(meteorobs) Rayxar X-ray lenses.

[Swift, Wesley]

ED,

	Schneider has is a whole family of 400-1000nm c-mount "Xenonplan"
lenses.  I call lenses for this range "silicon APO" lenses.   

http://www.schneideroptics.com/oem/c-mount/visible_through_near_ir/

I use the similar "Xenon" 25mm f/0.95 for my 2/3" format cameras and the
17mm f/0.95 for my 1/2" format cameras: not quite "silicon APO" but faster
and part of the same family.  To capture more meteors you need both more sky
and more aperture and these seem to be a good ballance.   THese lenses work
great both on bare CCDs and with GenIII intensifyers.  Sharp stars at the
edge of the detector are a clue to the quality.  There are much cheaper
lenses to be had.

	For UV work, most folks use mirrors and suffer the slow speed.
Nikon makes a UV lens for medical work in  f/4 at 55mm and 105mm focal
lengths but it is hard to find:

http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/special/
55mmUV.htm

I hear Sony makes a c-mount, 1/2" video camera sensitive to 300nm called the
XC_EU50.  I saw it in my Edmund industrial catalog, but didn't see any UV
lenses.

Wes




-----Original Message-----
From: meteorobs-bounces at meteorobs.org
[mailto:meteorobs-bounces at meteorobs.org] On Behalf Of Ed Majden
Sent: Monday, August 29, 2005 10:05 AM
To: Global Meteor Observing Forum
Subject: Re: (meteorobs) Rayxar X-ray lenses.

on 8/29/05 7:52, Swift, Wesley at Wesley.R.Swift at msfc.nasa.gov wrote:

> These lenses are designed to couple the green tube image to film or a 
> CCD detector.  They are designed for near unity conjugate (like enlarger
> lenses) and only corrected for the green.   I would not expect great
> performance with infinite conjugate (star like) meteors, especially with
> detectors with a large red / IR sensitivity.   I wouldn't buy one of these
> expensive lenses new, but if I had one or could get it cheep I would 
> certainly give it a try.  My favorite lenses are the Schneider "silicon
APO"
> f/0.95 lenses:  Nothing beats a sharp focus!
> 
> Wes
> 
Wes:
    I agree with your comments re the Rayxar.  Image Intensifiers do indeed
have poor response at the blue end of the spectrum, 450.0 nm to 900.0 nm.  I
do have a surplus sample which I will give a try when I find the time.  I
was really looking for a lens that has good UV transmission for UV end
meteor spectroscopy.  Dr. Ian Halliday secured some nice near UV spectra a
number of years ago using a quartz precision replica transmission grating
and a special lens.  Where can you get the Schneider "silicon APO" f/0.9
lens and what do they sell for?  Also what is the f.l.?
Ed

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