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Author Topic: HP LP2475w calibration from scratch  (Read 74698 times)

digitaldog

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« Reply #40 on: January 11, 2009, 04:25:31 pm »

Quote from: trinityss
I'm measuring it with my EyeOne display2 in Eye-One match.

Try i1 Share (free). You can see the spectral curve which is quite interesting.

Quote
I'm a little bit "white point" confused.
So i don't need to worry about the white point of working spaces, and it's allowed to have a white point more close to that of my ambient light/ottlight.
But then i don't meet the ISO3664...

Those white points are separate from themselves. As is the "gamma" (TRC or Tone Response Curve). They don't have to match.

Quote
Your question about the spectrum of the 6500K, did you mean the the spectrum of the white point of my monitor after calibrating towards 6500K?

Lots of colors correlate to 6500K. 6500K is not an exact color. The display is not really producing 6500K (or it would melt on your desktop). As to spectrum, the one that's interesting to look at is the one for viewing the print. I suspect despite the claims of "full spectrum", if you look at the plot of the OTTLight in i1 Share, you'll see some nasty spikes.
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Tim Lookingbill

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« Reply #41 on: January 12, 2009, 02:22:16 am »

trinityss,

The reason your display gray looks red after viewing your prints under the OttLight is because this light has a blue green spike your eyes can't detect because your eye can't see color tint in the brightest whites on a print due to adaptation kicking in staring at bright white. Same thing happens on your display. It looks neutral but it's really not. It still doesn't affect your edits which is what's important.

I get the same thing on my calibrated iMac. This is the nature of all artificial lighting. Your eye constantly color corrects. You can try matching your display's white point color tint to a white piece of paper viewed under your OttLight, but like I said it can be very hard to see this because by the time you do make out the actual tint of paper white the eye is already adjusting. You'll be quite frustrated trying to achieve this level of perfection.

In addition to this different papers reflect different color casts under different brands of lights even though the lights look neutral.

This can be seen in the shot posted below between the spectrally flat 4700K Solux lamp which prints may at one point be viewed under like at a gallery and the 5500K OttLite CFL that I have and the one you may be using. I don't have your model. Mine is the new 100watt output OttLite HD Natural Lighting CFL.

I have yet to know what the color tint of D50 or D65 looks like since no one has made this clear to me.

[attachment=10850:SoluxVSo...ik_LL_Lg.jpg]
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digitaldog

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« Reply #42 on: January 12, 2009, 09:47:04 am »

Quote from: tlooknbill
trinityss,

The reason your display gray looks red after viewing your prints under the OttLight is because this light has a blue green spike your eyes can't detect because your eye can't see color tint in the brightest whites on a print due to adaptation kicking in staring at bright white.

That and the possible effects of OB's and that spike can really make some papers look way, way off.
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Tim Lookingbill

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« Reply #43 on: January 12, 2009, 02:13:29 pm »

Yeah, I started noticing the Solux light brings out all of these spectral differences in papers over the other lights I tried out. I included lazer printer paper with optical brighteners in the shot and as you can see the Solux shows it and the Ottlight doesn't. That Solux is one mysterious light.
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trinityss

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« Reply #44 on: January 12, 2009, 03:23:35 pm »

Quote from: digitaldog
Try i1 Share (free). You can see the spectral curve which is quite interesting.

Those white points are separate from themselves. As is the "gamma" (TRC or Tone Response Curve). They don't have to match.

Lots of colors correlate to 6500K. 6500K is not an exact color. The display is not really producing 6500K (or it would melt on your desktop). As to spectrum, the one that's interesting to look at is the one for viewing the print. I suspect despite the claims of "full spectrum", if you look at the plot of the OTTLight in i1 Share, you'll see some nasty spikes.

The EyeOne display isn't supported in i1 share, i'll try with an EyeOne pro and will post the spectrum...

