Sigma 30mm F2.8 EX DN Review by Tobias Giesen

Page 1 - Intro and Product Images          Page 2 - Photographic Tests

The Sigma 30mm is fairly sharp but not stellar across the frame from F2.8 thru F8. Starting with F11, the effects of diffraction
start to blur the images. I have not tested vignetting but I don't see it in my test shots and it is unlikely to be an issue because
the lens was made for a larger image circle. The main problem that these test shots reveal is chromatic aberration, which
can reduce the positive impression of a fairly sharp lens considerably. Interestingly, chromatic aberration is not corrected
even on a Panasonic body. This has been verified with a Lumix DMC-G3.

On Olympus bodies, you can get the clicking noise known mainly from the Panasonic/Leica 25mm lens, although a bit softer.
This is caused by the camera stopping down during Live View when there is a lot of light. I don't consider this to be
an issue with the lens. But it is interesting that the AF motor is much quieter than the aperture.

When the camera is off, or the lens removed from the camera, you can hear some lens elements moving inside. This
is not caused by an IS unit as with Panasonic lenses - this lens does not have any IS. Instead, the lens element
used for focusing is apparently let free in absence of electric power.

The following images were shot with an Olympus E-P3 and I am showing the jpegs developed by the camera.

Regardless of what you think of the 100% crops further down below, it is entirely possible to shoot
very nice photos with this lens. These photos were shot with F2.8. As you can see, only one eye is
sharp with this aperture. So it really should be sufficient for shallow depth-of-field shooting.
Click on the images for the unedited original jpg:

The lens is not a macro lens, this is as close as you can get:

Now for the stricter tests. The left motive was shot hand-held with fast shutter speeds,
while the second one was shot with the camera pressed hard on a table. I am showing
the full images shot with F2.8 and 100% crops for various apertures below.

And here are the 100% crops:

F-stop		Center	Corner
2.8
4
5.6
2.8
3.2
3.5
4
5.6
8
11
22