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View Full Version : Complete Setup of a Monitor - Calibration, Profiles, Colour Space etc



etherial
14-04-2011, 7:00pm
I've read heaps about calibration, profiles, colour space etc but how do I fit it all together. I'm trying to decode all of this to understand the best way to set up a monitor for photo editing.

Colour Space - sRGB vs AdobeRGB. I understand the difference, but where should I set this. My monitor has an AdobeRGB setting but do I need to do it on the PC as well? And how does this effect how my images are displayed. I've always had my camera set up sRGB, does it matter for raw??

ICC Profiles - I've read about these, had all sorts of issues trying to get photoshop displaying things properly at one point because it was using a different profile to windows so depending where I opened a file it looked completely different! Windows 7 seems have have a few profiles but I'm not clear on how to use them.

Calibration - now I know people will say go and buy a calibrator like Spyder and I'm looking at doing just that. But...this monitor comes with a calibration certificate, ok, but that doesn't mean is suits my installation etc ie my monitor is very bright (completely out of the box settings) I would like to adjust it, but will that stuff the calibration? Then there is the calibration that Windows 7 can do? Or the ones you can do online, by bringing up their test images and making adjustments on your screen. AHHH?? Does calibration take effect by creating a ICC profile or is it software that sits running over the top of your graphics software or windows?

Graphics Card/Windows/Monitor settings - Where should these settings be adjusted. I have colour settings in my graphics card software, and there are on screen settings??

Environment - I've read in various places about the type of lighting you should have around your workspace, ie incandescent vs fluoro, warm vs cool vs natural light. Where does this get considered in al this?
So each of these areas I've read a lot about and have a basic understanding of, but how do I tie them all together? Have I missed something? What comes first? Starting from scratch, how do you put it all together?


Maybe we could come up with something for the Library for this??

PS - In my case I am setting up a new Windows 7 64bit system with Radeon 6850 Graphics Card, and a Dell U2711 IPS monitor.

mclean8
20-04-2011, 1:40pm
my two cents

re: calibration without hardware, i found this page with a link to quick gamma, to be very helpful http://epaperpress.com/monitorcal/

re: colour space, i don't set it to any colour space on my monitor, just use the separate brightness, contrast and RGB controls to get to a specific gamma and colour temperature and away i went.

re: environment, very important. if you work during a bright day you will post-process bright shots, at night you will make them duller. consistency is the key. specific temperature bulbs is probably overkill to start, just find a consistent lighting.

re: ICC profiles. work in a decent colour space like adobeRGB in photoshop. generally export with sRGB for print unless the target device/workflow can handle a bigger colour space.

cheers
michael

arthurking83
20-04-2011, 4:49pm
Apparently colour spaces and profiling is a very complex and easily misunderstood process, and my understanding of it(all) is limited to a large degree.


....

re: environment, very important. if you work during a bright day you will post-process bright shots, at night you will make them duller. consistency is the key. specific temperature bulbs is probably overkill to start, just find a consistent lighting.

.....

first off, Michael is slightly correct in that specific temperature lighting is a bit of overkill, that is until you experience it for yourself in some way.
of course being a tight @$$ penny pinching geek, I'm not about to order high CRI light bulbs over the net for about $40 each, when I can get normal light bulbs for $5 a pop.
But these annoying energy saver light bulbs cast a horrible cast, even tho they may look OK. Actual temperature numbers don't really reveal the level of unbalanced lighting they produce, but my last set of energy saver globes cast a very ordinary looking green cast, even though they were daylight white in colour temp.
Using a grey card to get a WB preset on the camera always set the WB to a green tint, so the effect is subtle but it was obviously more green that it otherwise should have been.

Went into a specialist lighting (wholesaler) with a retail outlet(in Hawthorn) and asked the chap if he had any specific high CRI index light globes I could try out. He didn't specifically have any, but did have a brand that did have a high CRI index, according to feedback he was given, so he recommended I try them. From memory they cost about $10(maybe less), and his comment was that many photographers use them with above acceptable results.
FWIW, the brand is called CLA and is rather plain in packaging, but now with my study lit with this one globe the difference in colour cast is immediately obvious.
I reckon the cost was kind of cheap too, as the rated power of the globe(that I got) was 30W, equivalent to 150W standard globe. Brightness is way more than the 18W normal energy saver in the corridor(next to the study), and the 30W globe was the lowest power globe he had(and I think that they make). The other globes were 45 and 60W, and could easily be used as studio lighting.
To the naked eye, the colour cast was basically nullified, and then confirmed with a preset WB capture on the camera too. Perfect looking grey now! :th3:

So.. start at the start, and do yourself a favour if you're using standard energy savers to light up the room, and try to find globes with a better light balance.
I can give you the lighting company's details if you want to try these globes yourself.
One day I was going to try to do a small write up on how much nicer these globes are to use ... but there doesn't appear to be enough time! :(

Anyhow, back tot he screen and PC(as I understand it all).