I've recalibrated my display with the following settings 5600 / 1.8 / 120 cd m² and may match is much better, but there is still a red cast.
Taking into account that there always be a red cast (due to the spikes in my OttLite, any recommendations on how to minimize further the red cast?
Can i manually play with my rgb controls, or should i just try to find a better color temperature?

Thx!
« Last Edit: January 12, 2009, 03:47:56 pm by trinityss »
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trinityss

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« Reply #45 on: January 12, 2009, 03:43:44 pm »

Quote from: tlooknbill
trinityss,

The reason your display gray looks red after viewing your prints under the OttLight is because this light has a blue green spike your eyes can't detect because your eye can't see color tint in the brightest whites on a print due to adaptation kicking in staring at bright white. Same thing happens on your display. It looks neutral but it's really not. It still doesn't affect your edits which is what's important.

I get the same thing on my calibrated iMac. This is the nature of all artificial lighting. Your eye constantly color corrects. You can try matching your display's white point color tint to a white piece of paper viewed under your OttLight, but like I said it can be very hard to see this because by the time you do make out the actual tint of paper white the eye is already adjusting. You'll be quite frustrated trying to achieve this level of perfection.

In addition to this different papers reflect different color casts under different brands of lights even though the lights look neutral.

This can be seen in the shot posted below between the spectrally flat 4700K Solux lamp which prints may at one point be viewed under like at a gallery and the 5500K OttLite CFL that I have and the one you may be using. I don't have your model. Mine is the new 100watt output OttLite HD Natural Lighting CFL.

I have yet to know what the color tint of D50 or D65 looks like since no one has made this clear to me.

[attachment=10850:SoluxVSo...ik_LL_Lg.jpg]

Hi tlooknbill,

That is interesting info you write...

I have this model:
http://shop.colourconfidence.com/product.php?xProd=2248

What is your personal experience with the solux, do you reach a better macht compared with the OttLite?
Is the gray more neutral? Has the Solux less spikes?

Do you know if there is a kind of a recommended way of comparing between hard and soft copy?
Some procedure that tells you to wait 3 seconds and look inbetween to a black or white solid?

Kr,

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Tim Lookingbill

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« Reply #46 on: January 13, 2009, 01:18:17 am »

I find the Solux and the GE Sunshine fluorescent T8 tube provide the best appearance of neutrality of B&W prints as long as it's printed with black ink only. The printed grayramps that appear in the side by side comparison shot of the two lights I posted were printed with black ink only from my Epson 1270 on Epson's matte paper. B&W prints using all inks will give off different color casts among all the lights. The Solux will be a bit on the brownish red side, GE Sunshine will appear a tad on the olive green and the OttLight will appear dull blue with a bit of olive green. Some of this may be due to the printer profile used combined with adaptation.

These are all subtle differences.

I just conducted an adaptation test on the Solux by staring for about 2 minutes at the scene depicted in the previous posted image with only Solux on and all ambient light turned off while at night and then looked back at my iMac and found no noticeable red cast in my gray desktop. It retained neutrality. The GE Sunshines do cause a slight maroon-ish red, but the OttLights create a stronger more noticeable brownish red.

I don't know how red your display is with your print viewing lights. If you have concerns about the cause, calibrate your display at night with all lights off and see if your gray's on your display look neutral. And if you want to neutralize your eyes with the lights on I'ld suggest closing your eyes and cover them completely with a dark cloth that blocks all light. Even when you shut your eyes you can still see reddish orange from your eyelids and this does affect adaptation as well, but this is really splitting hairs on this.

