The current XR 3.8/5.6 lenses by Tamron and Promaster appear to be identical in all but a few cosmetic areas ie. rubber grip on the lens barrel.
Personally, I would still say that £50 - even if it's for the previous model, is excellent value for money and I would seriously consider buying - subject to it's condition.

It should be noted however that we are entering the realms of the 'superzoom' with this lens (28-300mm is now quite common) and while the performance of such lenses is now remarkably high they can not and most probably will not ever be able to compete with prime lenses or zooms of a more modest range in terms of optical perfection.
Zooms have always represented a trade off between optical quality, speed and flexiblity.

I love Pentax gear but am also particularly fond of Tamron lenses.
As a very popular multi-award winning manufacturer, many photographic experts around the world think they're pretty good too.
The version with the Pentax badge may be superior although I doubt the difference would be noticeable and for £50, the Promaster sounds like a real bargain to me.

I have several adaptall lenses and have recently been looking for a 90mm.
They still seem to be holding their value on the 2nd-hand market (which is an indication of quality) but I missed out on a nice one on eBay that sold for just £31.
The real bummer, was the fact that the seller was local and I could have picked it up and saved the postage

Bob,
You asked for comments regarding the use of such lenses but you didn't indicate which one you actually had.
Pentax glass is renowned for quality and there's a certain aesthetic appeal that devoted Pentax users appreciate but as with all top brands, it comes at a price.
If you are pleased with the results from you lens and it's a cheaper alternative, then your recommendation could well help those of us that can't afford the Pentax.

Kim.

Sounds as though you're getting there Mark.
To maximise the depth of field and help ensure that critical areas are in focus, stop down to the smallest aperture available (larger number on aperture ring - think in terms of fractions!) and consider shorter focal lengths as wide angles have better depth of field characteristics.
I don't think the Me Super has a depth of field preview button (sold mine to a friend years ago) but you can see the effect if you carefully begin turning the lens as if to remove it, this will stop the lens down to the aperture set. The image will darken but you'll notice that areas that appeared slightly out of focus, infront of and behind the subject, will become sharper and this is how it will appear on the finished print.
Having partially released the lens, take care not to let it fall from the camera
I found that using this technique and relating what I could see through the viewfinder to the depth of field scale on the lens, helped me to visualize the effect I wanted to achieve - it's all too easy with digital these days

Thanks for clarifying that John, like I said, I wasn't too sure about M42 having never used that set up.

I presume you mean the A setting on the aperture ring, this enables a suitable camera to automatically select an appropriate aperture for the shutter speed you have chosen.
In the case of a program camera, such as the Super A, the camera will select both the aperture and shutter speed for the type of photo you wish to take ie. action or landscape.
With the lens set to A, modern cameras base the 'decision' not only on the program setting and lighting conditions but also on the image characteristics of the lens fitted (the camera knows which lens you're using and the focal length), which is one reason why it is advisable to use own brand lenses!
Such cameras usually allow you to manually select the aperture/shutter speeds from within the program menu or you can change from the A setting on the lens itself and totally override the auto functions.
Manual only lenses work perfectly well on such cameras but the program features of the camera are then more limited.

I'm not sure what features were available when M42 was the standard but I would think the same would apply.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=3807904159&category...

Danny,
My 120 now appears to be ok - following a second trip to Pentax.
I think they actually replaced the winding mechanism this time rather than just giving it a service.
With new camera prices now being so low, I was hesitant to pay the repair cost but my 120 is a particularly nice example and does have a few features that are not available on some newer models.
Your 115V is a relatively recent addition to the model lineup and I'm amazed that this problem is still a major issue and it's not just confined to Pentax!

Hope your good luck continues with you digital model.

That certainly doesn't sound good to me!

Incidentally, it looks as though my 120 is going back to Pentax - first film since the repair and the darned thing's playing up again.
It performed flawlessly up to frame 34 and then began rewinding, not only was this somewhat early but was also erratic. The frame counter displayed 0 but I suspected that the film had only partially rewound.
My fears were confirmed when opening the back to discover that very little of the film had actually been wound back into the cartridge.
I suppose what I should have done was to send the camera back without attempting to remove the film so that Pentax could save it - but what a lemon I would have felt had it been ok!
Thankfully the warranty is still valid and hopefully Pentax can attempt a further repair and it'll just cost me the postage and the annoying loss of a film's worth of shots (some of which I am very annoyed about )