Better lens = higher ISO?

I've been using the 50mm/1.8 since I purchased my T1i. If I bumped the ISO up to 1600+ I always seemed to get a lot of grainy texture in image.

I just purchased the new Sigma 17-50 /2.8 and in taking some very brief shots last night in low light, it seems that bumping the ISO up doesn't make the image grainy like it did with the 50mm.

Am I just imagining things or does a lens make a difference in how high you can set the ISO?

deronsizemore wrote in post #11586612
does a lens make a difference in how high you can set the ISO?

No.

David

I noticed this too. I think that the greater detail and sharper image hides some of the grain. It's still there though... just less noticeable.

The lens shouldn't make a difference in regards to grain. Unless the image is the same subject with the same exposure then the exposure and lighting will affect the image at higher ISOs more than the lens will.

It may be that you were underexposing the grainier shot