I only use soft proofing for controlling gamut clipping. I find using Relative Colorimetric with Black Point Compensation on and leaving Ink Black and Paper White off is all I need with my current setup which is currently using several GE Sunshine T8's one on each side of my display and another under the table for more focused light.
« Last Edit: January 13, 2009, 01:19:41 am by tlooknbill »
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Mikko S

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« Reply #47 on: May 26, 2009, 08:38:00 am »

sorry .... wrong button
« Last Edit: May 26, 2009, 08:54:29 am by Mikko S »
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Mikko S

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« Reply #48 on: May 26, 2009, 08:52:53 am »

Hi, I am trying to calibrate the LP2475 and came up with a problem which is very strange. The red shades are far too strong, i.e medium red and even orange-red areas turn to far too red (darker skin tones as well) . I have used three calibrating devices trying to calibrate it: ProfileMaker 5 with EyeOnePro photo spectrometer, MonacoOPTI(xr) and ColorMunki Design. All ending up at more or less same results, I have also tried different color temperatures from 5000 to 6500K, etc, no effect on red boost. I know that reds are too boosted as I have a test sheet that I print to a color calibrated Epson 4880 that I use as a test sheet for prepress work and my primary monitor is (calibrated) 24" iMac that gives perfect visual match with the Epson Color proofs (same good results on another iMac). My intention was to use the lp2475 as secondary monitor for the iMac but as such it can not be used for color accurate photo or prepress work. Is there something in this LCD monitor technology that it can not be calibrated (easily) for color accurate work? or is there a problem in my unit. For normal office work it is probably perfect. I feel that the profile should be edited to compensate the red boost and the ProofMaster 5 bundle has the ProfileEditor module that could probably do it but I have never used it (as never needed before with any other monitor), the user guide is useless for a beginner. Anyone knows a good reference for instructions how to use the ProfileEdtor to fine tune the profile. Thanks in advance.  (PS this is my second unit of LP2475 as the first one had so strong horizontal color shift from green to red that I asked replacement right away)
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neil snape

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« Reply #49 on: May 27, 2009, 01:04:05 pm »

I have the Dream Color 2480 which may be similar. What I saw withit as if I used say i1MAtch the reds were richer than they should be compared to a proof as you also saw. The only thing I found to work , and work well is to calibrate with Color Eyes, an i1 Pro, and let the monitor run to it's maximum gamut.

What also works of course is use HP monitor APS with it's specific i1 colorimeter. The results were more accurate with Color Eyes, but APS is overall quite good now too.

I also saw a rapid change in the first weeks, but now after 6 months colors are very stable and reliable for all color managed apps.
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Mikko S

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« Reply #50 on: June 04, 2009, 05:37:35 am »


Hi thanks a lot, the ColorEyes really did the trick just with the default settings, hope I had known that from very beginning as none of the other SW could do that and I spent days with them, I used the MonacoOPTIX XR calibrator with ColoEyes. The nice thing is also that ColorEyes can set the iMac screen (which I use as a primary monitor) which is far too bright even when the brightness is set to lowest level, none of the other calibration systems could set that as well to target level.  Thanks again.
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Mikko S

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« Reply #51 on: June 23, 2009, 09:49:48 am »

Quote from: Mikko S
Hi thanks a lot, the ColorEyes really did the trick just with the default settings, hope I had known that from very beginning as none of the other SW could do that and I spent days with them, I used the MonacoOPTIX XR calibrator with ColoEyes. The nice thing is also that ColorEyes can set the iMac screen (which I use as a primary monitor) which is far too bright even when the brightness is set to lowest level, none of the other calibration systems could set that as well to target level.  Thanks again.

One more thing I noticed, as I am using the LP2475 as a secondary monitor for 24" iMac and just updated to PhotoShop CS4. You have to turn the Enable Open GL OFF from the preferences >performance settings of CS4 or it will not apply the profile correctly to the external monitor, took me another couple of days to figure this out. Everything looked ok with CS3 on all other settings were similar. This open GL support is new in CS4 but does not work properly with dual monitor setting in iMac.
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IanWorthington

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« Reply #52 on: July 04, 2009, 11:51:18 pm »

Hi.  

Thanks to all for the invaluable information in this thread.  Whilst in the UK last month I bought one of these: they're not available in Colombia where I currently live (and if they were they'd no doubt be twice the price due to supply chain issues here).

It survived it's exposure to airline baggage handling unscathed, and is currently sitting next to me, earning me jealous looks from my teenage sister-in-law. (That's got to be a good thing, right?) My next problem is how to profile it.  I have a Monaco Optix XR DTP95 (iirc), but it's in storage up in DC, and it will be another 6 months before I'm back there (and then there appears to be mixed opinions on if that colorimeter can cope with the extended gamut of this screen).