Forget windows and graphics card calibration.
The hardware calibrators are a more accurate way to do this. The PC(software only) based version is 'open to interpretation' as your eyes best see this. The hardware(calibration device) way to do it, is impartial and scientific.
(but all hardware types seem to do things slightly differently, so that one calibrator brand may be different to another).
The hardware measures the output lighting(of the screen) and then does a software dance and jiggle to set the software(on your graphics card) correctly.
All this is in the ICC profile that you load up for your calibration attempt.. and from memory I think you downloaded the TFTCentral profile.
That profile will be the same as any you would make for yourself via a hardware calibrator. Well in a basic sense anyhow... they could have used a different calibration device as you may end up using, but it will be close.

OK, so that's the hardware and calibration, and the screens colour profile is different again!
The choice of sRGB or aRGB on the screen, is not as important as the profiling, or overall ambient lighting conditions.
The choice of screen profile here, on the screen is more to determine which colourspace you can see accurately, as you work in a colour managed software program as you edit the image itself.

That is, if you're editing an image, say in aRGB mode(set in the software), then if you set the screen to sRGB(via the OSD on the screen) the conversion from sRGB is software based either by the software you're editing with, Windows driver or maybe the graphics card, and driver(most likely the graphic card driver on higher end graphic cards). So you may not see fully accurate conversion from sRGB to aRGB on the screen as you edit.
What will most likely happen is that as the screen is hardware limited to sRGB(as set on the screen) and you;re trying to view in aRGB(via the software you're editing with) the conversion to the higher specced aRGB is done in a kind of simulation mode, rather than a more accurate hardware rendering by the screen itself. What you could see in this situation is posterisation, or banding in some of the graduatiuons of colour on the screen.
Your trying to render more colour where it really can't be seen(due to hardware limits) but is being software manipulated to give you an impression of a correct rendering.

Because sRGB falls within the aRGB colourspace, any software conversion from aRGB to sRGB will be made pretty well. It's when you try to do it the other way, where aRGB contains colours out of bounds to what the sRGB colourspace can produce, is where you can get errors.
(what I've read!!)One problem with aRGB screen settings is that while the image data can contain accurate info, and hence display this accurate info, your printer may not do so. So you may get strange printing results when you print in colour(not just for photos, for any and all printing). The colours you then see, may not be reproducible by the printer. Higher end printers shouldn't pose a problem. Using a high end photography specific print lab should also nullify this issue if it ever exists.
if your screen is set to aRGB, and calibrated(or a calibration profile loaded) editing in sRGB mode will present no problem(or shouldn't). But again this is going to be dependent on the software you choose to edit with!
One issue I hate about LR is that you can't specifically set a working colour profile for the image being edited. It simply reads the image and uses that profile. This can be important for some images.
I like to choose the colour profile that any image editor is going to use. But in saying this, even tho raw files are colourspace unaware, LR will always choose the highest possible quality colourspace.
For pure raw images, this should be ProPhoto(apparently??.. I have no idea really, and I don't think anyone does).
In the export process, I think you set it to either output as aRGB or sRGB to suit the need. There is no direct way to alter the working profile to any other, other than as a print proofing thingame(which I've never used).
With Capture NX(and almost all other colour managed software, you can choose which colour profile you want to use and easily save the working image on the fly. With LR you have to export individual images, which is kind of a clunky way to do this.
If you print in high quality a lot(almost all landscapers should for that small increase in quality it gives), you should choose aRGB. If you simply rattle off a hundred images via the kiosk system at the local Kodak store.. I think sRGB is about the max you can expect in quality anyhow.

You may find it difficult to see the exact differences between an aRGB screen and an sRGB screen trying to emulate an aRGB mode(via the software used) but I'm lead to believe that the difference is marked when viewed directly side by side.
I think the actual hardware of the screen(the sRGB screen) is really going to be the major factor, and newer technology screens likely to be less obvious.

summary: set the screen to aRGB(as it really doesn't make enough difference to your final output). Even tho you may choose to stay with sRGB for the majority of your images, the aRGB set screen will render them fine, as long as they are worked in the sRGB mode in your editor, or converted too.
I reckon 99% of net connected folks are now using a colourspace aware web browser, so even if you do upload aRGB images, they should see them correctly.

Short condensed version(because I only just realised ho long an convoluted the above reply is! :p)

Start. Good quality ambient lighting (that you can justify or afford).

