Ooops - thanks, Carl - it should have been 6 bits (= 64 greyscale
values)...

IAN

"Carl F. Huber" wrote:
>
> Hello folks,
>
> I guess Ian meant 6 bits, not ! 64  - rule of thumb for human
> vision is that we can't see better than about 5 1/2 bits, so if
> your images are for human visual use only, 6 bits is plenty.
> Also, if you are looking at them on a typical video monitor, the max
> display is 8 bits (even for so called 24 bit images, because those
> are three color planes of 8 bits each).  You only need those
> higher resolutions if you are going to do some digital image
> processing to view  (visually or mathematically) the finer details.
>
> Carl Huber
> Microcosm
>
> > -----Original Message-----
> > From: Ian Gibbins [SMTP:[log in to unmask]]
> > Sent: Monday, October 18, 1999 7:45 PM
> > To:   [log in to unmask]
> > Subject:      Re: CCD for fluorescence work
>         [Carl F. Huber]   <snip>
> > cameras have moderate resolution and sensitivity , but for 90% pf the
> > people 90% of the time, they are fine. In two of the systems we use
> > Scion frame grabber boards, and in the other one we use the built-in
> > video board of the MAC. These are nominally 8-bit systems, but there
> > is
> > a lot of built in noise in the camera and the acquisition system, so
> > they probably operate closer to only 64 bit - does this matter?
> > Usually
> > not! We can easily get publication quality pictures from most of our
> > preparations (see examples below).

--
Professor Ian Gibbins
Anatomy & Histology
Flinders University of South Australia
GPO Box 2100, Adelaide, SA 5001
Australia

Phone:  +61-8-8204 5271
FAX:    +61-8-8277 0085
Email:  [log in to unmask]