Tamron SP 90mm

Hi
I have been given a fairly old Tamron SP lens its a 90mm Tele Macro F 2.5, i intend to use it on my old Pentax MV bu have been told it is incompatable with my MZ7 (Or is it compatable), i beleive the lens to be aleast 20 yrs old but is in perfect condition (never used) i know i have to get a Adaptor for this which is no prob, but my MV is aperture priority, so do i leave the lens aperture set on AE or do i use it like my normal M series lens and just turn the aperture ring until the green light comes on, anybody tell me where i can get a cheap K Mount Adatall 2 for this lens, at the moment its a Canon Mount any help gratfully recieved.

This lens is very highly thought of. Set an aperture just like an "M" lens and you can use aperture priority. If it has an "A" or "AE" setting it might be suitable for Shutter Priority with suitable cameras.

On an MV, the lens will function exactly like an M series except that the focussing ring will turn the opposite way to infinity.
It is indeed a superb lens and although you can't use the AE setting on the MV, I'd suggest looking for a KA mount as it'd probably cost the same (£10-15 or even less) and then be suitable for a more sophisticated camera such as the ME Super or Super A should you ever wish to use one.
Also, keep your eye open for a Tamron macro extender (gives 1:1 repro) and the SP flat-field 2x teleconverter - often available quite cheaply on eBay!
If you had all three, you'd have an excellent portrait/short tele lens with 1/2 life size repro capability, a high quality 200mm telephoto lens and the ability to reproduce an image at full 1:1 macro.

If you're not too familiar with the adaptall system, you can either leave the mount on the lens or fixed to the camera body. The SP extender and converters are universal (like the lenses) and do not have their own mounts. You'd fix the extender/converter onto the lens where the mount would usually be and then fix the mount between the converter and the camera body.
It sounds complicated but is actually very simply and works a treat.

I also have an old Tamron 90mm F2.5 and it gives first class results.
My Tamron Adaptall mount is PKA. I have tried this lens and mount on my Pentax MZ6 and it seems that all metering features ( symbols, AV, TV, Manual) work. I would think that the MZ7 would be the same.

Thanks every for the the replies, a am glad to read it will most prob work on my MZ7 but only in certain modes, you do hear a lot of stories where the manufactor say lens become stuck and won,t come off again but i guess they say this to get you to buy the makers lens instead of the independents, now i will get the adaptor and try my hand at close up, thanks again

It's probably worth mentioning that some lenses not necessarily designed for Pentax can actually get stuck on the mount. I think this applies particularly to some Ricoh lenses.

That's a very good point John and where possible I'd advise 'trying before buying' as well as simply examining the lens itself.
Obviously this can't be done when buying on-line but where used equipment is concerned, I like to ascertain exactly what camera it had been used with.
I've personally never had any problems with Tamron mounts and have only had one Rikenon (Ricoh) lens - 35-70mm, that worked perfectly on an ME Super.
I think therefore that the risk is small but well worth bearing in mind.

Oops, forgot to log in for that last post!

Just to clarify, I have only owned one Ricoh lens - I didn't mean that I only had one that worked (just in case you were wondering)!

There is one small downfall with the adaptall system, but it's pretty insignificant.
Advanced cameras with dedicated lenses often have MTF functions and actually 'know' what lens is fitted. The auto program shifts according to the exposure and focal length being used.
For example, with the SFX, the CENTIC icons shift from wide angle through standard to telephoto when zooming with the 35-135mm F lens and the programmed exposure settings shift accordingly.
When the Tamron adaptall system is fitted, the camera has no idea what focal length has been selected and cannot therefore compensate automatically for the lens characteristics.

Once again thanks,regarding other makes, i will stick to what i own now which is my 28-80 pentax (came with body) and my Sigma 70-300 macro super which is brilliant in all aspects, and my newly aquired Tamron SP 90mm macro, thanks for that email Kimbo, a very interesting set of lens. the trouble with our hobby is that there are always things we need, (new lens) but i suppose we must learn to make do with what we have . Thanks