Originally posted by interested_observer Here is a comparison between the two lenses.
Comparing numbers is one aspect, the other aspects that I can think of are...
- How their respective images compare - Opinions of others in terms of the imagery produced. The 55-300 is no prime 300, but it is a very good lens. I have one and I like it. Its a zoom so it does cover a wider set of focal lengths than a prime. Obviously the prime would be sharper.
- The one item that does stand out to me is the OS designation on the Sigma lens. Its optical stabilized. This gives you an option of either using the in body stabilization or the lens stabilization. Never use both - why, you might ask? Both the body and the lens will sense the movement, the lens will adapt to the movement stabilizing the light that is sent to the body. As the now stabilized light enters the body and hits the now moving sensor, the stabilization provided by the lens will be undone by the body stabilization of the sensor, essentially adding the movement back in, there by blurring the image. Now, I have not heard of any outright OS failures of the Sigma lenses, like Pentax's SDM lenses, but its another source of failure. I know that OS and SDM are apples and oranges in terms of functionality. however, I have a tendency to shy away from any and all additional capabilities that can break.
- Price, the Sigma goes for $350, and now on sale for $300, while the Pentax is going for $380. That is a 25% savings in favor of the Sigma. That may be worthwhile
I was looking at the lens comparison website and saw that Sigma makes the same lens with out the OS and it is cheaper by $100 at $200 and change. That may also be an alternative to the Pentax.
.
Thanks so much for all the info.
I found a Pentax 55-300mm on sale at a very compeitive price to the Sigma, so I grabbed it.
I really do appreciate all the help.
Now I can't wait to get it home.