t4i and 1.4 extender

[neuroanatomist]

Agree with getting the 100-400L. I bought a 300/4L IS used, ended up selling it and getting a 100-400 for the extra reach in a native lens.

[conropl]

Also take a look at item 5 in http://www.lensrentals.com/blog/2010...-the-whole-set

#6 makes sense also.

Stuart - I do not think anyone answered your question about taping the contacts when using a TC. I have tried it with my 100-400 L with a 1.4X II TC on a 7D (which I would guess should be better than your rebel), and it performed horribly. If you want to increase your frustration level with missed shot after missed shot while you are waiting for the focus to acquire, then it is a way to go... or you could just put it in live view and auto focus with the little box (even have the option of 5X and 10X focusing) without the tape and still achieve focus almost as fast as taping contacts. I am not sure how it would perform with the 400 mm prime, but I would guess it would have similar results.

The other problem with TC's on a camera that does not have good high ISO capability is the light seems to always be to low to get a decent shutter speed (the problem I had with the 7D focused using LV... auto or manual). I finally made the jump to FF with a 1D X, and I am really loving the ability to set my ISO at 1250 to get my shutter speed faster that 1/1000 sec. The bad part is I miss the 7D crop factor... so the 1.4X TC lives on my 100-400 mm most of the time. However, because I now have the ability to get shutter speeds up with higher ISO, it outperforms the 7D (even if I crop some). I very seldom produced an acceptable image with my 7D with the TC/100-400 combo, but I regularly do with the 1D X; and I attribute much of that to being able to get the shutter speed up. Which is also the reasons why neuro was pushing the IS need.

I wish a 600 mm f/4 L IS II was in my future, but that is not likely.

[sedwards]

wow tthanks for all the posts guys ! my original plan was to get a 100-400L but i read on quite a few sites that the image quality wasnt very good. i found that weird because i thought all L lenses where top of the line. a 400 prime would be nice but im pretty sure it will be to long sometimes. a zoom would be a definite advantage. i have seen a lot more used 100-400 lenses than primes too. easier on the wallet lol

[conropl]

A bare 100-400L is a great lens. It is versatile, and has IS. It is not going to be great in low light, but you are going to pay much much much more for that privilege. I was faced with the same choice as you a few years back, and I chose the 100-400L over the 400mm. I have not regretted it. The IQ is great if used correctly. Here are a few examples with a 7D (same sensor as yours)... if you want to see a larger size, then click on the picture or title and you can see larger sizes in flickr:


Green Heron-7893 by westmichigan, on Flickr


Duckling-3911 by westmichigan, on Flickr


Twin Fawns -1000 by westmichigan, on Flickr


Deer Along the River-9866 by westmichigan, on Flickr

[neuroanatomist]

Yes, the 100-400L is known to produce soft images, especially on APS-C. Just look for yourself...

[clemmb]

A bare 100-400L is a great lens. It is versatile, and has IS. It is not going to be great in low light,

That was my thinking for the price. f5.6 is a bit limiting in low light but the price is right.
Canon EF 400mm f/5.6 L USM with no IS, Canon EF 300mm f/4 L IS USM+ 1.4x = 420 with IS or
the Canon EF 100-400mm f/4.5-5.6 L IS USM.
With the zoom you get 400 with IS and no TC for the best IQ @400 IMO

[sedwards]

Thanks again for all the replies guys. Im pretty happy that i posted this and you guys showed pics of what the 100-400 can do on a crop sensor. Like i said my first plan was to get the zoom lens but when i read a few reviews they were all saying the prime was way better. A zoom will be much more versatile for me so thats the way im gonna go. Thanks to all that answered you have helped a lot !
Happy New Year every one.