Calibrating a laptop...

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Originally Posted by Mike Buckley

I have always admired dpbestflow.com for their explanation of best practices. Their explanation of calibration and profiling shown below seems to be the same as yours.

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Calibration

Calibration is the process of setting the monitor to the desired neutral output. It includes settings for luminance, white point and gamma. Once it's been neutralized as well as the monitor's controls allow, it's time to measure the color and help to perfect it with software.

Profiling

Profiling is the process of measuring the imperfections in the monitor, and creating a "filter" that compensates for those imperfections. Using the parameters set in the calibration step, profiling requires using a hardware device, often referred to as a "puck" (a Colorimeter or Spectrophotometer), that hangs over the monitor screen and reads several sets of red, green, blue and grey patches generated by the profiling software. The color patches are measured by the puck as they are displayed. The differences between the colors the monitor displays in its native state and the true colors of the patches are used to create a monitor profile which will cause the monitor to display the true colors more closely than it did in its native state.

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It still isn't enough really. For instance there are several forms of profile. A single one applied to all channels, one for each channel and then the more complicated one where as I piece it together it seems some of it is actually done in the video card. I'm not aware of a single good explanation. It seems there are even more types. The single one is likely to be poor, the complicated one less smooth but more accurate on the tested colours - colours in between may vary. From what I have seen the affordable colorimeters don't even mention which one they produce. Top end ones often come in 2 forms. Crippled software or hopefully the full thing.

Part of the problem is that colour people talk a different language.

John
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There are series of 3 interesting monitor tests starting on this page.

http://www.drycreekphoto.com/Learn/C...itor_black.htm

John
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Originally Posted by Mike Buckley

Once again, you seem to be the only person who is surprised. :D

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A made a statement - you suggested that even the manufacturers don't really agree with me - then you posted a reference to a source you respect that does agree with me. I'm just not sure what the point is?

I'm just joking, Colin. You posted a joking rant. I posted a joking rant. It's all in good fun.

Having said that...

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Originally Posted by Colin Southern

you suggested that even the manufacturers don't really agree with me

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I suggested no such thing. You inferred that on your own. I only explained that when people such as myself who have no technical background call a duck a duck because its provider calls it a duck, then you should be ranting about the provider, not us.

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I'm just not sure what the point is?

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There is no point, at least nothing important. Have fun this weekend, which is a far more important idea!

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Originally Posted by Mike Buckley

I suggested no such thing. You inferred that on your own.

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Originally Posted by Mike Buckley

You will be glad to know that Datacolor calls their Spyder4 product a colorimeter, but only if you drill down into their specifications and press releases. Otherwise, they call it a calibrator.

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I'm very strongly getting the impression that you want to win an argument, whereas I have no argument with you. Again, have a great weekend!

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Originally Posted by Mike Buckley

I'm very strongly getting the impression that you want to win an argument, whereas I have no argument with you. Again, have a great weekend!

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Originally Posted by Mike Buckley

I'm just joking, Colin. You posted a joking rant. I posted a joking rant. It's all in good fun.

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The difference appears to be Mike, that I'm not joking. I'm serious. If inaccuracies aren't corrected then they become accepted and as a rule that just makes it even harder to educate people. HDR has become the classic example; how many times are we new getting people posting an over-processed image shot from a single exposure, referring to the "HDR look"? Same with "calibrators". It's a slippery slope that is making a rod for peoples backs.

Thank you, Colin. Now that we're back on track...

I understand and appreciate your concern. When you originally made the clarifications that explain the difference between a calibrator and a colorimeter and the difference between the calibration process and the profile process, that was very helpful to me and I'm sure others. I trusted that your explanation of that was more accurate than Datacolor's explanation for two reasons: I have the helpful experience of seeing over time the consistent detail that you attend to in your posts and I also have the experience of seeing over time the inaccuracy of marketing information provided by companies.

Even so, I want you to appreciate that you were complaining, importantly after I had written my post, that people who write the sort of stuff that I did do not properly understand the terminology. So, I explained that you should be complaining to the companies that sell their products to people such as me who don't have the technical background to understand that they too are using terminology incorrectly for whatever reason.

In that context, perhaps you can now appreciate from the perspective of my keyboard, I never suggested that Datacolor disagrees with you. Just the opposite, I actually would be willing to bet a lot of money that Datacolor agrees with you and that they are instead using the lingo of their potential customers to increase sales at the expense of accuracy.

Please understand my confusion and my importance placed on the more humorous side of the discussion. I got that idea because you wrote, referring to Datacolor, that you'll "join them and just opt out of these 'calibration' discussions." You now seem to have changed your mind about that. Fair enough.

