It's a Sigma Ultra Tel, I've seen one for sale on e-Bay a few years ago. It went for a lot of money. They are relatively rare, probably fewer were made than the Vivitar Series 1 450mm solid cat, there were only 800 of those made. They have a reputation of being very, very, very good.
Thibouille wrote: > 500f/4 mirror ? I'd be heaviliy suprised of a F/4 mirror lens. > Those are usually 500/600mm f/8 or 300/350mm f/5.6. > > On Nov 15, 2007 1:54 PM, <[EMAIL PROTECTED]> wrote: > >> I do have a Simga 500mm F.4.0 mirror lens, which is sort of heavy and I do >> like it. >> Here is a link to to a photo of it on my photo.net page.There are three >> photos of it on that page....Joe >> >> http://photo.net/photodb/photo?photo_id=5771640 >> >> >> >> -------------- Original message ---------------------- >> From: Thibouille <[EMAIL PROTECTED]> >> >>> I think mirror lens have the realyl advantages (well more or less) of being: >>> >>> * portable (but a bit too much, they are too lightweight for the focal >>> length IMO and as such difficult to stabilize). In the end you still >>> need a tripod which kinda negates the argument. >>> >>> * cheap. and I think this is the major point why people buy those. I >>> have one although I didn't pay for it (long term loan ;) I'm sometimes >>> very happy having it. I know I will *never* be able to pay for >>> "proper" 500mm lens. so I'm happy with my Tamron. >>> >>> True the bokeh is indeed very problematic. But as a chgeap astro lens >>> like moonshots (at least for a newbie like me) I think it is a very >>> acceptable solution... not without obvious drawbacks. >>> >>> -- >>> Thibault Massart aka Thibouille >>> ---------------------- >>> K10D,Z1,SuperA,KX,MX, P30t and KR-10x ;) ... >>> >>> >>> -- >>> PDML Pentax-Discuss Mail List >>> PDML@pdml.net >>> http://pdml.net/mailman/listinfo/pdml_pdml.net >>> to UNSUBSCRIBE from the PDML, please visit the link directly above and >>> follow >>> the directions. >>> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. >> >> > > > > -- The difference between individual intelligence and group intelligence is the difference between Harvard University and the Harvard University football team. -- P. J. O'Roark -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
