Aperture Question...

[pAthdoc]

My question pertains to the aperture of lenses that have the same focal length. The 24mm I want comes in apertures of 1.4, 2.8, and 3.8. I understand the DOF and speed differences, and setting aside the price differential, wouldn't it make sense to go with the 1.4? Or am I missing something here?

[RichardTaylor]

Normally yes,
The only things may be - you don't like the weight or it may be soft or slow focussing compared to the other models etc.

[edbayani]

i;d go with the f1.4 having an advantage in low light conditions.
dof is caused by, aperture, smaller, deeper. focal length, shorter, more dof. distance from subject and in some lenses if you have tilt and swing you can control dof.

[pAthdoc]

Originally Posted by RichardTaylor

Normally yes,
The only things may be - you don't like the weight or it may be soft or slow focussing compared to the other models etc.

The lenses I'm looking at are all manual focus so the speed of focusing won't really be an issue. The weight and dimensions part makes sense. I'm targeting a 24mm (or maybe 21mm), a 50mm, and a 75mm (or 90mm), each available in varying aperture sizes. I guess I'm looking at it from this perspective: the 24mm/1.4 can do what a 24mm/2.8 can do since it covers the 2.8 aperture. At least that's what my logic tells me.