Teleconverter Pros and Cons

[mjschocken]

I have a Canon Eos 80D and a Canon 100 - 400 mm F4.5 - 5.6 L IS USM lens and use them mostly for bird photography.  I think the 400 mm is not enough to capture small birds that tend to be skittish of humans.  Admittedly, I have lens envy when I see birds photographed with a 600 or 800 mm lens.  In generally, I really like the lens that I have but want to consider getting a teleconverter, at least a 1.4X.  I know about giving up an F stop but it's less clear to me about the effects of the teleconverter on focus points (I have 1, 9 and 45 on the camera) and on autofocus.  I would also like to know your thoughts on the pros and particularly the cons of using one.  Appreciate your feedback but if I'm asking a question that's already been asked, please let me know and I'll try to find the discussion.  Thanks.

[Waddizzle]

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@mjschocken wrote:

I have a Canon Eos 80D and a Canon 100 - 400 mm F4.5 - 5.6 L IS USM lens and use them mostly for bird photography.  I think the 400 mm is not enough to capture small birds that tend to be skittish of humans.  Admittedly, I have lens envy when I see birds photographed with a 600 or 800 mm lens.  In generally, I really like the lens that I have but want to consider getting a teleconverter, at least a 1.4X. 

I know about giving up an F stop but it's less clear to me about the effects of the teleconverter on focus points (I have 1, 9 and 45 on the camera) and on autofocus.  I would also like to know your thoughts on the pros and particularly the cons of using one.  Appreciate your feedback but if I'm asking a question that's already been asked, please let me know and I'll try to find the discussion.  Thanks.

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Use just the center AF point.  I'm pretty sure that the center AF point in the 80D can focus to f/8.  I would strongly advise only using a Canon teleconverter, though, if any. . 

Image quality with the 1.4x is a whole other conversation.  The 150-600mm lenses out there are pretty popular.

[jrhoffman75]

Remember that your 80D is a so-called "crop camera" with a 1.6x crop ratio.

So, if you are looking at photos taken with a Canon 1D X or a 5D, which are popular professional birding cameras, with a 600mm lens, you will get the same effective view (actually a liitle more) with your 80D and a 400mm lens. (400*1.6=640).

[cicopo]

You may get by with stationary birds but will have lots of trouble (slow to no AF lock) on birds in flight. Highly recommend considering a 150-600 C from Sigma or maybe the newer version Tamron has out now. It's a lot of magnification on a crop body.

[mjschocken · Accepted solution]

Thanks for these comments.  I do want BIF so I guess I need to start thinking about the Sigma 150 - 600 which I have seen images from.  Those that have it seem to like it.  It seems like an affordable solution for me. 

[ebiggs1]

"... recommend considering a 150-600 C from Sigma or ... the newer version Tamron ..."

This is the correct answer.    Your choice.  They are nearly identical in IQ.  Either will work well on an 80D.

[ebiggs1]

A word of warning.  Even a 600mm lens is not going to make a tiny bird, ... large!  Even with a 600mm lens you need to be very close to the bird.  Generally under 50 feet. 

[TTMartin]

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[mjschocken]

Thanks much for your comments and for an illustrative image with the lens and extender.  You've told me everything I wanted to hear as I do have the second, more recent version of the Canon telephoto zoom lens.  I also know a few guys who have the Sigma 150 - 600 mm lens and so I was also interested in your comments about the Canon versus Sigma/Tamron lens and their image quality.  Again, thanks.

[ebiggs1]

"The EF 100-400 L IS II with the 1.4X III extender still bests the image quality of the Sigma or Tamron 150-600s."

Of course this is wrong.  Even if you take published data on the three lenses mentioned, they are nearly identical in IQ.  Actually owning and using all three confirms it.  Adding a teleconverter to any one of them vs one without one, will degrade its IQ.