Which Tele Converter?

Very often my 100-400 is not long enough for shooting birds and wildlife. I plan to add a 1.4 or 2X converter. Is it a good idea ? Which one is better 1.4 or 2X ? What brand delivers the best IQ and value for the $$ spent ? Canon, Tamron, Sigma ? prefer to be able to use AF. Thanks for the advice.

Which camera body are you using? With a 1.4x TC, you'll only retain AF on a 1D- or 1Ds-series body - and, at f/8 max aperture, iffy AF at that. With a 2x TC, you won't retain any AF whatsoever.

Getting a camera body with a higher photosite density will land you more 'pixels on target' for more cropability, but cropping is always at the expense of IQ. Your only alternative is to go for a longer lens - Sigma 50-500 (albeit arguably at the expense of some IQ), or a supertele prime (500L, 800L, 600L, in order of increasing weight).

Shadowblade wrote in post #10563861
Which camera body are you using? With a 1.4x TC, you'll only retain AF on a 1D- or 1Ds-series body - and, at f/8 max aperture, iffy AF at that. With a 2x TC, you won't retain any AF whatsoever.

Getting a camera body with a higher photosite density will land you more 'pixels on target' for more cropability, but cropping is always at the expense of IQ. Your only alternative is to go for a longer lens - Sigma 50-500 (albeit arguably at the expense of some IQ), or a supertele prime (500L, 800L, 600L, in order of increasing weight).

Camera: Canon 40D

For my 30D and 100-400L, I borrowed several different 1.4x converters from my local shop and spent a week or so testing them. The Canon 1.4x TC was good, but even better (and cheaper) was the Kenko DG PRO300.

I have taped the pin on the converter* to fool the camera. Thats all it takes to make it AF perfectly.

*Instructions for this are in a sticky here somewhere.

Get a 1.4 converter or extender. Personally I'd forget the idea of a 2X.

I will repeat here the same reply I had for a similar zoom last week;

On that lens you will absolutely lose sharpness and detail regardless of what TC you use unless you can stop down considerably.

TC's work best on Primes, they do well on some fast zooms, and get pretty rough on the long range, small aperture super zooms like your BIGMA. (100-400mm in this case)

that said, if you are interested in a TC< the Kenko is a great option as it will fit more lenses than the Canon's or Sigma's will,. I doubt the IQ will be different from one to the other,. the Canon TCs were designed to match the big Canon primes,. I don't believe you'll get an advantage from them on their zooms. (the same exact thing can be said about Sigma TCs by the way)


With any TC you need to stop down to get decent IQ (especially on a zoom) and with that f/5.6 lens with a 1.4x your already @ f/8 "wide open"..
Now your shutter speeds are plummeting,. so you need to push ISO.. and a tripod is almost mandatory,. Moving subjects? Not very likely.

See how hard it is to get a sharp image with a TC on that lens?

Yes in a pinch, you cna add a 1.4x. But good results are hard to get.

A 1.4x is worth trying, certainly. Grab a Kenko DG and tape the pins, see how AF works for you. You may find one-shot keeps missing, but AI servo is ok for moving subjects (what I've found to be the case on the 400 prime). If AF is too unreliable but the IQ is still good then don't rule out manually focusing, it's not as daunting as some people make it out to be.

Re taped pins,

...by all means try it, but do not expect it to work reliably.
This a touch and go trick, trying to force a camera to function out of spec. It does work often enough, but it often does not.

and there is no sure fire formula, one 30D with one 100-400mm may AF with taped pins on one Kenko Pro300, but the guy in Iowa with the exact same set up may get no joy. When it works, be happy, when it doesn't, don't fret, you should not expect to get something for nothing, and most often you don't

I'll also add my recommendation for the Kenko 1.4x pro300 DG.

Be sure NOT to get the pro300 DGX, which is the newer model. Lots of people report having problems with it...

Cyberdyne,

"With any TC you need to stop down to get decent IQ (especially on a zoom) and with that f/5.6 lens with a 1.4x your already @ f/8 "wide open"..
Now your shutter speeds are plummeting,. so you need to push ISO.. and a tripod is almost mandatory,. Moving subjects? Not very likely".

All I can say is that the 100-400L with the Kenko 1.4X is my motorsports lens on the 30D. I cannot justify buying a 500mm or bigger prime so it has to do the job. It is surprising how dificult it is to tell the difference between MotoGP shots I've taken with a 500mm prime and those shot with the 100-400/1.4x combo.

This comes up frequently and any of us that are faced with the problem of more focal length without much $$$ has experienced it. The reality is that even though you occasionally see a very sharp photo posted that was taken with a 100-400 and a 1.4 TC or especially a 2X TC it is the exception and not the norm.

I shoot birds (not BIF) quite often with a 30D + 100-400 + 1.4x TC (Sigma). It doesn't AF and I had no luck taping the pins, but it works rather well assuming you are using a tripod. Even with a 2x the results are normally acceptable. Stacking them works, but the results need quite a bit of work in post processing.

Here are a few sample shots.
1.4x - 1/250s f/8.0 at 560.0mm iso400 (f/8 is wide open when you add a 1.4x TC).

Lowner wrote in post #10566205
For my 30D and 100-400L, I borrowed several different 1.4x converters from my local shop and spent a week or so testing them. The Canon 1.4x TC was good, but even better (and cheaper) was the Kenko DG PRO300.

I have taped the pin on the converter* to fool the camera. Thats all it takes to make it AF perfectly.

*Instructions for this are in a sticky here somewhere.

"Perfectly" is a mis-nomer there bro. The tape trick works, but ultimately when the AF sensors don't get enough light... they don't get enough light - which makes the AF hunt.

But the tape-trick (or a TC that doesn't report its existence) does work to some degree.

I can attest to the Kenko Teleplus300 PRO DG 1.4x... I love the bejesus out of mine.

nureality,

Never known my 100-400 hunt with or without the converter. Unlike a 500mm prime I hired to shoot the 2009 British MotoGP, which hunted a lot spending ages winding from one end to the other and back again! Thankfully its got a "stop that! - get back to that focus" ring just behind the lens hood.

My 30D is slow, it does get there eventually, just takes its own time about it, unlike my Eos-3, which AF's with the self same kit in a fraction of the time.

Im picking up a tamron 2x for 50$ to try with my 100-400L. Is it worth 50 just to see what kind of results I get, or is it a bad idea?