Re: Spectral sensivities
Re: Spectral sensivities
- Subject: Re: Spectral sensivities
- From: Ben Goren <email@hidden>
- Date: Wed, 16 Mar 2016 09:50:16 -0700
On Mar 16, 2016, at 9:36 AM, Wüller Dietmar <email@hidden> wrote:
> The easiest and cheapest way to get spectral sensitivities for a single device is to have it measured as a service.
Easiest, maybe, but certainly not cheapest. And perhaps not best, either.
The bill of materials for a suitable spectroscope is under $20. You'll need to know the transmission efficiency of the diffraction grating, and the least-worst way to get that is with a monochromator...but you can get a monochromator for cheap off FleaBay, and a spectroscope design can be adapted to a monochromator design if you want to continue the dirt-cheap route.
And virtually nobody I'm aware of (with one notable exception who's reading these words (Hi Iliah!)) takes the lens into consideration when determining a camera's spectral sensitivities. Some lenses have rather complex spectral absorption characteristics. If you must use a lens, use Canon's "Plastic Fantastic" 50mm f/1.8; its transmission is as spectrally flat as you'll find in any lens and significantly flatter than many, including lots of top-of-the-line L glass. But if your commercial service (or whatever) assumes that the optics are spectrally flat, you've got the lens permanently "baked into" all your data.
Cheers,
b&
_______________________________________________
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