Al fresco focus stacking using flash
Macro and close focusing work is often limited by available light. The closer the camera gets to the subject the shallower the depth of field for any given aperture, Stopping down helps - with my 60mm macro I can use f9 or f10 without running into more than minor diffraction problems - but that does require adequate light. And in many cases that means the use of flash. The alternative is to use more open apertures and focus stack multiple images. But even then flash is often needed.
My Olympus Em1 mkii supports in camera focus stacking using flash - but only under certain parameters. They are that'the shot limit in the in camera stack is 8 and manual mode (M on the top dial) must be used to set a speed of 1/50 sec to enable the camera to sync with the flash. Additionally the charge time in the bracketing menu must be set to zero if you want to trigger a rapid sequence of shots. Olympus flashes do this automatically but I use Godox so I have to set this up.
I would like to use my Olympus STF-8 twin flash for in camera focus stacking but it's not powerful enough to generate the rapid series of flash pulses needed to light eight images in quick succession, essential for handheld or non tripod supported shooting. I use a Godox TT685o with an 11in softbox angled down to illuminate the subject from above. The flash is set to manual mode rather than TTL to ensure consistency between each flash. A preliminary shot or two allows me to set the flash intensity correctly and I can then switch the bracketing / stacking on.
I'm old, I shake a little, and I'm not as steady as I used to be so handholding can be a little hit and miss. But the results, when they work, can be superb.
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| Fruticose lichen, possibly Usnea sp. |
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| Chaenomeles x superba 'Crimson and Gold' |
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| Crumpled leaves of curly kale |
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| Lesser celadine flower |
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