Screw size of Nikon PB-5 bellows

dhmiller · Post by **dhmiller** » Tue Feb 04, 2020 2:10 pm

I'm (again) trying to put a PB-5 into service and I need to find an Arca Swiss plate for it plus screws of the correct size. I measure the bottom at very close to 8" and found a 200mm Arca plate, but it is sold with either 1/4 or 3/8 screws and I don't know which will fit the bellows. Also not entirely sure the holes on the bellows and the plate will line up, but worth a chance (just paying shipping charges for a return). Any info about this device would be much appreciated (Nikon's website has nada...).

ChrisR · Post by **ChrisR** » Tue Feb 04, 2020 5:49 pm

It's 1/4 inch. I have a cheap arca plate across the ends of mine; as you say about 200mm. Just check the dimensions and you'll be fine

.

naturepics43 · Post by **naturepics43** » Tue Feb 04, 2020 5:59 pm

The screw size is 1/4 20 (The standard used on photography gear). NO, the holes on a 200mm arca plate will not line up. This is what I used. https://www.amazon.com/DLR-2502B-Desmon ... B00HJD6BCM
The slots in the plate line up nicely. One thing you want to check is that the plate and the rails of the PB-5 are parallel. The front mounting pad may need a shim to make them parallel. I used a thin (About 1.25mm thick) washer on mine. It works great. I use my PB-5 a lot.

dhmiller · Post by **dhmiller** » Tue Feb 04, 2020 6:21 pm

Thanks much. So I take it the screws can be moved to the respective ends to grab the holes in the PB.. That makes sense, being adjustable.

And just to be clear, I had no trouble mounting the camera body V or H, but what exactly do I use on the front end to attach an RMS (Nikon 40x) objective?

I will check that all is level and thanks for the tip.

naturepics43 wrote:The screw size is 1/4 20 (The standard used on photography gear). NO, the holes on a 200mm arca plate will not line up. This is what I used. https://www.amazon.com/DLR-2502B-Desmon ... B00HJD6BCM
The slots in the plate line up nicely. One thing you want to check is that the plate and the rails of the PB-5 are parallel. The front mounting pad may need a shim to make them parallel. I used a thin (About 1.25mm thick) washer on mine. It works great. I use my PB-5 a lot.

dhmiller · Post by **dhmiller** » Tue Feb 04, 2020 6:22 pm

Thanks much, Chris. I'll find the right plate and hope to get this into service.

ChrisR wrote:It's 1/4 inch. I have a cheap arca plate across the ends of mine; as you say about 200mm. Just check the dimensions and you'll be fine .

naturepics43 · Post by **naturepics43** » Tue Feb 04, 2020 10:39 pm

dhmiller wrote: but what exactly do I use on the front end to attach an RMS (Nikon 40x) objective?

Lots of different adapters for the front. Here is what I use, Nikon BR2-A (F mount to male 52mm threads) + 55mm to 52mm step down ring (MUST have 52mm female threads all the way thru) + M52-M20.3 adapter (Also ca be called 52mm-RMS adapter)

Put them together, install your objective and mount the assembly like a normal lens. Hope this helps. Search Amazon for the parts. Good luck.

dhmiller · Post by **dhmiller** » Wed Feb 05, 2020 9:01 am

Thanks much. So if the BR2-A gets you from the F mount to 52mm threads, do I still need the 55mm to 52 step down or can I just go from the BR2-A to the 52mm-RMS adapter to the objective? Not sure whey I need the 55-52 step down if I am already at 52 coming off the BR2-A.
And it's the Br2A "reversing ring" that I need: https://www.bhphotovideo.com/c/product/ ... _Ring.html

Thanks again - very helpful.

ChrisR · Post by **ChrisR** » Wed Feb 05, 2020 11:00 am

You can do it in one hit. This one is

from Rafcamera but there are Chinese ones too:
Nikon F to M42 and M42 to rms is another way to go.

