I think it was ingeneous and inspired. Rather than make and require sellers to stock the same lenses in different mounts, make lenses that can be fitted with the mounts for the various camera types. Is that not brilliant?
I can’t really explain the history and variations better than it’s already been done here on the excellent medium format home page. But I can do something else, and that is tell you what the manual says regarding the different adapters. My New Old Stock Ricoh XR-P adapter came with a generic manual meant to be inserted in any of several of the Adaptall Custom Mount boxes (which were themselves simply stamped with the relevant mount type). The most important thing to remember is to open to max aperture before mounting or unmounting the adapter, then align the green dots and if necessary the tab(s) to the slot(s) and turn the adapter clockwise to lock. To unlock press the silver tab, hold the lens and aperture ring firmly and twist the adapter counterclockwise. It does take a little practice.
Pentax KA notes: Meant to work with Pentax A series cameras. While most Tamron lenses have a minimum aperture of f32, due to ‘Pentax design limitations’ the functional minimum working aperture of the lens will be f22 with Pentax A series cameras. The f/32 position will function as AE only. NOTE: for Tamron lenses with a max aperture of f4.5 or slower, use aperture priority AE or manual modes when a viewfinder-indicated aperture value is faster than the original max aperture to avoid accidental underexposure. Don’t ask me, that’s what the manual says.
Nikon AI notes: The Nikon adapter has its own aperture scale and so has a second tab that needs to align with a second slot on the lens when mounting.
Ricoh notes: Like the Nikon adapter, the Ricoh XR-P adapter has its own aperture scale and so has a second tab that needs to align with a second slot on the lens when mounting. It locks to AE on the f32 setting (releases with white button) and is compatible with the 16 exposure functions of the XR-P. It can also be used on other K mount cameras but not in any auto exposure capacity, manual exposure only. NOTE: for lenses with max aperture of f5.6 or slower, you can only use the following four modes — aperture priority AE, TTL manual metering, aperture priority auto-flash, TTL metering flash.
Konica notes: Special to the Konica adapter is a ring inside the adapter where you need to set the lens maximum aperture prior to fitting it to the lens. Loosen the two large thumbscrews (the slots are extra wide to accept a coin – this was before geeks like me carried their Leatherman everywhere) and move the scale so the pointer aligns with the line that leads to the max aperture. Then tighten the screws. If you’ll notice, there are set standards in the max aperture of the Tamron lenses, most of the basic primes open to f2.5. In other words its possible to have all f2.5 lenses and not ever have to change this setting. There is also a little round button on mine that seems to need to be pressed in conjunction with the silver tab when unmounting, this isn’t mentioned in the manual.
More importantly, the combination of adapter and lens may be too much for the weakish spring system on the Konica Autoreflex T3. I can use mine with my TC (best) and my T (works most of the time) but the T3 will cock and fire once, then prefire (fire upon cocking) the second time, every time, with the Adaptall-2 adapter and a lens. Works most of the time with the adapter alone but not when you add a lens. This is also a problem with the T3 with some other third party lenses if their aperture spring is too strong. IN FACT I went so far as to try and replace the spring in my adapter but that didn’t help. Oh well!
Pentax-ES (screw mount) notes: I thought ES must be for Exakta Screw, thinking that Exacta was affiliated with Praktica when Praktica came out with the M42 screw mount, but they weren’t, that wasn’t till much later that Exakta-branded Prakticas were briefly sold. So I figure this adapter must have came out at the time the Pentax model ES did (“Electro Spotmatic” according to a knowledgeable reader), it was I believe their first AE SLR and had M42 mount, even before the Pentax ME. ANYWAY it’s a pretty simple ring, with a spinning gear that sticks out in a lump on the side. The gear bump acts as a lever to help turn the ring on and off, while the gear itself keeps the inner ring indexed to the lens aperture. Best part? Auto aperture! Woo! Also, the box says it works with Adaptall, Adaptall-2, and SP lenses, I don’t know that any of my other adapters work with both Adaptall and Adaptall-2.
Contax/Yashica notes: According to the manual, like with the Konica adapter you need to set the maximum lens aperture before you mount the lens. You do this by loosening two screws and on the inner ring and sliding it over to line up the aperture indicator to match the maximum aperture on the lens you’re using it with. HOWEVER, I have in my posession a later (?) C/Y adapter that does not require this. So your mileage may vary depending on the one you find….
Minolta MD notes: Joke’s on us, it says Minolta MD but there’s no shutter coupling mechanism that would make this MD as opposed to MC. It would be obvious if it was, like on a MD 2x converter. Simple ring that on mine is kind of inconsistent, the way the aperture-pressing lever is coupled is pretty weak and doesn’t stop the lens down all the way. I’m figuring out how to modify it to work better.
- Comprehensive info at adaptall2.com, fantastic site!