Couple questions about calibration.....

Yes start out with a cal disk and experiment with settings, read, learn, experiment, read learn, etc...

I don't really think that using a disc and your eyes can be fairly called "calibration" -- call those discs "setup" discs... they will usually help you get the basic controls set reasonably well... especially Brightness and Sharpness. Calibration really requires "equipment" to avoid all the issues with eyes being easily fooled into making inappropriate adjustments (once you get past brightness and sharpness. The Setup discs don't even get you to the correct Contrast setting... all they do is help you determine at what point the Contrast control causes white clipping (or that there is never any white clipping no matter what Contrast setting is used). But the setup discs cannot help you get the Contrast control set to a specific level, like 35 fL for a panel display or 16 fL for a projector unless you have a meter and calibration software. A setup disc can be used for setting Brightness and Sharpness and you'll get perfect results for those two settings and that's about it. Everything else they claim to do is a bit of a crap-shoot as to whether they are any real help or not if you do not have meter and calibration software.

Perfectly put, Doug.

Absolutely, that's where I started, playing around with calibration discs. I suspect every professional calibrator started there as well.

There are really only two choices out there and I work for one of them, so my advice is a little biased, but the basic CalMAN package comes with a C1 (spyder 4 based meter) and the next level up uses the x-rite i1 Display Pro (oem version). The i1 Display Pro is a much beter meter, so if you have the means that's what I'd grab, but C1 can still give you excellent results.

well for displays with a backlight control (LED/LCD flat panels), you get the correct contrast setting (you can use the highest setting that doesn't result in clipping or discoloration) and then set backlight either with a meter to the desired fL or to a level comfortable to your eyes in your typical viewing environment (while viewing a 100% white pattern)

I agree with the rest of your post, though.
Edited by PlasmaPZ80U - 7/27/12 at 12:01pm

The whole premise of my post was that you were using the disc without a meter, hence calling them 'Setup' discs instead of "calibration" discs. You can't find the right backlight setting without a meter. If you have a meter, you get something approaching calibration depending on your skill and how good the meter is.

As for how much you can/should spend on a meter... they start at a little under $100 and go up to more than $25,000. Pro calibrators typically use meters that cost between $700 and $20,000+.

The problem with most inexpensive meters is that they use color filters that fade and/or change color over time making the meter progressively inaccurate. So your brand new $250 meter could be fairly inaccurate by the time it is 5 years old. Higher temperatures and humidity accelerate aging. Some people have been known to freeze their meters in bags loaded with silica desiccant packets to absorb humidity... all in the name of trying to get more years of use out of their meters. Whether freezing helps or not is completely unknown (as far as I know).

Spectroradiometers measure light differently... without filters. They cost more, though, and inexpensive ones (about $700-$800 new) are fairly slow reading at darker levels. Some of them also require fairly frequent dark calibrations (like every 20-30 minutes). Even though Spectroradiometers don't have filters, they still need to be re-calibrated every so often (varies among brands/models) but figure every 2 years or so.

So calibration isn't something you spend money on one time and your good forever... there are on-going costs.

This is contrary to what most in this forum have posted about the original i1Pro spectro. Aside from dropping the meter, it will stay in spec for a very long time when stored properly, well beyond 2 years.

Also, if you use the spectro to profile a colorimeter, that effectively re-calibrates the colorimeter for the display the profile was created on, thereby bypassing the need the re-calibrate the colorimeter. So, having a colorimeter like a D3 and a spectro like an i1Pro or i1Pro 2 can be an effective way to do calibrations yourself without having to worry about meter accuracy (initial and long-term). The only limiting factor remaining then is how good you are at calibrating.
Edited by PlasmaPZ80U - 7/28/12 at 5:05pm

So you get an inexpensiv spectro and a moderate cost colorimeter, now you're at $1000 for calibration hardware.

I've heard the "stories" about the i1Pro several times and don't believe them because every time I measure one with my own freshly calibrated meter, they are "off" enough to be an issue. This has happened about 6 times over the years.

You cannot assume that simple characterzation of a "faded" colorimeter against a specto is going to produce accurate readings in the colorimeter. The aging process of the filters is a complex process and the filters not only change color, their linearity (bright to dark) an become non-linear. So if you measure a single point as a calibration reference, only that particular luminance level might be correct. To get away with making a "faded" colorimeter accurate (temporarily), you'd have to build a correction matrix that would require measuring white, red, green, and blue at 10%, 20%, 30%... 90%, & 100%. That will take a while with a meter as slow as the i1Pro and the calibration software would have to support that sort of matrix calibration rather than the much more basic characterization. The newest colorimeters that have the filters in a sealed chamber in an attempt to extend their useful life before the filters begin to change significantly, but they are pretty expensive for someone looking for entry-level calibration hardware/software combos.

