14mm will not be wide enough, you need 12mm maximum for APS based on the 2/3 f.l. factor vs. the 18mm FF lens. jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Stenquist Sent: Friday, December 22, 2006 7:01 PM To: Pentax-Discuss Mail List Subject: Re: Determining a Focal Length And the DA 14/2.8. Paul On Dec 22, 2006, at 6:58 PM, John Francis wrote: > On Fri, Dec 22, 2006 at 12:53:26PM -0800, Shel Belinkoff wrote: >> There is a photo I'd like to make, but the widest lens I have is >> still too >> long as it forces me to include an undesirable object in the frame >> and I >> don't want to mess around with cloning the object out of the >> scene. I will >> need to borrow a wider lens, but I don't know what focal length >> would work. >> Is there a way to determine the focal length I need based on the >> subject >> distance and framing I want using the longer lens. I know how >> close I must >> get to the subject to eliminate the unwanted element. Perhaps a >> formula of >> some sort? >> >> For what it's worth, the subject is about 12-feet long and I have >> to get >> about six feet from it. > > > So, as you know now, for APS-C the answer is somewhere around 15mm > (give or > take; I assume your distances quoted above aren't absolutely precise). > > That leaves you with three or four choices: > > o The A 15mm > > o A DA 16-45, if you can get away with a 16mm > > o The DA 10-17 fisheye zoom, if distortion is OK > (although you can defish the image digitally) > > o The DA 12-24; probably your best choice. > > I don't know what access you have to loaner lenses, but if > you decide on the fisheye I've now got one of those in my bag :-) > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
