Bright 26

Tricky thing, I have the hard task of being the first to give his opinion on this.
Personally I use a Nikon D90.
I start with the negatives, and yes there is!
- No seal, as on the NIKON goals.
- Something incredible, impossible to make a focus ring during AF editing mode has this effect remains fixed, unless you disable auto focus. Also has the support of the AF mode trigger, the focus ring on the lens rotates, so pay attention not to have your hands on it.
- To end the negative side, if you take the lens in your hand as you gently stirred, we expect very clearly something that walk inside, it's FEAR! In fact, after contact with SIGMA FRANCE, it turns out that it is the stabilizer that are not powered moves. I then mounts the lens, then fed my D90 miracle noise actually disappeared. Being very suspicious, I still went to check the noise on an identical goal FNAC, and OUF, is the same, so do not worry it is NORMAL.

I sold my excellent NIKON 16-85 for the purchase of this objective, and I hardly regret it.
My regrets compared to 16-85 NIKON is its versatility, its seal, but that's it.

Now the positive things of SIGMA.
This objective therefore has a constant aperture af / 2.8 and it makes all the difference. I also think the quality of the lenses are superior to those of NIKON. Before selling the 16-85 I went to several identical photos with these two objectives. Verdict is undeniable SIGMA is really much brighter, sharpness is truly greater than the Nikon. These measures were taken in "P" mode for each picture and each objective, so the NIKON D90 makes all settings. After verification of the photos, it appears that the opening parameters are the same with the NIKON and with SIGMA, yet at the same opening SIGMA is extremely brighter on the pictures and especially in very dark areas. For the same opening, in some situations, 16-85 forced to climb the D90 at ISO 800 SIGMA while with the unit has been ISO 200 for a superior result.

That I did my best to give you my impressions.
Stephane.