So what are you trying to say? Correct me if I'm wrong, but it seems to me that you're suggesting the only way to get a true, full calibration is to hire a pro like yourself or spend thousands on a periodic basis to maintain your own hardware.

Perhaps if you shared some data that shows the difference between your reference spectro and the i1Pro spectro on several displays types/samples, I'd be more inclined to believe what you're saying.

The same goes for the four-color matrix as a means of profiling a colorimeter to a spectro on a given display. (CalMAN uses a XYZ matrix, which does apply a luminance correction and ChromaPure uses a xyz matrix that is color-only.) If those methods are ineffective for an 'faded' colorimeter, why are they the recognized standard for meter profiling?

Essentially, I am asking for some hard data to back up your claims, since most of what you have posted in regards to DIY calibration seems to be suggesting it's not a valid alternative to professional calibration unless a great deal of money is spent. Also, it goes against what I have read and seen on this forum plenty of times (and that includes posts/data from other pros).
Edited by PlasmaPZ80U - 7/29/12 at 2:12pm

Do we need to revisit this yet again?

Nobody should expect a $150 (or $250) colorimeter to outperform a ~$750 10nm spectro.

Nobody should expect a $750, 10nm spectro to outperform an $8000, 5nm spectro.

Meters will drift over time. The only question is one needs to answer is how much one is willing to spend for a certain level of "surety."

One can certainly make the case that a "professional" calibrator will probably maintain their instruments better that the average home DIYer.

OTOH, one could make the case that a "professional" calibrator is time constrained and may not necessarily be able to wring every last drop of improvement out of a given display versus a home DIYer who (at the very least) has the advantage of being able to experiment on their displays at will.

For my part, having lived through the era when Optical Comparators were, in many respects, considered superior to colorimeters I find these arguments a wee bit amusing (and sometimes tedious.)

There's no black and white answer here, only shades of gray.

Ain't that the truth.

I agree, which is why I'm saying using the term "accurate" in the binary sense is not helpful when discussing meter accuracy. The real question is not whether a meter is accurate or not but rather how accurate it is (degree of built-in error). What I am also saying is that meter drift on a spectro like the i1Pro is negligible for the DIY user and so in that context, it doesn't need to be periodically re-certified and/or re-calibrated.

(I'm not claiming a $150-$250 colorimeter will outperform a ~$750 10nm spectro or that a $750, 10nm spectro will outperform an $8000, 5nm spectro.)
Edited by PlasmaPZ80U - 7/30/12 at 8:26am

You're assumptions and presumptions are completely wrong. I'm not providing my hard data about results with a number of i1Pros over the years, get your own hard data that shows I'm wrong.

And I'm not saying pro calibration is the only solution. I'm saying you can't buy your own meter and expect it to be a one-time/one-cost purchase because the meters change over time... period. The newer "sealed" colorimeters MAY have longer expected lives. Many inexpensive meters have no option for being re-calibrated also. If you want to purchase a meter that you can maintain over time (by shipping it off to be re-calibrated, probably by the manufacturer) you have to make sure that service is available for the meter you are considering purchasing. If you choose to purchase a meter that has no official re-calibration service available, you have to understand that the money you spend isn't going to get you a meter that will be useful over the long haul. Characterization against a more accurate meter is OK, but only up to a point. The problem being if you Characterize a meter against a reference meter but do not then check the "full spectrum" response of the characterized meter, you won't know if that particular meter is accurate at other luminances than the one used for characterization and you won't know if all 3 colors are equally accurate without measuring all of them.

There is no easy answer to this question. It all depends on whether any given person wants to invest 100+ hours in learning and practicing calibration and spend 100s of dollars on a reasonably good meter plus learn a software package (and decide whether to pay for the software or deal with the free version)... or whether it is worth paying a pro calibrator to just get the job done and not worry about all the details. Each person has to decide for themselves, but they can't make an intelligent decision if they don't understand all the variables. Too many DIYers sugar-coat the DIY solution, making it seem like a no-brainer when the truth is really something quite different.

N00b question here: if a television only has a general setting for color, and not specific controls for different degrees of luminance, what does it matter if the meter correction is only valid for one luminance? I mean, i believe the "best" way is to calibrate at 75% since that is closest to the most common real video image you will get. So if at 100% or 50% its a bit off, i can't do anything about it anyways. And if you really want to measure it you can correct the field meter for each luminance seperatly. It takes less then a minute to do a field meter correction.

