Does f/4 work for 5DmkIII in low light?

[lexonio]

Hello happy MK III owners, I'll be joining you soon among other happy folk I currently have the 24-105L, and I was thinking of buying 70-200 f/4 or f/2.8. However with ISO improvements in the latest 5D, I was windering if it's possible to get away with using f/4 and still getting workable images? Not taking bokeh and DoF into account?
Thank you in advance for your replies!

 

[Fooleryl]

I've been using a 70-200 f4 with the 5d2 for 3 years now. I'm not sure how it stacks up to the new 70-200 2.8II, but compared to the old one the f4 version was smaller/lighter/sharper and has better IS. The new f4 is due soon I think, and it'll probably retake the spot of sharpest canon zoom if the old still isn't.

I'm not going to lie, I have found myself wishing that I had that extra stop maybe 1 or 2 times, but in the end it just not worth it to me.

I'm expecting the 5diii's iso improvements will make it even easier to get by with a f4 lens.

-I shoot weddings for a living.

 

[Drizzt321]

I'm a bit confused by your post. f/4 has always worked fine on the 5d2 for me, although as Fooleryl mentioned, sometimes I did wish for that extra stop between the 24-105 & 24-70 a few times. But, the IS & extra 35mm on the long end were useful a lot more often, for me.

For the 5d3, you likely can go up a stop in ISO and get similar results to the 5d2, but you'll have that extra stop of shutter speed/aperture to play with.

 

[Stephen Melvin]

Hello happy MK III owners, I'll be joining you soon among other happy folk I currently have the 24-105L, and I was thinking of buying 70-200 f/4 or f/2.8. However with ISO improvements in the latest 5D, I was windering if it's possible to get away with using f/4 and still getting workable images? Not taking bokeh and DoF into account?
Thank you in advance for your replies!

Well the improvements to the low light capabilities of the camera will help f/4 lenses as much as they'll help f/1.4 lenses. I was able to AF my 24-105 in much less light than I could on my Mk II, that's for certain.

 

[t.linn]

It looks like a 5D3 + 70-200 f/4L should allow you the same IQ as a 5D2 + 70-200 f/2.8L II because of the ISO advantage the 5D3 enjoys. This advantage is different depending on whether you are talking RAW or JPG but it's there either way. Both lenses are among the best zooms Canon makes so I don't think you gain IQ by choosing one lens over the other, all other factors being equal.

In my opinion, the extra stop of light is not the reason to choose the f/2.8 over the f/4; it is the increased control over DOF. You are trying to divorce that issue from your question but I don't think you can. That, to me, is the f/2.8's big advantage. Having said that, I shoot with the f/4 IS version. The reason is weight. The f/2.8 is so stinkin' heavy. I shoot landscapes and wildlife. Lugging that beast up a trail is a non-starter for me.

 

[tt]

Hello happy MK III owners, I'll be joining you soon among other happy folk I currently have the 24-105L, and I was thinking of buying 70-200 f/4 or f/2.8. However with ISO improvements in the latest 5D, I was windering if it's possible to get away with using f/4 and still getting workable images? Not taking bokeh and DoF into account?
Thank you in advance for your replies!

It was workable with the 5DMkII - and that's why it's a kit lens!
Go and try one - in the conditions you'll want to use them. The main improvement it seems is from 1600-128,000 - the 5DMkIII is an improvement on the MkII. They're pretty close at lower ISO. But you could just bump up the ISO a stop, and go for the f/4.

Your main issue might be the difference in focal points f2/8 vs f4 on the MkIII.