Re: OptiCal Spyder USB Problems
Re: OptiCal Spyder USB Problems
- Subject: Re: OptiCal Spyder USB Problems
- From: Stacy Cates <email@hidden>
- Date: Sat, 14 Dec 2002 13:30:34 -0500
Regarding Doug Brightwell's post: "I'm having trouble with OptiCal 3.7, the
Spyder sensor and Mac OS 10.2.2...." (see the remainder at bottom):
My response:
I just calibrated my Apple Multiple Scan 20 Display on Mac OS 10.2.2 with
Optical 3.7 and the Spyder. I did it many times in standard and precision
mode and did not have a problem saving the profile, and I did not get any
error messages. The only thing I thought MIGHT have been a problem is that I
couldn't get my contrast high enough to closely match the target contrast
setting.
I found something that was very important, I think--there is a much better
and more detailed manual for OptiCAL for MAC users at:
http://www.colorvision.com/download_manuals.html
Spyder with OptiCAL
*Spyder with OptiCAL User Guide for Macintosh Users - NEW
(file size: 1,729,285 bytes)
It's more clear than the one that comes with the OptiCAL for OSX download. I
noticed there are some important things in the "Before you start" section.
Did you read all those things?
I do have many questions about calibrating a monitor, however, if anyone
could help:
1. The manual above says that if you are in a pre-press environment and
preparing CMYK files for press (which I am) and output or view your prints
in a 5000K lightbooth (Which I don't have in my office yet, but I use in a
lightbooth at the printer. In my office right now, I only have 5000K
flourescent light bulbs in the ceiling fixture, which I know isn't ideal,
but hopefully better than the warm white I used to have.) then you should
set the OptiCAL gamma at 1.8 and the Calibration Target Settings to
5000K/D50. Does that sound reasonable? I've read conflicting information
from various resources about this topic.
2. In the past, I've calibrated my same MAC monitor with Lacie
software/hardware (although I know that won't change any physical thing in
my MAC monitor like it does in the Lacie monitors), then have gone into the
RGB sliders in Adobe Gamma and adjusted them separately ("tweaked") to make
the screen view match some color proofs from a particular printer that I was
preparing files for (I couldn't find in the LACIE software where you could
adjust the RGB colors SEPARATELY). (I believe I'm using CMYK profiles
correctly when viewing the files used for these proofs.) Then, I saved that
tweaked monitor profile. Since proofs from different printers look
different, this seemed a reasonable approach to monitor calibration before I
color correct files for a particular printer.
But the things I've read about monitor calibration don't say to do this.
However, Don Hutchison's ColorSync article on the Apple Web site says to do
this while looking at a piece of neutral white proofing stock (but proofing
stock from where? From whatever commercial printer you're going to? From
whatever injet printer you're going to? Does it matter?). He also says don't
pick a certain temperature like 5000K, that you should end up with the
appropriate temperature by doing the tweaking. In any case, I can never get
white on my monitor to match any blank white proofing stock I view beside
the monitor. What are your thoughts on these approaches?
3. I noticed that my newly-OptiCAL-calibrated-monitor view of a file, using
that printer's custom CMYK profile that I ASSIGNED to the file, does not
look like the same color as that printer's proof of the image, and I know
that this printer matches their proofs almost exactly on press. The image on
my monitor looked too green. I thought I would try to tweak the RGB curves
that are available in OptiCAL to get the screen view to match those proofs,
or to TRY to match the color of some white proofing stock. I thought maybe
if I took out a little green by altering the green curve, or tried altering
one of the other curves so that the image didn't look too green, that might
be the right thing to do. But, the points on the curve are not smooth
points, and I find the curves box confusing. For one thing, I didn't have
the options "calibrated" and "uncalibrated" like the manual says. And, I
altered the curves while looking at the image, but when I closed the box and
went into Photoshop, the color of the image looked very different than it
did while I was altering the curves. Should I forget about this tweaking
stuff? Please comment.
4. I've never read a good explanation about why you would use 1.8 gamma as
opposed to 2.2 gamma. Bill Willmore, for example, in one color management
article, suggested using 2.2 for MACs, then in his new book, he suggested
using 1.8 for MACs, but didn't go into great detail about why in either.
I've noticed that the gamma, while I've read that it refers to the
brightness of the midtones, affect the shadow areas in addition to the
midtones. If my monitor is darker than it should be, I'll tend to lighten
the shadow areas too much when I'm correcting. If it's lighter than it
should be, I'll tend to darken the shadows too much when correcting. So how
do I know I've calibrated with the appropriate gamma?
Any comments will be appreciated.
Stacy Cates
on 12/13/02 6:34 PM, Doug Brightwell at email@hidden wrote:
>
I'm having trouble with OptiCal 3.7, the Spyder sensor and Mac OS 10.2.2.
>
Haven't yet got any answers from tech support, and was wondering if any on
>
the list has encounters/solved this problem.
>
>
Every time I try to calibrate my monitor, at some point during the process,
>
I get error messages that basically have to do with Optical not being able
>
to properly keep it's connection with the Spyder. The calibration never
>
completes.
>
>
The most frequent error is:
>
>
An error occurred while taking a reading. Make sure the sensor is properly
>
attached. Error [3|SpyderUSB.cpp|275]
>
>
After the error message(s) appear and are dismissed, I cannot quit Optical.
>
It freezes. If I unplug the Spyder from the USB port, Optical then is able
>
to quit.
>
>
I've tried restarting, trashing the OptiCal preferences file, and relocating
>
the USB cable to the main Mac USB port, a USB PCI card, and the keyboard USB
>
connector. Errors occur in all locations.
>
>
This same Spyder had always successfully calibrated the same monitor on the
>
same computer in OS 9.
>
>
Any ideas?
>
>
Thanks,
>
Doug
>
>
------------------------
>
Doug Brightwell
>
email@hidden
>
------------------------
>
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