With the larger negative size the field of view of medium format lenses is much wider than the field of view with the same focal length on 35mm. To make a comparison with 35mm film SLR fields of view multiply the focal length by 0.48. For instance, 90mm is ~44mm in 35 film SLR terms.
I do not see a consensus on which lens series is the best. The non-C single anti-reflective coating lenses seem to be the “worst”, but the optical difference between the K/L and C lenses is not so clear. Some commentators have indicated that the C series had poor quality control, whereas the K/L lenses–being optically the same–are better by virtue of better quality control.
Original
Single anti-reflective coated lenses released in 1970 with the original Pro
NB
These lenses are optically identical to the original lenses, but have a newer barrel design (NB) that matches the later C lenses. They only were produced briefly and are comparatively rare on the market.
C
C, apparently, stands for “Design Improvement”. These lenses are multi-coated. Released with the Pro-S in 1974. Has a “C” on the front name ring.
K/L
Most recent. These lenses are, apparently, a slightly newer design with better coatings than the C lenses. The K/L is a code to indicate which bodies the lenses are compatible with. K indicates the Pro/Pro-S bodies and L indicates the Pro-SD bodies. KL lenses all shipped with an adapter attached to the lens so that they can be mounted to Pro-SD bodies. This adapter should be removed to mount to Pro/Pro-S bodies. This adapter is a fairly simple rubber O-ring for light sealing rather than for any mechanical reason. I, personally, have not had any issues using C lenses on my Pro-SD body without the small adapter ring.
Has a “K/L” on front of the barrel.
L lenses
Compatible with Pro-SD *only*; these are the 75mm Shift lens and 500mm APO only.
APO/L
Apochromatically corrected lenses. Sometimes known as A lens. More expensive, heavier, but chromatic aberrations are better corrected.
eBay Links
Hi, this site costs money to run! These are eBay affiliate links so I get money if you buy something. Hooray!
Listings from eBay
Mamiya RB67 90mm F3.8 Sekor C Lens 90/3.8 RB-67 #284
 | $94.00 End Date: Thursday Apr-30-2020 13:21:25 PDT Buy It Now for only: $94.00 Buy It Now | Add to watch list |
Mamiya Sekor C 50mm f/4.5 Prime Lens for RB67
 | $99.99 (0 Bids) End Date: Thursday Apr-9-2020 13:40:12 PDT Bid now | Add to watch list |
[AS IS] Mamiya Sekor C 90mm f/3.8 Lens For RB67 Pro S SD #118367
 | $65.00 End Date: Saturday Apr-18-2020 12:28:32 PDT Buy It Now for only: $65.00 Buy It Now | Add to watch list |
| Length (mm) | Maximum Aperture | Generation | Angle of View (in degrees) | Weight (g) | Details | Notes |
|---|---|---|---|---|---|---|
| 37 | f4.5 | C | 180 | 1240 | Details | fisheye distortion |
| 50 | f4.5 | C | 82 | 960 | More details | |
| 50 | f4.5 | Original | 82 | 960 | Details | |
| 65 | f4.5 | C | 0 | |||
| 65 | f4.5 | Original | 68 | 840 | Details | |
| 65 | f4 | K/L | 68 | 1070 | Details | This is a new, different optical design than the earlier original and C 65mm lenses |
| 75 | f3.5 | K/L | 61 | 980 | Details | |
| 75 | f4.5 | S/L | 61 | 1700 | Details | |
| 90 | f3.8 | C | 52 | 0 | ||
| 90 | f3.5 | K/L | 52 | 960 | More details | |
| 90 | f3.8 | NB | 52 | 0 | ||
| 90 | f3.8 | Original | 52 | 705 | Details | |
| 100 | f5.2 | C | 47 | 1660 | Details | 100mm-200mm Zoom |
| 127 | f3.8 | C | 39 | 0 | ||
| 127 | f3.8 | Original | 38 | 655 | Details | |
| 127 | f3.5 | K/L | 39 | 780 | More details | |
| 140 | f4.5 | C | 36 | 800 | Details | Macro lenses with floating element to adjust plane of focus curvature. |
| 150 | f3.5 | K/L | 33 | 840 | Details | |
| 150 | f4 | C | 33 | 790 | Details | Soft focus lens |
| 180 | f4.5 | K/L | 28 | 900 | More details | |
| 180 | f4.5 | C | 28 | 0 | Details | |
| 180 | f4.5 | Original | 28 | 875 | Details | |
| 210 | f4.5 | APO/L | 24 | 1020 | More details | Apochromatic correction |
| 250 | f4.5 | Original | 20 | 1310 | Details | |
| 250 | f4.5 | APO/L | 21 | 1370 | More details | Apochromatic correction |
| 250 | f4.5 | K/L | 20 | 1130 | More details | |
| 250 | f4.5 | C | 21 | 1020 | Details | |
| 350 | f5.6 | APO/L | 15 | 1440 | Details | |
| 360 | f6.3 | Original | 14 | 1360 | Details | |
| 360 | f6.3 | C | 14 | 1040 | Details | |
| 360 | F6 | K/L | ? | 0 | Details | |
| 500 | f8 | C | 10 | 1980 | Details | |
| 500 | f6 | APO/L | 10 | 2360 | Details |
Lens Accesories
Auto Extension Tubes
Two extension tubes–for use in close up photography–were produced, the No. 1 (45mm) and No. 2 (82mm).
