Many thanks for the further replies
I've had the Tamron 18-270 much longer than the 70-300. The 18-270 is a much better all around lens mostly because of the 18mm focal length. I believe that prime lenses offer the best image quality but are not as versatile as a multi focal length lens. I think it's a shame that so much importance is placed on image quality alone. What ever happened to the 3 Cs': Color, composition, content ? In the studios of the Art Institute of Chicago in the early 60s we would place a piece of women's nylon stocking over the lens to soften it for portraiture. Wollensak lenses in the early 1900s were valued as soft lenses for just such work.
Modern lenses with 3 -4 magnification may have an advantage over extreme zooms but the improvement is not so great that it would prevent me from using a lens such as the 18-270. That being said, the 18-270 is a good everyday lens.
I believe prime lenses offer the best image quality too, but as you say they are not so versatile with their fixed focal length.
I'm not sure exactly why image quality seems to be so important today, all I can say is, if you look at a photo on the net where the IQ is sharp it stands out. Of course I realise other things such as the 3 C's will need to come into play for that to work well.
Your reply has renewed my interest in the Tamron 18-270 lens
, meaning I now have to decide between three lenses rather than the original two I'v elisted
I've had alot of experience on the Canon and only used a sigma/tamron equivalent a couple of times, i'll hold my hands up high and say that the Canon is a far greater lens than the Tamron. The image quality is brilliant, the IS is super fast and smooth and the zooming feel is very natural.
This is what I'm trying to find out, which is the best at the long end of the lens, because this is the main reason why I would like to invest in one. Do you find the Canon 70-300 IS lens soft at the long end?
My opinion so far is that the Canon 70-300 IS lens has a 2nd stage image stabilization setting for panning (I'm not sure how good this is though) which the Tamron does not, but the down side of the Canon lens for me is the front of the lens turns when focusing. This would mean if I wanted to use a graduated ND filter attached to the front of the lens not very practical IMHO. The Tamron lens however has IF (internal focusing) so the front of the lens does not turn when focusing.
Ive had the canon 70-300 a good lens...heres a snap taken with it..
Liking pets, especially dogs myself, that is a cracking shot
No doubt that your 7D has something to do with that, that I won't get with my 40D.
Many thanks to everyone who have replied, very much appreciated and helpful