Advanced Techniques

Why F/16?

Late-October aspens near Silver Lake, June Lake Loop, Inyo NF, CA, USA

Late-October aspens near Silver Lake, June Lake Loop, Inyo NF, CA, USA. I used f/16 to get everything in focus in this 2008 photograph from the eastern Sierra. (The shutter speed was 1/6th second, the ISO 400.)

I sometimes post my camera settings here on the blog, and I’ve had many people ask me why I often use f/16. Is that the sharpest aperture on my lens? (No.) Don’t you get diffraction at f/16? (A little bit.) Is it for depth of field? (Bingo!)

As many of you know, most lenses are sharpest at middle apertures – generally around f/5.6 to f/11, depending on the lens.

Better lenses will perform decently at wide apertures like f/2.8 or f/4, but usually the corners are softer compared to the middle apertures. On the other end of the spectrum, at smaller apertures diffraction causes all lenses to get softer over the entire image (not just the corners).


Eclipse Tips

Sequence showing the annular solar eclipse, May 20th, 2012, from Manzanita Lake, Lassen Volcanic NP neutral-density filter

Sequence showing the annular solar eclipse, May 20th, 2012, from Manzanita Lake, Lassen Volcanic NP

The total solar eclipse in the United States is just over a week away (August 21st), and eclipse mania is sweeping the nation. There are many, many articles on the internet describing how to photograph the eclipse (this one by Todd Vorenkamp on the B&H website is the best I’ve found), but I’ll try to cover some topics that haven’t been discussed much elsewhere.


Focusing in the Dark

Lunar rainbow from Cook's Meadow, Yosemite NP, CA, USA

Lunar rainbow from Cook’s Meadow, Yosemite; from June, 2011, a very wet year

Lunar Rainbows and the Milky Way

There will be a full moon this Saturday, and I’m sure many photographers will be heading to Yosemite to photograph the lunar rainbow. Astronomer and “Celestial Sleuth” Don Olson has updated his website to include predictions for when the moonbow will appear on Upper Yosemite Fall from Cook’s Meadow, in addition to his previous predictions for Lower Yosemite Fall.

I think there should be enough spray to make the rainbow visible on Upper Yosemite Fall this month, but probably not in June, when there will be less spray. The Lower Yosemite Fall bridge might work in June, because you don’t need as much water to see a rainbow from that spot, but I expect the bridge will be rather wet this month, which will make it hard to keep spray off the front of your lens. Of course the weather always plays a role, and there are showers in the forecast for this Friday and Saturday nights, so the moonlight might get blocked by clouds. But if you want to try your hand at either location, here are some tips for photographing lunar rainbows.

This is also the beginning of Milky Way season here in the northern hemisphere. The brightest part of the Milky Way can now be seen rising just after 10:30 p.m. here in central California, and will be visible in the evening sky through September.


May Showers

Spring sunrise, Gates of the Valley, Yosemite NP, CA, USA

Spring sunrise, Gates of the Valley, Yosemite, Sunday morning

First, to my subscribers, thanks for your understanding about the email glitches yesterday. I really appreciate all the supportive emails so many people sent. Your kind words turned a frustrating day into a great one.

I haven’t posted anything new on the blog for awhile because I was teaching a workshop, and then working on our new website. The new site is still a bit of a work in progress, so if you find any broken links or other issues please let me know. But the new site better integrates the blog with the other content, makes it easier to add and update portfolios, and will work much better with phones and tablets, so I hope it will be a better experience for everyone.

Meanwhile we had a great workshop, with flowing waterfalls, fresh spring greenery, dogwoods, and some interesting weather and clouds. And the cool, showery spring weather has continued, which I love. I’m not ready for the summer heat, and always happy to have clouds and mist to photograph.


Focus-Stacking Season

Poppies, lupines, goldfields, and tri-colored gilia, Merced River Canyon, Sierra Nevada foothills, CA, USA

Poppies, lupines, goldfields, and tri-colored gilia, Merced River Canyon, Wednesday afternoon. A focus-stacked blend of four different frames.

It’s spring, which means it’s wildflower season, and focus-stacking season.

There’s been a secondary poppy bloom in the eastern end of the Merced River Canyon near El Portal. No big swaths of poppies, but smaller patches, and some of those patches are mixed with other flowers, which always makes things more interesting. Claudia and I spent the afternoon up there on Wednesday, and had a great time. I’ve included a couple of my favorite images from that day here.

As I was processing the images later, it occurred to me that all of them required focus stacking. Literally every single one. And this is very common for me when photographing wildflowers. I don’t need focus stacking often in other seasons, but in spring I use this technique all the time. It’s just difficult to get everything in focus with one frame when photographing wildflowers. I’m frequently picking out a particularly dense patch of flowers, and using a telephoto lens to emphasize patterns and visually compress the space, making the flowers look closer together. Even with careful focusing and f/22 it’s impossible to get everything in focus with a long lens raking across a field of flowers like that. But even with wide-angle lenses it’s sometimes difficult to get everything in focus with one frame, because I’m getting really close to the foreground flowers, so there’s a tremendous amount of depth.


San Joaquin Valley Sunset

White-faced ibises, goldfields, and a vernal pool at sunset, San Joaquin Valley, CA, USA

White-faced ibises, goldfields, and a vernal pool at sunset, San Joaquin Valley, Calfornia

There’s often an element of luck in landscape photography. Of course, as Ansel Adams said, “Chance favors the prepared mind.” You have to try to put yourself in the right place at the right time, and then make the most of the opportunities you get. But sometimes luck goes above and beyond.

Yesterday Claudia and I made a day trip to the Bay Area on business, and on our way home we decided to check out some vernal pools in the San Joaquin Valley. Vernal pools fill with water during the winter rainy season, and then slowly evaporate during the spring. As they evaporate, flowers grow along their shores, sometimes forming concentric rings of color. As California’s Central Valley got plowed and paved over, vernal pools became increasingly scarce, so they’re home to several rare species of plants and animals. Most of the remaining vernal pools can be found along the edges of the valley, where the land rises slightly, but the San Luis National Wildlife Refuge complex and Great Valley Grasslands State Park have preserved some vernal pools in the heart of the San Joaquin Valley, and that’s where we headed.