Archived posting to the Leica Users Group, 2007/04/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Doh! Yes of course you are absolutely right. Showing my 25 years of SLRs there before finding the true path. When I went through this process testing my 1.4 50, I used the 45 degree angled focus chart, which George has since pointed out is invalid as well. I muddled through empirically, as I had a physical measurement from the film plane to target to compare to lens markings and RF coincidence. Cheers Hoppy -----Original Message----- From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org [mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of Leonard Taupier Sent: Monday, 2 April 2007 09:43 To: Leica Users Group Subject: Re: [Leica] Focus shift on 50/1.4 Nikkor on M8 Hoppy, The rangefinder is not linked to the lens aperture. Len On Apr 1, 2007, at 7:22 PM, G Hopkinson wrote: > OK, well I think that may add another variable. The focus point may > not be identical if you change the aperture AFTER focusing. I > thought that the back focus (or front focus) issue was when the > rangefinder was coincident, at the shooting aperture, but the image > has a different point of sharpest focus? This error would be most > visible with large apertures, and closer subjects, due to the > inherent lack of DoF? > > Cheers > Hoppy > > > -----Original Message----- > From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org > [mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On > Behalf Of > Jeffery Smith > Sent: Monday, 2 April 2007 08:54 > To: 'Leica Users Group' > Subject: RE: [Leica] Focus shift on 50/1.4 Nikkor on M8 > > I'm focusing with each shot, and stopping down the aperture one > stop at a > time. > > Jeffery Smith > New Orleans, LA > http://www.400tx.com > http://400tx.blogspot.com/ > > > > -----Original Message----- > From: lug-bounces+jsmith342=cox.net@leica-users.org > [mailto:lug-bounces+jsmith342=cox.net@leica-users.org] On Behalf Of G > Hopkinson > Sent: Sunday, April 01, 2007 5:45 PM > To: 'Leica Users Group' > Subject: RE: [Leica] Focus shift on 50/1.4 Nikkor on M8 > > > Just so we are all on the same page; you guys are setting the > aperture, then > focusing with the rangefinder, resulting in the described results? > > Cheers > Hoppy > > -----Original Message----- > From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org > [mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On > Behalf Of > Jeffery Smith > Sent: Monday, 2 April 2007 06:33 > To: 'Leica Users Group' > Subject: RE: [Leica] Focus shift on 50/1.4 Nikkor on M8 > > I suppose that I should set up some sort of contraption to find the > "soft > spots" on all of my lenses. It would have been a prohibitive pain > in the ass > without the M8. But the test I ran on the Nikkor tells me that if I > took a > portrait of someone at 5' and at f/5.6, her eyes would be out of > focus. > > For now, I think I need to decide which one of my 28's, 35's, and > 50's will > reside most of the time on my M8 and test them. > > Jeffery Smith > New Orleans, LA > http://www.400tx.com > http://400tx.blogspot.com/ > > > > -----Original Message----- > From: lug-bounces+jsmith342=cox.net@leica-users.org > [mailto:lug-bounces+jsmith342=cox.net@leica-users.org] On Behalf Of > Leonard > Taupier > Sent: Sunday, April 01, 2007 3:21 PM > To: Leica Users Group > Subject: Re: [Leica] Focus shift on 50/1.4 Nikkor on M8 > > > Jeffrey, > > This is similar to what I see on the Noctilux. Your Nikkor is > probably on the edge of a back focus point and then shifts at f4. I > think most lenses focus shift somewhat. > > I just checked my 1.5 Summilux. > > 1.5 Very soft. just out of focus. front focus. some flare. > 2.0 Soft (low contrast). just in focus. still front focus. > 2.8 -> 16. In focus. sharpens up nicely. focus in center of DOF. > > Len > > > On Apr 1, 2007, at 3:25 PM, Jeffery Smith wrote: > >> Well, I wasn't expecting this. Shooting a copper wire about 5 feet >> from me with the M8 and 50/1.4 Nikkor LTM: >> >> 1.4 In focus but soft >> 2 In focus >> 2.8 In focus >> 4 Slightly out of focus >> 5.6 Even more of of focus(!) >> 8-22 In focus >> >> Optics guys, is this a reasonable result? >> >> >> >> Jeffery Smith >> New Orleans, LA >> http://www.400tx.com >> http://400tx.blogspot.com/