Sigma bokeh has got me stumped again

maulrat · Oct 6, 2008

Ok, so I didn't go out and buy the Sigma 18-200mm OS over the Canon 28-135mm... just yet. I have been looking at hundreds of sample photos from both lenses. The Sigma takes really nice colored photos but its bokeh has got me stumped. Its bokeh is really nervous looking and very colorful. Its really a distraction and concern so I may go with the Canon after all. The Canon 28-135's bokeh in most sample photos has been pretty smooth and not as bright as the Sigma's. For me, I prefer bokeh quality over a bit of focal length. But then again, I do like the wide-angle perspective of the Sigma. Ahhhh! I am pulling my hair out.

Do you have a Sigma 18-200mm OS? If so, what are your takes on its bokeh capabilities?

Do you have a Canon 28-135mm IS UMS? If so, what are your takes on its wide-angle capabilities?

I have read so many reviews on the web but I would really like to hear personal responses from you all here at TPF. Thanks to all in advance.

GeneralBenson · Oct 6, 2008

Well, as far as wide angle capabilities, they pretty much don't exist. 28mm on a crop body is not wide at all. It's equivalent to about 42mm. I have a 28-75mm and I love it, but it's basically standard to medium telephoto.

manaheim · Oct 6, 2008

I actually wasn't aware that the blurring effect on lenses had an effect on colors as well as just general blur. Are you sure that's the case? Are you getting a side by side comparison of the same images and the same exposures?

maulrat · Oct 6, 2008

When researching some sample photos of the bokeh, this is what I come up with. Bokeh tests aren't too easy to find but here are some samples of each.

Sigma 18-200mm OS HSM
#1

#2

bah, pbase image links are messing with me. Just click here please.

Canon 28-138mm IS UMS
please click on the numbers to follow link to sample image. sorry for in convenience.

#1

#2

#3

Is it just me or can you see a reasonable difference in bokeh here? Am I going about this all wrong? Are these photos so different that they should not be compared against each other? Please, if it can be shown that the bokeh in the Sigma 18-200mm is quite nice then help show me this as I am dying to get one just for the color and sharpness.
Thanks a bunch,

beaminge36 · Oct 6, 2008

Well i believe the pictures are like comparing apples with oranges. The background in the first sigma picture is very close to the subject and very brightly lit so it doesn't blur very well and appears very bright and colorful. The second picture with the canon seems like its shot in completely different lighting conditions and the background seems like its much further relative to the subject. Overall though, the canon does appear to have a smoother bokeh quality. Also, do you know what aperatures these were shot at? Maybe the flowers with sigma was shot more stopped down because of the intense sunlight where as the canon flowers were shot wide open? Hard to base off of these images. Just some food for thought, sorry if this leads to more hair pulling.

Nick

manaheim · Oct 7, 2008

If you're going to compare "bokeh" (term seriously needs to die), then you really should be doing it with a constant scene and equipment remaining the same across lenses. I don't know if dpreview has something like this... I don't recall seeing it.

Overread · Oct 7, 2008

something looks off with that linked dog photo - you have doughnut rings in the background - not something typical of a sigma lens (they tend to have better bokeh than canon many a time

). I would scout about and look for more, but I agree with Beaminge36 - its hard to compare unless you have tests between the two under test conditions

Dao · Oct 7, 2008

I believe user davebmck has the Sigma 18-200mm OS lens. See if he can give you some idea.

ksmattfish · Oct 7, 2008

maulrat said:
Its bokeh is really nervous looking...

That harsh, double line look is typical of super zooms and cheap zooms.

maulrat · Oct 7, 2008

Dao said:
I believe user davebmck has the Sigma 18-200mm OS lens. See if he can give you some idea.

Great idea

I spoke with him just before your response and he likes his lens. He said he would buy it again but doesn't recall paying too much attention examining its bokeh.

I am just going to stop beating myself up over this. I've got better things to do with my time. Since I am still new to photography, I enjoy taking all different types of photos; from lanscapes to portrait type. I am just going to go for the Sigma. Its range is perfect for an all around lens and probably good for learning zoom techniques; somthing I wasn't able to learn since I only have a 50mm prime. The 18-200 is also known for producing some fairly sharp and colorful photos which I like. My 3rd lens will have to be a portrait lens of which bokeh will be of more importance. At least an f/2.8 or better.

Thank you all for your help and responses.

dEARlEADER · Oct 7, 2008

maulrat said:
Great idea I spoke with him just before your response and he likes his lens. He said he would buy it again but doesn't recall paying too much attention examining its bokeh.

I am just going to stop beating myself up over this. I've got better things to do with my time. Since I am still new to photography, I enjoy taking all different types of photos; from lanscapes to portrait type. I am just going to go for the Sigma. Its range is perfect for an all around lens and probably good for learning zoom techniques; somthing I wasn't able to learn since I only have a 50mm prime. The 18-200 is also known for producing some fairly sharp and colorful photos which I like. My 3rd lens will have to be a portrait lens of which bokeh will be of more importance. At least an f/2.8 or better.

Thank you all for your help and responses.

lol... focusing too much on the out of focus area can steal all of your focus on the focal point... IMO don't expect too much bokeh out of this slow lens... you have to have all the variables just right....

if you are a bokeh freak you may want to keep on your prime path... like the 85mm 1.4 ....

GeneralBenson · Oct 7, 2008

Yeah, you have to take those super zooms for what they are. Image quality suffer at both extremes. But you get that much range in a single package. Personally, I feel like if you in photography for the long haul, you're always better off getting great image quality with a smaller focal range, than getting it all, at lesser quality. If I could only have one lens, I'd much rather have a high quality 24-70 than a medium quality 18-200. But at the same time, it sure must be nice to have all that range in one lens. It just a trade off, and you have to be aware of what trade you're making.