Are there any techniques that might get me most of the way to a usable set up I can use in the mean time? Or if I begged a profile off of another user, along with their panel settings for it, is there sufficient tightness in manufacturing that that might work? (I'm happy to supply my profiler serial number as proof that I really do own one of these).

Any advice happily received.

i
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Stormhalvorsen

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Re: HP LP2475w calibration from scratch
« Reply #53 on: November 01, 2013, 11:54:36 am »

I have re calibrated AGAIN and got much better results. It is a little bright but still matches my prints nicely and banding is minimal, if you really look closely you can see very slight banding middle to dark tones.

White Point = 6500K
Gamma = 2.2
Lumi... = 120
Brightness = 42
Contrast = 100
R = 176
G = 149
B = 145

I don't get this at all. Where do you se these numbers? I have a Spyder 4 Elite and it doesn't change settings on the actual monitor like this, does it?

Before getting the Spyder I set the monitor to settings like these found online and the results looked pretty good both on home prints and on other devices I have, like an iPad.

After resetting the monitor to facory setting and doing the Spyder calibration, the photos I output from Lightroom look absurdly saturated and too dark on other devices. In other words with the Spyder calibration, results elsewhere look nothing like on my monitor, which somewhat defeats the purpose.

So I'm not supposed to manually set anything on the monitor apart from factory defaults? (It asks me to set brightness during setup which I did)
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Simon Garrett

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Stormhalvorsen

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Re: HP LP2475w calibration from scratch
« Reply #55 on: November 02, 2013, 06:36:25 am »

Thanks for the link! Interesting reading!

It doesn't answer my questions unfortunately, about how to use the Spyder for this display. What I have landed on for the moment is:

-resetting the monitor to default settings.
-calibrating using the Spyder.
-restoring the custom settings to the monitor, using the setting they arrived at in the article.

This doesn't seem like a logical workflow at all, but it seems to yield better results than merely using the Spyder. Perhaps this Spyder thingy simply won't do the job on a wide gamut display. Perhaps I should start with the custom monitor settings from the article and then use the Spyder based on that instead of a factory reset.

I simply don't know and that is my concern.
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Simon Garrett

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Re: HP LP2475w calibration from scratch
« Reply #56 on: November 02, 2013, 07:16:06 am »

I don't use the Spyder, so I can't help with their software.  I use a ColorMunki Display with Argyll software.  I have brightness 28 and contrast 75, and set the RGB levels using the Argyll software.  This provides a mode where you can set R, G and B levels to give approximately the right white point for the chosen colour temp.  Then I let the Argyll software do its stuff. 
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D Fosse

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Re: HP LP2475w calibration from scratch
« Reply #57 on: November 02, 2013, 10:02:53 am »

Quote
This doesn't seem like a logical workflow at all

And it isn't. It completely invalidates the profile, so you're back to square one. First off you need to realize that there is a fundamental difference between color managed software (Lightroom/Photoshop) and non color managed software. The process of calibration/profiling affects them on different levels.

There are many common misconceptions about monitor calibration, but the most common of all is that it's all about modifying the monitor response to meet a certain standard, and that's it. While this is true in a non color managed situation (it's all the tools you have), this is merely the starting point in a color managed situation.

In proper color management a new level is introduced: the icc profile. An icc profile is a description of a color space. Adobe RGB is a color space, while AdobeRGB.icc is the description of that space. Similar for monitors: <monitor profile>.icc/icm is the description of the monitor's color space. And here's the key to understanding the whole thing: The monitor profile is the description of the monitor in its current (calibrated) state. Change the calibration, and you need a new profile to describe the new state.

