Using a Teleconverter with a TS-E lens
Teleconverter use with a TS-E tilt/shift lens
Altering the focal length of a tilt & shift lens by 1.4x or 2x
Changing focal length for TS-E lenses with a teleconverter
A quick test using the Canon EF 2x Converter (Teleconverter) with the TS-E 17mm f4L tilt shift lens.
The 2x teleconverter is my concession to rarely needing a long lens when I’m out and about. I’ve got it in the bag for attaching to my 70-200 2.8L IS to get an equivalent 400/5.6 IS lens. If I needed a 400 mm lens for the type of work I do then I’d get one, but as yet I’ve not come up with a good enough business reason…
I’ve heard people ask if the 17mm TS-E lens and 1.4 TC would be good enough to just buy the 17mm, rather than the 24mm. Note that 17×1.4 conveniently comes out at ~24mm.
To see the impact of the TC, which always lowers quality to some extent. I did a quick test in the street outside.
Here’s three shots (@f/11) using the 17mm, shifted 12mm either way.
A detail of the LH edge.
Sharp and with minimal CA
Let’s see the results at 34mm (17mm x2). These are with a lens setting of f/5.6 to get f/11 with the 2x TC
A detail shows softness and CA
By using the canvas extension technique I described in my original tilt/shift lens article, I was able to use the lens correction filter in Photoshop to fix the basic CA (not actually that much)
This is the ‘fixed’ version, after a little sharpening with the CA fix
This is at the extreme edge of the field, with some residual CA after fixing it to look best in the rest of the image.
I extended the canvas by 233% rightwards to place the middle of the image along the lens axis.
Here’s a combination of images from the ’34mm’ set-up, showing how the shift (12mm) looks.
So, is it of any use?
The fact that I have to use the lens at f/5.6 to get f/11 equivalent is a major cause of softening of the image, along with the extra glass in the optical path.
I could use f/8, to get f/16 (equivalent with 2x TC), but at f/16 I’m potentially getting diffraction softening of the image (with a 21MP FF sensor)
I did try some other settings and found that the image was a tad better at a lens setting of f/8, but not really enough to show here. I’ve not got a 1.4x TC, but I’d expect the results to be somewhat better and potentially usable if you can’t justify the 17 and 24mm.
I now know that with modest shift, I now have 34mm available as a T/S lens, although I suspect that I’d just use the 24mm and crop ;-)
No doubt, as the 17mm ships more widely, we’ll see some detailed comparisons, but I thought I’d give it a go…
All articles and reviews are listed on our main Articles and Reviews page, or use the search box at the top of any page. Experimental items, hacks and how-to articles are all listed in the Photo-hacks category.
Some articles that may be of interest:
- Using a tilt/shift lens - what it is they actually do
- Focus with tilted lenses - lots more information about what's going on when you tilt a lens. See also: Focusing the view camera - External link to [very] detailed coverage of camera movements
- Keith's tilt table spreadsheet (zipped file)
- Using old lenses on your DSLR - fun with adapters
- Keith's lens reviews and lens related articles
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