Re: Any use for the D65 filter on the Spectrolino?
Re: Any use for the D65 filter on the Spectrolino?
- Subject: Re: Any use for the D65 filter on the Spectrolino?
- From: Robin Myers <email@hidden>
- Date: Thu, 7 Apr 2005 18:34:17 -0700
On 7 Apr 2005, at 16:53, Roger Breton wrote:
The D65 filter shapes the spectrum of the tungsten halogen
illumination
in the SpectroScan to be close to the D65 spectrum. This increases the
amount of blue in illumination. This will improve the signal to noise
ratio in the green/blue/violet region of the spectrum. Additionally,
it
does a better job of activating fluorescent whitening agents in the
paper, if you are into measuring such things.
I use the D65 filter on most of my measurements because it does a
better job of simulating real world lighting than tungsten halogen.
Robin Myers
Are you saying that the D65 filter absolutely increases the light
output in
shorter wavelengths? Or does it not simply attenuate the light energy
in
longer wavelength by partially absorbing light from, say, 580 to 750
nm,
like the Solux 4700K lamp does?
I should have said it increases the "relative amount of blue in the
illumination". Of course, if you put any filter into a light path there
is some absorption, so the total amount of light decreases. In this
case, the D65 filter is a blue filter, which decreases the amount of
longer wavelength light. To compensate for the lower amount of total
illumination, the SpectroScan increases the integration time to get
back to a good signal to noise ratio.
Robin Myers
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden