CRT colour calibration

[andykara2003]

I'm looking to calibrate the colours of a Sony consumer CRT - and in the process learn enough to do the same with my other CRT TVs and monitors. I'm looking to find a middle ground between just doing a rough & basic setup and having to go down another rabbit hole of learning a huge amount of technical info and getting lost in that.

I'm happy to spend a bit on a Calibration tool to help (say under £200).

I have an SD2SNES so can use my SNES for the test suite.

Can anyone help me find this 'middle way'?

[NJRoadfan]

For NTSC monitors, all you need is a SMPTE test pattern (find disc image of test patterns and burn to DVD) and a blue filter (gel) to put over your eyes. Professional monitors usually have a "blue switch" to eliminate the need for the blue filter.

https://www.videouniversity.com/article ... to-use-em/

Note that standard calibration will set "black" as 7.5 IRE per US NTSC requirements. This is the same procedures the pros used on CRTs back in the day, although they usually had a waveform monitor and vectorscope to verify the test pattern signal as being accurate. Bars outputted by a DVD player and usually spot on, so I wouldn't worry too much about that.

[andykara2003]

Thanks for that - It's a PAL TV but using all RGB inputs (from NTSC consoles). Is there an alternative resource/method for PAL CRTs?

[bobrocks95]

SMPTE with a blue filter won't calibrate your colors, just the tint settings. Color calibration I believe requires a colorimeter, or maybe on some sets you can use a multimeter on certain test points to check voltage.

[Ikaruga11]

How much does it cost for good calibration equipment?

[Einzelherz]

I use a Colormunki Display. It was $80 used CIB on eBay and works great with the HCFR calibration software. It's not super fast or anything but it works well. I've used this with the 240p test suite to calibrate all of my monitors and tvs.

[viletim]

andykara2003,

What do you mean exactly when you say 'calibrate the colours'?

If you mean adjustments to the CRT bias and drive to compensate for CRT ageing then normally the procedure is to use a greyscale test pattern. It should be at least 16 shades from white to black. You make the adjustments so that both the light and and the dark ends of the gradient look pure by eye.

[andykara2003]

I use a Colormunki Display. It was $80 used CIB on eBay and works great with the HCFR calibration software. It's not super fast or anything but it works well. I've used this with the 240p test suite to calibrate all of my monitors and tvs.

Thanks Einzelherz, I'll look into that

andykara2003,

What do you mean exactly when you say 'calibrate the colours'?

If you mean adjustments to the CRT bias and drive to compensate for CRT ageing then normally the procedure is to use a greyscale test pattern. It should be at least 16 shades from white to black. You make the adjustments so that both the light and and the dark ends of the gradient look pure by eye.

It's not to compensate for ageing as the TV is hardly been used and has a *mint* image (very lucky find). The problem is, like with a lot of CRTs out there that the image has a slight bluish tinge. A pro calibrator from HDTVtest says this is apparently very common in CRTs, as they were never thoroughly calibrated at the factory - but it's subtle enough that most people don't notice it. A member of this forum (CMcK) had their Loewe Aconda calibrated by the same guy and it was as if the blue tinge had been lifted from the image - very nice. The colours were more vibrant and true.

Problem is that these guys charge £250 per TV, which is quite expensive. I wouldn't mind learning a bit about it as I'll end being able to do my other sets as well..

[Einzelherz]

It's not just CRTs. Most screens, tv/monitors/pc monitors/crt/lcd/plasma/etc tend to be higher color temp (more blues). I might be off base here, but I think that's because blue fades more easily and it's a form of compensation (conjecture).

And to Tim's comment, in my own personal experience trying to do it by hand can really bugger up your colors.

[andykara2003]

Having located the relevant comment from the aforementioned professional calibrator, Tim is right to say that calibrating grayscale will give the strongest results. Unfortunately he's left the forum so I can't contact him - here's what he said:


"It's worth doing, absolutely. The biggest difference is going to be to the Grayscale tracking. Right now, grayscale is probably tinted blue (or bluey-green as I often found). I calibrated a Loewe CRT for CmCK and he was delighted with the difference that removing the colored 'mask' from the picture gave. Even on modern displays, getting grayscale right is the most critical part. Consumer CRTs didn't have any advanced color management controls because they could only reproduce one gamut, and that was decided by the makeup of the phosphors at the end of the tube. So yes, that part will not need adjusting like a modern TV would."


So would Tim or anyone else have any more detailed info in regards to calibrating the grayscale from the service menu of the Sony (1996 model)? I'm not sure how to adjust this and what I would be looking for to ascertain whether both ends of the gradient look pure by eye..

[Einzelherz]

Calibrating the greyscale is what you use the colorimeter for. You pull up shades of grey and adjust the high and low blues and reds until it is as close to 100% across the three colors for each 10% luminance interval.

Here's a lot of words and pictures that I used to learn how to perform it: http://www.curtpalme.com/forum/viewtopic.php?t=10457

[andykara2003]

This looks to be an incredible resource and exactly what I was looking for, thanks very much! I'll look into this, buy the kit and get back here at some point with an update...

[vol.2]

Also researching this. How about using a Minolta color analyzer? Is this more accurate than a colormunki or an xrite?
there is a second hand store with one for cheap that I can easily get.
Is this better than the PC based ones?

[Einzelherz]

I'm sure if it reads from light projection sources and has the ability to mount a meter on the screen, it'll work. I can personally speak to the ease of use with the colormunki and HCFR, though. I think so long as your meter is consistent (the Xrite stuff rates highly) any setup that can measure color levels will achieve positive results.

[andykara2003]

Reading Kal's guide I might try and get the Eye-one display 2 or LT, just to be safe. From what he says it seems they're pretty accurate and consistent without costing the earth - they're discontinued now but go for about £50-£80 new on eBay..

[22point8]

Reading Kal's guide I might try and get the Eye-one display 2 or LT, just to be safe. From what he says it seems they're pretty accurate and consistent without costing the earth - they're discontinued now but go for about £50-£80 new on eBay..

I wouldn't recommend the d2, if you can find a DTP94 despite being older it has sealed optics. I started out with the d2, found a dtp94 on ebay very cheap, then got a i1 pro (spectrophotometer), then a i1d3. With the i1 pro I made a reference measure, the d2 was way out of spec, the dtp94 was much closer to reference. The d3 with inbuilt tables is the closest to reference.

[andykara2003]

Thanks for that :)