Basic concept is clear, so we conclude the steps of calibration as following..
1. Zeroing: set the lens to infinity, and make sure the mirror arm is attached with cam, on the mark line.
2. Align overlay image at infinity object.
3. Align overlay image at closer object.
That are all steps we will follow, then here comes the detail...
1. Byron camera with prime lens, ground glass panel, magnifying loupe, tripod.
2. Screw drivers, one tiny flat head, one normal philips head.
3. A sunny day and clear view
Choose a contrasty object as infinity target, like a high-voltage tower, about 2 km away from my house.
4. A high contrast object for close focusing
What I pick is a Big number calender panel. Hang it on wall, at the same height of the tripod, parallel with camera.
Step 1. RF housing removal
* Byron uses two screws to hold the RF housing, one is beneath the cold shoe, you need to remove tiny screw on top, and peel apart the plastic sheet to reveal the screw.
* Another one is in the side plate of film chamber, this screw need a long neck driver, or you can temporary take off the sliding tooth set for easier un-screwing.
* Once two screws are removed, carefully take the housing off, and put it aside.
* Now the RF mechanical parts are revealed, what we will adjust later are three parts, as explained at beginning, they are fixed screw, mirror, and lens cam (from left to right).
Step 2. Zeroing
Now we are going to calibrate infinity end, this is no extension for rail, so called zeroing.
* Mount Byron onto the tripod, face the infinity object. (high voltage tower)
* Mount on your prime lens, here is a Ysarex 4.7/127mm lens as example, if your prime lens is 150mm, mount it on.
* Pull the front standard to the correspond infinity stop, engage the groove. Byron engraves lens length for each infinity stop, so it is easy to distinguish.
* Set shutter to B, and with a cable release lock, make the lens shutter keep opening, and the aperture to full opening.
* Make sure that rail is not extended, distance scale marked on infinity. You can check with loupe on ground glass panel.
* Check lens cam, mirror arm should engage cam curve at the engraved line, adjust the cam by loosing locking screw if necessary.
* View through the RF eye window, align the tower in the center, observe the overlaying image, do necessary adjustments, till images align with each other.
* (In this step, we use two screws on mirror for adjustment)
Step 3. Close distance calibration
* After zeroing, turn camera to close distance object (calender), adjust camera distance to object about 4 feet, about the nearest distance the lens can focus.
* with loupe and ground glass panel, turn the focus knob to focus the object, after focus is set, DO NOT TOUCH THE KNOB ANYMORE!
* View through the RF eye window, align the object in center, observe the overlaying image, do necessary adjustments, till images align with each other.
* (In this step, we use fixed screw for adjustment)
Step 4. Re-check, further adjustment
* Both infinity and close ends are calibrated, we re-check the result by turning back to face the infinity, to see if images in eye window keep align or not.
* If overlay images keep align, then the calibration is done, and you can put back the RF housing.
* If overlay images are not aligned with each other, then it may caused by wrong cam curve section. By loose the cam locking screw and turn the cam a bit, to make overlay images align again.
* Repeat step 1~3, make necessary adjustments, till overlay images keep align on both end.
These are steps for calibration, I hope this answer some questions concerning about the RF adjustments.
And for Byron whose prime lens is set to 150mm, the original 127mm lens cam is replaced by custom made 150mm lens cam, they look alike, but curve is little bit different. (left: 150mm cam, right: 127mm cam)
Sometimes new cam needs a little bit of filing to match the lens, because each lens got its own character! That belongs to advanced fine tuning...