Extension tubes were produced for the Pro and Pro-S and a different model for the Pro-SD. The Pro-SD extension tubes fit the larger lens throat of the Pro-SD body. Because of this the Pro-SD extension tubes do not fit on Pro or Pro-S bodies.
Bibliography
Mamiya Corporate Website
DiSante, T. (1981). How to Select & Use Medium-Format Cameras. HP photobooks. Tucson, AZ: H.P. Books.
Introduction
37 Comments
Thanks for the informative and nicely designed site.
I wonder if you could also add a note on the lenses marked as “A” (in addition to others); like K/L A.
The answer is “yes” to “Extension tubes were produced for the Pro and Pro-S and a different model for the Pro-SD.” The SD extension tube will not fit on the Pro.
Thanks for the info. Recently I have acquired a Pro with 2 90mm lenses, on NB and the other not. Yours was the only explanation I’ve found for this abbreviation.
Just received a c 50mm lens the rest of my lenses are Kl so I am not use to C lenses and I have a question.
On the base of the lens there is a dial labled M and N – is the the miror lockup – how does it work?
That is correct. I added a description of how to use mirror up mode to the Using page. I hope that answers your question!
Hey…thanks for the info on the rubber ring on KL lenses. Had just bought an RB No. 2 extension tube and it wouldn’t fit until I simply slid off the ring. Works perfect now!
Thanks for the information. I just bought a mint 65mm 4.5 I was basically just looking to see if there was anything wider than the 50mm.
There is the 37mm fisheye, https://rb67.helluin.org/lenses/c-37mm-f4-5/
Have you ever has any trouble removing the 65mm from the camera, the reason I ask is because I have a 65mm mamiya lens on a rb67 pro-s body and have been unable to remove it, any suggestions. Thanks in advance for any kind of help.
Not personally, but there is a manual override, see https://www.photo.net/discuss/threads/pics-of-paperclip-trick-for-removing-lens-from-rb67-with-a-jammed-cocking-lever.437516/
I have search many websites, i found ONLY at this site, that Sekor C 50mm has filter 80mm.
Other sources suggest, that 50mm C has 77m.
I make some plans to B/W photography, it is important for me.
What is correct information?
My apologies, I had it wrong. The 50mm C definitely has a 77mm filter. Thanks for catching the error!
I reply myself.
I;m almost sure, focusing screens are compatible Pro/S/SD, but in years of “SD” have different marketing names.
i have a Mamiya RB67 Pro SD.
i would like to ask if i can use this lens —- Mamiya Shift C 50mm F4 to my RB67 Pro SD.
Thanks
No. The Mamiya Shift C 50mm is a lens for the Mamiya 645 series. There is no compatibility between the 645 and the RB67. The only shift lens offered for the RB67 is the 75mm f4.5 S/L
Pingback: Lots of firsts – and a fail | Jonathan Gazeley
I just received a sekor c 100-200mm lense for my mamiya pro s. It came with an adpater ring. How does one safely remove the ring?
Thanks
Fred
There is nothing special, just gently pull.
Great website, it’s been very helpful as I begin learning about my new RB67. Just a note, there is a 127mm f/3.8 Sekor NB lens. I don’t have any details as to weight and etc., but I have one sitting on my camera so I know it exists!
Nice table! Great info in a single location.
I’d add the fiter size of each lens and the proper Mamiya lens hood for them.
Thanks!
There are (at lest) two versions of distance scale plate on Pro-SD bodies – later were added curves for 210, 150 and 110mm lenses.
