16-35mm v 17-40mm bokeh difference

[razyl]

Hi all,

I've read the numerous posts on this forum and many external reviews (fredmiranda, LL) on the differences between Canon's 16-35mm & 17-40mm Canon L series lenses. I was initially all for the 16-35mm, mainly because of the extra 1mm width and faster speed, but I'm now swinging around to the 17-40mm due to better sharpness, a much cheaper price, an extra 5mm at the longer end, and thinking that the extra stop might not be critical to what I need.

The one question that remains about these two lenses which (i dont think) hasnt been covered in any reviews, is the bokeh or background blur you get from either lens. How much difference is there between f2.8 and f4 in this respect? Does anyone have photos they can post?

My main concern is when doing people shots I really want good bokeh. Is the f2.8 essential to get this?

Thanks,
Darryn

[Sam]

Well, in general wide angle lenses are not what you reach for if you are looking to blur the background. It's possible, but much better with long lenses.

I don't have the 16-35, but I do have a 35mm lens so I took two shots for you. One at f/2.8 the other at f/4. Hope it helps a little.

forgive the camera shake, these are hand held in my kitchen about ten minutes ago :)

F/4
http://i7.photobucket.com/albums/y291/tborquez/June%202006/062206f4.jpg

F/2.8
http://i7.photobucket.com/albums/y291/tborquez/June%202006/062206f2point8.jpg

[EDIT] you do get 2x the shutter speed at f/2.8...

[razyl]

that's great, exactly what i'm after. thanks!

[edit] I guess i could do the same sort of test with my 50mm 1.8 eh? Admittedly not the same length lens but it will help make the decision.

[Sam]

Just for kicks... Here is the same shot at 85mm f/4

http://i7.photobucket.com/albums/y291/tborquez/June%202006/06220685mm.jpg

I used a tripod this time :D

[razyl]

cool. I'm really thinking the extra stop isnt worth the $$......and i can put the money saved towards a midrange zoom :D

[Krapo]

I like the bokeh of the 17-40 wide open.
Problem is, you have to be quite close to your subject to have the background blurred given the focal length.
What I like the most with this lens is its sharpness and contrast.
Here is an example of bokeh with that lens at f/4

88666

[Sam]

I like the bokeh of the 17-40 wide open.
Problem is, you have to be quite close to your subject to have the background blurred given the focal length.
What I like the most with this lens is its sharpness and contrast.
Here is an example of bokeh with that lens at f/4


What focal length is this shot taken at?

[Krapo]

What focal length is this shot taken at?

Yeah that's a good question :)
Answer is, I don't remember and I'm at work so I don't have the original version with the EXIF.

It's definitely on the long end, though (around 30-40mm).

[razyl]

that looks fine, no problem with the f4 there....and solinger: i think you could learn a trick or two from krapo when it comes to choice of subject matter in order to explain a technical point ;)

[petrolhead]

I like the bokeh of the 17-40 wide open.
Problem is, you have to be quite close to your subject to have the background blurred given the focal length.
What I like the most with this lens is its sharpness and contrast.
Here is an example of bokeh with that lens at f/4

88666
Great photo :)

[Sam]

that looks fine, no problem with the f4 there....and solinger: i think you could learn a trick or two from krapo when it comes to choice of subject matter in order to explain a technical point ;)

Hahaha :lol: I don't think my wife would have been to happy with me if I snuck into the room at midnight and started taking picyures of her.

[Krapo]

Great photo :)

Thanks a lot!

I must say that I very seldomly use that lens for its bokeh, although I like its creamy aspect. I use it mainly for landscapes.

I would like a 24-70 2.8 on top of it for more versatility and better DoF control.

[razyl]

How do you find it goes for landscapes? That's my main interest, hence the wide angle. Will be even better if/when I get a FF camera too. On the 350D should be good for a general walk around lens.

[Sam]

Will be even better if/when I get a FF camera too.

Yes, if you consider wider better. You will get more distortion and a little vignetting with a full frame camera though.

[cjm]

Sam those two shots look almost identical. I've noticed the same "background blur" with my 17-40 as you are getting.

Darryn I think if you want really good bokeh then you will want to use either a 50mm f1.8 (or lower) or a telephoto. The 17-40 will give you some but not extreme.

[steved110]

The 17-40L is a superb lens, can't be beat for the money, and has all the yummy goodness an L lens should have. for a wide angle, bokeh is not the primary thing I'd look for. sharpness and clarity are much more important. I decided to go for the 17-40 because firstly I could afford it, and secondly I prefered 40mm at the long end. I'd like it even more if it was 70mm - but there you go. life is a compromise!