Need your advice to choose between 300mm f/4 and 400mm f/5.6

Ladies and gentlemen,

I need your advice to choose between 300mm f/4 and 400mm f/5.6.

I have 5DM2 and 1.4x. I would like to shoot birds and surfers. After saving money for my lens purchase, today is the day when I am going to push the Buy button. At this time, I have two choices: 300mm f/4L IS USM or 400mm f/5.6 USM. They are both at the same price where I live. I am leaning toward 300mm f/4L mainly (to the best of my limited knowledge) because of my 1.4x. I know that I can not use the 1.4x on the 400mm f/5.6 with auto focus.

What do you guys think?

blueskyoveraquatic wrote in post #15769918
Ladies and gentlemen,

I need your advice to choose between 300mm f/4 and 400mm f/5.6.

I have 5DM2 and 1.4x. I would like to shoot birds and surfers. After saving money for my lens purchase, today is the day when I am going to push the Buy button. At this time, I have two choices: 300mm f/4L IS USM or 400mm f/5.6 USM. They are both at the same price where I live. I am leaning toward 300mm f/4L mainly (to the best of my limited knowledge) because of my 1.4x. I know that I can not use the 1.4x on the 400mm f/5.6 with auto focus.

What do you guys think?

400 f/5.6. It's the poor birder's lens.
TC might introduce degradation. When you can get better IQ why settle for less.
You are using FF, so longer is better..

Both lenses are well regarded. From what you describe as your primary shooting, I would lean toward the 400. The AF is quite fast. The 300's advantage is that it has a short MFD, for close ups.

Since you already have the 1.4x I would go with the 300 f/4.

The 300 also has the advantage of IS.

^ And a better minimum focus distance.

All the bird shooters will say 400mm. If you want any versatility at all though I'd go with the 300mm. The 300mm has IS, and you already have the 1.4x TC making it a 420mm f/5.6 with IS. The 300mm has a better minimum focus distance and is one stop faster as well. If your primary goal is exclusively a lens for birding then get the 400mm, if you think you might shoot some motor-sports, landscapes or want to do some portraiture or things other than shoot birds, then the 300mm is more versatile.

400 is your lens

Thank you all for your advices - I bought a copy of the 300mm f/4L IS USM because of its versatility (ie. MFD, IS, etc...). I figure that when I need the reach for surfers and birds, I will put the 300mm + 1.4x on my 50D. 50D has 5.9 fps, but it is noisy for ISO > 800.
Once again - Thank you

blueskyoveraquatic wrote in post #15771262
Thank you all for your advices - I bought a copy of the 300mm f/4L IS USM because of its versatility (ie. MFD, IS, etc...). I figure that when I need the reach for surfers and birds, I will put the 300mm + 1.4x on my 50D. 50D has 5.9 fps, but it is noisy for ISO > 800.
Once again - Thank you

I think you made the right choice. If BIF was your main usage, the 400 would have been better. Surfing won't need particularly fast AF, and for anything else.. the IS, f/4, and short MFD will shine through. You won't lose a lot of IQ with a decent 1.4x, and as has been stated, the versatility will outweigh the slightly lower IQ. Hey.. if you decide you made a mistake, the 300 is a little more money, so you could probably sell it and go for the 400 with minimal loss.

If you were using a 1D, the choice would have been much harder (f/8 AF - 400+1.4x would smoke 300+2x).

Enjoy your new baby!

1Tanker wrote in post #15771373
If you were using a 1D, the choice would have been much harder (f/8 AF - 400+1.4x would smoke 300+2x).

Got that, no complaints.

Buy an APS-c body. For $600 (60D) you get more reach than the 300, if you use the 1.4 & 70-200 on the APS-c.

He has one.

TSchrief wrote in post #15771738
Buy an APS-c body. For $600 (60D) you get more reach than the 300, if you use the 1.4 & 70-200 on the APS-c.

Madweasel wrote in post #15771744
He has one.

Thanks. I missed that.

In that case, I don't get the question. Choosing between a 300 f/4 and 400 f/5.6 for use on a 5D2 when you have a 50D escapes me. I have 60D/5D. My two longest lenses are 70-200 2.8 and 100-400L. While I see the 70-200 as useful on both bodies, if I want/need focal length, I mount the 100-400 on the 60D. At that point the full-frame 5D is out of the equation, I have a more appropriate tool for the job.

I think the answer is either 70-200 & 1.4TC on the 50D, or 400 f5.6 on the 50D. OP is shooting moving targets. The 50D/400 is probably the fastest focusing combination, however. The 50D also has a (slightly) better burst rate.

300 f4 is far more versatile.

Good choice.