“Twin towers” is my name for a pair of autumn-red vine encrusted trunks of long-dead trees visible out of my bedroom window (figure 1, from the ground just below them). They are close enough to take up a surprising amount of visual real estate, yet far enough to really need a telephoto lens to capture them if they are not to be mere dots.

Figure 1. Twin tower trees. Photo: author.

All well and good, but even a good telephoto zoom lens like the one my wife bought for me (a Nikkor 18-200 f 3.5-5.6) has a hard time getting the trees and the hills behind them into focus, even at a high f-stop, and since I wanted to capture our bedroom window frame to provide depth of field, it was hopeless.

So, I sez to me, why not try focus stacking? I set up my camera on its tripod for stability and took multiple photos, changing only the focal point, bracketing the different planes in the view. For this inaugural trial, I took three photos, one focused on the window’s frame, one on the Twin Towers, and one on the distant hills. That made a certain amount of sense, since the view in fact breaks down into three fairly distinct planes.

Manual focus, of course, at 58 mm and f14. ISO 400. The shots themselves didn’t take long: the longest time was spent on each shot magnifying the image on the LCD on the camera’s back to make sure the focal point I wanted was in fact in good focus.

With the three images taken, I loaded them into Affinity Photo and let the program’s dybbuks have at combining the three images, taking the properly focused areas from each and producing (ideally) an image in quite sharp focus far beyond the limits of the optics by themselves.

Figure 2. Stacked-focus image of the Twin Towers. Photo: author.

The results were reasonably good (figure 2). I had to edit the image(s) on my iPad, which is OK but not ideal. I left it to the dybbuks to clarify the hazy background hills, and that was magic. I upped the contrast a hair and boosted the saturation of the reds and yellows a few points each. I reduced the luminance of those colors by about 5 points each.

In a serious trial I’d have used a remote shutter release and I’d have weighed down the tripod to keep it from shifting on the think carpet of our bedroom. I’d also have used ISO 100 and increased exposure time. But even so, I’m pleased to see that this technique is within the capabilities of even a rank amateur like me. Yay.

Published by gsb03632

A college professor living in Scranton, PA

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