Sigma Art lenses

[Cornfield]

If you are considering buying the Sigma 12-24 or the 85 read what Lloyd Chambers has found while testing these lenses.  It could save you a lot of cash!  I like when Lloyd tests lenses in-the-field with scenes that are selected to test lens focusing in three dimensions.  Field curvature is something most of the review sites seem to ignore when the place so much weight in resolving flat test charts.

[NancyP]

It depends on what subject you shoot. If you plan to shoot landscape or architecture at f/8 to f/11, field curvature may not be a huge issue.

[Telecaster]

I've never found field curvature to be a big deal with 3D subject matter. Which includes most of what I photograph. The first "wide" lens I owned, a 1960s Leitz 35/1.4 Summilux, was a Prince of field curvature if not the King. I used mine happily for years before discovering this…in a magazine article. 

-Dave-

[PeterAit]

If you are considering buying the Sigma 12-24 or the 85 read what Lloyd Chambers has found while testing these lenses.  It could save you a lot of cash!  I like when Lloyd tests lenses in-the-field with scenes that are selected to test lens focusing in three dimensions.  Field curvature is something most of the review sites seem to ignore when the place so much weight in resolving flat test charts.

Some people test lenses and make charts. Other make photographs. Which would you rather be?

[kers]

I have the 85mm Sigma Art and it has a flat field of focus.
The 12-24mm has a curved one but that is a common thing
with wideangle lenses.
For landscape it can be a problem since you often would like infinity
sharp at any point of the image.

[Paulo Bizarro]

This is a common problem. For example, see here:

https://phillipreeve.net/blog/review-zeiss-zm-35mm-1-4-t-distagon/#more-5842

There are ways to mitigate this issue.

[kers]

Some people test lenses and make charts. Other make photographs. Which would you rather be?

I do both, i like to know what i have in my hands and what it can do- how to use it.
At a moment of the photo i use that knowledge to get the best possible image...
for instance, ik know that the flare resistance of the Sigma Art 85 is better than the 85PCE nikkor ( contra to what i suspected)
so if i need flare resistance i know i have to use the Sigma...