Originally posted by X Man I'll try this one last time, against my better judgement.... He already has the SMC Pentax FA 80-320mm f/ 4.5-5.6 . The Tammy is not an upgrade... I give up.
Regards,
Mike
I see little reason to get frustrated. The original poster mention about about not liking the Pentax FA 80-320mm. But your point should be noted that the Pentax FA 80-320mm is likely NOT an upgrade as it share similar aperture and focal length with the Tamron zoom. I think both the Tamron or Sigma equivalent in 70-300mm offer good close up in 1:2 ratio, which do come in handy in the zoom.
Another note on going for the Adaptall lens is that the adaptall p/k or p/ka adapter is needed and that will jack up the overall price of the lens purchase, especially when you only use the adapter for single lens. It is something to be considered.
There are plenty of choices for inexpensive zooms, but the best will go to higher price in the DA 55-300mm in terms of IQ. As for me, I stay put with my Tamron zoom as I don't shoot tele shots often and the inexpensive zoom such as the Tamron fits my needs quite well. Its close up is something that I use quite often in hiking.
For fast action, none of the zooms mentioned seems fast enough for you to freeze the action in tele shot. At some point, you may need to look for a good prime in 200mm or 300mm.
Perhaps, you should push yourself in getting a work out with your existing FA 80-320mm and share with us what you don't like about the lens. All lens has some sweet spot to like about. I can tell you that the Tamron zoom serve me well in terms of sharpness, but the caveat always lie in more appearance PF/CA that I have to bear that in mind in shooting. Someone mention less fringing on K20D and I have not tried it myself yet. There is no perfect lens, you gain up and you lose some. Same can be said for your FA 80-320mm, I agree with others that getting the Tamron seems like a duplicate of what you already have with FA 80-320mm