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Setting Infinity on Baby Crown RF with Fuji Lens
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Velostiraptar
Joined: 20 Jul 2020
Posts: 8
PostPosted: Sun Oct 03, 2021 1:25 am   Post subject: Setting Infinity on Baby Crown RF with Fuji Lens

Currently trying to calibrate this 'D'-series Kalart RF on a 2x3 Baby Crown for an exotic Fuji 105.

The time comes to adjust this part per the Kalart manual:


Are they usually set so far back? - this thing came with a Wollensack Raptar 90/4.5 that was not original to the camera or calibrated to the RF, but maybe someone had been trying?


Its clockwise adjustment (the kind you can "use a dime" for) is starting to get tight and I still don't have the 'moveable image' high enough at infinity.

Wondering if I made a mistake with where I set the infinity stops. I started out by setting the focus scale tics to infinity, then pulling out the front standard until I had agreement on the ground glass, then set the stops there. In hindsight this seems like the wrong thing to do because who knows what the previous owner had done with the position of the movable scale bar. Due to where I set the stops, the knobs on the front bed can go about 1/5th turn past infinity. Should I have instead started by setting the bed to minimum extension, then pulling out the standard to infinity and setting the stops, then unscrewing and sliding the focus scale to agree? Right now, infinity focus in the ground glass looks like this:


The gap in red is the current position of the bed at infinity. The gap in blue is "pretty much" how far back in the bed could go (i.e. where the focusing knob bottoms out). I'm guessing I should to put the bed in the 'blue position' and set infinity stops from there? Then the RF feeler would be pressed farther back at infinity? Would this be preferable to changing the base position of the circled part in the second image? It looks like there's a few more mm on the track that it could go back on.

It still seems like it should be possible to get this Fujnon-W 105/5.6 to agree with the Kalart RF... would be interested to know if anyone has prior experience with this lens/camera combo.[/i]
Dan Fromm
Joined: 14 May 2001
Posts: 2165
PostPosted: Sun Oct 03, 2021 1:02 pm

https://www.graflex.org/speed-graphic/kalart-adjustment.html

The flange-focal distance of 105/5.6 Fujinon lenses depends on the version. See http://www.subclub.org/fujinon/byfl.htm, scroll down to 105mm.
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sun Oct 03, 2021 8:01 pm

From 1912 through 1946 infinity was set with the yoke fully retracted. From 1947 to 1973 infinity was set with the yoke .040 ± .010 inch forward from fully retracted. Its your choice of how you want to set your camera up. With infinity set forward from fully retracted allows one to focus past infinity or correct infinity if there is a shift over time from wear.
The eccentric for the RF is normally at or very near the rear edge of the yoke. The eccentric can be very hard to turn depending on the spring washer on the back side's condition.
Once infinity is set to the desired position loosen the yoke scale and slide it to line up with your chosen infinity position. The bed side of the infinity scale in fixed. Infinity scales were matched to the lens measured focal length which cam vary 3 or 4 mm either side of the marked focal length.
A better copy of the Kalart manual for download:
https://drive.google.com/file/d/0B1sPJkp-Mdghc0FwQkRuWEhFZEE/view?usp=sharing&resourcekey=0-Fnkr9CfqOmJOVsEgCtTchg
Velostiraptar
Joined: 20 Jul 2020
Posts: 8
PostPosted: Sun Oct 10, 2021 1:25 am

Thanks to both of you. Now I’ll have to start again from square one. Just wanted some confirmation before I started loosening things.
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