Merced Wildlife Refuge with the Sigma 150-600 Lens

Laurie and I traditionally use the Thanksgiving weekend to visit the Merced area refuges (Merced NWR and San Luis NWR) when weather permits, and this year was no exception. For me, it was the first chance I’ve had to head out there with the upgraded camera kit — the new 7Dii body and my recent acquisition, the Sigma 150-600 F5.6-6.3 Sport lens.

The Sigma is built like a tank, and weighs about as much. I’d taken it out to Moss Landing once to give do some testing with it and hung it off a tripod with a gimbal where I was pretty happy, but Merced and San Luis are both car-route tours where you’re expected to stay in the car. That implies hand-holding the lens and hanging it out the window. Would that be practical?

More generally, would the quality of the images be good enough, or would it, as I’ve heard from so many about the new Tamron 150-600, go soft at 600mm?

(You can view all images from this trip here)

All I can say after a full day of putting it through its paces is that I’m really starting to like this lens. That said, I’d argue this isn’t a beginner lens, it takes a fair bit of technical fussery to make sure you get quality results with it.

For instance, it’s really heavy, so holding technique is key unless you want to kill your arms and ruin images with camera shake. One thing you realize quickly is that getting onto the subject and keeping it centered in the frame requires precision because your field of view at 600mm is tiny. And your depth of field is quite thin:

Dowitcher SPP

If you look at this grouping of dowitchers (600mm at about 50m away) you’ll see that the back bird is well out of focus at about 18″ behind the other bird. There’s not a lot of margin of error here so if you aren’t very tactical about your focus and knowing how to get the autofocus to cooperate, you’ll get a lot of fuzzy shots. This is not a “green mode” lens.

But to me, it feels almost made to order for the 7D Mark II body, which has a very powerful and flexible AF and which has added some easy ways to adjust the AF on the fly without going into the menus, so you can fairly easily shift from a wider AF to spot AF as needed without fumbling; with this lens, that kind of managing the AF system is going to be necessary for quality and reliable results.

When the AF locks on, however, the results are glorious.

Great Egret in Flight

Ross's Geese

Red-winged Blackbird

Snow Geese

Yellow-rumped Warbler

Say's Phoebe

As someone who’s always shot with a maximum of 400mm of lens available, I was very curious whether the added length of the new lens would make a significant different. In short, yes. In reality, I found it a massive difference. The 400mm lens was just powerful enough to get me in range of many birds, but at the same time, so close than my proximity affected them, so a lot of the time, it was a challenge to get a shot without scaring off or impacting the bird significantly. The 600mm lens puts me far enough away that I had very little trouble. This red-tail on a squirrel kill, for instance, was hanging out in a pasture; we approached it very slowly and it looked but then ignored me as I shot.

Red-tailed Hawk on a Kill

With 400mm, this would have been a heavily cropped shot at best, because I wouldn’t have been able to approach that bird to any reasonable distance for that lens.

I was constantly impressed with the response of the lens. This is a Wilson’s Snipe at 600mm at about 10 meters away. It was busy feeding and ignored me completely, and left me with full sized, uncropped images.

Wilson's Snipe

I found shooting at F/8 gave me a bit more leeway on sharp focus, but for flight shots I found the lens consistently locked on quickly and gave me consistently good results. I was set to shoot AF SERVO (of course) and fast burst, and while often I’d find the first image in a burst a bit soft — likely because the image stabilization was coming online — by the second or third shot, things were rock solid.

Snow Geese

(yes, that one goose has some kind of string attached. and no, that’s not dust on the sensor, those are bokeh-blackbirds) Image stabilization in the lens was impressive. I found myself consistently shooting handheld out of the car at about 1/1000 or 1/1250 on the 600mm lens and getting great results. That let me keep the ISO down and limit noise, but even late in the day the lens responded well. This was taken about 3:30 as we were starting to lose light as the clouds rolled in, but even at ISO 1250, F/8 and 1/2000 the results are nice.

Ross's Geese

One thing missing from this trip’s shots? Sandhill cranes. They were there, in numbers, but well out of range and refused to cooperate. The normal location for geese at Merced was full of Snow Geese, which was a bit surprising because Merced is one of the best locations for Ross’s geese, but it turns out the Ross’s were hanging out nearby and as the light faded they all flew in for the evening, so we got a nice mix of both. I also ran into the obligatory blue morph Snow Goose — two, in fact, an adult and an immagture.

Snow Geese

All in all, a great day and a strong collection of quality images, and definitely time better spent than fighting crowds at the store. And the Sigma 150-600 looks to be a keeper.

Ross's Geese and Snow Geese

Ross's Geese