CurtPalme.com Home Theater Forum

bubsnews · Joined: 08 Jun 2008 Posts: 15

Hello, very new to this level of display calibration (previous use was AVIA and DVE). Just purchased the Eye One LT colorimeter and am using the HCFR software.

My gamma was spot on in the before readings but my greyscale was horrible. After running the HCFR software, my greyscale numbers are unreal (delta E; 316.1, 9.4, 1.7, 1.6, 1.8, 1.5, 3.0, 1.6, 1.5, 5.5, 5.1) but my gamma has gone all to hell.

I've read and re-read the guide but cannot figure out how or why this has happened but my gamma went from an almost perfect tracking of 2.2 to this, at 10% all four colors (which all track very close to each other throughout the range) are below 2.1, at 20%, they are down to 2.0, 30% around 1.9, at 50% down to 1.7 and 70% all the way down to below 1.4 and still dropping very steep.

Can someone point out why this happened and how I go about getting my gamma back to where it was before without losing my greyscale?

I adjusted Brightness and Contrast using the X .0065 method described in the guide and it worked wonderfully to my eye as the -4 bar was completely invisible and the +2 bar was just barely visible.

Thanks, I really appreciate any guidance here,
George -bub

Sorry, thought my gear would show up easier...

Optoma HD7100 720p DLP
Optoma HD3000 video processor
Tosh XA2

I used a combination of the DVE HD disk (only for needle and steps pattern) and the other reference DVD from the files made available here, HD DVD RC1 (used this for the greyscale percentages patterns).

Can someone explain why I can't EVER find any of the video calibration patterns on the DVE HD disk??? I consider myself a fairly intelligent person but I do not see the options available on that disk that is mentioned in the guide. I can not find any of the calibration patterns no matter which permutation of menu choices I make. I get so frustrated using the DVE disks that I have to really struggle with myself not to yank that POS out of my XA2 (I even have the BD version for my PS3) and stomp its guts out!

**kal** · Posted: Sun Jun 08, 2008 6:34 pm Post subject:

Can you post your before and after HCFR files? Much easier to figure out what's going on. Thanks.

Kal

**kal**

bubsnews · Joined: 08 Jun 2008 Posts: 15

bubsnews · Joined: 08 Jun 2008 Posts: 15

**kal**

**kal** · Posted: Mon Jun 09, 2008 2:54 pm Post subject:

bubsnews · Joined: 08 Jun 2008 Posts: 15

**kal** · Posted: Mon Jun 09, 2008 6:00 pm Post subject:

picree · Joined: 31 Mar 2006 Posts: 351 Location: Johnson City, TN

Don't feel alone bubsnews. I have the same problem (See before and after). I've asked this question here recently but I have found that there aren't too many offers to help (other than kal who wrote the great guide and whose time is, I'm sure limited). I suppose this is because many don't want to post on the forum just exactly how they make all the graphs line up properly (self-preservation). So, while having all these tools is cool, this is probably going to be primarily an individual effort. Crying or Very sad

This was much easier before HCFR. Getting grayscale flat was not really a problem. Now that I can see in charts that I was also messing with the overall gamma I'm really confused. For me the gamma went from over 2.4 to less than 2.1. Mad

The image is noticably more washed out and less punchy but I don't know how to adjust it other than trial and error.

I've pretty much resigned myself to figuring this out by trial and error at this point as most of the folks who know how to do this typically don't reply. If I figure out any tricks I will be sure to post results Wink

bubsnews · Joined: 08 Jun 2008 Posts: 15

**kal** · Posted: Mon Jun 09, 2008 8:50 pm Post subject:

You can also try posting over in the Display Calibration forum at AVS. A lot more people answering questions over there.

Link: http://www.avsforum.com/avs-vb/forumdisplay.php?f=139

The only rule is that you make sure to include a link back to my guide. Wink

Kal

bubsnews · Joined: 08 Jun 2008 Posts: 15

Kal, one thing I'm still confused about is how to set contrast initially? It seems that it is an arbitrary setting. And since all the other settings are based off this initial setting, doesn't that make the entire calibration process a crap shoot?

At least in my case, I turned contrast all the way up, then backed down until my ftL readings dropped (there was no change between +7 and +20). This is where I started my calibration, from contrast setting +7, which Kal advised was messing up my Y values in the upper range, which I believe affects gamma.

I would think that if contrast is as important as I think it is, meaning this is where you start to do all the rest of the calibrations, this adjustment should not be arbitrary but more precise using some absolute (or as near as could reasonably be) formula or technique.

