Sweet spot for 17-40 f4 L

Prophet

TPF Noob!
Joined
Nov 12, 2003
Messages
187
Reaction score
1
Location
NE Indiana
Can others edit my Photos
Photos OK to edit
Maybe this isn't an appropriate question, but anyone know where the sweet spot is for the 17-40 f4L and shows the best performance. I read that almost any lens performs best 2 stops up from the bottom. That would be about f8 on this lens, correct? Given a scene with appropriate light, can anyone tell me what a good point to get the best photo's?

I think I'm going about things the wrong way... but I'm just trying to refine a few things.

Thanks,

-JD-
 

tsaraleksi

No longer a newbie, moving up!
Joined
Jun 12, 2007
Messages
1,045
Reaction score
0
Location
Greencastle Indiana
Can others edit my Photos
Photos NOT OK to edit
The 17-40 is quite sharp starting at f/4, but I've found that a 'sweet spot' is probably f/5.6-8.
 

keith204

No longer a newbie, moving up!
Joined
May 20, 2007
Messages
1,643
Reaction score
2
Location
Bolivar, MO
Can others edit my Photos
Photos OK to edit
yep I haven't done any exact testing specific to thsi, but I recall shooting at f/8-f/11 on the 17-40L and noticing remarkable sharpness that I'd not witnessed before.
 
OP
Prophet

Prophet

TPF Noob!
Joined
Nov 12, 2003
Messages
187
Reaction score
1
Location
NE Indiana
Can others edit my Photos
Photos OK to edit
is that "or" or "through"?

-JD-
 

rufus5150

TPF Noob!
Joined
Mar 8, 2008
Messages
1,658
Reaction score
2
Location
Austin, Texas
Website
www.toddmckimmey.com
Can others edit my Photos
Photos NOT OK to edit
yep I haven't done any exact testing specific to thsi, but I recall shooting at f/8-f/11 on the 17-40L and noticing remarkable sharpness that I'd not witnessed before.

In Understanding Exposure, Peterson explains why just about any lens will be its sharpest at both F8 and F11, but I can't recall the specifics at the moment (nor can I quote because the book's out on loan). Made sense from an optics perspective, though. Many lenses have sweet spots of extreme quality but with a wider aperture. The 17-40 I used for exactly a day was amazing at 5.6 and a tad soft wide open.
 

soylentgreen

TPF Noob!
Joined
Feb 27, 2007
Messages
735
Reaction score
2
Location
Miami, FL
Can others edit my Photos
Photos NOT OK to edit
Best to check the MRF charts for the lenses since they are tested wide-open. That will give you an inkling as to where the lens stacks up. The premium lenses; in general, perform just as well wide-open as stopped down. I can live with my L's wide-open and only notice a slight performance boost stopped down. As long as there is enough light or you are shooting with a tripod, stopping down does not hurt, expecially for landscapes.
 
OP
Prophet

Prophet

TPF Noob!
Joined
Nov 12, 2003
Messages
187
Reaction score
1
Location
NE Indiana
Can others edit my Photos
Photos OK to edit
Thanks guy for the patient and good advice. I figured some old cow would come in here to chew some cudd...... class act from all....

-JD-
 

Big Mike

I am Big, I am Mike
Staff member
Supporting Member
Joined
Dec 16, 2003
Messages
33,896
Reaction score
1,853
Location
Edmonton
Website
www.mikehodson.ca
Can others edit my Photos
Photos NOT OK to edit
I've been told by more than one 'old pro' that lenses are sharpest at F8. Sounds good to me.

I also subscribe to the theory that most lenses are sharper at 1-2 stops down from wide open.

I think this is also an issue of lens quality. For example, most 'kit' lenses are poor when wide open but can be quite decent at F8 or F11. A pro lens will be good (even excellent) when wide open and maybe a little better when stopped down. I've heard that some lenses (telephoto primes) are designed to be at their best when wide open, because that is where they will be used most of the time.
 

Garbz

No longer a newbie, moving up!
Joined
Oct 26, 2003
Messages
9,713
Reaction score
203
Location
Brisbane, Australia
Website
www.auer.garbz.com
Can others edit my Photos
Photos NOT OK to edit
Where the lens is sharpest? f/5.6 at the border and f/8 at the edges for all focal lengths. This can be found on any halfway decent review of this lens like at photozone.de

But where this lens performs best is at exactly the focal length and aperture you need to get the picture. Even if there were a difference between apertures or focal length which is remotely noticeable that's no reason to not get the photo you want.

There's nothing worse than a sharp image of a fuzzy concept. -Ansel Adams
 

Muay_Thai_Dan

TPF Noob!
Joined
Nov 23, 2007
Messages
140
Reaction score
0
Location
From the Ukrain to Israel to TORONTO!!
Can others edit my Photos
Photos OK to edit
what big mike is saying is true....i have a 17-85 kit lens (canon)...and i recently noticed, how much sharper it is at f/8 when i took a few pics at that aperture not too long ago (not to test the sharpness, but i just wanted to have a deeper DoF).and when i uploaded the pics on the comp, i saw a big boost in sharpness....and from that, i concluded the same, that at f/8, its sharper/the sweet spot
 

JustAnEngineer

TPF Noob!
Joined
Apr 11, 2008
Messages
609
Reaction score
1
Location
Heart of Dixie
Can others edit my Photos
Photos OK to edit
With the 30D, you can go up to f/10 without worrying about diffraction affecting your sharpness.
 

Most reactions

ClickASnap

New Topics

Top