24-70mm 2.8L - - Filter?

Hi Learned members

I am looking at the 24-70mm 2.8L - still considering whether to purchase or not.

On inspection it looks as if the front element - due to its curvature - might just touch the filter when it is fitted - any comments please.

Thanks

Ray

20D
60mm Macro
70-200mm F4L
28-70mm 3.5 Macro (Old, but good)
Lots of bits and pieces

I do not have that lens, but I think that if Canon placed a filter thread in front of it they did tokk measures before doing so. Maybe I'm missing something or maybe it need a special filter, dunno...

I have the Tiffen Soft FX2 filter and it doesn't touch the front element at all.

I have this lens with a Hoya filter attached and it does not touch at all.

i had this lens and the HOYA Pro 1 i used on it did not touch the lens at all.
one trick i use to verify clearance between a lens element and filter is to cut a 1/4" square piece of copy paper, place it on the center of the lens, then as i screw the filter in place, i go all the way provided i don't see any movement with the paper as i screw in the filter. once it is in all the way i tilt the lens to make sure the paper falls to one side which tells me there is enough clearance.
the closest gap i've experienced was the 17-40 where there was just enough room for the paper to fall away.

Thanks all - and thanks for the tip Summerwind - why didn't I think of that?

I have a Hoya UV filter on my 17-40 and a Hoya Polarizer and neither of those filters contact the outer lens element. It never even occured to me that it might quite honestly...