Canon 17-40 vs Oly 21mm f/3.5?
/forum/topic/986355/0



marko1953
Registered: Mar 30, 2004
Total Posts: 634
Country: Australia

I have a Canon 17-40 lens and am thinking of getting an Olympus 21mm f/3.5 for landscape/seascapes of the bay and beaches where I live. I have an Olympus 50mm and have been using it on my Canon 5D with adapter. My question is "how much better and in what way will I see any improvements by using the Olympus 21mm lens over the Canon?
I have read good things about the OLY lenses but never seen a direct comparison with Canon lenses. The 17-40 seems a bit soft at the edges with the FF 5D but is otherwise good in respect to colour and contrast. I want to be able to to make big print enlargements.



ingardj
Registered: Feb 02, 2009
Total Posts: 132
Country: Norway

Curious as well!



jcolwell
Registered: Feb 10, 2005
Total Posts: 20844
Country: Canada

Hi Mark,

The Oly 21/3.5 is generally sharper in the corners than the 17-40L. The 17-40L is generally sharper in the centre. Here's some test photos that I took last year, to compare the Oly 21/3.5, Voigtlander 20/3.5 (F-mount), Tokina AT-X 17/3.5 (EOS AF version), and EF 17-40L. The first thing that I discovered is that ultra-wide Alt lens performance is greatly affected by the quality of the adapter that you're using. In particular, focus accuracy and sharpness across the frame is affected by asymmetry in adapter thickness.

The first set of images below compares the four lenses with generic adapters on the Oly and Voigtlander. I'll only post the images at f/8. Trends are similar at f/3.5 and f/4.



jcolwell
Registered: Feb 10, 2005
Total Posts: 20844
Country: Canada

Here's a few more comparing the four lenses.



jcolwell
Registered: Feb 10, 2005
Total Posts: 20844
Country: Canada

After musing over these results for a while, I decided to get better adapters. The next set of two-panel images compares the Oly and Voigtlander with both lenses on Fotodiox Pro adapters.

Overall, I figured the right side of the Voigtlander was better than the left side of the Oly, and so I sold the Oly and bought a Leitax mount conversion kit for the Voigtlander. Now the Voigtlander gives great results across the frame. The Voigtlander still has slightly better performance on the right side than left, but the difference is moot, unless you're peeking.

Cheers, Jim

P.S. The Tokina AT-X 17/3.5 is a very nice lens. In my experience, it's better than the Tamron SP 17/3.5 [151B].



RustyBug
Registered: Feb 02, 2009
Total Posts: 12946
Country: United States

Jim ... interesting comps.

I found my Oly to be more even across the frame vs. my Nikon 20/2.8 AIS, with the Nikon showing better central sharpness.

Re: the Tokina 17 ... how is it with distortion? I think the Tamron 17mm SP can have some mustache going on which has me looking more at the Oly 18mm. Should I be looking harder at the Tokina 17 ??



brucemuir
Registered: Dec 24, 2008
Total Posts: 3316
Country: United States

Yea, adapter variation truly sux.

I'm going to get a micrometer to check these from now on.

Wonder if will do any good? ? ?



jcolwell
Registered: Feb 10, 2005
Total Posts: 20844
Country: Canada

RustyBug wrote:
Jim ... interesting comps.

I found my Oly to be more even across the frame vs. my Nikon 20/2.8 AIS, with the Nikon showing better central sharpness.

Re: the Tokina 17 ... how is it with distortion? I think the Tamron 17mm SP can have some mustache going on which has me looking more at the Oly 18mm. Should I be looking harder at the Tokina 17 ??


Hi Kent,

I can't say that I noticed moustache distortion in either or these lenses, but the Voigtlander 20/3.5 has a touch of it. It normally doesn't bother me too much. If I start shooting a lot of ultra-wide architecture or similar images with strong linear elements, then I'll get the TS-E 17mm f/4 L. For now, the TS-E 24mm f/4 L II handles my needs in this territory.

Here's the best images that I have on hand to compare distortion of the AT-X 17/3.5 (first) and SP 17/3.5 (second). The third image shows more details on the AT-X distortion - it appears to be moderate, simple barrel distortion. The fourth image shows moustache distortion with the Voigtlander 20mm.

Jim



jcolwell
Registered: Feb 10, 2005
Total Posts: 20844
Country: Canada

brucemuir wrote:
Yea, adapter variation truly sux.

I'm going to get a micrometer to check these from now on.

Wonder if will do any good? ? ?


Hi Bruce,

I'm sure that any thickness variation you can measure will have an effect on IQ. OTOH, it might have as much to do with how well the adapter fits on the native mount, as with variations in adapter thickness. I've decided to stick with Leitax for ultra-wide Alts, but I'll only get one after tests with adapters suggest that the lens will be a keeper. I haven't noticed any problems with adapters for 28mm and longer focal lengths. Most of mine are now Fotodiox Pro, but I have a couple of old generic F-mount adapters that work fine. One of them's on my C/Y Distagon 28/2.8, which is a very fine lens.

