SV: [APML]: Advice on Canon FDn 300/f4 L

["Jonas Carlsson" <jonas.carlsson@mbox322.swipnet.se>]

Hi Michael & Greg,
Thanks for the information of the lens.
I think I will stick to my old FDn200/2.8. It seem to me that the 300/4 L
doesn't really live up to the reputation of the other 'L'-lenses. For
others interrested in Canon FD, check out this site:
http://www.kjsl.com/canon-fd/
Jonas

----------
> Från: Greg Mueller <mueller@silverlink.net>
> Till: astro-photo@nightsky.com
> Ämne: Re: [APML]: Advice on Canon FDn 300/f4 L
> Datum:  den 31 december 1997 01:29
> 
> 
> Michael Stecker wrote:
> > 
> > 
> > Jonas:
> >     I once considered buying a used Canon 300 mm f/4 FD "L" lens
because
> > Canon had such a good reputation for fine optics.  I did buy this used
> > lens from KEH Camera Brokers.  KEH will refund all money with no hassle
> > if you are unhappy with the lens for any reason.  I tested the lens on
> > rich star fields with color film.  To see if there were any problems
> > with the image I studied the photos with Adobe Photoshop.  The lens
> > showed significant color (chromatic aberration) and did significantly
> > vignette at f/4.  Also the peripheral stars were radially elongated and
> > the RGB star images were not concentric in the periphery.  The result
> > was that peripheral stars had a red-green-blue "traffic light"
> > appeareance in the corners. The Nikon 300 mm f/4 ED I found somewhat
> > better but not perfect. All these 300 mm f/4 lenses I have studied have
> > significant vignetting requiring stopping down the lens to f/5.6 or
> > f/8.  You of course can use special printing and Photoshop techniques
to
> > remove the appeareance of vignetting.
> >      I might have had a defective lens even though KEH guaranteed it
> > against defects.  If you decide to get this lens, check it out first
> > with an astrophotograph or two before you buy it.  Do not believe
anyone
> > who says the photos are perfect unless he has done astrophotography
> > which is far more critical and demanding then conventional photography.
> > 
> >                          Michael Stecker
> 
> 
> 
> Michael
> I think most people will agree that it almost mandatory that you stop
> down ANY lens at least one f stop, preferably two.
> -- 
> Greg Mueller
> Amateur Astronomer, Machinist, Filmnut
> 
> Every passing hour brings our Solar System forty-three thousand miles
> closer to Globular Cluster M13 in Hercules...
> and still there are some misfits who insist there is no such thing as
> progress!
> 
> mueller@silverlink.net