My Impression: Sigma 70-300 APO DG Macro

I like loud AF, it's kind of cool to me. I have the sigma 55-200 and canon 50 1.8, they are real loud when it's dark. BTW, what does "apo" mean?

BruceC wrote in post #2090501
I like loud AF, it's kind of cool to me. I have the sigma 55-200 and canon 50 1.8, they are real loud when it's dark. BTW, what does "apo" mean?

I agree.

BruceC wrote in post #2090501
I like loud AF, it's kind of cool to me. I have the sigma 55-200 and canon 50 1.8, they are real loud when it's dark. BTW, what does "apo" mean?

Apochromatic

dictionary.com says: corrected for spherical aberration at two wavelengths or colors and for chromatic aberration at three wavelengths.

so this is good right

Good but this lens probably dosn't really have it, just the name.

NordieBoy wrote in post #2091115
Good but this lens probably dosn't really have it, just the name.

yeah it does. Two extra apochromatic SLD making it three over the previous non-APO which has only 1 at the rear. And from photozone.de, the difference is noticeable.
Anyhow the AF noise as I have observed is just the initial focusing when the focusing mechanism isn't within the area. Once it's focused, it is fairly quick and quiet. I've been using it with AI Servo and after the initial focusing noise, it fine.

But if you look at the conclusion from photozone...

"It delivered pretty decent results in most aspects, specifically at 70mm and 200mm, but at 300mm the border resolution is nothing short of dismal - certainly not apochromatic as claimed by Sigma (nor would we really expect that from such a budget lens)."