Re: Display colours with photocal on LCD
Re: Display colours with photocal on LCD
- Subject: Re: Display colours with photocal on LCD
- From: Anthony Sanna <email@hidden>
- Date: Wed, 27 Nov 2002 13:02:53 -0600
Do you have Photocal or Optical? And are you saying that it works
great for
you? What gamma and white point do you choose? And what colour space
as a
starting point? On the 17inch you hav to have a colour space as a
starting
point and the default of the monitor is recommended which I believe is
Apple
Studio Display. What settings do you have in Color Sync??
When I got the Spyder/PhotoCal bundle, I didn't even open the CD
envelope. I've been using PreCal/OptiCal for a long time with my
X-Rite DTP92usb under OS9, but ColorVision balked at supporting the
device in their OSX version, although I understand that they're writing
the drivers for it now. I decided on the Spyder/PhotoCal bundle as the
cheapest way to get the Spyder. That was the only part I needed. For
$259 it would bridge the gap until the DTP92 support is ready in
OptiCal (I can't work without a calibrated monitor), and it would have
the added benefit of being able to profile my pallet monitor, which is
one of the older Apple LCD Studio Displays (bondi blue on a pedestal).
So far. so good.
Well, I've been rethinking my Spyder purchase after using it. First I
profiled the LCD (aka: LittleApple) before I moved on to the 21" Sony
(aka: BigSony). I don't have any comparisons to make regarding the
LCD, since I've never profiled one before, but, correct or not, here's
what I did....
Right off the bat, I noticed that between the hanger strap and the
Spyder's distortable rubber cup, the device did not hang flat against
the screen (hanger) and had wide gaps in its ambient light blockage
(rubber cup). I removed the cup and worked with it a while to get it
more symmetrical, then I tilted the display waaaay back (think of
getting eye drops at your optometrist), and finally turned the room
lights out because it still wasn't 100%.
There aren't many controls on the LCD, but I did choose a 6500 White
Point from the display's menu. I opened OptiCal, selected LittleApple,
checked LCD, and left the other selections at their default "Gamma
1.8", "Native White Point", and luminance values of "1.0" and "200.0".
Then I just clicked "Calibrate". As I said, I don't know if my
selections were the best ones, or if these same options are available
in PhotoCal - I've never used the program. This is how I came up with
a profile that was pretty identical to A98 and ColorMatch when swapped
around in the Displays Preferences - at least when rendering my gray
desktop.
Then I swapped the Spyder's foot from the rubber cup to the CRT's, and
began my standard PreCal/OptiCal routine on BigSony. If you haven't
worked with this combination, first you run PreCal, setting your target
white point in PreCal (6500 in my case). Then, with the Spyder
attached, you measure and adjust the display's RGB levels to that white
point through the monitors own controls.
With my old OS9/Pre-OptiCal/DTP92 setup I could always get the color
levels adjusted to the point where the DeltaE difference with my chosen
white point was 0.00. Once I got to 0.00, I'd double-check the color
temp another half-dozen times, and maybe on one of those
re-measurements I'd get a slight deviation to about 0.78. Most of the
time, however, it would stay rock-solid at 0.00.
When I did the PreCal routine with the Spyder, the first thing I
noticed (same monitor settings as my last calibration in OS9) was that
the monitor's brightness, which was set at 95 cd/m, was now reading 126
cd/m. Strange. Then, when I began adjusting the guns to the white
point, the Spyder's readings were all over the place. I could get the
DeltaE to 0.00, but the second reading would be 2.46, the third 0.78,
fourth reading 0.74, fifth time 1.34, and on and on and on. Basically,
what I was getting from the Spyder in PreCal was meaningless.
However, I did the best that I could and moved on to the OptiCal
profiling. I set BigSony's OptiCal options as I always had: Gamma 2.2,
White Point 6500, and Luminance 0.3 and 95.0. But when I began the
calibration process, after the first patch or two, I got a dialog
telling me that BigSony was not a CRT, but had the characteristics of
an LCD (BTW, CRT was the checked option under Monitor). I rechecked
settings and repeated several times, but always got the same response.
Forging on, I clicked "Continue" and soon came to the screen where
black level is adjusted to 0.30 by using the monitor's brightness
control. The bar was pegged to the right, but when I started to lower
the monitor's brightness, I could only get it down to 0.46. One click
less would drop it to no reading at all. That was it - 0.46 or nothing.
It was also a bit of a trick to get the Spyder to attach to the glass.
The triangular light baffle extends far enough past the suction cups
that it was a real job getting all three of them to stick. I had to
force-bend the clear plastic feet and use a lot of spit to keep the
Spyder from popping a foot off.
One difference between the good 'ol OS9/Pre-OptiCal/DTP92 days and the
new OSX/Pre-OptiCal v3.7/Spyder setup, is that during my move to OSX, I
got caught in the ATI PCI/non-ATI AGP system bug-crash, and had to
replace my nVIDIA GeForce3 AGP card with an ATI 8500. But would a
different card make such a difference in brightness and stability? I'm
going to see if I can boot back into OS9 and check with the DTP92.
Anyway, that's my story. One of the half-million in the this big city.
Of course names, numbers, and descriptions have been changed to
protect the innocent.
Tony
-------------------------------
Anthony R. Sanna
SACO Foods, Inc.
6120 University Avenue
Middleton, WI 53562
1-800-373-7226
email@hidden
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