I’m just using my experience, and being conservative, making sure there’s plenty of overlap between frames. I’m not very scientific about this I don’t measure how much further back I have to focus for each frame, or anything like that. I’ll wait for a lull in the wind, click the shutter (using a remote or cable release of course), focus a little further back, click again, focus further back again, click again, and so on, until the focus reaches the flowers furthest from the camera. I start by focusing on the closest flowers, usually at the bottom of the frame (or one of the bottom corners). I also focus manually, through the viewfinder. You need to use manual exposures for focus stacking, as any variation in brightness between exposures will make it harder to blend the frames together later. Using f/16 gives me more depth of field, so the focus overlaps more between frames, requiring fewer images and less time. I’m usually trying to capture the whole sequence during a lull, when the breezes are minimal, so the fewer frames I need the better. More frames would be okay if there was absolutely no wind, but that’s rare. I could try f/8 or f/11, but then would have to capture more frames to cover the whole range and make sure every flower is in focus in at least one image. I typically use f/16 for focus-stacking sequences, because on all my lenses that’s the smallest aperture I can use before getting objectionable diffraction. That means making a series of exposures focused at different distances, and then blending those exposures together in software. But having said that, they’re perfect for wildflowers, because the flowers are usually on the same plane, so maybe one day I’ll bite the bullet and get one.īut in the meantime I can use focus stacking. They also have their limitations: there are no zoom tilt-shifts, so you can only use certain focal lengths, and they don’t help with situations where the near and far objects aren’t on the same plane, like tree branches in front of other tree branches. But I’ve never gone that route, mainly because tilt-shift lenses are quite expensive. With a tilt-shift lens you can change the plane of focus to match the receding plane of a field of flowers, making it easier to get everything in focus. One solution to this problem is tilt-shift lenses. And I’m more reluctant to use very small apertures like f/22 because the softness caused by diffraction at these small apertures also becomes more apparent with high-resolution sensors.
A slight fall-off in depth of field that wasn’t very noticeable with a 16- or 20-megapixel camera becomes glaringly obvious with a 36- or 42-megapixel camera. Using high-resolution cameras the last couple of years has only made it more difficult to get everything in focus. 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. 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. 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. It’s just difficult to get everything in focus with one frame when photographing wildflowers. I don’t need focus stacking often in other seasons, but in spring I use this technique all the time. And this is very common for me when photographing wildflowers. It was a little past the peak of the wildflower season there, but we still found some nice patches of poppies mixed with other flowers.Īs I was processing the images later, it occurred to me that all of them required focus stacking. Last week my wife Claudia and I spent an afternoon photographing flowers in the Merced River Canyon, just west of Yosemite. It’s spring, which means it’s wildflower season, and focus-stacking season. A focus-stacked blend of four different frames. Poppies, lupines, goldfields, and tri-colored gilia, Merced River Canyon, Sierra Nevada foothills.
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