Extention tubes for my 400mm f5.6?

Can you fill the frame with lets say, a chickadee with this lens or is the MFD too far? For those that use them, how many mm of tubes do you use and for what? (bugs, birds etc) Does adding them affect infinity focus too? **Edit, i see they will indeed limit max focus distance!

Thanks in advance!

Yes adding an extention tube will eliminate infinity focus. The 400 5.6 is a great lens, and it is capable of getting close enough to most birds, but it's strength is for birds in flight, where its long MFD actually helps by minimizing focus searching. If you feel for your particular application being closer is more important than maximum reach, the 300 F4 IS is capable of much closer focus distances.

Just did some tests with my sigma at ~400mm and at 3.5m it definitely works for me (chickadee size subject).

Well you certainly can fill the frame with a small subject, here is a woodpecker of mine taken with the 400 5.6:
http://www.pbase.com …hotography/imag​e/79262046
and an osprey portrait:
http://www.pbase.com …hotography/imag​e/68883479

It has always been close enough for me.

Great shots, looks like it will work for me! Just wanted to make sure... Thanks!

You can't fill the frame without tubes, but with a little cropping you can. Adding an extension tube limits your focus range and leaves you with a very shallow depth of field. For example adding the ET-25, your focus range will be limited to 8ft to about 21.5ft and your DoF wide open at 8ft will be 0.02 inches. So for birds I use the bare lens and add a tube for insects (stopped down with tripod) or portraits.

http://www.flickr.com/​photos/marco_5280/6968​427229/

Billy, what was your distance from the Woodpecker?

BufordFZ1 wrote in post #14072923
Billy, what was your distance from the Woodpecker?

That was years ago, but I know exactly where it was taken, I am going to say, 20' probably.

Get a set of kenko tubes and you will be happy. Now bird never come so close to me, only happened twice, once was baby swallow where I needed all three tubes on my 500mm f4 as it was so close I could touch it. Second time was a little shorebird who come so close as I was lying in the nud for more than an hr. But no tubes with me that day.

Great Shot!

Awesome shot! I might just get the tubes anyways...

The tubes are worth owning generally, but keep in mind that the longer the lens the more extension is needed to have a significant effect.