I am currently deciding between the 100-400 L f 4.5- 5.6, 400mm f 5.6 prime and the 300mm f4 lenses.

[RonL52]

I currently have a 70-200l f4 lense and would like to purchase an additional lense which would provide me with more reach. I am considering the three I mentioned above, but am favoring the 300mm f4 prime at this time. I would appreciate any feedback that anyone could provide on these lenses or any other recommendations.

Thanks!

[cicopo]

What do you intend to shoot with it? This may be important in the decision. 2 have IS but the 400 doesn't and that may be important too. Next question is whether you intend to hand hold primarily or shoot from a tripod mainly. The longer the lens the better your technique needs to be.

[RonL52]

I will be shooting horses, head and profile shots and some action. I recently purchased a  6d which I will be using and plan on hand holding, something I have done with my 70-200 without IS. This did take some getting used to without IS but have become successful with it.

Thanks!

[ebiggs1]

I have all three of the lenses you are considering.  From you last post, get the EF 300mm f4.

As a general rule of thumb a 50mm is 1 power (on a EOS 6D).  So a 200mm is a 4 power and the 300mm will act like a 6 power telescope.

Does that give you the magnification you want?  If not the 100-400mm (8 power) has IS for hand holding better.

Have you considered a tripod with a gimbal head?  

[RonL52]

I think the 300mm f4 may be my best bet, but  am considering the 100-400. I have eliminated the 400 f5.6 prime because it does not have is. I don't know much about tripod's but will take your advice and do some investigating.

Thanks, Ron

[marcosphoto]

Don't know if you're still following your post but I'll give my 2 cents.  I don't have any primes other than a 50mm.  Do I think primes are better in IQ?  I'd bet my life on it!  Do I think that a prime will always get the best shot?  Don't think so!  I am of limited photo backpack space and limited funds and photos are not my career.  Under these circumstances, I cannot afford nor justify primes.  I believe it is more important to get the shot, rather than risk loosing it due to focal length and/or lens selection issues.  I have the 100-400, hate the push/pull but for the money I love the optics and live with the design.  It's a super sharp lens for what it costs to buy - especially now that the replacement is out.  I say if you're under limited budget or space, get the zoom, I am pretty sure you would not regret it.

[RonL52 · Accepted solution]

Thanks for the advice, I ended up purchasing the 70-300L lense. I agree with you regarding only being able to afford so many of these lenses. I have been really happy with my decision to purchase this one.

Thanks, Ron

[hjphotog]

I've used the 100-400 for years. It's razor sharp, and once you get used to that trombone zoom, you'll never part with it.

I shoot a lot of birds and animals which most of the time are moving fast. This puppy with its IS and zoom focus is like shooting a top grade assault rifle.

Don't let the F5.6 deter you. fiddle with the f-stops and it works as well as the 70-200 with a lot more reach.

[ebiggs1]

"It's razor sharp, ..."

It is the least 'sharp' of the three lenses he listed! 

"...  it works as well as the 70-200 ..."

  

[hjphotog]

It's a zoom. No zoom is as sharp as a prime, generally, but when you're hauling lenses around from the airport to your backpack and up a hill in the forest, you really don't want that F2.8 70-200 and you don't want four prime lenses in your back and an extra body to fiddle with. And when you have just so much cash, on $2k zoom is going a lot further than three primes at $3k apiece. I shoot professionally for publications and I've never had a sharpness problem with the 100-400, even when I add the 1.4 teleconverter and hang it off my 7D.