Do you have any idea about 110mm RB lens? Maybe there were some (later cancelled) plans to do it?
I’m wondering about buying a Pro SD body and want to know if the “C” lenses will fit OK and are there any problems with using them in an SD body.
Do you loose any functionality ?
Thanks
Martin
All lenses will fit SD body, but you SHOULD have adapter ring on them. Not critical piece, but feels better and lines up the lens in the mount perfectly before locking ring is swung over (but same can safely be done without the ring, just take it slow). KL lenses where originally supplied with the ring as they were introduced with SD body, but many KL lenses on used market do NOT come with the ring and ring can run up to 20-25 bucks easily. All the same you may find an older lens with the ring on it. Ring itself slips off fairly easily so it can be moved from lens to lens in case you only have one.
Also, if you need to use extension rings, there were 2 types produced. The earlier fits all bodies, but the later SD model will ONLY fit SD body as in this case, they were made with larger tube diameter without any compensating rings. So a lens will mount on older extension ring WITHOUT adapter ring, but that same older ring should have the ring to mount on SD body. I would add that in such a case the ring is far more important as the longer lens/ring assembly exerts more downward pressure on the mount and ring helps distribute that pressure more evenly around bottom the mount.
All lenses function the same on all bodies in a mechanical sense so no, you will not loose anything from that perspective.
I have a couple of non C lenses for a Mamiya RB67 (50mm, 90mm 127mm and 180mm) and one C-lens (180mm). Unfortunatelly I don’t have a RB67 camera because I only used the lenses with a 4×5″ camera with a DSLR-back. So I did not ever need the shutter of the lenses.
Now I would like to sell all lenses on eBay but I don’t know exactly how to check if the shutter is still working. I don’t want to sell the lenses as working before I know that they are.
So far I checked the shutter by cocking the two pins on the back of the lenses to the red/green dots an then move the two pins to the other end of the slot (of course after releasing the tiny pin on the back of the lens). The shutter releases imediatelly and I think it is working.
But my two 180mm lenses (the non-C and the C-lens) have a short delay of about half a second. Normally I would have guessed that the shutter is not working propely but both 180mm lenses act the same way.
Maybe someone knows something about this phenomenon. Any help would be much apreciated.
I am have a hard time finding a 75mm L shift lens for the ProSD. Find em all over for the RZ but not the RB.
Any leads would be appreciated.
Hi, I was wondering if anyone could explain in detail (step by step) how to focus and use the K/L lens Floating System ring on the 90mm and 65mm K/L lenses? Many thanks for any help or advice.
Pietro
Thanks the all the work you put into this. This has been very useful in choosing my lens kit. Please keep up the good work.
Pietro:
1. Focus on subject as you please
2. Read distance off from side plate
3. Adjust floating ring to match that distance
For critical focusing, after step 3 repeat from 1 again, just to ensure you got the best of it (in macro work you may notice small adjustment again)
This is very useful, thank you for the reference! I would also like to know the “filter size” of each lens. Are they fairly standard?
They are fairly standard. The details page for each lens should have the filter size, generally 77mm.
Thank you very much for this informative Mamiya site.
Have with her help my lenses much better known and could eliminate some errors or dirt.
Also the light seals of the camera (RB67proSD-rotation) could be renewed with your help.
The Japanese Seal Supplier provides exquisite quality.
Yours sincerely …… FILMFRITZE
Hi, I have an RB67 Pro SD, the 90mm K/L lens when in place on the camera is wobbly on the section adjacent to the locking collar, it is the same if I try it with just the end cap in place, is this normal ?, the other two lenses I have 127mm and 180mm are fine, no movement at all, any suggestions chaps.
Thank you.
Peter.
No, a wobbly lens is not normal. Options are to buy another one, have it repaired, or simply use your 127mm lens in its place, the focal lengths are not very different.
So I’m a bit confused. If I get a Pro SD body, will I be limited to a certain kind of lenses (of which there are more of or are better) ? Like the C lenses ?
Actually, the opposite. The Pro-SD is compatible with every single lens in the system. Pro and Pro-S bodies are compatible with all lenses except the 75mm Shift lens and 500mm APO only. Some of the newer K/L lenses have a small metal collar that is easily removed if trying to use them on an older body.
Pro-SD is definitely the preferred body, even if you don’t plan on using either of those two exclusive lenses.
Hi
I want to know what means ”A” on K/L lens?
Regards
I think you are looking for
Hey I recently purchased a 65 mm sekor original lens and was told that they do not separate? Is this true?