And Kal, could you clarify the gamma boost for me? I have a gamma adjustment with my HD3000, range being -5 through +5, would this be considered gamma boost? And, if my gamma curve is low, meaning below 2.2 (say 1.9 or so), would increasing the gamma adjustment, say +2, would that move my gamma curve closer to 2.2 or farther away???

Thanks again for all your guidance and for the great guide Kal! I'm really interested to get as far through the calibration as I can with my projector. I'm really liking the changes so far.

George

**kal** · Posted: Tue Jun 10, 2008 12:14 am Post subject:

bubsnews · Joined: 08 Jun 2008 Posts: 15

OK, another round of calibration last night. Following Kal's advice, I reset contrast to zero and re-adjusted brightness (my earlier calibrations had contrast at +7 and brightness at -3, new calibrations were contrast 0 and brightness -7). I really wanted to set contrast maybe +2 or +3 and recalibrate but the HCFR software crashed and I would have had to dismount the sensor and I just didn't want to go through that all again right then. I think contrast at +7 was too high, and now contrast at 0 too low, that's why I was looking forward to trying +2 or +3.

Anyways, I did three calibrations with only the following changes, the tb4 file will be with my HD3000 gamma settings at +3, the t2 file with gamma set at 0, and the t3 file with gamma at -2.

As Kal suggested, when setting gamma to -2, that actually increases the gamma average from 2.07 to 2.23 without affecting the curve very much at all. Interestingly enough, when setting gamma to +3, average gamma was still about 2.07 but the curve was much flatter. At gamma -2 and 0, the curve was well above 2.2 at the lower percentages and well below over towards the higher percentages (about 2.65 to the left and about 1.9 to the right). So, I guess the HD3000 does a better job of subtracting gamma than it does adding gamma, at least as far as the gamma curve (I'm a bit stumped as to why the gamma set at 0 is not flat, anybody?).

The Optoma HD7100 tracks D65 very well with the RGB levels almost spot on above 20%, luminance curve is very tight, and the delta E numbers great, especially between 20 IRE and 100 IRE (144.8, 10.3, 1.2, 2.6, 0.4, 2.5, 1.0, 1.9, 0.3, 2.3, 1.3).

My concerns are down to two. I really need to try again with contrast set somewhere between zero and +7 as I think zero is too low and obviously +7 is too high (the dang HCFR software keeps crashing after about an hour of calibration and it is too hard to remove the sensor from the mount without having to completely start everything over, not something I feel like doing after calibrating for an hour or so already).

The second concern is why the gamma reading isn't as flat after calibration as it is before calibration. It's odd that setting the HD3000 to +3 gamma flattens the gamma curve but a -2 gamma or zero gamma setting causes the curve to slope dramatically. If anybody has any advice, I'm all ears.

I will attach the three files.

Thanks and good luck everybody,
George

GEBrown · Joined: 08 Mar 2006 Posts: 729 Location: Denver

I was interested in just what this Optoma HD3000 was, as I'd never heard of it in the Video Processors forum on the "A" site. I Googled it and found this review by Tom Huffman: http://www.avsforum.com/avs-vb/showthread.php?t=704674

His initial impressions were VERY rosy, but then in a subsequent post he backs off a little - but still, it seems like a pretty good VP. It has a Gennum VXP processor in it.

Just a couple of observations: Earlier Bubsnews you complained that you weren't getting much "help" with calibrating your DLP projector. That's probably because this site is overall primarily a CRT Front Projector site (analog) and there aren't too many digital guys here. Also, my impressions from using HCFR (on my Marquee) were frustrating at first. A colorimeter is a pretty technical toy and it just takes a lot of practice and MANY passes at greyscale calibration to begin to get stuff figured out. After all, there are professional calibrators out there - not that they use HCFR - but it is a skill that they use to make their living with.

But it seems that you are making good progress now.

My 2 cents,

Gary

**kal** · Posted: Tue Jun 10, 2008 6:14 pm Post subject:

bubsnews · Joined: 08 Jun 2008 Posts: 15

GEBrown · Joined: 08 Mar 2006 Posts: 729 Location: Denver

Bubsnews - I'm sorry - I didn't double-check my sources before publishing that report!! LOL

It's PICREE who was the culprit.

Old-age and good memory are on oxymoron!!

Again, my apologies.

Gary

bubsnews · Joined: 08 Jun 2008 Posts: 15