Originally posted by Andrezao I was just lurking around Ebay and came across a few lenses that caught my attention. Alrighty, so I have a Pentax K20D (which I love) and I can't decide Between the Pentax DA 50-200mm or the Tamron 70-300mm. I heard the Tamron is useless over 200mm, is that true?
Certainly not, although it's not as sharp at 300mm as it is a bit below that.
I'd suggest browsing this forum for previous discussions of this topic;' it comes up pretty often. Also the Sigma 70-300, and the Pentax 55-300 are generally included in any such discussions.
For my money, the 50-200 is tough to beat if 200mm is long enough. IQ is at least as good at the 70-300's if not as good as the 55-300, but it's much smaller and lighter than the others, focuses faster, has quick shift unlike the 70-300's, and is cheaper than the 55-300. If I felt it absolutely necessary to have the extra length, I'd get the 55-300 over either of the 70-300's for the better quality as well as quick shift. but for my purposes, either 200mm is enough, or 300mm isn't, so the extra length just doesn't really matter to me.
Quote: I saw this Tamron 100-300mm Lens, which suit both Film and digital, so is it better going for a fully digital dedicated Lens or are older Lenses better IQ wise?
Whether it was originally designed for film or digital is not relevant to IQ - there are great and not-so-great designed-for-film lenses, and the same for digital.