Which filter size needed for this lens?

Hi,

On my Canon 17-55 2.8 (77mm) lens, will a 84x120mm GND filter be sufficient or is a 100x150 mm needed for enough movement latitude?

I'm looking at buying Singh-Ray ND and GND (.6) filters.

Thanks for any experienced advice.

I have a 10-22mm and 100-400mm lens, both requiring 77mm filters. Atop the CPL's typically used I'll handhold Hitech P sized (85 x 110mm) GNDs. Laterally I do have to be somewhat careful to ensure that the edge of the GND doesn't encroach into the frame. Normally the positioning of the transition zone is such that the height is rarely, if ever, a problem, ie so high or low that the opposite end encroaches into the frame. That said, a larger GND would give you more latitude....but typically at 2x the cost and bulkier as well. Your call!

trailguy,
84x120 or 100x150 are not screw-in type filters. Are you planning to use Lee Filters or Cokin Filters?

On the 17-55, the 84 mm (Cokin P size) with the Cokin WA holder would just about suffice. But if you think you might go wider down the road, I'd get the 100 mm filters and start looking for the Lee holders and WA adapter ring. Cost you less in the long run than having to start over with the bigger filters after having started with the smaller ones..

Thanks for the advice. I'm wanting to buy some Singh-Ray (not screw in) .6 filters. My 'larger' lens, Canon 70-200 L IS is, I think (without going and looking) actually smaller diameter than the 17-55 lens. So, I suppose the 84x120 would work.
Is a Lee holder the best to avoid vignetting? I plan on hand holding, or using painter's tape if necessary.

If it's the f/4 it's not a 77 mm. But it's the lens' angle of view that matters more than the filter diameter. If you were to go to the 10-22, or FF with a 16-35, you'd want the 100 mm filters. Lee filter holders are 100 mm wide; Cokin P are 84. So there's less likely to be vignetting with the Lee. And hand-holding the filter is fine if the camera's on a tripod, but some times you need to hand-hold the camera, so using a filter holder means getting the shot.

Which (Lee or Cokin) would fit it closer to the lens? I belive closer is better?
I attached a recent shot, with a CP, and I like the composition, but a GND added would have (I think) given me more to work with.