Your thoughts, Canon 70-300L 4-5.6 or canon 100-400L 4.5-5.6

Having a time deciding between these 2 lenses. I know the 70-300 can still auto focus with a 1.4 teleconverter, but the 100-400 can't and manual focus is used. I am shooting with a 5D markll. Which of the 2 do you think is sharper and is the focusing ring on the 70-300 more convenient than the push pull on the 100-400? thanks in advance for any imput.

Been shooting with a 70-300 tamron for some time, and getting tired of the limited reach, so struggling with the same issue. Tamzooka seems too big, it is another option.

Heya,

Not even a contest. The 70-300 with 1.4TC is not a good option compared to the 400L. Get the longest reaching lens you can with the quality you can afford. Don't even mess with TC's on these lenses unless they're F2.8 or F4. The F5.6+ stuff, just get a longer lens. TC's are not benign and have impact on the image quality and operation of the lens. The 400L here is the only option in my mind, between the two.

That said, if you're definitely going to use a TC regardless, look into the Kenko PRO 300 series TC's instead of the Canons.

Very best,

From what I understand the 70-300 has a marginal edge on the 100-400 in sharpness, before you consider the 1.4 extender. The bigger question really is, do you need 400 on a regular basis? If so, get a lens that goes there in its native state. Extenders are good for occasional use, and for big white primes, but for regular use on zooms they are not all they are cracked up to be.

MalVeauX wrote in post #16755544
Heya,

Not even a contest. The 70-300 with 1.4TC is not a good option compared to the 400L. Get the longest reaching lens you can with the quality you can afford. Don't even mess with TC's on these lenses unless they're F2.8 or F4. The F5.6+ stuff, just get a longer lens. TC's are not benign and have impact on the image quality and operation of the lens. The 400L here is the only option in my mind, between the two.

Very best,

100-400, not 400L

Thanks Charlie, I here the 150-500 tamron is also a very good lens for the money but it is a bear of a lens!

Thanks guys, So you don't recommend TC's with these lenses? Do they degrade the image?

I don't know about the teleconverter, not having used one with either lens. However, I looked at both these lenses last year, to use on my 7D as a replacement for a 70-200 f4 IS. After renting, I chose the 70-300L. I much preferred the size and format (it's a good bit smaller and lighter than the 100-400), I found the IS system on the 70-300L to be outstanding, and yes, I liked the focusing ring better than the push pull mechanism (although this latter is personal preference only; I have a friend who prefers the push-pull). In terms of sharpness, I didn't pixel-peep, but I had a slight preference for the images from the 70-300L; they seemed clearer somehow.

As an aside, I got the 70-300L because I didn't much like using a teleconverter with my 70-200. Teleconverters do affect focusing speed and image quality; the effect wasn't huge with the 70-200, but it was noticeable. I would imagine it would be more noticeable with the 70-300. If you think you're going to need a teleconverter on a regular basis, I'd suggest buying a lens with the reach you need instead.

Don't need the 400 on a regular basis gonzogolf.

MalVeauX wrote in post #16755544
Don't even mess with TC's on these lenses unless they're F2.8 or F4. The F5.6+ stuff, just get a longer lens. TC's are not benign and have impact on the image quality and operation of the lens.

This is excellent advice. The teleconverters work best on faster lenses, particularly faster prime lenses. Using a TC on either the 70-300mm or the 100-400mm will result in loss of ability to resolve fine detail most of the time. Plus, the AF, even if it will work, will be excruciatingly slow; it takes a few/several seconds for the lens to hunt as it focuses throughout it's entire range over and over again until it finds what it is looking for. Without a TC, both of these lenses focus quickly.

thanks ceegee, good info. Has anyone ever used a TC with the 70-300?

Here is a test chart comparison. 70-300L + TC vs 100-400L.
http://www.the-digital-picture.com …omp=0&FLIComp=7​&APIComp=0

I have the 100-400L and I'm quite happy with it. I use it often at 400mm. It's quite sharp. I picked it for the versatility over the prime, along with IS and shorter minimum focus distance. Now, if I maxed out my needs at 300, I'd get the 70-300L instead. In my case at least, I had a learning curve with the 100-400 to get the best results. I try to keep my shutter speed pretty high.

I don't mind the push-pull of the 100-400L at all. It seems quite natural with the lens.

Thank you John (sawsedge). Is the 100-400 sealed pretty well?

johnnyvman wrote in post #16755676
Is the 100-400 sealed pretty well?

It's nicknamed "the dust pump." That name isn't really fair, it isn't nearly as bad as that sounds, but it's not like the lens is hermetically sealed.

The 100-400 is not sealed, unfortunately.