For those Canon users with the f/2.8 vs f/4 problem

[Bendihossan]

Just found this on the Canon CPS website. Made for an interesting read and uses the 24-105 f/4 L IS USM vs 24-70L USM as an example along with the 17-40L vs 16-35L lenses.

Some things to think about when making your choice from that article are:

...the slightly longer focal length range and image stabilisation of the EF24-105mm f/4L IS USM lens, along with the smaller size and lighter weight of this lens, will outweigh the need for an extra wide f-stop in many shooting situations.

if the background is extremely far away from the subject, or you are shooting in a controlled studio situation with flash lighting and a plain background, then the choice of f/2.8 over f/4 will be negligible.

 

[seltechpc]

Thank you for that link Steffan, it makes interesting reading. I own a number of the lenses mentioned and tend to agree with much of what the author said on reflection.

I am glad I did not read it before I bought the 300mm 2.8, that is such a sharp lens

Cheers,
Paul.

 

[desantnik]

Its difficult to make comparisons by numbers to be fair. There is more to a lens than its maximum aperture that will decide how pleasing the image is.

My own opinion on the subject is that a f4 lens on a Canon body will never allow the AF system to perform at its best (when using the designated "precision cross point AF sensors" - a fact documented by Canon themselves and not my opinion or rumour)

However that being said ultimate precision in focus is not a factor in most photography anyway, with "close is good enough" for nearly every type of subject. Certainly your average newspaper journo won't really care whether or not the picture of the vicar at the church fete is completely 100%-bang-on-couldn't-be-improved vs say someone producing something super spot on for the cover of Vogue.

So for a journo chasing down the typical daytime job, a lighter lens is probably more valuable than something big and heavy. Which is why you see the 24-105 used an awful lot for those sorts of roles.

The journo also doesn't care about sympathetic natural lighting either, if its too dark, blast it with the (on camera) flash.

Does this produce images worthy of detailed critique or praise by photographic socities? Nope, but it does sell newspapers and by the time its printed on newsprint and only a few inches across no b****r can tell the difference anyway.

 

[Bendihossan]

My own opinion on the subject is that a f4 lens on a Canon body will never allow the AF system to perform at its best (when using the designated "precision cross point AF sensors" - a fact documented by Canon themselves and not my opinion or rumour)

Yep, I do agree but f/4 is fast enough for most scenarios. Given the choice of course I think we'd all take f/2.8 if the price was equivalent but it's usually a matter of justifying the extra cost and weight which is why the 24-105 is such a sought after lens.

Tell you what though, if Canon ever release an EF 24-105 f/2.8 L IS USM I'll be first in line!!

 

[david1701]

seriously f4 is too slow, f2.8 is quite slow I like f2

 

[grumpybadger]

My own opinion on the subject is that a f4 lens on a Canon body will never allow the AF system to perform at its best (when using the designated "precision cross point AF sensors" - a fact documented by Canon themselves and not my opinion or rumour)

Depends on the body. 1D4 works with cross sensors on f/4 with some lenses (including the 24-105) and the 7D offers cross sensors sensitive at f/5.6.

 

[madhouse]

Depends if you're subject is still or not, if it's moving then no amount of IS will help whereas the faster f2.8 may make the difference.

I'm biased though - I chose the 24-70

 

[Bendihossan]

Depends if you're subject is still or not, if it's moving then no amount of IS will help whereas the faster f2.8 may make the difference.

I'm biased though - I chose the 24-70

I'm biased too...that's why I went for the extra reach and IS

 

[Pippy_Neville]

And I'm just waiting for my 24-70 to arrive... HURRY UP!