When I saw the early reviews for the Sigma 35mm f/1.4 DG lens I though it had a lot to offer me. 35mm is probably my favorite focal length for general photography. Reviews praise the lens for how sharp it is wide open. It also seems to have decent bokeh (out of focus rendering). I have been using a Rokinon 35mm f/1.4 lens on the D800E since I bought the camera last spring. I am really happy with the image quality of the Rokinon, but I have lots of trouble achieving perfect focus with it since it’s a manual focus lens and the D800E has a screen that’s not very good for manual focus. This really limits my use to the tripod and Live View focusing. So I ordered the Sigma, even though it was on back order.
Last Thursday it arrived. I quickly did some indoor focus tests and like all the other lens on this particular camera it seems I needed no Fine Tune focus adjustment. Cool. But my tests were done inside at close distances. We got some snow that evening and then is stopped midmorning Friday. I went out for a walk at lunch, despite the ugly gray sky. I brought a tripod to do a few tests to see if the lens was obviously decentered, and also just shot a lot of hand held shots around the village, since this is how I hope to use the lens much of the time. On Sunday I went to my brother’s house and shot a few pictures of his dog (and the rest of the family, but I won’t put them in this post), again hand held.
Upon review of the images I found some were perfectly in focus, and some were way off. I noticed the close up ones were good, and the more distant ones were soft. So I shot a lot of tests in the backyard and found that with the lens adjustment at 0 the auto focus was right on for close distances, but infinity was way off. I adjusted for infinity which requires a -11 for the Auto Focus Fine Tune. Close up shots are now noticeably soft. I’m not sure what to make of this. Sigma will be making a USB dock and software to adjust the focus points, so maybe this is the solution. But it’s not available now, and I don’t know when it’s coming out. It also seems crazy that we need to spend more money to make our lens work as it should. I haven’t decided if I should send it back to B&H and wait for another copy to come in, or send it to Sigma for repair.
Here’re a few examples:
Full image. Focus on hanging sign.
Focus point
Background that’s more in focus than focus point.
Full sized shot of mailbox. Take fairly close up. Focus point on red flag on front.
Focus point on red flag. I’d say it got pretty close.
Close up shot with focus point on left eye. f/4
Left eye. Again the close up focus is good.
There are a few more shots over on my SmugMug gallery. Most are at f/1.4 to show the focus errors more clearly. There are a few shot stopped down. It’s pretty amazing how well corrected this lens is at wide apertures. Over all I am pretty happy with the image quality. It’ll certainly take many more shots to learn the lens. But sadly it doesn’t look like I can trust the Auto Focus, so is it really any better than my manual focus Rokinon?