Wimberly Plate and Mamiya 500mm f/4.5 APO

[MB100]

Hi, I posted this on LuLa and I know a lot of people go on both forums so I won't repost the entire story. But I need help figuring out which Wimberly Plate to use with the 500mm f/4.5 APO Lens. I am also posting it here since I know there are a few people on here who have this lens.

Wimberly Mounting plate and Mamiya 500mm f/4.5 APO

 

[fotophil]

Mamiya made attachment difficult by only providing a single threaded hole. The shorter Wimberly plates (P10 - P30) have a lip which when fitted against the end of the rail will prevent rotation. The problem is that these rails are relatively short. I had to fabricate a lip for the longer P40 and P50 rails.

You might consider sending a couple photos to Really Right Stuff and Kirk Enterprises and see if they have any ideas. Another approach would be to drill and 1/4 - 20 tap a second hole in the Mamiya mount and use two bolts to fix the plate.You probably could skip the tapping operation and use a long bolt with a locking nut on the top side of the mount.

 

[MB100]

I didn't have any real issue with the P10 length wise, but even with its little lips the lens still seemed to rotate, although not as much as with the P40 or P50's......

I also just contacted both companies as well as Wemberely for help. Thanks,

 

[fotophil]

Drilling a second hole is probably the best solution. I spent a lot of time fabricating my "lip" for the long Wimberly plate. Some of the Wimberly plates have holes on one end for attachment of flash brackets. In other lens applications, I have used these holes to hold bolts extending to the top side to act as a restraint to rotation. Good Luck

 

[fotophil]

Contacting RRS and Kirk is good. Ask for Carla at RRS and Jeff at Kirk - both are very good. I have both the 300 f/2.8 and 500 f/4.5 and use them on the S2 - great lenses that are really heavy!!

 

[MB100]

So what did you end up doing for your plate?

 

[fotophil]

I wanted the length of the P50 plate so I used two of the flash bracket holes to attach a small "lip bar". The P30 lips are short and don't grip very well but they do stop most of the rotation. A couple drops of crazy glue might tie the plate to the mount and eliminate rotation.

 

[fotophil]

Take a look at the new RRS Catalog = on page 122 there are several multi-purpose rails; MPR-1 is 6 inches in length. On the same page is an index stop bar; MPR-B and flange piece; MPR-C. The description implies that anti-twist flanges can be installed on the multi- purpose rails. Call Carla on Monday and ask her if she can sole your problem with these parts.

 

[MB100]

Thanks, I ordered the solution you suggested along with a 6 inch rail (length of the bottom) and then the 7.~ inch rail as well.

 

[fotophil]

Based upon the catalog description it looks like it will work. RRS probably will not ship until Monday morning (I think they are closed on weekends) so you could call Carla early Monday to verify that all is O:K. Her direct number is 805-548-1510. I think you will enjoy your new lenses - they are pretty good wide openill