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Canon 17-40L and 16-35L lenses

bensonga

Well-known member
I've owned a 17-40L lens for about a year now, but haven't used it much. Decided to try it out on my 1D2 today. I was a little surprised at how much distortion I'm seeing. Admittedly, I've only taken a few shots, mostly towards the wider end and hand held.

I didn't find any threads here about these lenses, so thought it might be worth starting one....if there are still any Canon DSLR owners here on GetDPI.

Here's one of the images I took today with the 17-40L, at 17mm. You can see quite a bit of distortion in the tug boats. I'm just wondering if this is typical of this lens at 17mm (which I know is quite wide). I've already applied "lens correction" to this image in CS5, using the 17-40L filter etc.

Gary

 

matthewpereira

New member
I've been doing some reading on DxO's Optics Pro software for optical geometry corrections as well as RAW conversion and noise reduction, etc. It seems (on paper, at least) to be a pretty capable package, especially for architecture/interiors/landscape photographers.

Looks like it'll do a lot better at correcting that distortion than CS5 did, and it's cheaper than replacing your 17-40 with the the 16-35mm f/2.8L II :)

If anyone has any experience with how the program stacks up against C1 and Lightroom, I'd love to hear it. Maybe it deserves its own thread?
 

bensonga

Well-known member
Thanks for the links to DxOptics pro and PT Lens guys.....I will definitely check these out. I was surprised that the lens correction filter in CS5 didn't do more to sort out the distortion. I do like the 17-40L lens, so I hope that one of these applications will do the trick.

Gary
 

bensonga

Well-known member
I'm looking forward to trying the DxOptics and PT Lens applications....CS5 Lens Correction just doesn't seem to do the trick, unless there are some adjustments I'm not doing correctly.

This image from today with the 1D2 and 17-40L at 17mm....Spring has arrived!
 
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stewpid

Guest
Bensonga, what you are seeing is not really, or mainly, distortion - it is just that you need to get the camera parallel with the main verticals in your images. PS 5, DPP and PT lens will all do a good job on true distortion (eg barrel, pincushion, etc) and PT and PS will also correct the perspective problems you are having. But there's no substitute for getting it as right as poss in the camera. Next time you shoot, try altering the camera up or down and see how this "distortion" goes. Good luck.
 

bensonga

Well-known member
Bensonga, what you are seeing is not really, or mainly, distortion - it is just that you need to get the camera parallel with the main verticals in your images. PS 5, DPP and PT lens will all do a good job on true distortion (eg barrel, pincushion, etc) and PT and PS will also correct the perspective problems you are having. But there's no substitute for getting it as right as poss in the camera. Next time you shoot, try altering the camera up or down and see how this "distortion" goes. Good luck.
I was wondering if that might be part of the "problem". I had just been hand holding these shots. Next time I'll use a tripod and level the camera to get a true comparison. I guess with the really wide angle focal lengths, the distortion from being not level is greatly magnified.

Gary
 

Uaiomex

Member
A tripod won't do much for "that" kind of distortion because it is produced by you tipping the entire camera to frame some near front ground.

The wider the lens the more distortion you'll see.

In order to reproduce that same scene without the distortion you see, you'd need a TS lens. Of course a tripod and a level would help you to keep verticals lines "vertical" w or w/o a shift lens.

Elongation at the very ends won't disappear though. It will get worse towards the side of the shift. There's nothing wrong with it, it's the way photography is.

Eduardo



I was wondering if that might be part of the "problem". I had just been hand holding these shots. Next time I'll use a tripod and level the camera to get a true comparison. I guess with the really wide angle focal lengths, the distortion from being not level is greatly magnified.

Gary
 

raywest

Member
Hi Gary,

In cs5, try using the custom tab on the lens distortion filter - you'll get it more acceptable, at least you can get the verticals vertical.

Best wishes,

Ray
 

bensonga

Well-known member
I got out during my lunch break to do some "scientific" tests. :eek:

I mounted the camera on a tripod, leveled the camera (or at least, I leveled it per the Acra leveling base on the tripod and the level indicators in the tripod head itself) and took this photo, using the 17-40L lens set at 20mm. To my eyes, there is only the very slightest distortion in the vertical sides of the buildings.



Then, with the camera still on the tripod etc, I simply tilted it downwards to get the composition I preferred and took this photo. Voila...distortion has magically appeared.



So.....my conclusion is.....I need a Canon 24mm Tilt/Shift lens. :thumbs:

And now....I have the photographic evidence to show my wife when she questions why I really, truly NEEDED another lens. :D

Gary
 

bensonga

Well-known member
Thanks for the tip on CS5 Ray.....I will try that next. I am, of course, hoping that these adjustments will be insufficient....so I can still build the case for a T/S lens.

Gary
 

raywest

Member
Hi Gary,

That's wrong thinking... If cs5 is good enough, then the money you do not spend on the lens can be used to buy your wife a present. That would be a win, win, win situation :angel:

Best wishes,

Ray
 

Uaiomex

Member
Gary, that is a very strong argument! lol
If you buy a TS lens my advice is to leave some "residual distortion" by not having those verticals perfectly aligned, especially in editorial pictures. Try it, building proportions and volumes remain more natural. imo.
Eduardo
 
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