On this page

Tamrons' Adaptall System

About Adaptall

example tamron adaptall-2 lenses and mounts

The Adaptall system was created by Tamron in the 1970's to allow its lenses to be interchangeable between the camera mounts of the major manufacturers. The first adaptall lens range was updated in 1979 with the adaptall-2 range and "SP" lenses, the quality of these in particular gave the adaptalls a reputation that continues to this day. Production of the last adaptall lenses only ceased about ten years ago, manual focus finally giving way to autofocus (all the adaptalls are exclusively MF, the adaptall system could not be adapted to include AF).
The pic shows two lenses so you can see the identical base to the lens, and 3 mounts: (L to R) Pentax (PK-A), Contax (C-Y), Canon (C-FD).

magnifying-glass-icon-40 (1K) list of adaptall mounts from user manual c. 1980's
Note that the majority of manufacturers have changed their bayonets since the 70's so, for example, these Canon and Contax-Yashica mounts only fit on film cameras of the era. Pentax are an exception: this mount will fit the lens and work on current Pentax DSLR's. This page from an original user manual that accompanied an AD-2 SP lens lists the mounts available at the time (1980's).

So to figure out how to mount a Tamron Adaptall lens on your digital interchangeable lens camera read on.

Mounting the lenses

First a relevant mount must be attached to the lens. Relevant mounts are:

For new adapters look for third party adapters that have been manufactured to fill the gap in the market. eBay (Cameras & Photography > Lenses & Filters > Lens Adapters, Mounts & Tubes), Amazon and photographic shops can all supply these.

In summary there are few cameras for which a mount doesn't exist, either one of the original ones or a new third party adapter that's filled the gap in the market. I give more detail below.

Putting the mount on the lens

green dots to align adaptall mount with lens

On first acquaintance many find the mounts a bit of a faff (if you would like a video explanation I can refer you to Joshua Khoo's blog).

  1. The first essential step is to make sure the lens aperture is WIDE OPEN (spin the aperture ring round to the smallest F number).
  2. Now look for small green dots (pics) on the mount and the lens.
  3. Place the mount into position against the lens base with the green dots lined up.
  4. Note any tabs (see top pic above) that overlap the end of the lens, these must line up with shallow slots on the lens aperture ring. They can normally be eased into proper position (P-KA, C-FD... mounts: you may need to press the auto aperture button mentioned below).
  5. Twist the silver base with a serrated edge clockwise: should rotate smoothly, no great force, and then click as the release mechanism engages.
Mounts are slightly different, but a similar procedure is followed with all of them.

Removing the Mount

Removing the mount is the reverse: aperture wide open, depress small silver release lever on the side of the lens (pointed out with little red arrows in the pic above ), AE button adaptall-2 mounts rotate anti-clockwise.

Auto Aperture Button

In the case of the Pentax PK-A and Canon CFD AD-2 mounts there is also a small black press button (green arrow in pics) on the rim of the mount that locks/unlocks the aperture ring into AE/f32 auto-aperture position. Press this to lock the mount into AE mode, and to unlock to move to wide open aperture to detach the mount.

Using the Lenses

These adaptall lenses are not electrical and don't have motors or data chips in them. They are legacy lenses from the days of manual focus film slr's. So it's more work, learning good MF techniques for your particular camera, and figuring out which exposure modes to use, but the good news is the effort will make you a better photographer. The details depend on your particular camera model. Study your user manual (I owned my Lumix G1 for a while before figuring out the magnified focus assist mode - duh!) and look for (lots of) helpful information on line. This is a good manual focus advice page here and there are many more.

For Pentax KAF-mount dslr's (and the Samsung rebadged pentaxes), the ins and outs are essentially the same as for using Pentax SMC "K", "M" and "A" lenses, depending on the mount used see these pages.

More About the Mounts


pentaxM42-200 (50K) M42 (AKA Pentax M42, Pentax Universal) refers to a screw threaded mount that was widely used up to the 1970's. An M42 mount is very handy because just about all interchangeable lens cameras1 offer some sort of M42 adapter. So you can set up as follows:
Lens > M42 mount > M42 adapter > Camera.
M42 adapters are usually very cheap, and of course they can also be used with fixed M42 mount lenses.
However there can be a technical issue with the closing of the iris in the lens (ie stopping down). The Tamron M42 mount has a small pin sticking out. If the cameras' M42 adapter doesn't depress this pin - the iris won't close down to the f-stop you have chosen with the aperture ring (more info about M42 mount lenses and the auto aperture pin here).
Remedy: a quick "mod". The pic shows an M42 mount with a short bit of sleeve (a few mm cut off the end of a cheap ballpoint pen ink tube works well), arrowed, holding the pin in.
It's also worth noting that the first generation adaptall lenses have a manual A-M switch with which to close the iris.
1Nikon users should note that Nikons will not focus to infinity with M42 mounts unless the M42 to Nikon adapter has optical correction.

