birdfromboat wrote in post #12145115
Sorry, yeah i am thinking 300f4.0, and leaning heavily on first hand advice versus the website lens theorists, I am hoping to find someone that has made this change first hand.
I did that swap. I had my 100-400 for over 5 years before I sold it and still rate it as the most versatile long lens available, as well as an excellent wildlife lens. However the (my) 300mm F4 IS is significantly better from 300mm on. The better IQ and sharpness allow me to crop and get a better 400mm+ equivalent image than the 100-400 also the slightly higher magnification is great for larger insects etc.
I have used my 300 with the Canon 1.4 Mk2 converter with reasonable success, but generally I don't bother, I simply crop a bit.
Recently I was photographing a Tit (bird) extracting seeds from a Bulrush with my 600mm F4 IS. As I had a bucketful of images I invited a friend (the current owner of my 100-400, who now wants my 300!) to put his 1D3 on my lens and get some shots. As I now had nothing better to do I put my Canon 2x converter on the back of my 300 and had a go shooting hand held just to see what it could do. Well my 1D4's lightning fast AF was quite pedestrian with this combo, but it was accurate! IQ was not perfect but IMHO would produce a quite decent A4 print.
To me the 300 F4 IS was a definite upgrade, but it is less flexible - so you need to work within it's limitations to see it's advantages. Whilst mine was surprisingly good with the 2x converter, if you need more reach you really need a longer (expensive!) lens, if funds are limited then the 400mm F5.6L makes a lot of sense - try one before you decide. If 300mm will do what you want then the 300 F4 is a stunner at the price.
Life is for living, cameras are to capture it (one day I will learn how!).