Rangefinder Closeup Accuracy

Iskra 2

Iskra 2

Kodachrome Rules!
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Joined
Apr 9, 2005
Messages
234
Hi Yashica experts,

After I adjusted my GT rangfinder for infinity focusing, the closeup values seem to be off about one foot when focusing on a subject about ten feet away. Is this typical or should I readjust the rangefinder to focus correctly at approximately the ten foot range?........ or should I get an M3? :)
 
It should be possible to make that much more precise, iskra. Both of my GSN's are focusing accurately at short and long distances.
 
Thanks for the info, when I finish the current roll of film I'll re-adjust the rangefinder. I've assumed that the mechanical lens coupling is correct but I think a quick check with ground glass is in order.

Regards.
 
I test rangefinders at closeup range rather than infinity. I set my cameras on a tripod with the film plane exactly 5ft from my test target taped to a white wall. I use floodlights to light the target to focus on. I make a ground glass from scotch tape and an index card and put that into the film plane. I make a mark on it to focus my eye on and I use a eyesocket loupe
to make sure I am really focusing on the film plane. The lens barrel should read 5ft when I am in focus. I also do my horizontal adjustments at this time, then recheck everything. Depth of field is so shallow closeup I want my focus to be correct here. Infinity will take care of itself.
 
Rob said:
I test rangefinders at closeup range rather than infinity. I set my cameras on a tripod with the film plane exactly 5ft from my test target...The lens barrel should read 5ft when I am in focus.
Click to expand...

I assume you also check the rangefinder to make sure the images coincide? Otherwise you'd just be checking how accurately the distances are marked on the lens barrel...?
 
greyhoundman said:
If available, use a reversed 50mm lens as a loupe. At infinity, the two images should just coincide.
Click to expand...

Would this work for checking infinity on a 55mm lens? I'm getting ready to relube my Industar-61, but buying a loupe is what's made me put it off for so long.

-Rick
 
Some kind of support is indeed good. I usually just put the lens on something of the correct height (a box, a pile of cd cases, etc).
A 28mm (slr) lens is even better, by the way. But at some moment the grain of the ground glass/tracking paper/frosted tape will be the limit, not the loupe.
 
ha! I didn't even know loupes were that cheap. I kept putting it off because I'd only use it for this relubing, until I get a lightbox. Now I'll probably get one, which means the lightbox will follow, then some Kindermann tanks ... where was that Diafine thread again? :p
 
I assume you also check the rangefinder to make sure the images coincide? Otherwise you'd just be checking how accurately the distances are marked on the lens barrel...?

Yes, the rangefinder I set to focus correctly at 5ft via the method I described sorry for the
confusion about the lens barrel 5ft mark but it is usually very close. I make sure looking thru
the lens at 5ft the focus is good then adjust the rangefinder to match the lens...
 
Rob, I like your method. Better to be focused correctly up close than at infinity. When you adjust this way do you see any major problems with distant focusing?

Regards.
 
Vertical focus

Vertical focus

OK, I found the vertical range adj. screw.
How can I set?
I have to adjust the vertical focusing at a certain
distance, at infinite?
If I set it for 2 meters it is not good for infinite.
What I was doing?

Thaks

Federico
 
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