Archived posting to the Leica Users Group, 2010/09/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Its a "rule" of photography that once you compensate for magnification and the picture area is the same size "head and shoulders say" than DOF Is the same at the same f stop with any focal length lens. But as in many basic photo rules as Rei shows us it just does not work out quite that way. -------------------- Mark William Rabiner Photography mark at rabinergroup.com > From: Rei Shinozuka <shino at panix.com> > Reply-To: Leica Users Group <lug at leica-users.org> > Date: Sat, 18 Sep 2010 10:01:12 -0400 > To: Leica Users Group <lug at leica-users.org> > Subject: Re: [Leica] Wow! 200mm f/2G ED-IF AF-S VR Nikkor - Oly 250mm f/2 > > yes and no. i you focus the noctilux at 5 feet, you get a DOF (under > a 0.03mm COC) of just over 2 inches total. > > if you focus a 200/f2 at 5 feet, your DOF (under the same assumptions as > above) about 1/4 inch total. > > however, to capture the same target area as the noctilux at 5 feet, you > would need to shoot the 200mm from about 20 feet away. At that > distance, DOF is a little over 4 inches. > > if the film/sensor format is fixed, and the area you wish to photograph > is predetermined (e.g., a head and shoulders portrait) and you will > compensate for magnification of differing focal lengths by changing > distance to the subject, then f stop becomes the primary determinant of > depth of field. hence the 50mm summicron wide open has virtually the > same DOF at 5 feet as the 200mm f2 wide open at 20 feet. the 21 lux at > 6.3 feet has about the same DOF as the 75 lux at 22.5 feet (2.3-2.4 feet > DOF). > > -rei > > > On 09/18/2010 01:51 AM, Mark Rabiner wrote: >> 250mm f/2 That's more Noctiluxlike like than a Noctilux! >> >> -------------------- >> Mark William Rabiner >> Photography >> mark at rabinergroup.com >> >> >>> From: Alan Magayne-Roshak<amr3 at uwm.edu> >>> Reply-To: Leica Users Group<lug at leica-users.org> >>> Date: Sat, 18 Sep 2010 00:01:26 -0500 (CDT) >>> To: Leica Users Group<lug at leica-users.org> >>> Subject: Re: [Leica] Wow! 200mm f/2G ED-IF AF-S VR Nikkor - Oly 250mm f/2 >>> >>> On Fri, 17 Sep 2010 Mark Rabiner<mark at rabinergroup.com> wrote: >>> >>> Would 200mm f2 but as thin a slice as a 50 f1 DOF wise? >>> Seems like it would. >>> ============================================================================ >>> == >>> ========= >>> I have an Olympus 250mm f/2 that should have even thinner DoF than that >>> Nikon >>> lens. >>> >>> On a 5D MkII with adapter: >>> <http://gallery.leica-users.org/v/Alan+Magayne-Roshak/LensFun/Brian250_f2_AM >>> R. >>> jpg.html> >>> <http://gallery.leica-users.org/v/Alan+Magayne-Roshak/LensFun/Brian250_f2_AM >>> R_ >>> Crop.jpg.html> >>> >>> I'd use it more if it wasn't such a monster to carry. >>> >>> Alan >>> >>> Alan Magayne-Roshak, Senior Photographer >>> UPAA POY 1978 >>> University Information Technology Services >>> University of Wisconsin-Milwaukee >>> amr3 at uwm.edu >>> http://gallery.leica-users.org/v/Alan+Magayne-Roshak/ >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information