I side with John for writing "It's best to laugh Colin." I think you're battling wars you'll never win. If you decide to pursue your uphill battle, I only ask that you please understand that the technically uninformed people such as myself should be excused rather than blamed for getting the misinformation about this topic from the manufacturers.

Still hoping you have a wonderful weekend!

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Originally Posted by Mike Buckley

Even so, I want you to appreciate that you were complaining, importantly after I had written my post, that people who write the sort of stuff that I did do not properly understand the terminology. So, I explained that you should be complaining to the companies that sell their products to people such as me who don't have the technical background to understand that they too are using terminology incorrectly for whatever reason.

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I feel that there's little point in complaining to the companies - it would simply be a waste of my time. I do however rest in the hope that I can have a more effective influence here; if nothing else, it may enhance our reputation as the site that pays attention to the details, and gets a more informed photographer as a result.

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I side with John for writing "It's best to laugh Colin." I think you're battling wars you'll never win. If you decide to pursue your uphill battle, I only ask that you please understand that the technically uninformed people such as myself should be excused rather than blamed for getting the misinformation about this topic from the manufacturers.

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It's more just a frustration; somewhat of a protracted game of "whack the mole", on several fronts.

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Still hoping you have a wonderful weekend!

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Thanks. The Jury is still out on that one; on one hand it is the return of Formula 1 this weekend, but on the other hand, my favourite team appear to have a few issues to work through. Can't fly my RC helicopters (storm about to pass over), but who knows, I might be able to get out afterwards for some "stormy photos" instead of spending too much time online.

I have an LCD monitor, and I've been calibrating it every 2 weeks which I'm understanding from this thread to not be necessary.

However, after each calibration I can view a calibrated/uncalibrated view and I see a definite difference, which means I need to calibrate every 2 weeks even if I have an LCD monitor?

Thank you.

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Originally Posted by Christina S

However, after each calibration I can view a calibrated/uncalibrated view and I see a definite difference, which means I need to calibrate every 2 weeks even if I have an LCD monitor?

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No. You and I use the same device and that comparison that you mention shows the difference between the unprofiled (Ha! I invented a new word!) state and the profiled state. That particular comparison has nothing to do with how long you can go without profiling again. That explains why I changed the setting in the software to remind me in six months, which is the longest setting provided.

Colin has a thing about HDR and calibration / profiling. I have a thing about LCD / TFT type screens :D which I wont go into other than say having used a LIQUID CRYSTAL DISPLAY many years ago I wouldn't use another one. it was so bad in so many ways that it makes me shudder each time I see the 3 letters.

How often depends on the type of monitor. Some use a LED backlight and some use something which is similar to a fluorescent tube. Those age were as the LED types hopefully remain stable. The quality of the electronics that is driving them may vary as well. Then there is question of how stable and accurate the colorimeter is. In short unless very expensive gear is used some variation might be seen even calibrating every 10 mins. I usually only calibrate in the early evening when temperatures are likely to be more even through out the year. My monitor is a good one, Dell but is still cheap for what it is. My colorimeter is an Xrite Display - not exactly a premium device but they are calibrated when they are made. None are supremely accurate unless rather a lot of money is spent. The software I use is way way more accurate than my gear. It uses a series of colour patches that are 0.6 delta E apart - supposedly beyond our ability to detect the changes.

The frequent periods such as 2 weeks or even more often largely go back to crt displays. I would say every 3 months wouldn't be a bad idea but it's better to use software that generates a report rather than a before and after image - if I was marketing something like that I might even make sure the images looked different even when there was no need. I also know from running software that does it that way that it didn't really make a decent job of it. I ran that 1st and then used the alternate software that most people could use. Just search DispCalGUI on the web. That way you can really compare colour variation from one run to another but do expect variation. The time to profile again is when a report shows a truly "bad" result.. On my last LED monitor that was never over about 12 months or so. That one was ViewSonic picked because tests showed that it would calibrate well.

John
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Thank you :)

PS That's a real word but the context with which you have used is it, is music to my ears...

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Originally Posted by Mike Buckley

No. You and I use the same device and that comparison that you mention shows the difference between the unprofiled (Ha! I invented a new word!) state and the profiled state. That particular comparison has nothing to do with how long you can go without profiling again. That explains why I changed the setting in the software to remind me in six months, which is the longest setting provided.

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Originally Posted by ajohnw

Colin has a thing about HDR and calibration / profiling.

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I rest my case ...

https://www.cambridgeincolour.com/fo...hread22281.htm

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Originally Posted by Colin Southern

I rest my case ...

https://www.cambridgeincolour.com/fo...hread22281.htm

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I think the term LCD is much worse Colin. They went out a long long time ago and good riddance.

John
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