« on: December 31, 2014, 10:27:49 AM »
I started with the 70-200 f/4L and a 1.4x II extender to get close to 300mm for landscape. I loved the weight of it and image quality was top notch. Ultimately, I wanted IS and made the short hop up to the 70-200mm f/4L IS. Only slightly heavier, but otherwise completely comparable to the non-IS version. This summer I made the jump to the 70-300 f/4-5.6L IS. I decided to jump because I wasn't liking my shots with the extender and attaching it was cumbersome. I wanted to just have the reach there. I spent a little time on the Digital Picture website comparing image quality at the different f-stops between the 70-200 and the 70-300. Ultimately, it looked to me like the 70-300 was a little softer wider open and little sharper stopped down, certainly so at 300mm compared to 70-200 with the 1.4x II or III. LenScore numbers support this as well, for whatever that's worth. I decided image quality between the two was a wash and that the extra weight of the 70-300 compared to the 70-200 with extender was worth the convenience. I haven't shot with the 70-200 f/4L IS since I made the switch, though I can't quite bring myself to unload it. One thing to consider: 70-300 needs a UV filter on the front to complete the weather seal. I'm pretty sure this is not the case with the 70-200s. Factor that into price. With a high quality UV filter, image quality remains a wash, in my opinion. Also, neither lens comes with a tripod collar. Somewhat optional with a 70-200; absolutely necessary with an extender or the 70-300. Factor that in as well. If you need the reach of 300mm for landscapes (and it's a great focal length for landscapes), I think the 70-300 is worth the ounces over the 70-200 and extender.