24-70 versus 24-105 AF performance

[PeterJ]

I've got a 24-70 f/2.8L (original version) and I've been thinking about a 'cross-grade' to a 24-105 f/4L. With a crop I used to use it a lot for portraits but since moving to FF (now own a 5D3) I normally use a 70-200 for that and 24-70 only gets used at f/4 or above most of the time anyway and often for things where IS would be a benefit. I use a 50mm if I want something faster.

Anyway I know a f/4 lens will technically focus slower in low light than a f/2.8 but just wondered from someone who's used both how low light AF between the two compares? I thought maybe despite f/4 the 24-105 may have a more modern / faster AF drive so maybe not too much of a difference in practice?

[michi]

Well, according to this:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=101&Camera=453&Sample=0&FLI=0&API=0&LensComp=355&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0

the 24-70 may be a tad better than the 24-105.  But it's really not much.  I have both of those, and I use the 24-70 2.8 more often.  I just like the image results better, but honestly, that may also be just my imagination.

[wickidwombat]

Well, according to this:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=101&Camera=453&Sample=0&FLI=0&API=0&LensComp=355&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0

the 24-70 may be a tad better than the 24-105.  But it's really not much.  I have both of those, and I use the 24-70 2.8 more often.  I just like the image results better, but honestly, that may also be just my imagination.

I have both and in very low light you will notice the 24-70 being faster but generally the difference in any other situation wont be noticable the 24-105 AF is very fast its only low light were the 24-70 get the extra benefit from the f2.8 points

[symmar22]

I can confirm both previous posts, I have both lenses as well, in very low light the 2.8 will be a bit more efficient, but for me the IS and extended range of the f4 make it more useful. I like the lower weight as well and prefer the general handling of the f4 24-105mm. When the extra IQ matters, I use primes. But your shooting style might require the extra stop.

[pwp]

Over a number of years I have had the misfortune to have had four 24-70L f/2.8 MkI lenses all of which can only be described as dogs...unusable for professional work. While there are brilliant copies of this lens around, this is a greatly unloved lens by plenty of photographers. In spite of not being keen on an f/4 lens, I got a pre-owned 24-105 f/4is just to see me through until the 24-70 f/2.8II shipped. This took a couple of years longer than expected! But the 24-105 f/4is is an absolute cracker, pin sharp wide open (and I'm fussy) and useful extra reach & IS.  When I get the new 24-70 f/2.8II the 24-105 f/4is will be a keeper.

Last week I had a 48 hour test drive of the new 24-70 f/2.8II and have to say this lens is absolutely fantastic. It was a long time coming but worth the wait. At $1000 more than the MkI it needed to be first class and in my view, it delivers.

So if you're comparing the 24-105 f/4is with the original 24-70, I'd put the 24-105 f/4is well ahead in most respects. But up against the new lens, it's no contest. The new 24-70 wins gold. With regard to AF performance, the f/2.8 glass will usually outperform an f/4 lens...particularly in low light.

-PW

[crasher8]

I switched from the mk1 24-70 to a 24-105 and haven't looked back. The 50 1.4  in the same bag takes care of my faster moving/low light images.  (so does the shorty 40 on the 5D3.) I'll compliment it further with a 35 from either Sigma or the Canon IS soon.

I think the AF response is very close, negligible for most uses. The 24-70 is a brick, I sure like the lighter 24-105 for a walkaround and the reach. I don't use my 70-200 as much thanks to the switch.

[Dylan777]

I had tried 24-70 mrkI(3 copies) and 24-105(2 copies), none of these lenses gave me the sharpness I'm looking for.

I was little skeptical about 24-70 f2.8 II sharpness when I placed my pre-order. Now, this lens remains on my 5D III most of the time. The sharpness at f2.8 is amazing. Highly recommended

[Mt Spokane Photography]

I have bought and sold five of the 24-70mm L lenses, none could match my 24-105L.  Many used ones on the market need repair, they are easily decentered and the guide bushings that support the telescoping part of the lens break and jam and then the lens stops focusing accurately.
 
If you get one, plan on sending it to be repaired, since many selling used ones don't recognize the subtle problems, they just know that they want something better.  This means allowing $350 or so in the price you pay.  Obviously, if the lens has just returned from a Canon servicing, that would be better, but I'd then wonder if Canon was unable to put it into the condition that the owner expected, so he is dumping it.
 
The worst MK II is better than the best MK I in lens rental testing, and they are better constructed.  Thats something to consider.
Also note that the IQ of the Tamron 24-70 IS is better than the Canon MK I, so for the price, I'd prefer it.
 
For walking around in fair to good light, its hard to beat a 24-105mmL.  Again, there are good and bad, so if buying used do not accept lens creep, and plan on a trip to Canon for checkout and repair.  New 24-105mm L's from kits can be found for under $800, I paid $700 locally a few years back.

[PeterJ]

Thanks everyone,  based on the feedback I'll sell my 24-70 and get the 24-105. Looking at used prices locally it looks like I should be able to get a new 24-105 for about $0 - $100 more so think I'll go that way.

[crasher8]

I sold my two year old 24-70 to Keh and they gave me a great price, especially considering I got it for a song refurbed from Canon. Then I bought a 24-105 LN- from them. Got a check as well

[pwp]

Thanks everyone,  based on the feedback I'll sell my 24-70 and get the 24-105. Looking at used prices locally it looks like I should be able to get a new 24-105 for about $0 - $100 more so think I'll go that way.

This is a great time to shift a MkI 24-70 f/2.8. I got $1400 for my last one, sold not long after the 24-70MkII was released, sold on Gumtree in under 3 hours. From the number of enquiries I could have asked for more. The stratospheric price of the MkII has had the effect of ramping up the price of good, pre-owned 24-70 MkI lenses. There are great deals around on 24-105's right now. You'll come out with spare change.

-PW