I’ve had my new Sigma 8-16mm F4.5-5.6 DC HSM UWA Lens for a few days now and have left just this lens on the camera and taken a number of shots with my Nikon D90. I’ve pretty much taken almost all of the shots at maximum wide (8mm – which equates to 12mm equivalent on my 1.5x crop sensor) to exaggerate it’s effect for each purpose.
The first shot below was taken to show both some perspective distortion and close focusing as well as how the lens would fare from a chromatic aberration (CA) point of view. CA would appear as colour fringing (a sort of purple or green halo around the boundaries between very light and dark transitions in a photo). One of the new technologies touted with this new lens is Sigma’s new FLD glass elements (four of them), which Sigma claim have the performance equal to fluorite glass (which is only found in the most expensive of lenses) to compensate for colour aberration.
This shot was taken with me lying on the ground and facing the camera up to the sky with the girls leaning in close to the lens above me – it does show that the closer to the centre the less distortion and the closer you get to the edges the more distorted the view. I needed to expose for the girls faces which were pretty shadowed facing down and this resulted in totally blowing the sky as expected. I only had a moment to take the shot before they’d all run off however the HSM focusing was fast and accurate and the CA seems to be reasonably well restrained even under these most extreme of conditions.
1/60 sec at f/8, ISO 640, 12mm equiv
The next shot after is probably a more typical shot where you might see problems with CA with lots of leaves against the bright sky and even at 300% I can’t really detect anything I’d be worried about.
1/160 sec at f/8, ISO 200, 12mm equiv
In the following shot the hard afternoon light (after 4PM) is streaming in from just to the right of frame behind her hair which does introduce some lens flare – then again I’m almost pointing the lens into the sun so…. Again I’m fairly close to her which has provided distortion and the beginnings of some background blur even at f/8 @ 8mm.
1/100 sec at f/8, ISO 200, 12mm equiv
The following image is an HDR I processed out of three bracketed shots at 0, -2 and +2 EV. This shot has actually turned out as well or even better than I might have hoped so I’m pretty happy with the result.
1/125 sec at f/8, ISO 200, 12mm equiv
Some more perspective distortion shots of the girls – big feet and big heads are always good for a laugh.
1/60 sec at f/8, ISO 400, 12mm equiv
1/60 sec at f/8, ISO 720, 12mm equiv
Thus far I’ve been pleasantly surprised and happy with the new purchase.
I had been expecting to see some fairly significant vignetting (darkened corners of the photograph) especially at the wide angle end and if you take the camera at 8mm indoors and point towards a white wall you can fairly easily see that the corners of the frame are darker so vignetting is definitely there. However in real world use I didn’t see a lot of obvious corner darkening in my everyday shots so I’m more than happy with the actual use.
Another thing I tried but didn’t include shots of here were photos taken indoors of rooms with my SB-600 flash with the diffuser at maximum wide and bounced off the ceiling for maximum spread (still not enough to cover the lens field of view but good enough 🙂 ). Basically you can stand near a corner and the frame will take in both walls leading away from you and the whole room (making it seem stadium sized).
It appears to be sharper than I had been expecting for such a wide and distorting lens (I’ve yet to take any shots wide open so will reserve judgment under f/8). The HSM focusing mechanism has been fast, quiet and accurate in all lighting conditions I’ve used it in so far.
The lack of VC (Vibration Control – or VR in Nikon parlance) is probably pretty much irrelevant at these focal lengths and for the purposes I’m likely to use the lens for.
I’m very happy with the build quality so far – it feels solidly built with no loose parts and the the zoom and focus rings are smooth to use.
In my next post I’ll cover a number of long exposures I took with the lens last night down on Sydney Harbour.