Aperature sweet spot on 100-400L?

[morehtml]

Getting this lens tomorrow and heading to the zoo for a test shoot. What is the aperature sweet spot for sharpness in the 300-400 mm range?

Also to get best sharpness at 300-400mm handheld what minimum shutter speeds would you recommend trying to attain on a 20D?

[Jon]

Aperture, like any lens - stop down 1 or 2 stops from wide open. f/8-f/11. Speed - even with IS, a faster shutter speed will be better. Without IS, at 400, the rule of thumb would be around 1/750. With IS, at least 1/250. If, that is, your objective is to test for sharpness.

[mebailey]

F8 is definitely the sweet spot for this lens, imho.

[robertwgross]

The vast majority of all of my shots with the lens are at f/8 or just beyond.

---Bob Gross---

[JBillings]

My vote is f8 too, even at 400mm, this lens is sweet.

I have been able to hand hold 1/100 of a sec, but prefer to be around 1/250.

[ssim]

I'd have to agree that f8 is generally the best for this lens though I have had really good results wide open as well. It depends on lighting and other shooting conditions.

[Scottes]

Damn, I shoot this lens at f/5.6 probably 90% of the time... Guess I should try f/8.

Ya always learn sumtin aroun here.

[Jon]

Damn, I shoot this lens at f/5.6 probably 90% of the time... Guess I should try f/8.

Ya always learn sumtin aroun here.
I didn't say I usually shot there . . . just that it'd be sharpest there. Ya gotta take the aperture you need to stop the subject, not the one that'll give you the sharpest possible motion blur. But you knew that.

[Scottes]

But you knew that.
Yes, but I so often just stick it on f/5.6 and start shooting. In other words, I'll have to remember to try f/8 sometime.

[robertwgross]

Ya gotta take the aperture you need to stop the subject, not the one that'll give you the sharpest possible motion blur. But you knew that.

That's odd. I always thought of shutter speed as stopping subject motion blur, not aperture.

---Bob Gross---

[Jon]

That's odd. I always thought of shutter speed as stopping subject motion blur, not aperture.

---Bob Gross---
I was trying to humorously allude to choosing the best possible aperture for a sharp picture at the expense of a slow shutter speed on a moving subject. Guess I was too subtle for Mr. Gross.

[condyk]

I've always tended to shoot at f8 on all my long lenses and results are really good with 100-400 tho' I haven't had chance to really put it through its paces and test other options as yet. Best thing to do is try some test shots at different values to get a broad idea. After trying all kinds of settings I discovered my 24-70 is about as good as I've ever seen at 5.6 and so that's become my default, tho' I change if needed.