On Mon, Oct 6, 2014 at 9:23 PM, Stanley Halpin <s...@stans-photography.info> wrote: > > On Oct 6, 2014, at 4:26 PM, Larry Colen <l...@red4est.com> wrote: >> >> P.J. Alling wrote: >>> and wonder of wonders it's got some interesting information for free. >>> >>> http://www.luminous-landscape.com/techniques/pentax_645z_astrophotography.shtml >> >> Excellent link, though I'm afraid that if I were to spend $10K on a 645Z, I >> wouldn't have any money left over for the $500 astro mount. >> >> I was surprised to find that there don't seem any lenses faster than f/2.8 >> available for the 645. Doing some quick web search, there don't even seem >> to be any manual focus lenses faster than f/2.8 available. >> > > There are adapters that support the use of Hassleblad etc. on the 645. Maybe > you can find the faster glass you need by going that route?
I always assumed that there isn't faster glass because there doesn't need to be. The DoF on medium format is already razor thin compared to 35mm and APS-C and perhaps a 1.4 on a 645z would create a serious focusing problem? Or ridiculously OOF portraits? In other words, we have what's practical to sell, as with other formats. Or am I way off base? -- -bmw -- 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.
