SUN-MOON-STARS

our week on the river

Your daily sun/moon/stars trip forecast.

We set out under a full moon on July 13th— the moon is up shortly after sunset— so lots of interesting long exposure night photography possibilities for the first few days.

On the 16th there’s a small window of dark sky after the twilight ends, before the moonrise, so there might be some good star fields between 10:42 and 11:21 pm. We also get a glimpse of the Milky Way starting at 10:40.

On the 19th, our last night out, we get the best look at the Milky Way, which pops up at 10:38 with good views until the moonrise, which happens at 12:35 am (7/20).

All week long, that sun pops up early at 6AM. If you want some of that soft predawn light, 5:30 AM is your time. Golden hour in the evening is from 8-9:15ish pm each night, so plan on a walk after dinner (bring your headlamps) to find some good angles for last light. And astronomical twilight ends around 10:40 each night, so that’s when we get some dark skies. Starting on the 16th we have a gap between that time and moonrise. We max out on Milky Way views on the 19th, with a two-hour gap, and the highest elevation of the Milky Way.

Of course, we’ll be in a canyon for most of the trip, so our local horizon lines will shift some of these times, depending on where we make camp. Also, these times will shift a little since the chart is based on the coordinates of the Sand Wash launch site¹, and we’ll be moving south.

I am bringing a Move-Shoot-Move star tracker with me. Everyone is welcome to try it out. It was recommended by a friend who does excellent Milky Way shots, as being affordable, compact, and simple to set up. Helpful if your camera uses an Arca Swiss style tripod plate, but not nesc., as I will have an extra in my kit.

Night photo pro-tips:

• Prefocus to infinity. Much harder to do in the dark, although with a mirrorless camera or live view on a high-resolution camera screen, it’s much more doable.

• Wide-angle lenses are more forgiving. The star movements will appear much more minimal at 16mm than at 200mm, for a longer exposure.

• Basic star exposure to start with: ISO 6400, ƒ2.8, 15 seconds. From there you can do the math, or use PhotoPills to equivocate an exposure — EG if you want a longer exposure or to add an ND for a super long exposure.

• Histograms: not a great reference tool for these kinds of exposures, unless you train yourself to see them correctly. The stars make up a TINY portion of the image, and their data is therefore tiny, which means on the histogram, there might be the tiniest of spikes in the highlights, almost invisible unless you are looking for it.

• Higher ISO means shorter exposures means shorter star trails means more amplification noise from high ISO.

• Lower ISO means longer exposures with less amplification noise, BUT, might add heat buildup on the sensor which can add similar-looking noise.

• There are a bunch of AR apps for your phone to show you where things are—or will be—but test them for use w/o signal before relying on them in the desert. I have one great app that absolutely fails when there’s no cell signal.

Alright, I know I’ve filled your heads with too much information again, so signing off.

-andy

PS There are still a couple of seats left in the boats, so if you are sitting on the fence, or know someone who is spontaneous and into photography and rafting, please pass this along.

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