Here's an example.
Edited by PlasmaPZ80U - 7/30/12 at 3:15pm

I for one am glad to finally see this particular discussion come to light. I've asked a couple times in the past about the validity/accuracy of commercial "hobbyist' meters in respect to their initial accuracy, what they are referenced against, how long is the accuracy guaranteed for, re-calibration etc but never received a response. As long as the discussion stays civil, I think the information from both sides is extremely useful to those who are thinking about DIY calibration vs a professional calibration and want to know what the pros and cons really are concerning both approaches.

I think the more data points others reading this thread can provide, the easier it will be to draw general conclusions. For example, if the i1Pro spectro is 'off' compared to a reference grade-spectro, how 'off' is it? Is it off by an amount that is visible to the human eye or are any differences beyond human perception?

I agree with Doug on this one and would further add that there is absolutely NO guaranty that using a hobbyist level meter of any sort is any kind of guaranty that your TV is calibrated to the extent of the standards that multi thousand dollar pro equipment can, nor that the picture will look any better compared to using one of the several discs available to make Media Assisted Settings. . . on many home TVs. As comments from many owners testify, many do not like the "calibrated" picture obtained by using a hobbyist meter. And then there is the question of methods used (BT1886 gamma for one) and other factors including the person using said meters.

I would no longer put faith in any hobbyist meter. I would no longer spend $250 to $1,000 or more for meters that offer questionable accuracy let alone a better picture. And, paying for a pro calibration begs the same questions, although more likely to result in more accuracy if all things are up to snuff. Honestly, it is a crap shoot. So you either pay some money and see what you get, spend a huge amount of time and some money on DIY, or go the Media Disc "Calibration" route.

After my experience, (having owned a Spyder 3 and then an i1 D2) unless you just enjoy the DIY route as a hobby/learning experience, I would rather research and pay for a pro calibration from a reputable person. . . also providing I have a TV that is worth it and has the necessary controls (ie, not broken) to do it. It's a matter of degree then, as to the actual accuracy of picture quality desired and obtained.
Edited by Phase700B - 7/30/12 at 4:02pm

I think there might be a different reason for DIY calibraters to be unhappy with their results. Firsf of all there's a lot of meters to choose from, from the known to be less then stellar spider series to the supposedly reasonably accurate display 3 pro and the i1 spectro. Secondly not all tv's are equal and expected results may not be achievable. Thirdly not everyone has a "feeling" for calibration, or the insight to understand what they are doing. And finally, there is no question that there is a huge gap in experience between a DIY person doing their tv and their moms when they have a free evening or two, and a pro who has done hundreds and hundreds of tv's for a living, after having followed extensive training.

Taking myself as an example regarding my "experience" argument, I have been calibrating my plasma for a month now, at least 10 times, and eventhough after the first calibration it looked heaps better, I am just now beginning to understand the calibration proces more deeply, and sadly will most likely be crap at it again should I attempt a different display then my own.

I have talked with X-rite a couple of times and they have stated that almost all of the i1pro's that are checked for recertification are still within original specification. One of their CS reps even suggested picking up a second 'used' i1pro before sending off for re-certification since they can be found at a very reasonable cost (many on ebay have sold around $200-$250 and some of the UV cut for even less). I was also told by another Pro that he had sent several meters in for re-certification many times over the years and none of them actually required re-calibration, he said he did it to assure his clients and his own peace of mind.

Now does any of that mean they cannot be 'off', certainly not, but my guess is it is not very common regarding the i1Pro. I would also venture to guess that even if one happened to be very slightly off it would probably not be detectable to the majority of the population (meaning for the DIY calibrator as obviously Pro's should have their gear at least re-verified regularly for the benefit of their paying customers).

Jason

I guess everyone's experience may be different. Doug is a pro and states his experience.

To be fair, it would be much better if there were an actual third party calibration service such as is available for standard electronic test equipment to verify and certify something like a spectro. I don't know that I would trust the seller of a DYI device to say, "Yeah. . . looks good, the meter is just fine!" My point is , as a DIYer, you have no other way of knowing the condition of a spectro or colorimeter unless you have a professional higher costing spectro to compare it to or some other pro with accurately calibrated and certified equipment to compare the DYI equipment to. . . on a regular basis. Plus, all this is a moot point if the TV does not have at least a 10 point IRE available and working well and hopefully, a working CMS. Owners should at least be aware of their TV's capabilities. If there is only a one or two point system I don't know that I would either pay for a calibration, nor buy DYI equipment to calibrate such a TV.

