix" the C5 sync problem.

[Bob Walters]

bodosom,
Just going by Derek's remarks:

"In CalMAN v3.41 we have changed the Plasma mode to use auto-sync but not require sync as a step. So this should be a good solution for everyone."
__________________
Derek
THX Certified Professional – Video Calibrator
ISF Certified Technician

SpectraCal CalMAN Professional - Sencore ColorPro by CalMAN

[bodosom]

bodosom,
Just going by Derek's remarks

Right, and four posts later I asked (indirectly) if that was in a yet to be released version since it doesn't work that way in 3.4.1 beta 226 (I run the beta code because it fixes a bug in 3.4 that breaks mine).

I'll make my 3.4.1 point in a different way:
Is v3.4.1 usable

3.4.1 hasn't been released yet.

[tony22]

I'm going to try 3.41 tonight.

[tony22]

3.41 does not fix the Plasma sync problem.

[Bob Walters]

Tony,
Thanks...Derek & the boys have a tough job so it's better to use the CRT workaround & WAIT. Thanks again!

[bodosom]

3.41 does not fix the Plasma sync problem.


Do you mean 3.4.1 beta?