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RB
06-09-2008, 08:33 PM
If you're into image processing/printing and are quite serious about colour correction then you probably perform some sort of monitor calibration.
Monitors tend to loose their calibration over time and need to be calibrated regularly.
Basic calibration can be achieved through software like what's bundled with Photoshop (Adobe Gama) or your graphics card (like nVidia etc) but this requires a 'guesstimate' on your part when viewing the test image to try and set the correct grey levels (Gama).

The problem is that the human eye can be tricked when viewing these test images especially under different ambient light and hence have the Gama set incorrectly.

Just have a look at the image attached and notice how much of an apparent difference there is in the two grey levels between A and B, but if you open the image in Photoshop and run the eyedropper over the two you'll see they both have identical RGB values.

This is where a Monitor Calibrator is a better solution than just using software alone.
There's a big variety of units available like the Spyder range, Huey, EyeOne or the new ColorMunki, just to name a few.

In the past I've used a basic Huey and found it makes a big difference to my monitor profiles, it even has an ambient light meter which checks the lighting in the room.

The Spyder2Pro which is what I use now is superb and allows for multiple monitor setups and individual profiles.

So if you calibrate your moitor using software only, maybe consider investing in one of these units to get the most from your display.

Anyway just wanted to share with you what I've found to be a very important initial step in my image processing workflow.

Alchemy
06-09-2008, 08:50 PM
i will take your word for it as the gadgets should give you an exact callibration (and im all for having it correctly done .... budget doesnt extend for one just yet)

but surely this is created specifically to have that optical illusion, and would probably seem to exist on a fully calibrated monitor too.

RB
06-09-2008, 08:58 PM
The point is that if you check the RGB levels on both these squares you'll see they have the same values, but to the human eye they look different hence adjusting the Gama points on a monitor visually, using software that requires you to judge the grey scales, is not necessarily as accurate as having it done via hardware/calibrator.

Alchemy
06-09-2008, 09:10 PM
ah i see the point you are trying to make.

h0ughy
28-01-2009, 10:30 AM
All i can say is you are a huge influence on me RB LOL. I went out and bought a spyder3elite just after christmas. Absolutely fantastic, the difference is more than remarkable, it is breathtaking. In one instance i calibrated Scott Alder's monitor - the difference in his images was revealed, showing in some a green tinge that was not visible originally. Reprocess time ;)

I calibrated the 81cm LCD hdtv i am using as a monitor, wow the difference is huge!! even on the lappy, the difference is huge!!! best tool yet!!

leon
28-01-2009, 10:40 AM
Hmmm, very interesting indeed, as some of you may know my new Monitor is on it's way, as the CRT went to monitor heaven, mind you it was only 3.5 years old.

I expect that it would be wise to look at one of these gadgets, so where would i be able pick up these units.

Leon

Geoff45
28-01-2009, 05:42 PM
You definitely need to calibrate the monitor and the Spyder Pro is quite good, but not the top of the line thing a professional would use for way more cost. You also need to consider calibrating your printer. It's pointless getting a good pic on the monitor if the print looks terrible. The software and hardware for this is over the top expensive, but you can get it done here (http://www.imagescience.com.au/ColourControl/colourServices/customProfiles.html) for $75. Once a year should keep your printer up to date. What happens is that you print out the test chart they email you and then send hard copy back. They go over your results with their equipment and produce a printer profile which you load into your computer. This synchronises your screen colours and printer output.
Geoff

h0ughy
28-01-2009, 09:56 PM
I have the elite version, the printer set costs 1000 that utilises the elite spyder, but since i dont print on a printer anymore for images (i get them printed via a calibrated photo shop;)) http://www.imagescience.com.au/ColourControl/colourProducts/spyder3Elite.html is what i have

Geoff45
02-02-2009, 09:36 AM
Hi David
Where do you get your pics printed? Locally or by ImageScience?

h0ughy
02-02-2009, 10:06 AM
just locally at the moment