Adaptall-1 vs Adaptall-2 (vs third party new ones)

This is one area of distinct confusion: differences between the first generation Adaptall and the later Adaptall-2 lenses and mounts. Its a bit complicated because Tamron were trying to keep pace with changes being introduced by the camera manufacturers. However there were no fundamental changes in camera mount bayonets at the time so all AD-1 and AD-2 mounts for a particular manufacturer can actually fit the camera bayonet.

Tamron adaptall mount variants for Pentax magnifying-glass-icon-40 (1K)

Pentax Mounts

The mounts available for Pentax are:
  1. A first generation manual P-KM mount, easily distinguished from the later P-KM mount by the lack of a black flange with f numbers on, and only one tab. On camera the lenses operate in the same manner as "K" and "M" series manual focus Pentax lenses. On DSLR that means "green button" metering in M-mode, Av mode wide open only. The only loss of function relative to the later mount is when used on certain pentax film cameras (KX, MX, LX) of the era with an f-stop viewing window. The later mount with the f-stop flange lets you to see the f-stop in the viewfinder.
  2. A later/AD-2 PK-M mount with two tabs, this has the black flange with the f numbers on and works with all my lenses in the same manner as the previous one.
  3. A P-KA mount with two tabs. Note the electrical contacts, and no flange with f numbers on. This also works with all my adaptall lenses. When set on AE/F32 (press the auto button to click into AE/f32 and lock) the lenses operate in the same manner as Pentax "A" lenses: aperture is set on the camera using the speed/aperture dial, automatic modes Av, P, Tv can be used and the camera will record the F stop in the EXIF data. Sometimes there are exposure issues/inconsistencies - see links below.
    One technical point to note: the PKA mounts don't recognise the slow lenses like the 300mm f5.6's, the 200-500mm's correctly: your Pentax DSLR will display f4 (but will otherwise mostly work the same). This can be corrected with a small piece of insulating tape see here. They also read the f2.5 lenses like the 24mm 01B/BB and 28mm 02B as f2.4, and the 80-210mm f3.8 zooms (03A/103A) as f4.
    PKA not working? A quick fix is often to scratch the small screw head (arrowed in pic above) nearest to the electrical contacts on the mount. This is rubbing against one of the electrical contacts on the camera and can have poor contact due to thread locker chemicals.
    With adaptall-1 1st generation adaptall lenses you have an additional option to achieve automatic aperture priority metering: you can use a PKM mount and then manually stop down in Av mode with the A-M switch present on all AD1 lenses.
  4. Finally there are new third party ones from China. These are manual with no aperture connection/lever. They are usually painted black (on the camera side), and on camera they make the adaptall lens operate like an M42 screw or swappable T-mount lens: M mode and stop-down metering with the green button OR stop-down Av mode. Which is good and versatile but there can be exposure issues in Av mode which are discussed in detail on my using MF lenses on Pentax pages. One user remarks on a forum "With no mechanism at all, they are more flexible in use than the original adapters, and nothing to break". Point.

danger-25 (1K)Note: the Adaptall Ricoh RI mount is also K-mount fitting but should be AVOIDED for use (unmodified) on Pentax DSLR's because of the "ricoh pin". The location of this on the mount means it passes over the hole for the AF mechanism on the camera mount as the mount+lens is rotated into position and will spring into the space. If the pin is the longer pointy variety the mount+lens may then be difficult to remove!
A fix to use an RI mount on pentax is to epoxy the pin in.

For more discussion on using PKA mounts see links below.

Tamron adaptall mount variants for Nikon magnifying-glass-icon-40 (1K)

Nikon Mounts

danger-25 (1K) Important: Nikon DSLR compatibility with older f-mount lenses is not straightforward, and some combinations, specifically non-AI mounts, can damage a DSLR. Not being a Nikon user I can't be more specific. See here and this mflenses forum discussion for more info. The issue is most specifically with the design of the aperture ring on older Nikon lenses. As far as these adaptall mounts are concerned, I do not believe there is any problem with the mechanical fit of any of them.
Moreover, some Nikon DSLR models are designed to only operate fully with "chipped" lenses with electrical connections, for example models D40, D40X, D60, D80, D3000, D3100, D3200, D3300, D5000, D5100, D5200, D5300 etc. Lenses without a chip and contacts can be mounted and pictures taken but the only mode available is manual, without metering. Check your model, user manual and Nikon online information. The best mount to try with those Nikon models is the last one illustrated with "AF chip".

