[tjk911]

Guess what I found?

A Tamron Adaptall 300mm f/2.8 and an Adaptall 2x teleconverter. Both just lying about on a storeroom where I work.

So I'm looking for an Adaptall adapter (that's fun to say).

They're quite costly on e-bay, and I'm not sure if adaptall 1 adapters work with adaptall 2 lenses and all that, so I'm relying on the knowledge of wise forumers here for that.

I don't know the average price for them, so just let me know what you think is fair. I've been trying to sell lenses for some of my basic expenses, but I don't mind starving a little if it means I can use a 300mm f/2.8 with that teleconverter.

[excanonfd]

That's a great find, congrats! There is a PK/A adapter for sale on the Marketplace and the price is average but the picture show the adapter to be in better than average condition. And yes, you only need one adapter for the 300/2.8 + 01F TC combo.

Thanks,

[duncsuss]

To get full use of the lens (P, Av, etc, modes) you will need an Adaptall-2 PK/A adapter like the one excanonfd refers to. These do get expensive - I paid around $90 each for the ones I got from eBay a few years ago.

If you only want/need M exposure mode, both original Tamron and 3rd party PK adapters are available much cheaper (often below $20).

For the lens you've found (and I am envious!) the PK/A adapter is the way I'd go. If you had one of the mirror lenses (fixed f/8) it would be pointless paying the extra.

BTW, which version of the 300/2.8 is it? I think Tamron made 3 models, 107B, 60B and 360B - getting progressively better optical performance with each revision.

Best regards,

Duncan

[tjk911]

Just checked and it's the 360B, is that a good one or...?

Also, any idea how I can remove the teleconverter? I mounted it on in curiosity (before I even knew what that lens was, never seen an adaptall) and can't seem to get it off.

And and! The aperture of the teleconverter does not align with the aperture of the lens (lens set at f2.8, teleconverter showing f8).

[duncsuss]

The best source of data on Adaptall lenses I know of is adaptall-2.org -- THIS LINK takes you to the page for the model 360B ...

Overall optical performance is "best in class" when compared to other similarly priced 300mm F/2.8 lenses.

Sounds pretty good to me!

Attaching and detaching the 2x converter (and the mount adapter when you get one) should never be a struggle, but if you don't know the technique it can become one. I once had a link to a PDF of the manual pages showing how to do it, maybe a Google search will find one.

Whatever you do, don't force it!


... here's a low-res shot of the manual pages ... http://www.flickr.com/photos/nesster/415470981/

... and here's a good informative post ... https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/101240-adaptal...ml#post1040982

[excanonfd]

Just checked and it's the 360B, is that a good one or...?

Also, any idea how I can remove the teleconverter? I mounted it on in curiosity (before I even knew what that lens was, never seen an adaptall) and can't seem to get it off.

And and! The aperture of the teleconverter does not align with the aperture of the lens (lens set at f2.8, teleconverter showing f8).

You have the best of the lot with 360B. In order to mount or dismount the TC or the PK/A or PK/M adapter, the lens' aperture has to be moved to the widest (f2.8) setting. The TC should show f5.6 as the focal length is doubled, you lose 2 stops of maximum aperture. If the TC shows f8.0 instead of f5.6, it may be caused by improper mounting of the TC to the lens. Once you start mounting the TC or the Adaptall-2 mounts, it should be mostly problem free.

Hope this helps,