TS-E Depth of Field newbie question

LovePhotography

Texas Not Taxes.
Aug 24, 2014
263
13
Picked one up on eBay. Waiting for delivery.
While shopping, found this commentary. Thought it was interesting.
Thoughts?

24 and 17mm T/S aren't useful.



The lens does two things that are practically unrelated, and both of which are borderline useless in the extreme wideangle. Firstly, the shift mechanism allows perspective correction. This was a critical part of photography in the days of large format, and I used this lens to get the same benefit on film when I started out with Canon. However, if you are working digitally, it is far easier and cheaper to correct perspective while editing. Second, It allows tilting of the plane of focus, which allows near/far compositions to simultaneously be in focus when simply stopping down doesn't do enough (or isn't desired for other reasons such as stopping subject motion, etc.) However, these extreme wide angles, with small apertures even wide-open, have extreme DOF already and it'd be a rare photograph that needed more DOF than a normal lens could accomplish at 24mm (or even more so, 17mm). On the other hand this ability would be very attractive at 45-90mm. (A related trick is to tilt focus in the opposite direction of your composition to minimize DOF. But again at 17 and 24mm, I'm sorry but nothing gets very defocused anyway.) As far as other details of the lens go: the construction is the very best Canon makes, comperable to the 70-200Ls or better. The image quality unfortunately suffers as you shift off-center, as the lens resolution falls off as with every lens. (There is also extreme cos^4 vignetting, though that can be fixed in your editing software.)
 
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Jan 13, 2013
1,746
0
LovePhotography said:
Picked one up on eBay. Waiting for delivery.
While shopping, found this commentary. Thought it was interesting.
Thoughts?

24 and 17mm T/S aren't useful.



The lens does two things that are practically unrelated, and both of which are borderline useless in the extreme wideangle. Firstly, the shift mechanism allows perspective correction. This was a critical part of photography in the days of large format, and I used this lens to get the same benefit on film when I started out with Canon. However, if you are working digitally, it is far easier and cheaper to correct perspective while editing. Second, It allows tilting of the plane of focus, which allows near/far compositions to simultaneously be in focus when simply stopping down doesn't do enough (or isn't desired for other reasons such as stopping subject motion, etc.) However, these extreme wide angles, with small apertures even wide-open, have extreme DOF already and it'd be a rare photograph that needed more DOF than a normal lens could accomplish at 24mm (or even more so, 17mm). On the other hand this ability would be very attractive at 45-90mm. (A related trick is to tilt focus in the opposite direction of your composition to minimize DOF. But again at 17 and 24mm, I'm sorry but nothing gets very defocused anyway.) As far as other details of the lens go: the construction is the very best Canon makes, comperable to the 70-200Ls or better. The image quality unfortunately suffers as you shift off-center, as the lens resolution falls off as with every lens. (There is also extreme cos^4 vignetting, though that can be fixed in your editing software.)

Funny how things are not useful when you don't know how to use them in the first place ;D
 
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Sporgon

5% of gear used 95% of the time
CR Pro
Nov 11, 2012
4,722
1,542
Yorkshire, England
LovePhotography said:
Picked one up on eBay. Waiting for delivery.
While shopping, found this commentary. Thought it was interesting.
Thoughts?

24 and 17mm T/S aren't useful.



The lens does two things that are practically unrelated, and both of which are borderline useless in the extreme wideangle. Firstly, the shift mechanism allows perspective correction. This was a critical part of photography in the days of large format, and I used this lens to get the same benefit on film when I started out with Canon. However, if you are working digitally, it is far easier and cheaper to correct perspective while editing. Second, It allows tilting of the plane of focus, which allows near/far compositions to simultaneously be in focus when simply stopping down doesn't do enough (or isn't desired for other reasons such as stopping subject motion, etc.) However, these extreme wide angles, with small apertures even wide-open, have extreme DOF already and it'd be a rare photograph that needed more DOF than a normal lens could accomplish at 24mm (or even more so, 17mm). On the other hand this ability would be very attractive at 45-90mm. (A related trick is to tilt focus in the opposite direction of your composition to minimize DOF. But again at 17 and 24mm, I'm sorry but nothing gets very defocused anyway.) As far as other details of the lens go: the construction is the very best Canon makes, comperable to the 70-200Ls or better. The image quality unfortunately suffers as you shift off-center, as the lens resolution falls off as with every lens. (There is also extreme cos^4 vignetting, though that can be fixed in your editing software.)

What the guy says is true - if you gloss over certain things. Yes, 24 and especially 17 have great dof anyway, especially if you stop down, but beware of 'hyper focal' distance with digital, especially for distant landscapes: your horizon will be soft. A lens such as the 24 is at its best fully open, you can achieve dof with this wider aperture with all the benefits this brings: resolution and light gathering.

Correcting extreme perspective in post: OK for small prints, not so good if you are producing A3 or A 2 size prints. Your computer program has to make a lot up.

Again on the new 24 IQ remains superb with 6 degrees ( which is a lot ), only falling off a little at the full 12 degrees ( shift).

You can see that here:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=486&Camera=453&Sample=0&FLI=8&API=1&LensComp=0&CameraComp=0&SampleComp=0&FLIComp=0&APIComp=0

For many people he is correct in saying the longer focal lengths offer more benefit. However try telling that to someone who shoots in extremely confined circumstances, room interiors or outside of cathedrals in built up areas for instance.
 
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