And, as Doug said, the investment for an "inexpensive" spectro and colorimeter would be ~$1,000.00. The few i1 Pro on Ebay are going for more like $400 or more and you would have to be concerned with their condition as a used device. . . so probably would want to verify it's operation and accuracy against a known good professional spectro of higher quality.

As someone else said, more shades of gray.
Edited by Phase700B - 7/31/12 at 10:01am

Yeah, this is consistent with what I was saying about the i1Pro spectro. The D3 + the i1Pro is a great combo for DIY users, as it offers solid accuracy thanks to the spectro and great speed and low light sensitivity thanks to the colorimeter. Buying the spectro used makes it a real great value and accessible to the averager DIY'er.

Good points made on both sides of the net so I'd call the match pretty much even at this time (too much Olympics watching)

It seems to me that one of the bigger issues is cost. Is it better to buy multiple meters to validate accuracy, keep one in reserve when the primary meter is sent off for re-calibration (another cost), etc? Or is it better to just pay a professional $400 every 2 to 3 years (whatever the drift time is for a given set) knowing the quality of the instruments used (proper maintenance) and the experience of the calibrator? We all have expensive hobbies and the satisfaction of doing it yourself can't be quantified by cost alone, but I think the "hidden" costs to the novice can be unsettling once they get further into the calibration process and learn more and more. Excellent discussion guys

I'd rather do it myself (calibration) since the end result is that much more satisfying and I can do it exactly the way I want to and spend as much time as I want to.

Also, I'd rather just get a used spectro instead of sending in my D3/C6 for re-calibration since that not only seems more cost-effective but I don't need to pay for it more than once. I know Doug says profiling is only done at one luminance point (typically 75% stim or 100% stim), but usually when a colorimeter is off versus a spectro (reference grade or not), it's off by about the same amount across the entire brightness range (aka across the whole grayscale). I don't expect to get results exactly as accurate as with pro-grade equipment that is sent in for re-certification and/or re-calibration every 1-2 years, but as long I have a spectro like the i1Pro and a good colorimeter like the D3, I should get quite close.

How often does one need a calibration. If you calibrated your projector at say 100 hours, how much would it be off at 1000,2000, etc...

Just curious if by the time a year passes if your already in need of a tune up.

The problem I have is I'm not close to a calibrator and if I did pay one to come in I think it would be costly, so if it needed done yearly that could be very expensive.
I have an Epson 6010 and use THX mode for critical viewing and it looks great, just wondering if I'm missing anything not calibrating it.

I'm assuming

THX Mode - Pretty Good
Self Calibrate THX -Slightly betger
Pro Calibrate - Better than THX self calibration

Sent from my SCH-I535 using Tapatalk 2

There is a list of traveling professional calibrators here on AVS in the Calibration threads. They may visit your area.

http://www.avsforum.com/t/586330/isf-calibrators-where-are-you-located-please-post-here


How often probably depends on your projector and bulb type and other factors. A professional calibrator with experience on your Epson might know or you can search AVS here to see if anyone has covered that.

A projector is quite different than an LCD or plasma TV in initial calibration and then routine touch ups in that the bulb light output may change more quickly tha the light output of and LCD/LED for instance. But an X-Rite i1Pro along with an X-rite D3 might be right for you as long as you can spend the time (hundreds of hours if you are meticulous) learning the essentials as well as the fine points of calibration. It is not as cut and dried as just loading software into a laptop and automatically making settings on your projector. If you enjoy learning though, it will at least help you understand what calibration does. Understand that hobbyist grade meters do drift and require routine checking every year or two. One reason I don't think buying used equipment on Ebay is a good idea for either an i1 Pro spectro or colorimeter. It is also a matter of degree that you find satisfactory for viewing accuracy. Have you tried the AVS HD709, Disney WOW, or Spears & Munsil discs to do basic Media Assisted settings on your projector? These might be a good starting point. It depends on how close you wish to get to optimum settings on your Epson. I, myself, did not find DIY calibration equipment to be worth the hours put into it, nor did I find the equipment to be reliable for the money spent.
Edited by Phase700B - 7/31/12 at 1:49pm

Depends on the lamp, but once you get it correct, you will want to keep it that way, I do mine about every 500 hours. The lamp changes a lot in the first 300 hours and after that it will stabilize but will change slowly over time. My current lamp has about 2500 hours on it and it has been a few hundred hours since my last touch up. I have notice it is going a little red as of the past few uses so may be time to tweak. Hardest part is getting time to do it when the wife is not around..