My New Sigma 17-70

As mentioned previously, I bought a new lens, my first autofocus lens, and guess what? I LOVE IT!! Here a few samples of what it can do. I have hardly screatched the surface of how versatile a lens it is. It can literally focus so close that the subject is almost touching the front of the lens. It is prety sharp and I think I will really really like it. Really.

Here is a near 100% crop of the main part of the shot. This is using the natural light from the comparison shoot between the 3 lenses I posted a few days ago.

The original.

This is also a cropped shot but not quite as much as the first. Looking at the original, leaves you amazed at how sharp it is.

This shot was taken hand held at work, right after a patient gave me these flowers to take home to my wife.

These next three shots were taken at a park near my work. This was my first chance to play with my lens outdoors. This goose was moving quite quickly, and was a little too fast for the autofocus.

I love how wide this lens goes, it is the equivalent to 26mm on a film camera, and it is quite sharp corner to corner, with very little chromatic aberration. I just LIKE it.

A close up of a budding twig, this demonstrates the uselessness of autofocus with macro, it is best to just turn it off and do it yourself. I was trying for the bed, and got the little budlet right in front of it.

Yashica Vs. Pentax Vs. Sigma

One of my Photography buddies recently acquired a screwmount Yashica 28mm f2.8 lens. While I was arrranging to purchase a zoom from him (more about this later) he asked me if I could/would play with it and test it out. Always eager to play with another lens I said sure. This is my first try at a controlled test. I did OK with setting up lighting, but I think I had one flaw with my methodology, in that I used the focus confirmation indicator in my camera to confirm that the two manual focus lenses were focused. I think somehow that the Yashica focused a little toward the front of the subject, while the Pentax was spot on. The Sigma 17-70 I had the camera focus the first shot then switched to Manual focus mode, assuming from chimping the LCD that it was correctly focused, I think it also was slightly front focused as well.

I will try to post a few 100% crops later to show the differences, but you should be able to see which was the sharpest from these shots.

I shot all lenses at wide open (f3.5 for the Pentax k-28mm f3.5 and the Sigma 17-70, and f2.8 for the Yashica 28mm f2.8.) with the Sigma zoomed to 28mm. Then at f4, 5.6, 8, 11, and 16. Except for minor differences in color, all were quite sharp at f11 and f16. At f8 they were all reasonably good with the Pentax slightly ahead in sharpness. The Pentax was by far the best performer at f3.5 (wide open). The Sigma tended to overexpose which I think compromised it's IQ a little bit as well.


Yashica f2.8 Yashica f4.0

Yashica f5.6

Yashica f8

Yashica f11

Yashica f16

Pentax f3.5 Pentax f4.0

Pentax f5.6

Pentax f8.0

Pentax f11

Pentax f16

Sigma f3.5 Sigma f4.0

Sigma f5.6

Sigma f8

Sigma f11

Sigma f16