These notes are evolving, and will be improved but are worth publishing now, as they may help others pursuing functional Mamiya Press camera kits.
Mamiya G-Adapter for Mamiya Press Cameras
The Mamiya G-adapter for Mamiya Universal Press allows use of Graflok backs on the Mamiya Press cameras, such as the 23, the Super 23, and the Universal Press.
In those days (back in 1950s and 1960s), even manufactured “standards” were not completely standardized. For example, Horseman brand “Graflok” backs manufactured for Horseman cameras will need a modification in order to fit on the Mamiya G-adapter, eventhough they were advertized as compatible with the standard.
The best approach involves a modification to the G adapter instead of the Horseman back, however. The mod to the Mamiya G adapter does not alter the behavior of the adapter when used with Mamiya backs, but accommodates the Horseman backs, without requiring any modification to the Horseman back.
It’s a slight resizing of a small bar that supports the back on the camera.
While I’m not a fan of any mods to vintage gear, in this case, it’s not much of a crime to alter a lip (or edge rail) on a G adapter, in order to gain use of excellent Horseman backs on Mamiya Universal and Press cameras. but I will still only do it to a well-used G adapter (and not my “near mint” specimens).
I’ll detail the G-adapter mod here in the future, if anyone is interested. I don’t need it myself for my Mamiya Press kit, because I have adequate other working film backs for 6×7 and 6×9, but I would like to use my Horseman backs on a Dora Goodman box camera (which utilizes Mamiya Press lenses) — the subject of another post for another day.
Choosing Film Backs for Mamiya Press Cameras for 6×9, 6×7, 6×6, and 6×4.5 Film Negatives
You may encounter Graflex, Graflok, or “Graphic” roll film backs for thedse older cameras.
Original Graflok backs had winder knobs, instead of wind levers or cranks. The slightly more modern Graflex “Rapid-Vance” (for “rapid advance”) roll holders have a color coded wind lever:
- Graflok w/Blue wind lever (RH-10 for 6×7 2 1/4 x 2 3/4)
- Graflok w/Red wind lever (RH-8 for 6×9 2 1/4 x3 1/4)
- Graflok w/Green wind lever (RH-12 for 6×6 2 1/4 x 2 1/4)
I note that the film back shells and winders are sometimes said to be interchangable between Graflex and Graflok backs, and it is reportedly common to encounter new/old shells paired with various winders, when rummaging through used photography gear bags and boxes of accessories. On the other hand, this excellent web page on 4×5 cameras and 120 film backs reports the contrary — that Graflex film carriers are NOT compatible with Graflok film backs.
Forum discussions have previously noted other subtle but important details that differentiate Mamiya, Horseman, Graflok, Singer-badged, or other “interchangeable” film backs:
“These are later backs that are lever wind, and usually contain the pin rollers to hold the film flatter. These are high quality backs. They are definitely less common than the “23 Graphic” 6×9 backs as well as all of the Graflex 6×7 backs.
Research and practical experience are essential ingredients for successful vintage film camera photography!
– me
The mention of pin rollers added to the Rapid-Vance roll film backs supports claims that these more recent backs were designed to support thinner 120 films, while still keeping the film suitably flat.
I would consider it very helpful to know that one brand or style of film back does a better job of maintaining a flat film inside the camera. This is especially true today (2023) when we have new films coming out that are rebranded with unique names, and which in many cases are on thinner substrates than was standard back when these cameras were new.
I certainly appreciate the extreme value held in the specialized equipment forums (I hope they never go away!).
Additional Note: See details of Mamiya RB 6×8 motorized back, said to fit the Mamiya Press with G-Adapter, modified. The RB back fits on Mamiya G adapter only if you remove “2 small pieces that aren’t needed”.
This thicker, heavier motorized back also creates a viewing challenge for photographers reliant on the built-in viewfinder eyepiece on the Mamiya Press. It’s too short, while the back sticks out more than the standard Mamiya “S” curve film backs do.
Mamiya offered an eyepiece extender for those using thicker film backs like the motorized ones. This Mamiya accessory is very rare. It has been reported that very few were ever made/sold, because it was a device intended to support photogaphers who already had sets of other brands’ film backs but who might try the Mamiya press camera — and not that many did. In 3+ years of scavaging Mamiya gear, I have only come across one eyepiece extender, and it was almost completely fogged, with some fungus, and expensive due to rarity.
Many photographers use dedicated auxiliary finders mounted on the top of the Mamiya Press, when using lenses other than the 100-127-150 mm lenses for which the built in finder was calibrated. This eliminates the need for an eyepiece extender.
https://www.photo.net/discuss/threads/graflex-6×9-plastic-handle-film-back-rare.5513848/