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Chris L Peterson
November 25th 03, 04:04 PM
On Tue, 25 Nov 2003 14:35:39 -0000, "GrahamH" > wrote:


>I compared a Toucam Pro 740k with Creative 4000 Pro in low light. The Toucam
>was significantly more sensitive and better SNR. No quantitative data but
>the difference was easy to see.

I'm not familiar with the Creative 4000 Pro. Do you mean the Logitech Quickcam
4000 Pro? If so, then you did something wrong. The 740K and the QC4000 use the
same sensor and the same chipset. The hardware gains are set slightly
differently, but that can be compensated for programmatically. For good results
you don't want to use either near maximum gain anyway.

I've tried both side-by-side for astronomical imaging. There is absolutely no
difference in performance.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

GrahamH
November 28th 03, 10:00 AM
"Chris L Peterson" > wrote in message
...
> On Tue, 25 Nov 2003 14:35:39 -0000, "GrahamH" >
wrote:
>
>
> >I compared a Toucam Pro 740k with Creative 4000 Pro in low light. The
Toucam
> >was significantly more sensitive and better SNR. No quantitative data but
> >the difference was easy to see.
>
> I'm not familiar with the Creative 4000 Pro. Do you mean the Logitech
Quickcam
> 4000 Pro? If so, then you did something wrong. The 740K and the QC4000 use
the
> same sensor and the same chipset. The hardware gains are set slightly
> differently, but that can be compensated for programmatically. For good
results
> you don't want to use either near maximum gain anyway.
>
> I've tried both side-by-side for astronomical imaging. There is absolutely
no
> difference in performance.
>

Ah, engage brain before posting eh? Yes I meant Logitech 4000 Pro. My "test"
was not on a telescope, just the standard cameras viewing a night scene. All
settings on auto so the gains would have been higher than you would usually
want. The 740K had more detail with less noise. Maybe it had a longer
exposure capability although IIRC there wasn't a noticeable difference in
frame rate. Your result is more relevant to this group. Are you sure they
use the same chipset?

Chris L Peterson
November 28th 03, 11:49 PM
On Fri, 28 Nov 2003 10:00:10 -0000, "GrahamH" > wrote:

>Ah, engage brain before posting eh? Yes I meant Logitech 4000 Pro. My "test"
>was not on a telescope, just the standard cameras viewing a night scene. All
>settings on auto so the gains would have been higher than you would usually
>want. The 740K had more detail with less noise. Maybe it had a longer
>exposure capability although IIRC there wasn't a noticeable difference in
>frame rate. Your result is more relevant to this group. Are you sure they
>use the same chipset?

I don't know how often these things change, but I've had both open together on
my bench (in June or July I'd guess), and there was no difference at all. The
circuits looked the same, too, except possibly for some component values (can't
read those of most surface mount parts).

That's when I compared their performance, too. To get the same results, I had to
set the gain slider a little lower on the Toucam, but once I did that I couldn't
distinguish between images.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com