(You're sure your Nikon 40x is rms?)

naturepics43 · Post by **naturepics43** » Wed Feb 05, 2020 2:53 pm

dhmiller wrote:Thanks much. So if the BR2-A gets you from the F mount to 52mm threads, do I still need the 55mm to 52 step down or can I just go from the BR2-A to the 52mm-RMS adapter to the objective? Not sure whey I need the 55-52 step down if I am already at 52 coming off the BR2-A.
And it's the Br2A "reversing ring" that I need: https://www.bhphotovideo.com/c/product/ ... _Ring.html

ChrisR has an excellent solution. Lots of ways to get from "F" mount to RMS. Yes, that is the BR2-A that I referred to. To answer your question about the 55mm-52mm step down ring, it has 52mm female threads all the way thru the adapter. The BR2-A and the 52mm-RMS adapter that I use both have Male 52mm threads. The 55mm-52mm step down ring joins them together. The F mount to RMS is a single purpose adapter. The BR2-A can be used seperately to attach different adapters to the front of your bellows or your camera. Ya, I know. Too many options.

dhmiller · Post by **dhmiller** » Wed Feb 05, 2020 3:56 pm

Thanks, Chris. Ordered the part.. I have it from a very reliable source that it is RMS. Is there some other standard that Nikon finite objectives use?

ChrisR wrote:You can do it in one hit. This one is

from Rafcamera but there are Chinese ones too:
Nikon F to M42 and M42 to rms is another way to go.

(You're sure your Nikon 40x is rms?)

dhmiller · Post by **dhmiller** » Wed Feb 05, 2020 3:58 pm

Thanks again. Turns out I actually had a BR2-A that I must have acquired at some point in the distant past. But I ordered the F mount to RMS from RAF, as I like the single component idea.

And yes, always too many choices!

ChrisR · Post by **ChrisR** » Wed Feb 05, 2020 4:02 pm

Not sure why I need the 55-52 step down if I am already at 52 coming off the BR2-A.

You need a "something" because the "reversing ring" has male 52mm threads, and so does the adapter which reduces to rms.
If you get the right type of step ring, you get a through-threaded 52mm (female!) hole so you can screw the other two in from each side. You just don't use the larger thead (55 here).
An old pic:

I tend to use M42 for most intermediate threads. Adapters are cheap. A Nikon BR2/ BR2A will be a better fit than an oriental F , though.

dhmiller · Post by **dhmiller** » Wed Feb 05, 2020 4:08 pm

Just bought the RAF adapter (F mount to RMS) based on your recommendation. So is there a better option? Not sure I can cancel that..

ChrisR wrote:
Not sure why I need the 55-52 step down if I am already at 52 coming off the BR2-A.
You need a "something" because the "reversing ring" has male 52mm threads, and so does the adapter which reduces to rms.
If you get the right type of step ring, you get a through-threaded 52mm (female!) hole so you can screw the other two in from each side. You just don't use the larger thead (55 here).
An old pic:

I tend to use M42 for most intermediate threads. Adapters are cheap. A Nikon BR2/ BR2A will be a better fit than an oriental F , though.

ChrisR · Post by **ChrisR** » Wed Feb 05, 2020 4:15 pm

See the FAQ on Threads We use - the BD finite Nikons are 26mm, otherwise all rms afai can remember - other than weirdos.
It sounds like you're sorted now, but a Nikon K ring set is a nice-to have. They can be very cheap - or not - and the ring which goes into the camera has a female 52mm thread. Then a set of 52mm tubes and an F female to 52male, plus the thinnest-available-ever Nikon F to F extension tube.

RAF's stuff is good, a level above most orientals. You won't be disappointed.

dhmiller · Post by **dhmiller** » Wed Feb 05, 2020 4:26 pm

I'm looking at a Nikon ELWD 40x and from the (potential seller) : "These objectives are not BD. They are RMS."

So that's official! And thanks for the other info about the adapters. I'll get there at some point.

ChrisR wrote:See the FAQ on Threads We use - the BD finite Nikons are 26mm, otherwise all rms afai can remember - other than weirdos.
It sounds like you're sorted now, but a Nikon K ring set is a nice-to have. They can be very cheap - or not - and the ring which goes into the camera has a female 52mm thread. Then a set of 52mm tubes and an F female to 52male, plus the thinnest-available-ever Nikon F to F extension tube.

RAF's stuff is good, a level above most orientals. You won't be disappointed.