Canon 400mm F5.6 USM L lens

This lens is a double edged sword. Once you've mastered it you'll be glad you took the time to. Until then you'll be muttering words you wouldn't hear on a family show - and often.

This lens needs a lot and I mean a LOT of light to use handheld. The amount of movement you'll get at 400mm has to be seen to be believed. No more do the 1/250th for static and 1/640th for moving rules apply.

You'll be looking at 1/1000th minimum. 1/1500th is ideal. Of course on a nice sunny day this isn't going to be a problem ( even at F5.6 trust me !! ) which is where this lens really shines - Skywards !

If you're pointing your lens at our feathered friends / airplanes or anything in the sky then you're going to find this lens much easier to use.

Of course as most nature photographers out there will have figured out you'll have a much nicer time with a tripod and a shutter release cable ( as you will with ANY long lens !! ) and this is where the F5.6 is the only real gripe about this lens, as on an overcast day at lower ISO's you're going to have a hard time getting the shutter speeds you'll need.

BUT...aimed upwards in good light the images this lens produces are absolutely amazing and as sharp as the 135mm F2 which so far is the sharpest lens I've personally used. The lens hood design is fantastic and I truly wish more of the lenses had this design - it simply slides back or forward and stays where you want it. No more fiddling about screwing lens hoods on and off which I loved !

So once you obey this lenses limitations you'll be able to nail razor sharp nature photo's and realise why it's 1/4 the price of the F2.8 IS version. To emphasize just how sharp the 400mm I've included a side by side comparison of the sharpness compared to sharpest lens I currently own ( the Canon 85mm F1.2 ii USM L ) This way you'll not only see the difference in sharpness but the difference in ISO / shutterspeeds you'll need to make when adjusting to a slower ( and much longer ) lens. The sun came out halfway through this test so yes you wouldnt need ISO 1000, 1/6400th for such a shot. Either way - the image is still relatively noise free and it shows what I wanted to point out, the sharpness ! And at F8 it's even sharper still and in overcast shooting, you will be looking at ISO 1000 on a regular basis. Before the sun came out, at ISO 1000 I was still only getting 1/640th which is a very low speed to handhold a 400mm lens.

Focus speed is nice and fast which is essential when tracking anything in the sky. Birds and butterflies have no problem changing direction without notice and in both AI servo mode and single shot I've had very little hunting and plenty of fast focus locks.

Also for it's size and reach it's very light which is a blessing as in the environments this lens is designed for you dont really want to be dragging a heavy lens up and down hills / through dense woodland for hours on end.

As for the 1.4x extender - it stops this lens down to F8 which will drain away the shutter speed but in no way affects the image quality or focus speed so if you're tripod mounted or have a LOT of light then it's not going to be a problem.

So to wrap things up, If you want to experience the magic of a 400mm length at the price of a 24-70mm F2.8 USM L then you can ! Just look out the window and if you have a clear blue sky you're good to go and you'll get closer, sharper and very pleasing photo's of those things you always wanted to reach but were always just out of reach !

As with all lenses, if you can then try before you buy !