marameo
Established
Hi, Could yu please tell if the lens is mounted correctly? Unfortunately, I have the 50/75 adapter where the Voigtlander Type II 28/90 Screw mount to M adapter was probabòy required. Do I have to set the focus to infinity before mounting the lens? First time for me with both the Leica and the CV. Thanks
(I also have the 21mm viewfinder)
(I also have the 21mm viewfinder)
Attachments
_goodtimez
Well-known
It appears OK. Focus can be set at any distance for mounting it.
Have fun.
Have fun.
marameo
Established
I mean, the white dot on the lens is not perfectly in the center of the camera.
Larry H-L
Well-known
Should not be an issue.
In the older days, some LTM lenses lined up at 2 o'clock, so that the f-stop setting could be seen through the viewfinder.
Since this is such a wide lens, the great DOF is going to take care of any small registration distance difference.
But this sort of thing is annoying to some (myself included), so I put a thin sliver or two of transparent tape between the lens and adapter, that keeps the lens from turning past 12 o'clock.
In the older days, some LTM lenses lined up at 2 o'clock, so that the f-stop setting could be seen through the viewfinder.
Since this is such a wide lens, the great DOF is going to take care of any small registration distance difference.
But this sort of thing is annoying to some (myself included), so I put a thin sliver or two of transparent tape between the lens and adapter, that keeps the lens from turning past 12 o'clock.
Dez
Bodger Extraordinaire
It also keeps it from focusing to infinity, but I suppose the large DOF makes that unimportant.
Cheers,
Dez
Cheers,
Dez
marameo
Established
marameo
Established
Can yu explain this? I use http://www.dofmaster.com/dofjs.html to calculate DoF (CoC: 0.300mm)
If a stop the lens down to f/16 and set the subject distance to 0.5 meters I get "In front of subject" to 0.4m and "Behind subject) to infinite.
Istead if I set the subject distance to 1 meter I get 0.9m to infinity.
How is that possible?
So, if I am doing street photography I'd better set the focus to 0.5 meters and f/16?
Thanks
If a stop the lens down to f/16 and set the subject distance to 0.5 meters I get "In front of subject" to 0.4m and "Behind subject) to infinite.
Istead if I set the subject distance to 1 meter I get 0.9m to infinity.
How is that possible?
So, if I am doing street photography I'd better set the focus to 0.5 meters and f/16?
Thanks
marameo
Established
My bad, I should have set "35mm film" instead of CoC 0.030
jimmyca1219
Member
looks good on m2 as far as i can tell 
V-12
Well-known
The orientation of the lens on the adapter makes no difference at all to focusing accuracy. So if a traditional LTM is used with an adapter that has it's focus scale offset to the left the focus is not affected on an M camera. What does affect focus accuracy is if the adapter is thicker or thinner than it should be. The focus is only affected by the distance from the focus cam, not the orientation to the focus cam.
V
Godfrey
somewhat colored
Street photography is rarely done at half-meter distances. Most street photography happens at 1.5 to 4.5 meter (5 to 15 foot) distances in my experience. A 21 mm lens on 35mm film nets so much DoF there's little need to stop down so far (into the diffraction range) or set primary focus distance so close for best sharpness.
When using the 21 on CL, M4-2 or M9, I set focus at 2.5m (8 feet) and stop down to f/8. That nets 1m to infinity (3.5 feet to infinity), a perfect street photography focus zone, and two stops more light gathering power. You can open up to f/5.6 and even f/4 as light levels drop and still have enough focus zone to work with—f/4 nets the usual 1.5-4.5 meter zone where most of the action happens. .
G
blue4130
Well-known
And by putting the tape between the lens and the adapter, he is effectively changing the thickness of the adapter. (Or more simply, he is not screwing the lens all the way into the adapter - thus having the lens further away from the film plane that it should be)
V-12
Well-known
Yes of course.
Sorry I should have been clearer, I was agreeing with Dez, it just seemed like it needed elaborating as the OP appeared to be unsure if the focus would be correct with the lens offset.
v
Sorry I should have been clearer, I was agreeing with Dez, it just seemed like it needed elaborating as the OP appeared to be unsure if the focus would be correct with the lens offset.
v
Scrambler
Well-known
Thinking about this for a moment you realise the genius of the RF follower system. The lens is set further out than it should be - i.e. it is focused closer than infinity when set to infinity. And the RF follower in the camera will show that. And you also come against the limits of the system. With a 50mm lens this wouldn't matter at all. But with a 21mm it will. The difference will not be in the correct ratio.