I had the Canon 400/5.6 and it was a super sharp lens. Nice and light and the neat hood sliding over the body makes it even smaller to pack into your bag.
The 100-400 is a bit of a Marmite lens with the push/pull function. I personally didn't like it at all.
The Canon 100mm/2.8 L is reported to be a great macro lens and within budget second hand. :t:
I have a 105mm Sigma 2.8 which gets some amazing images and can be snapped up for around £200 second hand, although the AF isn't the quickest.
From my experience, I wouldn't go for anything under 100mm...
Just thought I'd say a quick hello to everyone on the forum.
Although more of a photographer then a "birder", I do enjoy watching and taking photos of birds, both in my garden and on occasion at Martin Mere.
I'm sure I'll be on here asking for the best spots and some bird ID's. :t: