Re: Light Source illuminant A
Re: Light Source illuminant A
- Subject: Re: Light Source illuminant A
- From: Robin Myers <email@hidden>
- Date: Wed, 25 Jun 2003 19:49:08 -0700
- Organization: Robin Myers Imaging
Steven Kornreich wrote:
>
>
I just started using PM 4.15 with my "older" i1 which does not allow you to
>
read ambient light with i1Share application.
>
I view all my work under tungsten halogen lights "illuminant A" according to
>
gretag. Color temp around 3800 with a cri of 100.
>
The illuminant A that comes with i1share is to warm. Like 2856K. Is this
>
right?? Does anyone out there have the newer eye one that can read ambient
>
light? If so I would be willing to pay for someone to measure tungsten
>
halogen light souce i.e. gallery lighting and email me the file.
CIE Standard Illuminant A is specified as 2856 K and corresponds to a
standard tungsten lamp (not tungsten halogen!). Tungsten halogen lamps
can go higher in color temperature but never as high as 3800 K. Tungsten
melts at 3410 K +-20 K. The halogen allows the vaporizing tungsten to
deposit back onto the filament and the close proximity of the bulb walls
to the filament keeps the tunsten from depositing on the glass. If you
are using 3800 K lighting then it is a filtered lamp or a standard lamp
in a filtered housing. If it is a commonly available lamp, then someone
could measure one for you and send the emission spectrum. If it is a
custom filtered housing, then you would probably have to measure the
emission spectrum in situ.
Robin Myers
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.