Are you looking for a wide-angle lens for your new FF camera ? I was looking. On FF, I found that 24mm was already wide enough. I wanted a little wider and better quality than the EF 24/2.8. Zeiss 21mm was out of my reach Based on the reputation from reliable sources, I chose Sigma 20/1.8. For bonuses, it has several advantages over Zeiss 21 - Price, AF, 1mm wider, and Yeah 1 1/3 stop brighter !
Here is my report.
Build/Design
It is well built. I don't like the rough textured finish but I can live with it. The dual clutch mechanism for AF/MF switch is somewhat bothersome when I do Manual Focus. And you can hear the AF motor.
Image quality
It doesn't have the brown tint that my old Sigma 15-30 used to have. Images are sharp and cool. The distortions exist but not much. 20mm is pretty wide on FF. It grabs too much sky. I think I would need a special training to go wider than 20mm. Sample shots below will show you the various attributes of the quality. Make your own judgment.
Flare
I couldn't find the sun all day. So I can't really tell. But the shot below include spot light sources directly. And it doesn't show the flare. Again, it is pretty wide. http://www.sesee.com/Photo/Exports/Sig2018-indoor.jpg
Macro close-up
The spec says the minimum focusing distance is 20cm. But that is measured from the film plane. You can focus as close as about 3 inches from the lens front. In practical sense, you can go as close as your body and the subject allow I got actually hurt by the Cactus as I was too close without knowing the distance.
f/1.8 http://www.sesee.com/Photo/Galleries/StanfordCactus/YZ5P0864.jpg
Further testing shows that it creates doughnut shape bokeh around teh highlights. When the close-behind subject is multiple needles like above shot, the bokeh can look weird. http://www.sesee.com/Photo/Exports/Sig20-18-bokeh.jpg
Conclusion
This is a keeper to me. Your mileage may vary as always.
Edited by Pondria on Dec 30, 2005 at 07:13 PM GMT (Reason: Added AF motor sound)
Edited by Pondria on Dec 31, 2005 at 11:15 PM GMT (Reason: Final bokeh section added)
Thanks Pondria. I think about this lens from time to time along with the 24 f/1.8 as well. Your test was interesting. You seem to be on a roll with new equipment lately! Congratulations!
I find it funny that you just purchased a 1DsM2, and you said "Zeiss 21mm was out of my reach." Something tells me that you could get it if you want to, it just isn't worth that much money to you. For whatever it is worth, this is how I have feel as well although I am sure it is a very nice lens.
Regarding the bokeh, your subject might be influencing the odd bokeh. You might try the same test on a variety of subjects to see if you get the same results. Bokeh can get strange with any lens based upon the background. Obviously some lenses do better than others. I just don't know that you have fully tested the bokeh at f/2.0 to really say that it is weird...although it could be. I would be interested in seeing more here.
Regardless, congratulations! It is nice to see you getting some new equipment and sharing your experiences!
BrianP wrote:
I find it funny that you just purchased a 1DsM2, and you said "." Something tells me that you could get it if you want to, it just isn't worth that much money to you. For whatever it is worth, this is how I have feel as well although I am sure it is a very nice lens.
I think we think the same way in this matter.
Regarding the bokeh, your subject might be influencing the odd bokeh. You might try the same test on a variety of subjects to see if you get the same results. Bokeh can get strange with any lens based upon the background. Obviously some lenses do better than others. I just don't know that you have fully tested the bokeh at f/2.0 to really say that it is weird...although it could be. I would be interested in seeing more here.
Agreed. My conclusion probably was premature. I just reported what was easily noticeable. I'll investigate further.
Regardless, congratulations! It is nice to see you getting some new equipment and sharing your experiences!
The new camera has inspired me somehow
Ive been using the sigma 20mm 1.8 on my 20D, and am quite happy with it. Detail is lost on this jpeg, but trust me the corner lights are quite sharp. This was taken at f/9.0 I believe.
Two thumbs up from me on the Sigma 20 f/1.8. Works well on both my 10D and 5D. Wide open, mine is pretty soft but it sharpens up very nicely even at f/2.0. Good color, great detail, good corner sharpness. A very worthwhile lens. It's fun to use it for vertical, stitched panos and auroras.
jdaily wrote:
To my eyes, that bokeh is very unpleasant. Please report back, as I'm seriously considering this lens.
Thanks for the review.
Further testing shows that it creates doughnut shape bokeh around the highlights ( Look at the top left corner ). It can be convoluted with special shapes of the object behind like the needles in the original sample. However, this is observable in very close close-up with wide-open aperture. http://www.sesee.com/Photo/Exports/Sig20-18-bokeh.jpg
Pondria wrote:
Further testing shows that it creates doughnut shape bokeh around the highlights ( Look at the top left corner ). It can be convoluted with special shapes of the object behind like the needles in the original sample. However, this is observable in very close close-up with wide-open aperture.
Sometimes, stopping down 1/3 or 2/3 stops will soften the hard edge on the bokeh "discs". Granted, they'll start to take on the aperture shape, but I'd rather have soft-edged septagons than hard-edged circles.
10DFT wrote:
Sometimes, stopping down 1/3 or 2/3 stops will soften the hard edge on the bokeh "discs". Granted, they'll start to take on the aperture shape, but I'd rather have soft-edged septagons than hard-edged circles.
I agree. The hard edge doughnut might create positively nice effect in some special cases. But it would prefer the soft fade-away in general.
You read my mind, Pondria. I was just thinking about this lens. I owned it when I shot film and was pleased with its results considering its price. Pretty useless at 1.8, but so what, stop down a bit and remember the cost. Big filter though... 82mm? I do remember a bit of a yellow/brown cast, not as much as the 15-30. Your copy looks good. Thanks for the test.
something to consider is that this lens actually weighs *more* than the 17-40. if only there was a quality 20mm 2.8 that weighed 250g, like Nikon's, and would autofocus/autoaperture on Canon
Based on the reputation from reliable sources, I chose Sigma 20/1.8. For bonuses, it has several advantages over Zeiss 21 - Price, AF, 1mm wider, and Yeah 1 1/3 stop brighter !
Congratulations!
