So I’ve started to run into the limitations of my Ricoh GR when it comes to low-light photography. Milky way shots, low-moonlight star trails shots and also the half hour or so after sunset. So I decided to go full frame with a used Sony A7.
The question is, which lens to get? I jumped on a good deal for the 16-35mm f/4 zoom. It should arrive tomorrow. It’s clearly the lightest way to get the focal length range I’d like, at just over a pound. However, it’s only f/4 – so I’m upgrading to a bigger sensor but getting a slower lens. I’ll either keep it or I might sell it used in a couple months, if I decide to go with option B.
Option B is to get two prime lenses – first is the Sony 28mm f/2 lens, which is relatively small and light (8 oz or so). That would be a better walkaround lens for use during the day. I would pair it with the Rokinon 14mm f/2.8 for wider-angle shots. Both lenses are faster, an advantage at night. And the 28mm would probably be nicer during the day. However, the weight penalty for this solution is 10 oz! If you count extra batteries I’d be carrying 3 pounds in just camera and lenses. Add another half pound for my trailpix tripod + extra trekking pole and that’s 3.5 lbs just for camera gear. Ouch.
Truth be told, I prefer prime lenses to zooms and I would go with the two lens solution without question, except for the weight. That’s a tough pill to swallow when I’m doubling my camera weight as it is. The question really is, do I *need* f/2.8 for astrophotography, or is f/4 good enough? We’ll see. For star trails shots I’m sure f/4 is good enough, but I haven’t experimented much with the milky way.
Alternatively, I could sell the A7 and switch to an A7s. This is the advantage of having used gear, the resale value is basically the same as what I paid for it.
So anyway, that’s the current dilemma. Thoughts? The solution for now is going to be to test the 16-35mm zoom out over the next month or two. I’ll try it in the conditions where my Ricoh hasn’t been good enough, and see what I think. I’ll update this thread if I think it’s a good enough lens for my uses, or if I break down and get the extra primes.



