Hi Dieter,
This is amazing! It took me almost two hours trying to figure out why none of my eyepieces from my F, F3HP or FM3A fit on my F2AS. Had no idea there was a thread ring missing in my finder! I have a few questions I'm hoping you can help with.
1. If I were to source a parts finder do you know how hard/easy it is to remove the thread ring and put in on my F2AS? And does the thread ring unscrew left just like the view finder?
2. Where did you find your ring? Did you have to make it yourself or can I find something to start with at a hardware store?
Really appreciate your post!
-LJ
Hi there LJ!
1: There are two different sizes of diameters of the eyepieces.
F, F2, FM have a 19 mm thread.
the F3HP (I think) have 21mm diameter.
Ya can force the 21mm eyepiece into the hole of the eyepiece-case. But not often and it is - brutal and not guaranteed to stay there.
2.: find a cheap damaged viewfinder of the same type as yours. Remove half of the leather carefully on both viewfinders. On the left and on the right of the eyepiece there are two tiny screws. Unscrew them and exchange the complete rectangular part. If yer lucky, the leather will stick again, otherwise use a little bit of glue and glue the leather back.
I dunno how the DP-11 and DP-12 (F2AS) are built, but the screws on the DP1 and on the DP3 are in a slightly different location. So to be on the safe side, try to find a DP-12.
3.: If ya cant find a crashed DP-12, take any viewfinder, check if the screws are in the same location.
Because the DP-3 / DP-12 have a shutter, the screws are located in a different position than the DP-1 / DP-11.
If the screws are in a different position, remove the leather, tke a water pump plier or similar,
grab the protruding part of the threaded ring (about 1 mm)
v e r y c a r e f u l l y and unscrew it from the eyepiece lens case
(If you don't have the dexterity of a watchmaker, it's better not to do it.)
and screw the threaded ring into your good viewfinder. (yes, there is a thread in the eyepiece case)
4.: I made the ring by myself.
Find a friend with a lathe (one like me), take a piece of brass, drill a 18,2 mm hole, cut a M 19 x 0,75 thread with a tap or cut it with the lathe, machine the outer diameter to a size that fits snuggly into the eyepiece case an secure it with a tiny drop of glue or take a two-component adhesive. Let it dry, srew in the eyepiece correction lens and smile.
The problem is not to machine the ring, it is a simple part, the problem is to machine it to the fitting outer diameter.
I measured 20,3 mm, but that does not fit, because the abused hole in the eyepiece lens case was not exactly round. So i cut it down to 20,2 mm and it slips in.
If the machined diameter is to small, the ring sits to loose and you need a thick adhesive (two komponent adhesive) to glue it in.
5.: Here is the repair manual for the DP-1, but ya can see how this whole thing is built together.
The part you need is 191A Eyepiece ring
6.: I hope you understand my english.
7.: any further questions -> ask.
8.: PS: I also made a hard to find or extremly expensive eyepiece correction lens out of brass and cheap glasses.
Greetings from Austria: Dieter
