Originally posted by zdeneczech Hi all, I am thinking about buying either Tamron AF 90mm f/2.8 SP Di macro or Sigma AF 70mm f/2.8 EX DG macro. Originaly I was going to buy pentax 55-300, but was told that if I crop the picture from either of the two other lenses, I would get a better result, better IQ. Would you agree? Which of the two would you recomend? Thanks, regards Danny
Not a chance.
I suspect you are confused between putting a TC on a lens vs cropping an image
from that same lens. Then it could be close, but in the case you describe, cropping a 90mm lens to 300mm, then the 300 will be better in almost ever case imaginable.