Re: Color CCD sensor with support hardware wanted

From: Roger Hamlett (rogerspamignored_at_ttelmah.demon.co.uk)
Date: 08/08/04 

Date: Sun, 08 Aug 2004 16:23:17 GMT

"Graham W" <graham@his.com.puter.INVALID> wrote in message
news:41160610$0$527$ed2619ec@ptn-nntp-reader02.plus.net...
>
> "Nautilus" <reply_in_newsgroup_thanks@example.com> wrote in message
> news:6eKdneT1Ku-UPojcRVn-tA@comcast.com...
> > On Sun, 8 Aug 2004 04:02:15 +0100, "Graham W"
> > <graham@his.com.puter.INVALID> wrote:
> >
> > >Nautilus wrote:
> > >> On Sat, 07 Aug 2004 09:53:36 GMT, "Roger Hamlett"
> > >> <rogerspamignored@ttelmah.demon.co.uk> wrote:
> > >>
> > >>>
> > >>> "Nautilus" <reply_in_newsgroup_thanks@example.com> wrote in
message
> > >>> news:4NmdnT_XA6EPxYncRVn-pw@comcast.com...
> > >>>>
> > >>>> Is there any Color CCD sensor (at least .5 inch square) available
> > >>>> that's suitable for the hobbyist budget? Hopefully with some
> > >>>> back-end support electronics so that I can get it to USB or 1394?
> > >>>> Capture & transfer speed is of no concern.
> > >>>>
> > >>>> I see this Sony commercial camera with the kind of 'guts' I want:
> > >>>> http://www.sony.net/Products/ISP/products/interface/DFWSX.html
> > >>>> but yikes, it's the better part of $3000!
> > >>>>
> > >>>> Thanks...
> > >>> The cheapest route, will be a standard digital camera. Something
> > >>> like the Canon 300D, since it supports removable lenses, will be
the
> > >>> easiest to connct to whatever you want. This sort of camera, sells
> > >>> often for less than the bare CCD can be purchased in limited
> > >>> quantities, so will allways undercut units like 'commercial'
> > >>> cameras, which are made for a small market. The CCD you want is
> > >>> relatively large (CCD sizes are normally quoted as the diagonal of
> > >>> the chip itself, so a 'half inch' CCD, will typically only be
about
> > >>> 9 * 7mm). For smaller CCD's, there are routes like wiring a larger
> > >>> chip, onto a webcam board, but for a unit this large, thge total
> > >>> cost of this, still runs to about as much as the Canon camera...
> > >>>
> > >>> Best Wishes
> > >>>
> > >>>
> > >>
> > >> Thanks, but darn, that puts the kaibash on my plan. Still too
pricey
> > >> and since that's a diagonal measurement, it'd still be a bit too
> > >> small. I was hoping to scan 16mm film frames in direct contact
with
> > >> the sensor, but I'd probably need about 13mm (~1/2") wide sensor
> area.
> > >> Looks like I'll need to use optics, and I think my bro's MiniDV cam
> > >> has a higher-than-video-res still capture mode... that gives me
> > >> another idea to play with.
> > >
> > >Even if a large CCD were affordable, direct contact is not the way
> > >to do it. The cover slip on the CCD has a discrete thickness and
> > >then the active surface has coloured dots on it for the RGB pixels.
> > >
> > >You'll have to use optics but then a webcam has sufficient resolution
> > >these days and also has a focusable lens. Its software will permit
> > >the saving to disc of the files.
> >
> > About the discrete thickness I think you mean that the image has to be
> > focused on the sensor, behind the cover slip & colored dot layers. I
> > did wonder about that.
>
> Yes, indeed. Any image formed on a plane other than the active
> surface of the CCD will not be in focus.
>
> > What particular webcam products do you think I should look at?
> > There's sooo many junk ones out there that google doesn't help.
>
> The Philips ToUCam Pro II is well regarded in astronomy circles.
> It isn't the cheapest at around $100 but has a lot of support around
> the 'net and in the QCUIAG group on Yahoo!
>
>
> > I'll need additional optics, right? I don't expect the usual webcam
> > will focus on a 16mm backlit object at full frame.
>
> No, the existing lens will focus down to extremely close and I have
> no doubt that you'll be able to get acceptable images for TV use.
> I have focused an image of a UK five pence piece (18mm dia)
> full screen on a TV monitor using a tiny security camera and its
> standard screw-thread lens . I shot a photo of the screen on my
> Olympus C3000z which I could make available later if there's
> some interest.
>
> You may need to be careful that you don't over illuminate the chip.
> but a layer or three of matt white plastic diffuser should do it.
>
>
> > Is there an easy
> > solution here that I'm missing?
>
> Webcam!
The largest chip that has been fitted to the Toucam, that I know of, is a
0.5" unit (I have one here, that I did myself). Though the Toucam is not
the 'cheapest' camera, as a whole, it is probably the cheapest 'route',
and is a very small assembly too.
As has been pointed out, 'direct contact' won't work, so some optics will
have to be added. The cheapest route that I can think of to scan film,
with reasonable resolution, would be to use a much simpler 'line' scanner
assembly, and a moving holder, with a simple focussing system. This will
give much higher resolutions than the Toucam approach. However you then
have to realise that small USB film scanners are available for about £100,
with everything allready built...

Best Wishes

Relevant Pages

  • Re: Im very new to this so please bear with me
    ... The other end screws into the webcam. ... BTW Is that a ToUcam or a ToUcam Pro II? ...
    (uk.sci.astronomy)
  • new webcam - nearly!
    ... We have finally acquired a webcam and we are in the process of seeing how it ... - its just a little Toucam on 3 USB repeaters to get to the computor! ... Does that give me the tools to capture frames and up load them like Alan's ...
    (uk.sci.weather)
  • Re: Vendor review site?
    ... Have a webcam I want to ... buy and eBuyer is the cheapest by far. ... Not wanting to use them however, ...
    (uk.comp.vendors)
  • Re: ToUcam Pro
    ... >...and when you are between scopes or the sky is cloudy the Toucam ... >Pro II also doubles up as a great webcam. ...
    (uk.sci.astronomy)
  • Re: WEB Cam
    ... Wood Co wrote: ... Even the cheapest ones seem to work. ... Do they have money back no questions asked over there? ...
    (alt.os.linux.suse)