The very first adaptall mounts (1, 2) for Nikon were the F mount with the "rabbits ears/prongs" for the early mechanical aperture coupling, and had one tab linking to the aperture ring on the lens. These fit fine on DSLR, manual operation only. If there is a reason to prefer either the upturned rim one (1) or the flat one (2) I am not aware of it. No 3 then is an "AI" aperture coupling Adaptall-1 mount with two tabs. No 4 is Adaptall-2 (font style of the labelling is distinctive) with two tabs but basically the same. All these later AI/AIS mounts can be found with or without ears. Nos. 5 (without ears) and 6 (with ears) are labelled AI but are in fact the AIS variant with a cutout in the flange (the wee "scoop" at the quarter-to position). New third party ones (7), both with or without the "dandelion chip AF confirm" contacts, appear to be manual with no mechanical aperture connections.

My understanding from reading around online is that the AI mounts will provide mechanical meter coupling with Nikon cameras (and Fuji slr's) that have/use AI mechanical methods of meter coupling (eg the D200, D300, D700, D1, D1X, D2X, D3, D4, Fuji S3, S4, S5.. etc.). The "rabbit's ears" are needed for meter coupling on the early (film) Nikon bodies such as the F, F2, and most Nikkormats.
For more on the distinction between the Ai and AIS variants see here. One reason you might want to prefer an AIS mount is it is more technically suitable for DIY rechipping, see links below.

Adaptall on Canon (and other) DSLR's

As already mentioned most original Canon adaptall mounts are for the C-FD mount which was discontinued in the eighties, and original tamron eos-m mounts are rare. Third party adaptall to eos-m mounts however are now plentiful.
I am not a Canon user myself so I am indebted to Mateusz (PhantomLord) on MFlenses for specific insight (original thread here).

  1. The CFD mount is of little use (except on CFD film bodies and CSC cameras), there are adapters for this mount but a compensation element is required with loss of image quality (and one stop).
  2. The main solutions then are: Tamron+AD-M42 mount + M42-EOS adapter; or direct Tamron Adaptall-EOS. No optical adaption with its compromises.
  3. Tamron Adaptall to EOS adapters are not the best solution in my opinion.
  4. In my opinion original Tamron-M42 and M42-EOS is more reliable solution and M42-EOS adapters are cheap as peanuts.
  5. For AF confirm, I would suggest buying adapters with EMF Confirmation chip, which allows you to set focus confirmation microadjustment within adapter. From experience, some lenses confirm focus straight away on perfect spot, but most of them need a little microregulation to adjust focus confirmation. You could do micro regulation in some Canon bodies, but on 600d it's impossible, that's why I prefer EMF chips. What's more, you could write into the chip focal length and max aperture of the lens, so those values will show in EXIF files (another useful feature in my opinion).
  6. In connection to focus confirmation... I was thinking it's good idea and it would work great, but well... truth is, it's not a reliable solution. All in all I ended up with focusing on LiveView with LCD Loupe for better camera stability and better view in strong light. In addition I installed Magic Lantern for Canon firmware which gave a few useful features when manually focusing (like 5x or 10x magnification when you press the shutter button halfway). This is reliable and almost 100% sure way of focus for me.

Sony is similar; the old MD mounts are of little use, the options are a straight to adaptall adapter, or M42 to Sony A adapter with an M42 mount used on the lens. I recommend Sony users to peruse this article posted on Flickr - Sony Alpha user group by Minolta/Sony veteran Arkku.

Other Cameras

For other camera/mount combinations I don't know more than is indicated above. My general impression is that it depends on the camera, but often there isn't any difference in operation or fit, particularly when using to mount on digital. The link below to Matts Classic cameras page provides some more information.

Why Bother if it's a Faff?

These lens have been superceded by modern lenses, computer designed with chips, autofocus, data connection to the camera so that exposure can be precisely automated.
Superceded but not obsolete!
Because lenses that can produce good Image Quality shall never be obsolete. Test any of the good tamrons against a typical kit lens and the comparison is normally favourable to the Tamron.
And thats before we start talking ££. This is about acquiring worthwhile, interesting or historic lenses of real quality for a fraction of the price of new ones. I acquired numerous lenses for my adaptall collection for a tenner or even less! See the lens list (link above) for an indication of the choice ones.

Useful Links/More Info

Adaptall-2.com (link at the top of the page) is home base (note that there has been some to and fro-ing of the domain name so you might encounter some old content or different cached content under both .com and .org).
Scans of lens user manuals - see lens list page.

Pentax PKA mount


Search terms: Tamron Adaptall lens - tamron adaptall-2 - adaptall information - adaptall mounts - mounting adaptall lenses

Contents by Marcus Brown, Copyright 2013 updated 17 November 2016.
     2CONTACT: PM me on pentaxforums.com or mflenses.com username marcusBMG