Here are Bjørn's instructions......
Posted 06 December 2013 - 20:12
As usual you can attack the modification of such lenses in different ways. There is no golden rule.
However, whatever you do remember this lens is very heavy. So any attachments must be able to hold the load.
A simple yet efficient approach is as follows;
Remove the retaining shroud at the end of the lens. Be care full so the rear lens cell doesn't drop out.
The removal discloses a thread which is small and pretty delicate. It can be used if you find the appropriate counter-threaded items. I do have used this approach once or twice but now find it's too weak to be trusted for a lens used in the field.
Instead, use either 40.5>52 or 42>52 mm step rings. Remove the smaller thread (Dremel at the rescue) so the adapter is flush on one side. I think 40.5 will have a light opening large enough, 42mm will give less support but should still suffice.
Put the modified adapter onto the rear of the lens ensuring it is flush to the cut-out of the main lens casing. The 52 mm threads should point backwards.
Add the retaining shroud and screw it home so the adapter is securely held in place.
This procedure will give a clean 52 mm female interface. A BR-2/2A will give a Nikon F mount but beware the reflex mirror of the camera. You can add a spacer such as a K-4 to avoid any issue with Nikons. Alternatively, find a suitable transition from 52 mm to m43.
Posted 07 December 2013 - 11:27
Another tip if you go the 52 mm way ending with the first adapter showing 52 mm female threads. For F mount use a BR-2 or similar plus a spacer (K-4 or similar). For m43 mount, add a step-down 52>42 mm which will present a flat outer surface to which you can attach say a C-mount>m43 adapter (the one by Fotga is perfect as it is thin yet very robust) by running three screws to hold these together. If you wish to use the Rayxar on a CX-mount camera (1 Nikon series), make a similar setup but substitute C-mount to CX instead.
You now have a versatile system in which you can easily juggle between 3 different camera mounts. Many of the "fat" X-ray lenses (Rodenstock Heligon, Oude Delft Rayxar, Kowa, Canon) can be dealt with in a similar fashion. The basic point is using the 52 mm thread as the common interface for all versions. The 52 mm threaded item has the strength to hold these heavy lenses securely, something which is less obvious with the smaller diameter threads.
