On Thu, Oct 03, 2013 at 05:50:27PM +0100, Steve Cottrell wrote: > Okay folks here's a question I'll throw to the floor. > > I've finally been able to mount a fully manual wide angle lens onto my > Fuji X-E1 and I was testing with it this afternoon. > > For the curious, this is what the combo looks like: > > <http://pdml.posthaven.com/fuji-and-wide> > > BUT if I try and 'zone' focus with it, the background is out of focus. > > Facts: lens is M39 mount and mates to camera via a M39-to-Fuji X (FX) > adaptor. Camera set to Auto so you offer it some light through the lens > and it will correctly calculate the exposure. This is flawless. Lens set > at (say) f/16, and infinity mark on focus barrel is moved to the f/16 > mark so that everything between the two f/16 marks should be in focus > according to depth of field. > > Result: foreground is sharp, everything from about 20 feet away to > infinity is soft.
If you set up posts at known spacing, open it up to full aperture, then set the focus to various distances, do the posts in focus match the focus point on the lens? > > However: if I leave the infinity mark at maximum focus (eg lens set to > infinity focus), and stop down to (say) f/16, then everything from about > 2 feet away to infinity is in sharp focus! http://www.dofmaster.com/dofjs.html 14mm f/16 hyperfocal distance of 2.06 ft, set focus to 2.1 ft Subject distance 2.1 ft Depth of field Near limit 1.04 ft Far limit Infinity Total Infinite In front of subject 1.1 ft Behind subject Infinite Hyperfocal distance 2.06 ft Circle of confusion 0.02 mm Set subject distance to Subject distance 99999999 ft Depth of field Near limit 2.01 ft Far limit Infinity Total Infinite In front of subject 99999997 ft Behind subject Infinite Hyperfocal distance 2.06 ft Circle of confusion 0.02 mm However, note that if you set the focal distance to 2.00 feet, DoF only goes to about 70 feet Subject distance 2 ft Depth of field Near limit 1.01 ft Far limit 72.5 ft Total 71.5 ft In front of subject 1 ft (1%) Behind subject 70.5 ft (99%) Hyperfocal distance 2.06 ft Circle of confusion 0.02 mm Set it to 1.9 feet Subject distance 1.9 ft Depth of field Near limit 0.99 ft Far limit 24.6 ft Total 23.6 ft In front of subject 0.9 ft (4%) Behind subject 22.7 ft (96%) Hyperfocal distance 2.06 ft Circle of confusion 0.02 mm My guess is that you are lining up on one end of the infinity sign, and need to line up on the other. It seems that that close to the hyperfocal distance, small differences can make big changes to the far limit of sharpness > > Supplementary question: > > To mount an M39 lens onto an FX body, apparently there are two routes: > just by using a M39-FX adaptor. OR by using an M39-Leica M (LM) adaptor > AND a LM-FX adaptor as well. Wouldn't the two methods produce differing > lens flange - to - sensor plane measurements? I appreciate this question > really needs to be addressed to something like the Fuji forum, but > thought I would put it past the ,might PDML collective first. > > Would an incorrect lens flange-to-sensor measurement create the zone- > focus issue above? > > Many thanks > > -- > > > Cheers, > Cotty > > > ___/\__ Broadcast, Corporate, > || (O) | Web Video Production > ---------- <www.seeingeye.tv> > _____________________________ > > > > -- > 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. -- Larry Colen l...@red4est.com http://red4est.com/lrc -- 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.
