Re: ATM amateur infrared imaging?

[George Anderson <georgea@CAM.ORG>]

The reciprocity failure rate of commercially available IR films is
horrific. That is using them stock, I don't know of anyone trying to
hyper them which may reduce the problem.

George Anderson
Montreal Canada

Clear skies and good health

Thomas Janstrom wrote:
> 
> OK, everybody seems to be forgetting that there are IR sensitive films out
> there. You could always use regular IR film, of course you still have the
> cooling problems, but you can be taking happy snaps for a lot less (multi $K
> less).
> 
> Just my $0.02.
> 
> Clear skies, Thomas
> http://www.geocities.com/t_janstrom/
> ----- Original Message -----
> From: Stan Kaufman <sekfmn@pacbell.net>
> To: <atm@shore.net>
> Sent: Thursday, June 14, 2001 8:25 AM
> Subject: Re: ATM amateur infrared imaging?
> 
> >
> > > From: Frank Henriquez <frank@ucla.edu>
> > >
> > > Assuming that you have an excellent machine shop and a diffusion pump
> > > handy, you're looking at maybe $60K - $75K (or higher) so the dewar,
> > > detector and electronics.
> >
> > Frank, thanks for the reality check. Now I see why this remains the realm
> of the professionals!
> >
> > Dominic-Luc Webb molmed wrote:
> >
> > > By contrast, photomultipliers can be had relatively
> > > cheap that can 1) do high speed pulse counting
> > > photometry and 2) be obtained for UV through infrared
> > > by use of dual PMT heads.
> > >
> > > <snip>
> > >
> > > The CCD idustry has thus far not offered any high speed
> > > and hi-res solution to PMT imaging and I have heard of
> > > physical limitations that may prevent CCDs from ever
> > > attaining these goals. I am sure such a CCD would not
> > > be cheap either. My PMT photometer is home made and
> > > dirt cheap.
> > >
> > > One possible future alternative may well be the
> > > avalanche photodiode (APD). We are presently
> > > investigating arrays of APD for high speed imaging
> > > of longer wavelengths. The ones I am familiar with
> > > use visible wavelengths, around 650 nm. I am not
> > > aware of any IR APDs. I think you could check with
> > > Advanced Photonics about this.
> > >
> > > Finally, I know of no one using photodiode arrays for
> > > spectral analysis. These are very impressive. The
> > > ones from the newer HP spectrophotometers can fetch
> > > a spectrum from 200 to 1300 nm with a 2 nm bandwidth,
> > > in parallel!!!! I am doubtful you ever find a CCD than
> > > can do this.
> >
> > Dominic, thanks for the interesting ideas about use of photomultipliers
> and photodiodes. Don't the issues Frank raises about cooling system
> requirements pertain to your devices?
> >
> > Perhaps the best way for amateurs to explore the IR universe will be to
> sit in front of their computers with a fast Internet connection and use the
> "Virtual Observatory" (May S&T p 20) into which the 2MASS data will go.
> Though is appears that one could grind lots of mirrors before it comes
> online...
> >
> > Stan
> >
> >
> >
> >