I can't check the thickness of the F and Oly adapters that I used in the comparison tests, as the F-mount adapter is on a Nikkor 105/2.5 AI that Conner999 is playing with for a few weeks, and the Oly adapter is attached to a 50/1.2 that's waiting for me on a ship.

Jim



RustyBug
Registered: Feb 02, 2009
Total Posts: 12946
Country: United States

Thanks for the quick pics on the distortion ... probably keeps me focused toward the Oly 18 ... although the elevator shot with the Tokina does look tempting.



mirkoc
Registered: Jan 26, 2008
Total Posts: 627
Country: Croatia

That is very nice comparison jcolwell. Great effort.
How is 17-40 in the corner stopped down to f16? Any better? That Tokina looks very good in my book! Voigtlander looks very nice too. Better than it is said in the reviews.
I wonder how my CSJ Flektogon F4 would look here. I does flare quite a bit but can also be sharp at f16 corner to corner, mustache distortion inclusive. Anyone did any comparison with other contenders?



Bob955i
Registered: Dec 14, 2008
Total Posts: 479
Country: United Kingdom

mirkoc wrote:
That is very nice comparison jcolwell. Great effort.
How is 17-40 in the corner stopped down to f16? Any better? That Tokina looks very good in my book! Voigtlander looks very nice too. Better than it is said in the reviews.
I wonder how my CSJ Flektogon F4 would look here. I does flare quite a bit but can also be sharp at f16 corner to corner, mustache distortion inclusive. Anyone did any comparison with other contenders?


No test shots to show you mirkoc but I do have the 17-40, Flek 4/20 and Flek 2.8/20. Here's my findings, based on 5D FF use (from memory and a long time ago):

The corners of my particular 17-40 didn't appear to get much better at f16 IIRC.

1. 17-40 is sharper in centre and more contrasty than either Flek.

2. Both Fleks appeared better corrected than 17-40.

3. Both Fleks overall sharpness appeared more even across frame than 17-40 - bears out 1.

4. Flek 2.8/20 appeared a bit sharper than 4/20 for a given aperture; 4/20 needed stopped down a bit more - say f8 for the 2.8 vs f11 for the 4/20.

5. Flek 2.8/20 appeared to have more contrast than the 4/20; the better contrast likely due to it being MC as opposed to the single coating of the 4/20 - this might explain the flare you note on your 4/20 assuming there's no haze on any of the elements.



mirkoc
Registered: Jan 26, 2008
Total Posts: 627
Country: Croatia

Bob955i wrote:
mirkoc wrote:
That is very nice comparison jcolwell. Great effort.
How is 17-40 in the corner stopped down to f16? Any better? That Tokina looks very good in my book! Voigtlander looks very nice too. Better than it is said in the reviews.
I wonder how my CSJ Flektogon F4 would look here. I does flare quite a bit but can also be sharp at f16 corner to corner, mustache distortion inclusive. Anyone did any comparison with other contenders?


No test shots to show you mirkoc but I do have the 17-40, Flek 4/20 and Flek 2.8/20. Here's my findings, based on 5D FF use (from memory and a long time ago):

The corners of my particular 17-40 didn't appear to get much better at f16 IIRC.

1. 17-40 is sharper in centre and more contrasty than either Flek.

2. Both Fleks appeared better corrected than 17-40.

3. Both Fleks overall sharpness appeared more even across frame than 17-40 - bears out 1.

4. Flek 2.8/20 appeared a bit sharper than 4/20 for a given aperture; 4/20 needed stopped down a bit more - say f8 for the 2.8 vs f11 for the 4/20.

5. Flek 2.8/20 appeared to have more contrast than the 4/20; the better contrast likely due to it being MC as opposed to the single coating of the 4/20 - this might explain the flare you note on your 4/20 assuming there's no haze on any of the elements.


Thanks Bob955i!
How would you describe them color wise?
According to reviews 17-40 also seems to be one of the best if not best lens regarding flare and gosting resistance. Distorsion can also be easy corrected via DPP software.
It seems to me that a good copy of 17-40 is a great workhorse. I tried a copy in a local shop and didn't find corners objectionable. On the other hand, I have no experience with other ultra wides.



Cinstance
Registered: Oct 09, 2003
Total Posts: 3774
Country: United States

I used to love using ultra-wide Alt lenses, but since DPP added the lens correction function, my preference shifted to Canon wide angle lenses. Wide angle lenses are those benefit most from the lens correction functionality. Sharpness in corner is often overated. What I feel more disruptive to a wide angle image is distortion and CA, without which an image looks tons better. With the software correction, a $700 wide angle lens suddenly is as good as, if not better than some $2000 ones.