While clearing brush in late afternoon this week, I happened to glance up at the precise instant the setting sun poked through a sliver in overcast skies, bathing a nearby wooded ridge in crimson and gold.

A moment later, clouds rolled in, and the scintillating view dimmed, as if by a rheostat on a light switch.

Lucky timing, I told myself, contemplating the often-ephemeral quality of nature. If I hadn’t been standing in that very spot, at that exact time of day, during peak autumn foliage, in partly cloudy conditions, and if I hadn’t shifted my gaze just then, I would have missed a breathtaking tableau.

After it faded, I thought of similar fleeting experiences.

One socked-in afternoon years ago, while ascending the Lion Head trail en route to the summit of New Hampshire’s Mount Washington, I emerged through the fog into sparkling, cerulean skies — dazzlingly clear except for one lingering shroud of mist.

Sunlight that penetrated through this hazy wisp created a rainbow arching over my shadow like a halo. Then, poof — it was gone.

A few winters later, I was climbing a ridge alone near Mount Adams just at sunset, hurrying to return to Gray Knob Cabin before dark to take up my post as a volunteer caretaker.

An expansive, frozen mountainscape glistened in the waning rays, and as I peered at the tangerine sky, a sun dog, or parhelion, materialized — an ember-like glow caused by light filtering through atmospheric ice crystals. I barely had time for a glimpse before it dissolved.

On another occasion, my son Tom and I were kayaking down the Erie Canal when a whirling dust devil blew up in a field 100 yards away and spun toward us.

As if it had eyes, the mini-tornado skipped across the water and slammed into our vessels, nearly tipping us over, before crossing to the other side of the canal and blowing itself out. The entire episode lasted less than five seconds.

I sometimes wish I had captured these experiences on video so I could relive them. For better or worse, our culture has become so programmed by the digital dynamic that we expect instant replays of every shooting star or wildlife close-up.

As much as I admire photography, though, it seems that too often people are so preoccupied while peering through lenses or staring at screens that they miss the moment something magical happens.

A viewfinder also shrinks peripheral vision. If I had been fiddling with a camera instead of scanning nearby bushes when Tom and I hiked Vermont’s Long Trail several summers ago, I might not have noticed a dark shape just off the muddy path.

We halted, held our breath, and peered at a moose and two calves that lay nearly hidden less than a yard away. The animals stared silently, as motionless as statues.

“Oops. Excuse us, just passing through,” I said, as we scurried away.

Somewhat related, friends and I were paddling down the Kennebago River in Maine early one morning, when I decided to photograph the group. I raced ahead in my kayak, turned around in midstream and extracted my camera from a waterproof pouch just as they appeared around a bend.

I was hoping for a candid shot, but for some reason, everybody insisted on waving crazily at the camera while I drifted backwards.

“No, no! Keep paddling! Look natural!” I shouted, but they kept gesturing.

“Behind you!” someone exclaimed.

I spun around in time to see a giant moose, not 10 yards away, splash ashore and crash through the woods.

Did I manage to snap the picture? Of course not.

No matter. I can always conjure up the image, just as I can forever see, without photographic reminders, a menagerie with whom I’ve crossed paths (or wakes) over the years: the finback whale my pal Phil Plouffe and I slipped past while kayaking in Maine from Monhegan Island to Port Clyde; the herd of yaks stampeding toward a narrow suspension bridge in Nepal that our group was trying to cross; the huge shark that circled the eight-foot pram when my buddy Rocky Tremblay and I were rowing across Long Island Sound in the middle of the night; and the grizzly bear that charged me outside Alaska’s Denali National Park.

Fear and excitement may help reinforce memory, but sudden, transitory moments also will long resonate. I know I’ll always see that scintillating autumn sunset when I gaze at the ridge near our house, whatever the time of day or season.