On Tue, 24 Dec 2002 05:34:48 -0500, you wrote: >Thanks everyone for the feedback. > >Weird. Distinctly weird. If I ever decide to try a reflex lens I will really have to >give it a lot of thought first. > >It maybe better to buy something like that Pentax 1000 on ebay, although it looks >almost five feet long. Hehehe. Naturally it and others like it obviously won't go >cheap. Which is a major consideration, of course. > >Still processing feedback. Thanks again. Weird. > >Doe aka Marnie :-)
Check out my old Mirror Lens page at http://www.photolin.com/john/mirror/index.html The donut effect of a mirror lens can be reduced if one chooses a distant, smooth background with few or no highlights. But anything in the background that reflects points of light can become a donut highlight. Be aware that old long lenses like the Pentax 1000/f8 and 500/4.5 have very long minimum focusing distances - the 1000 minimum focus distance is 30 meters, and the 500/4.5 minimum is 10 meters. FOV for the 1000 at minimum distance is 2.3 x 3.4 feet - not nearly good enough for birds or many small mammals. Mirror lenses are often very close focusing (about 1:3). To photograph something the size of a song bird with 35mm, one needs about 600mm focused at a distance of 17 feet to get the proper field of view for a medium size bird to fill the frame. The older long lenses just don't focus that close; real big glass is often just too expensive; so that leaves us with a few options (a) inexpensive but donut-funky mirror lenses, or (b) some 300mm with a teleconverter, or (c) go where the subject is accustomed to humans nearby so long lenses are not needed, or very soon (d) a 300mm plus 1.4 TC and the FOV crop of a DSLR which shoots just like a 600/5.6. -- John Mustarde www.photolin.com
