My Take on Flash Photography: Part 4

NB: This series of posts will convey my understanding of flash photography. While I hope it serves a useful purpose, I by no means describe this series as a be-all, end-all resource on flash photography. As ever, if you feel I have made a factual error, please correct me.

This week, I’ve decided to try and show three flash modes which I use now and then: high speed sync, stroboscopic, and trailing curtain sync. Brief summaries of each will follow pairs of pictures showing the difference the flash mode makes to the picture.

To try and preserve the sullen grey of the rainclouds in the background, I shot this at 1/1600s. The blossom is underexposed and not terribly appealing (as blossoms should be).
To try and preserve the sullen grey of the rainclouds in the background, I shot this at 1/1600s. The blossom is underexposed and not terribly appealing (as blossoms should be).
I resolved the issue of an underexposed blossom by using my Metz 54 in high speed sync mode. This allowed me to hold the grey in the background (it's enhanced the effect), while giving the blossom an appropriately happy complexion.
I resolved the issue of an underexposed blossom by using my Metz 54 in high speed sync mode. This allowed me to hold the grey in the background (it’s enhanced the effect), while giving the blossom an appropriately happy complexion.

High speed sync allows syncing with shutter speeds above the nominal flash speed, but sacrifices a lot of flash power in the process; it’s not uncommon for me to drop to 1/64th power or less, especially against strong backlighting.

Alright, the photo of the tonearm returning is nice enough without any kind of flash. There's a nice motion trail following the arm back to the rest. However, it's a bit plain...
Alright, the photo of the tonearm returning is nice enough without any kind of flash. There’s a nice motion trail following the arm back to the rest. However, it’s a bit plain…
Using stroboscopic mode on the Metz 76 at 1/64 power for 2.0s at f/16 with 10 flashes at 5 Hz (5 flashes per second), I was able to show the stages of the tonearm moving back to the rest.
Using stroboscopic mode on the Metz 76 at 1/64 power for 2.0s at f/16 with 10 flashes at 5 Hz (5 flashes per second), I was able to show the stages of the tonearm moving back to the rest. Note also the pattern the text on the label has made, leading to something more visually interesting than blurred lines. Another benefit of this pattern is that you can positively identify it as a Side B of the first LP in Tame Impala’s album “Lonerism”. It’s a jolly nice album, actually.

Stroboscopic mode allows control over the frequency and number of flashes, giving a similar effect to the strobe light on a dance floor (unless I’m imaging the existence of such a thing). This is quite handy for motion studies and similar applications. Like high speed sync, you lose flash power (the samples here were taken at 1/64 power). However, due to the cumulative effect of having multiple flashes, I find the exposure is a bit difficult to get right first time. This situation is exacerbated by forgetting how to use a flash meter for multiple flashes… It always pays to read the manual thoroughly!

With leading curtain sync, the tonearm is frozen at the point where it started to return, with the motion trail leading it back to the rest. A ghost image of the tonearm has formed on the rest, as it sat for a few seconds before the exposure finished. This could easily be mistaken for a photo of the record being played from start to finish.
With leading curtain sync, the tonearm is frozen at the point where it started to return, with the (faint) motion trail leading it back to the rest. A ghost image of the tonearm has formed on the rest, as it sat for a few seconds before the exposure finished. This could easily be mistaken for a photo of the record being played from start to finish.
Trailing curtain sync resulted in the motion trail following the tonearm back to the rest. There is no ghost imaging, and the actual direction of travel is both easily discerned and represented with a more natural appearance.
Trailing curtain sync resulted in the motion trail following the tonearm back to the rest. There is no ghost imaging, and the actual direction of travel is both easily discerned and represented with a more natural appearance.

Trailing curtain sync is applicable (and more noticeable) in long exposures. Rather than synchronising the flash with the opening of the first of the two shutter curtains, the flash is synchronised with the closing of the second shutter curtain. This freezes the object at the end of its travel; the motion blur from a slow shutter speed follows the subject, rather than leading the subject. Overall, this lends a more natural appearance, and minimises ghosting. Ghosting occurs when a subject is stationary long enough to be exposed by available light, such as at the end of its travel. When I’m doing anything with movement and flash, this is the method I usually use.

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