Graphics card: forget it. same with windows. if you create a hardware calibration setting, and then dive into the graphics card adjustments to adjust colour and brightness, you simply over ride the hardware calibrator's settings.

ICC profiles: created when you do a calibration of any type.. software or hardware.

Colour space/profiles: Use the one that's most suited to your needs. sRGB is fine. For that slightly higher quality aRGB is better, but it's a very rare situation to be able to differentiate between two images created in both.
(don't confuse the colour profile of your images with the colour profile capabilility of your screen. Having access to sRGB for your screen is only a bonus(more accuracy in viewing), whereas a colour space in your image has to be set(if not sRGB is assumed).

Calibration: no brainer! if you think you don't need it, then you are mistaken. If a calibration profile exists for your screen(somewhere on the net, or on another persons PC), this is the next best thing, so an attempt to get it and load it as the default ICC for the monitor is recommended.
Note: a calibration ICC for one screen is not going to work on another screen type/brand/model.(for giggles I tried this when I had my two monitor set up going. Not a drastic difference but a difference(mainly in contrast) that will make a difference.


The end result is simply: are you seeing a recognised standard image on your screen?, in terms of brightness, contrast and colour rendition. Another way to quickly and cheaply calibrate a screen is to compare an image you have printed(in a largish format using a high quality output), with what you see from your screen.
After all that is the real end result. If printer A prints all out images to the same degree of quality, and we all have a print from this printer A, then we technically all see the same images via our screens if we've all calibrated the screen to match our prints!
That's what colour calibration and the standards for colourspace and profiling is all about.

if the monitor manufacturers made an effort to set the default screen settings to a recognised level(brightness contrast and colour balance), half of this fooey would be already dealt with!

etherial
20-04-2011, 6:53pm
Hey Arthur, thanks for that! When I saw you had posted I expected an essay! But it was a very useful one and it has sorted out a lot in my mind.

In a nut shell what I ended up doing after playing with all the different settings and calibration stuff in windows and graphics card etc as well as downloaded profiles.

I downloaded ICC profiles from TFT central along with the on screen settings they suggested. I also did a windows calibration, and tried the default profiles in windows and that came on the CD with my monitor. In all I tested 4 profiles from TFT Central, 1 User profile from TFT Central, 3 windows profiles, 1 windows user calibration, 2 standard profiles from the drivers CD with the monitor.

I then selected every one of them (via Windows monitor settings) one at a time and set the screen to the required settings from the profile download or to standard settings of sRGB or aRGB on the monitor (as they are the ones Dell say are factory calibrated). Graphics card settings was set all to default (I found that they were rather crude settings anyway that seemed to always do more harm than good!)

When each one was loaded I assessed the result using the test screens at http://www.lagom.nl/lcd-test/. I found that of the many different profiles I tried the results weren't very noticeable when looking at web pages or photos in general. It was when I looked closer at the test screens that you could really see the difference between different profiles. They varied significantly on the test screens especially on the black and white tests and also on the contrast test. In many of them you couldn't see the bottom 10 shades of black, but white was fine, or visa versa. The contrast tests also would be very poor on many of them. So they were quite interesting results and much more differentiation than I expected. Even the ones I downloaded from TFT Central varied a lot considering they were all made with hardware calibrators. One significant point of note, screen brightness makes a big difference and many of them have the screen way to bright.

I settled on a User Calibration profile from TFT Central which seemed to perform well on all the tests and it also feels right to my eye (not that that means much!). I've ended up at 22% screen brightness which is what my profile suggested and is around the mark of many of the hardware calibrated profiles, even this at times can feel a bit bright on white web pages.

So I've learnt from this that oils aint oils profiles are not all alike and suitable for your screen. Just because you've bought a factory calibrated screen, it doesn't mean it will be perfect and fit nicely with your operating system/hardware. I've found a profile that I think seems to suit my computer and I'm happy with after a few hours of testing, but it is clear to me that to be certain, a hardware calibrator is the go to give me confidence in what I'm seeing.

mclean8
21-04-2011, 9:47am
re: color aware browsers

IE still has 40+% market share
http://en.wikipedia.org/wiki/Usage_share_of_web_browsers#Summary_table

and only IE9 is color aware as far as i can tell
http://www.ekdahl.org/kurs/colormanage.htm


re: real world results. agree, the ultimate test is that a printed image looks right on your screen and looks right on the print.

re: light. i generally work in the dark :-) i have hardware calibrated my monitor with the lights off (turned ambient light sensor on for when i am using it during the day), and have post processed many photos and printed. the prints come out how i imaging so i am happy. it works for me, might not be right but i get the results i want.