Canon TS lenses - extreme shift and image quality

[Ladislav]

Is there any guidance on what are "extreme" shift values on 17 TS-E L and 24 TS-E L Mk II lenses? Older TS lenses had red part of shift and tilt range showing "extreme" values where image quality was worse. Are shift values over 0.6cm still considered extreme? I'm trying to figure out if behavior I see is expected.

Background:
I have 24mm lens less than year and while I noticed that image quality becomes worse as the picture shifts more off center, it was still pretty good even when doing +1 cm shifts. I recently bought used 17mm and that one seems to be much more sensitive to extreme shifts - possibly due to front element. I did some hand held architecture photos with max +1.2cm shifts and all went directly to the bin. While lower part of the picture was very sharp, the upper part was visibly soft even without zooming image on monitor. Photos with less extreme shifts around +0.6cm were fine. I was disappointed.

I need to do more testing. Yesterday I tried taking pictures of our house on tripod with doing 2mm steps and comparing results but it really didn't provide much help.

 

[privatebydesign]

The shift range is +/- 12mm, so 0.6mm is probably a typo.

If you post an image to illustrate what you are thinking is unacceptable we can tell if it is normal or not, but remember, you are going to get extreme perspective distortion on heavily shifted 17mm shots they equate to an 11mm fov, so just the projection issues are probably all you are concerned with. I find different amounts of shift acceptable with the 17mm depending on subject and output.

 

[Ladislav]

Here is one of sample images. No processing - just default import to Ligthroom with default settings.

https://photos.google.com/share/AF1QipOa6TOC9H39v0hMk8osQByem4KiK9gCKLhGy10Tz4okqCoHXWSyksjV75JF_aF9Pw/photo/AF1QipNKWnYsLmdhsnv_RNwKQYnx-kWE-J51CvstbB2p?key=T0tERjB5RERTXzRqZFUwNEl1RWtTUEVvZ1k5NUF3
6D, 17 TS-E L, 1/60s, f11, ISO 100, +12mm shift , Handheld - manual focus and exposition before shifting

The area around the gate is fine but as it goes up towards towers and chimneys it becomes soft. There is also softness on both sides.

 

[Ladislav]

The shift range is +/- 12mm, so 0.6mm is probably a typo.

Yes, that was a typo. I meant 0.6cm - original question updated.

 

[Ladislav]

Looking at ISO-12233-Sample-Crops on The Digital Picture, I assume I should get a better quality on 6D.

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=487&Camera=453&Sample=0&FLI=8&API=3&LensComp=487&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=3

 

[Zeidora]

... I did some hand held architecture photos ...

Here's a significant part of the problem. Handheld TS-E architecture is asking for trouble.
A second problem could be focus. If you install a matt focusing screen, viewfinder focus is much easier to judge. But tripod with level, live view and using loupe is the much better approach.
Still, as you run further away from center, image quality worsens. That is just part of the game with TS-E. And even with large format lenses.

 

[GMCPhotographics]

Firstly, any TS-e lens should really be shot on a tripod. The lens movements need a stable base to get the accuracy and stability that these lenses require. They are slow to operate and that means a tripod. My copy of the TSe 17L is an extremely sharp lens. But as it shifts to the upper numbers, sharpness deteriorates and the exposure shifts too. But stopped down and the sharpness improves in the upper numbers somewhat....another reason to use a tripod.
If you are shifting to the max, hand holding with a random shutter speed (it's a heavy lens and the 1:1 shutter speed to focal length rule will not work) and iffy manual focusing....then yes you will see poor results. It's not a 16-35mm lens...it requires careful and specific handling to get good results.
I have seen a single copy of the TSe 17L which was well out of spec and had very soft corners on one side at max shift.

 

[Ladislav]

Firstly, any TS-e lens should really be shot on a tripod. The lens movements need a stable base to get the accuracy and stability that these lenses require. They are slow to operate and that means a tripod. My copy of the TSe 17L is an extremely sharp lens. But as it shifts to the upper numbers, sharpness deteriorates and the exposure shifts too. But stopped down and the sharpness improves in the upper numbers somewhat....another reason to use a tripod.
If you are shifting to the max, hand holding with a random shutter speed (it's a heavy lens and the 1:1 shutter speed to focal length rule will not work) and iffy manual focusing....then yes you will see poor results. It's not a 16-35mm lens...it requires careful and specific handling to get good results.
I have seen a single copy of the TSe 17L which was well out of spec and had very soft corners on one side at max shift.

So far, I had a very good experience with handheld shift on 24mm TSE. I don't think that it is absolutely necessary to use tripod for shift if you: focus before shift and use manual exposure configured before shift. Of course it will improve results and chance to get a better photo (+give other options like longer exposures with ND filter). Tilt is a different story and I couldn't do it without tripod and live view.

The reason why I don't think this is just focus or camera movement issue is that blur is not present in the center of the picture and is only present at the upper (shifted part) and on both sides. I expect quality to go down in shifted areas but my tests so far looked beyond a bar to be usable.

Anyway, I will do more tests with faster shutter speed handheld and compare them with usage on tripod. I'm not against using the tripod and if it is the only way to get good results with this lens, so be it, but sometimes tripod is not an option.

 

[hendrik-sg]

With the 17mm T/S the quality at the edges suffers badly when shifting to the extreme (specially in portrait direction. The reasons are:

- 17mm fully shifted is equal to a cropped 11mm picture, which produces huge geometrical distortions, making faces, cars, or just anything with a defined geometry looking deformed. This is no lens aberation, it's the nature of this projection.
- Vignetting is extreme, and it must be corrected manually, because there is no lens profile, and if it was, it would be useless, because the amount of shift is not recorded.
- It's right, in the corners (at extreme shift) the sharpness ist compromised and there are some chromatic aberrations.

BUT the available 11-12mm lenses all have the same problems, and after shifting this lens uses all the sensor, which is not when cropping a 11mm pic for the same shifted framing. This means the resolution might be better even when other lenses look better at TDP

BUT taking a pic with no shift and correcting the perspective in post harms the sharpness as well

So in my opinion, this is a fantastic lens, but it needs some practise, i saw several professional photographers who did not understand how to use it. Very helpful is a camera with electronic level, for me this replaces the tripod in many times for shifted pictures.

When using tilt, focussing is a itterative procedure with 2 parameters (focus and tilt) so be set correctly. this works best in live view and on tripod.

 

[romanr74]

with a little bit experience the ts-e 17 can be used handheld no problem!

i experience the exact same sharpness fall-off you do and honestly was a bit disappointed too!

 

[Hector1970]

Maybe I'm not understanding . I've had little issue with shift on the 24 TS-e II as it's good for panoramas. Tilt of a few degrees is fine. Larger titles or tilt and shift confuses the metering no end and what will be in focus is unpredictable. I don't use it much but really like it as a lens. Really slows you down and makes you manually focus correctly. I mainly use the tripod but have used it handheld.

 

[privatebydesign]

To me it looks like the sample image has some tilt applied, certainly that is how the dof falls off when you apply tilt. There is a very good spread of dof on the street yet nothing sharp at all in the top third of the image.