For you 100-400L users... quick question

[Adam Hicks]

I'm shooting the IRL races tomorrow, and shot quite a bit today out at Texas Motor Speedway. I noticed that a good amount of my shots were a little soft, but seem to be in focus. Is the 100-400 pretty soft at the long end at 5.6-6.3? I can stop it down as there's plenty of light (and I don't even NEED ISO200 for this, 400 is great.) but the more I stop it down the more I have to worry about cloning out CCD dust. Keeping the CCD clean is a continual battle.

Anyways I think my question here is what aperture setting folks have found gives the sharpest results with the 100-400L. I've gotten some great results, but I'm really very particular about my shots coming out as close to perfect as possible.

Thanks!
Adam

[shiningstardv]

Haha, I don't actually have an answer to your question, but I thought I would be annoying and make a correction to your post. :D The 20D does not use a CCD as you stated above, it uses a CMOS sensor, the two are different.

Sorry, I couldn't resist. :D

[chris.bailey]

I have found the 100-400 softens a touch at wide open. I would rather gain the extra stop by pushing the ISO if needed.

[Scottes]

I agree with Chris, I'd stop it down at ISO 400 since 400 is OK for you.

[Adam Hicks]

Ok that's what I'll do.

Oh and I don't like CMOS sensors so I had mine custom built with a CCD.

:roll:

[shiningstardv]

Oh and I don't like CMOS sensors so I had mine custom built with a CCD.

:)

[Adam Hicks]

Ok I stopped it down and shot all day at mostly F8ish. Wow what a difference! I'll post some comparos in a little bit as well as few images from the day. Had a lot of fun!

Adam