24-70 on FF or 17-55 IS on crop

I have a 5dmk2 and 50d. I need to rent something in the 24-70 or 17-55 range. Knowing that I have both of these bodies, this question is really about which of these lenses is better. Any thoughts?

What are you going to shoot mostly? how are you going to pair the lens you have with your two bodies?
Is it an event? What kind of event?
The 17-55 has IS and the 24-70 does not, the first on your 50D works as a 24-70 on your 5D

They are both great lenses, one more appropriate in many cases on the FF, and the other designed for crop bodies. The 17-55 has IS and will be less expensive to rent, if that helps the decision any. One final consideration might be whether you really need f2.8 on the 5D2 if you are going to just stop it down to get your subject material in focus as much as you need it. If you will, then again the 17-55 might be the choice to make.

borism wrote in post #12540537
What are you going to shoot mostly? how are you going to pair the lens you have with your two bodies?
Is it an event? What kind of event?
The 17-55 has IS and the 24-70 does not, the first on your 50D works as a 24-70 on your 5D

I believe the 17-55 gives an equivalent view of a 27-88mm on the 5D, so not quite as wide as the 24-70 would be on the 5D, but more reach at the long end.

TeamSpeed wrote in post #12540566
I believe the 17-55 gives an equivalent view of a 27-88mm on the 5D, so not quite as wide as the 24-70 would be on the 5D, but more reach at the long end.

True, You are 100% correct, But the standard zoom lens with f2.8 constant aperture on FF is the 24-70 and the standard zoom lens f2.8 on crop is the 17-55
Both lens cover similar uses and applications on each body EF lens for FF and EFS lens for Crop
that is what I meant but perhaps failed to explain

One thing to consider is that the DOF on the same framing/distance to subject on the crop body with 17-55 is slightly larger, on the FF the 24-70 is a bit wider than the 17-55 and will give you a narrower DOF control
That could be something to consider depending on your style of shooting

I think it largely depends upon what you will be shooting.... If it's somethng that's better done with the FF camera, such as low light/available light where the 5DII would have the advantage, rent the 24-70. If it would be adequate to use the crop camera, then the 17-55 would do fine.

can't go wrong with FF so i pick FF even if the 17-55 is a more superior lens in terms of sharpness and IS.

dmbpettit wrote in post #12540526
I have a 5dmk2 and 50d. I need to rent something in the 24-70 or 17-55 range. Knowing that I have both of these bodies, this question is really about which of these lenses is better. Any thoughts?

for your situation, i would get the 24-70 for two reasons.

1. you can use it on both bodies, you can't with the 17-55
2. the 5dmk2 is a better body then the 50d, so lens 'priority' would go to that body first for me.

If I were to go full frame, I would keep my crop body to have the use of my 17-55 2.8 IS. thats me.
My 7D is covering my needs for now though.

i would say if you mostly shoot outdoors the 24-70 is a great choice....if you shoot indoors the 17-55 is the better choice...

If you'd only have a crop sensor... then 17-55 is the way to go imo...

But... Given the fact you have both full frame and a crop body... I would go with the 24-70... Just because you could use it on both of your camera's.

I would get the 24-70 to use on both 50D and 5D

24-70 on the 5D, 70-200 on the 50D. Use the bodies in their best domain (one wide/one tele). Carry a 50/1.4 and 85/1.8 and you have a very capable duo.