300mm f4 vs 300mm f2.8, each with 2x iii converter
Hi Karsaa,
I recently made a comparison that might be of some use to you.
I own the 300 mm f4 and the 2x iii. ( I use the 2x iii mostly for the 70-200mm f2.8 ii.) I recently received a few days rental of the 300mm 2.8 ii as a gift. It takes the 2x iii very well. Naturally I wanted to see the comparison of these two for some real-word shots. Bryan already has great comparisons under standard lab conditions.
I already knew the 300 f4 plus 2x iii gives lots of color fringing on edges with hard contrast, so I looked for a subject that would not pose that problem. These hydrangeas were roughly 20 meters distant. There was plenty of late afternoon sun. The flowers were not really very attractive, but they seemed suitable as test subjects.
These were shot a few minutes apart on the 5D iii. For each of these I selected the sharpest of 3 handheld shots. I processed each in DPP to produce the sharpness and contrast that seemed best for that individual shot. The 300 f4 seemed to need and to tolerate a little more sharpening and contrast. These were then cropped to width 2048 pixels (roughly a 50% view) before jpeg conversion.
My impression is that the 300mm 2.8 is better, but I was surprised that the difference was less than I expected. I would expect a bigger advantage for the 300mm f2.8 for subjects with very hard edges.
I was also pleasantly surprised that the physical balance of the 300 f2.8 was good, so that the extra weight was very manageable.
https://farm1.staticflickr.com/670/2...07772ff8_z.jpg300mm f4 2x iii at f8 by Danny Watson, on Flickr
https://farm1.staticflickr.com/670/2...07772ff8_z.jpg300mm f4 2x iii at f8 by Danny Watson, on Flickr
https://farm1.staticflickr.com/674/2...0570371c_z.jpg300mm 2.8 2x iii at f8 by Danny Watson, on Flickr
https://farm6.staticflickr.com/5712/...cb934469_z.jpg300mm f4 2x iii contrasty edges by Danny Watson, on Flickr