Fed collimator target measurements?

[eli griggs]

I want to make up some viewfinder targets for collimating my Fed cameras and instead of measuring these myself and perhaps getting it wrong, I'd like to know if anyone has precise distances for the Fed 2s, both 3s and the 5 and 5b.

If you know the data for the Fed 4 you might pass that on as well as I hope to find a user one day.

Eli

 

[eli griggs]

greyhoundman, I want the measurments, if available, to use the indoor rangefinder method shown here
http://rick_oleson.tripod.com/index-123.html

If I can get precise measurements it would be helpful so as to avoid any mistakes on my part. I am concerned I might get the takeoffs wrong if I do it myself and if there are 'factory' numbers I'd rather use those for making my own targets.

Eli

 

[eli griggs]

greyhoundman, thanks. Perhaps I'm making this harder than it really is.

Eli

 

[ZorkiKat]

greyhoundman, I want the measurments, if available, to use the indoor rangefinder method shown here
http://rick_oleson.tripod.com/index-123.html

If I can get precise measurements it would be helpful so as to avoid any mistakes on my part. I am concerned I might get the takeoffs wrong if I do it myself and if there are 'factory' numbers I'd rather use those for making my own targets.

Eli

Eli,

As greyhoundman said, it's best to do the measurements yourself 🙂

Also, don't forget to check for minimum focus (1m, adjusted by setting the slope of the RF sensor tip) after lining up the rangefinders for infinity.

Before you do any RF adjustments, check if the lens mount flange to focal distance ("working distance") is indeed at 28.8mm. Or, since you're using FED with removable backs, use a groundglass set on the film rails to see if the lens can indeed focus to infinity. The lens to use should be one which is proven to truly focus to infinity.

If the groundglass doesn't show the infinite target to be in focus, but instead shows this when the lens scale is set at a lesser or greater distance than the infinity mark, remove the lens mount and add or reduce the paper shims beneath it.

Rick O. also has a method for "taking infinity" indoors.

Only when true infinity focus has been set for the lens should you start calibrating the RF.

Jay

 

[eli griggs]

Thanks greyhoundman, Zorkikat for the feedback and tips. I do want to get this right and I've been procrastinating for the longest while about checking the flange to focal distance on all my Feds. To tell the truth, though I have a good digital caliper, I have a difficult time telling if I have measured this particular feature correctly. I guess I'll have to buckle down and do them all, by the numbers, this weekend.

Cheers, Eli

 

[ZorkiKat]

To tell the truth, though I have a good digital caliper, I have a difficult time telling if I have measured this particular feature correctly. I guess I'll have to buckle down and do them all, by the numbers, this weekend.

Cheers, Eli

Eli

If you're using a caliper, put glass on the rails too. This will assure that the depth measured is really at the focal plane, and without the distortions introduced by a movable, spring loaded pressure plate. Make sure that the glass sits on the inner rails, not the outer ones. Glass microscope slides are perfect for this application. Their width is just enough to span the rails, and they can be taped into place.

Jay