[argyllcms] Re: Continuous reading mode ambient light temperature
- From: Jos van Riswick <josvanr@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sun, 29 May 2011 23:30:55 +0200
I decided to go with the multiple profiles option. Gonna measure a
number of profiles during the day (different color temperatures)
and then let a perl script measure the ambient temperature and load
a curve. See if that works well enough.
Now I've been looking at spotread to do the measuring. In the documentation
it says it can display the color temperature in K (ie D6500 like in the
icc files produced by dispcalGUI). I think I should do something like
spotread -a -T
the -T for displaying in K. However it doesn't seem to do that, only
Y: and L*...
Also spotread seems to be interactive. Is there some way to just let it
return the temperature?
jos
On Sun, May 29, 2011 at 10:49 PM, Jos van Riswick <josvanr@xxxxxxxxx> wrote:
> hi
>
> thnx. but the biggest problem for my setup *is* temperature.... but yes,
> using a number of different curves measured at different times of the day
> is possible. Then write a script that takes an ambient temperature
> measurement,
> and then pick the curve closest to the measured temperature... But still
> a bit cumbersome.
>
> And yes, controlling the enviroment light is the best option, but...
> hmm It's kind
> of not nice to spend all day in a darkened room with blue fluorescent
> light, when
> the sun is shining outside..... Also, I just feel that judging colors
> in my paintings
> is best done in day light..
>
> I'm wondering if it isn't possible to just convert the measurements in
> an icc monitor
> file to a different temperature. ....
>
> jos
>
> On Sun, May 29, 2011 at 2:47 PM, Roger Breton <graxx@xxxxxxxxxxxx> wrote:
>> Jos,
>>
>> Depending on the OS, I can see a small application that continuously reads
>> ambient light levels and switches monitor profiles around, when needed, but
>> you would only have a few monitor profiles, not make a new monitor profile
>> continuously? Like, you would have to characterize the ambient light in your
>> studio, say, at different times of the day. Say you identified 5 or 6
>> different distinct illumination levels, like 32 lux or 64 Lux or 128 Lux or
>> 256 Lux. Keep the "color" of the light out of the equation for now. You
>> could create 1 monitor profile, keeping the same calibration, for those 4
>> different levels of ambient illumination. Then, you have a small application
>> that continuously monitor the level of ambient lighting. When the light
>> falls into, say, into 128 Lux territory, it would change the system's
>> monitor profile, and so on. But if you were to do it continuously, it would
>> require two instruments, or you would have to have an instrument that you
>> could leave attached to the screen that could have two sensors: one facing
>> you, to measure ambient light, and another, facing the monitor, to measure
>> the display . As soon as it detects a noticeable change in ambient level, it
>> would launch Argyll to create a new monitor profile and set it as the new
>> default system profile, and so on. Hueys are so cheap that you could almost
>> afford to have two instruments, one for making monitor profiles, that you
>> leave attached to the screen permanently, and another that would measure
>> ambient light, that you can leave on your desk. It would require some
>> programming but it would work. For your application, you night like the idea
>> of those monitor profiles that have a sensor to monitor ambient light
>> changes. But does the monitor manufacturer provide an SDK so that you can
>> program this yourself? And, come to think of it, it is cheaper to buy a
>> second Huey than a new monitor with ambient level measurement capabilities
>> buil-in?
>>
>> Roger
>>
>> -----Original Message-----
>> From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
>> On Behalf Of Jos van Riswick
>> Sent: May-29-11 4:34 AM
>> To: argyllcms@xxxxxxxxxxxxx
>> Subject: [argyllcms] Re: Continuous reading mode ambient light temperature
>>
>> Reason is: I'm an artist (painter, see www.josvanriswick.nl ) and
>> occasionally I use photographic reference material to paint from.
>> So what I do is constantly compare the colors in my painting and in the
>> reference. Using a computer monitor seemed ideal for me, because I can
>> change the reference's colors to my liking, unlike with a print. But
>> unfortunately, the temperature of the light outside keeps changing. So a
>> painting that I started in the morning, will look completely different from
>> the image in the monitor later in the day. I tried to use artificial light
>> (constant) but didn't suit me. (kind of depressing). What I tried yesterday
>> is just manually adjust the rgb gains of the monitor now and then, and
>> compare a white image to a patch of white paint. This really makes a
>> difference, but is kind of cumbersome.
>>
>>
>> So I'd really like to find a way to do this. I have a huey pro colorimeter,
>> which is able to take ambient light temperature measurements. I tried to do
>> this with 'spotread -a'. Seems to work.. I'm kind of handy with writing perl
>> scripts. So maybe I can write a script to read the temperature, adjust a
>> previously measured curve and then just apply it again with dispwin. Then
>> run the script when the discrepancy becomes too disturbing.
>>
>> So if you have any suggestions on how to do to the calculations needed, or
>> what programs I could look into, would be welcome....
>>
>>
>> Jos
>>
>>>
>>> Hi,
>>> Why would you want to do that ? -i.e. it may be a good gimmick, but
>>> I'm not aware of any serious color reason to do something like that.
>>> The assumption is that if you are looking at a monitor, your eyes are
>>> mostly adapted to the display, since it dominates your field of view.
>>> In addition, there are serious trade-offs to be made in calibrating a
>>> display to a particular color temperature, such a reduced brightness,
>>> loss of resolution in the channels etc., and in addition there is the
>>> issue of how to make the profile track the change in display
>>> calibration, and no applications (as far as I know) have any facility
>>> to dynamically update the profile they are using.
>>>
>>> Graeme Gill.
>>>
>>>
>>
>>
>>
>
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