This is the difference between color managed and not. The color managed application uses the monitor profile directly when it displays the image. It's a straightforward profile conversion, although done under the hood and on the fly. The non color managed application just sends the RGB numbers straight to the display. It's calibrated, yes, but the profile has a much higher precision level than that. For a wide gamut monitor this difference is crucial, because only the profile can account for the extended gamut and remap the image RGB values accordingly.

So this explains why it's oversaturated when you view in a non color managed environment. The image is created in sRGB and has sRGB numbers. But the monitor is closer to Adobe RGB.

----


Now to part 2; how you do this:

First reset the monitor (and video card) to defaults. That part is OK.

Next, the calibration will adjust the video card to reach the desired gamma, white point temperature and luminance level. Here's the thing: You don't want those adjustments to be too dramatic, because the video card is a low-bit, low precision link in the chain. Much better to do as much as possible in the monitor's internal circuitry. That's why the Spyder asks you to adjust brightness.

Then, when the calibration part is finished, the profile is created. This profile, which is what Lr/Ps will use, describes the monitor in its present state. Don't change anything on the monitor from this point, because if you do you will need a new profile.

(EDIT: I should add, just to cover everything, that the monitor profile is set up on system level automatically by the calibrator. No further user intervention required. I say this because some people will then proceed to set the monitor profile up as working space in Photoshop, which is totally wrong in every conceivable way and defeats the whole purpose).
« Last Edit: November 02, 2013, 10:33:36 am by D Fosse »
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Stormhalvorsen

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Re: HP LP2475w calibration from scratch
« Reply #58 on: November 02, 2013, 11:21:42 am »

Thanks a lot for answering and at great length too! :)

The problem is that this is what I did to begin with: resetting the monitor to its factory defaults, calibrating with the Spyder and adjusting the monitor's brightness in the process.

This is what I though looked terrible and that I didn't think could be right. I suppose I won't know for sure how right or wrong it is until I have a print professionally made for comparison.

I did the calibration again and turned the room lights off this time after the ambient reading. Looks a bit better or maybe I'm slowly getting used to the new look. I certainly have a case of maybe a thousand badly edited photos on my hand which is the price to pay for having started this only now.

I still don't understand it all:

Why the various web sites has tweaked settings for the monitor itself to display most accurately, while mine will simply have factory default.

Why it starts out calibrating at 6500 and then says white point 5000 recommended at the next step (a number than cannot be set by me anywhere at least. Then why is it recommended?)

Why the display gets a bit brighter the minute you click save on the calibrated profile, even though I'm supposedly already viewing it at that point.

If Lightroom and my scanner will need to be set by me to load the new profile or if it is now the default setting everywhere.

Why the icons on my operating system look fine while the photo thumbnails inside folders are now horribly over saturated.

Included three screenshots of the finished calibration.
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D Fosse

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Re: HP LP2475w calibration from scratch
« Reply #59 on: November 02, 2013, 12:45:11 pm »

Turn off the ambient light measurement, it only introduces another variable which is the last thing you need. (Plus it's a wholly unnecessary feature if you ask me). Once you've done that, it isn't very difficult. Just do what the Spyder asks you to, and it will show you on screen when you get to the correct level.

OK, the other things. My usual advice in these situations is this: Don't buy a wide gamut monitor unless you fully understand the implications. It changes a lot of rules, and there are special requirements that have to be fulfilled. The two most important are these:

1) Use only software that is fully color managed. Anything else will display oversaturated and incorrectly. You need to learn to ignore that, if you have to use such apps (Windows Explorer is one).

2) You must have a valid monitor profile for those apps to use. A valid profile is one that describes the monitor accurately. If the description is not accurate, it will not display correctly.

What you need to do when starting up the calibrator is to set a couple of parameters: Gamma, 2.2. White point temperature, D65 (6500K). Ignore the D50 recommendation. Luminance, 120 cd/m². These are average settings that work for average conditions. When you gain more experience, you may want to modify them.

Then just let the calibrator do its thing, the rest is handled automatically. There's basically nothing more you need to do, except observe what I wrote above.
« Last Edit: November 02, 2013, 12:49:04 pm by D Fosse »
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