Queer Tamron Adaptall-2 question

[xkaes]

I have three Adaptall-2 mounts for Minolta. Only two have packages marked Adaptall-2 even though the mounts themselves are all marked Adaptall-2. That's odd, but I can handle it.

The top box is what it should be -- Minolta-MD -- and the mount looks as it should with f-stops from f1.4 to f32.

The second box is marked Minolta-MD-L, and the mount is identical to the one in box #1. I've never seen a Minolta MD labelled MD-L. Anyone have any idea what that might mean? I know Minolta made some tele-converters that were marked "-L" meaning they were designed for lenses that were 300mm or longer, but that makes no sense with a lens mount.

The third box is even weirder. It is marked for lenses with maximum apertures of f2.8 and f5.6 -- not f2.0 or f2.5 or f3.5 or f4 or f4.5 or f8 -- and the mount itself has an additional sticker saying the same thing. The only other difference I can see in the mount is that the f-stops only go to f2. There is no f1.4 setting, as with the other two mounts. I'm not familiar with all of Tamron's Adaptall-2 lenses, but I assume they have other lenses -- than the four listed on the box -- that have maximum apertures of f2.8 or f5.6, nor can I think of a reason why they would do this. And why would a normal Adaptall-2 mount, like #1 and #2 not work on these four f2.8 and f5.6 lenses?

Does anyone have any explanation for this wacky mystery?

 

[loccdor]

MD-L is the same mount, it's a line of lenses with cheaper and lighter construction without the Rokkor name.

The custom mount specifies f/2.8 and f/5.6 lenses because that's necessary for the in-camera metering to be correct. The mount needed to communicate the maximum and minimum aperture and this wasn't possible in a one-size-fits-all solution.

As far as the first and second ones without labelled aperture, it's possible they're not communicating max/min aperture to the camera at all, and the camera would make an assumption that might cause incorrect metering.

 

[xkaes]

Are you saying that Minolta made a line a MD lenses labeled "MD-L" without the Rokkor name? Even if that's true, Minolta never made lenses that needed a Tamron Adaptall lens mount.

If you are saying that Tamron made cheaper lenses to fit on Minolta cameras, why would they need a different Adaptall lens mount. I have both lens mounts and they look identical to me.

Each of the Adaptall lenses mounts have the exact same range of f-stops from f1.4 to f32. The only one that is different is the one marked for the four f2.8 and f5.6 lenses. That mount runs from f2 to f32. It does not stop at f5.6 or f2.8. And besides, the 35-80mm lens marked on the box is a f2.8/3.5 optic.

All of the mounts are Minolta MD mounts. They not only communicate the set f-stop to the camera meter with an MC tab, they press the MD tab on camera to set the minimum f-stop of the lens (f16/f22/f32).

 

[loccdor]

Sorry my answer was a bit off.

MD-L stands for the Late MD mount. The bayonet is the same. Aperture coupling geometry changed slightly. It's for Program and Shutter Priority modes for later cameras like the X-700.

So what Tamron is saying with MD-L is that it's fully compatible with the metering/aperture of the later cameras in that mount.

Minolta bodies that require MD-L (late MD)​

X-series (Program-capable and late models)​

• X-700
• X-500 (X-570 in North America)
• X-300 (X-370 in North America)
• X-300s / X-370s
• X-7A
• X-9

---

Bodies that do not require MD-L (early MD is sufficient)​

These cameras predate the late MD change and do not have Program mode:

• XD / XD-11 / XD-7
• XG-M
• XG-9
• XG-7
• XG-1
• XE / XE-7
• SR-T series (MC lenses era)

They will usually mount and work with MD-L lenses, but they do not need MD-L.