I’ve always had a fascination with flash photography. As I’ve been using the M10-P as my “camera” I decided to get some flash units for the Leica system for occasional use. The first one is the SF-24D. This is not the most compact Leica flash, but it is small enough to shove in the pocket of loose jeans. I wouldn’t recommend sitting on in though! These are available used on ebay and that’s where I picked mine up.
On the first day playing around, it felt like the TTL pre-flash proceeded the imaging flash by a significant and noticeable gap. I could easily discern that gap. The process was the pre-flash provided metering with the shutter open to allow the M10 image sensor to do a quick exposure calculation and transmit the results to the flash. Then the second flash was the exposure for the image. Right from day one that time gap between pre-flash and flash felt long to me with the SF-24D.
After a short time, I decided to move up the Leica hierarchy a little and picked up a SF-40 flash. This unit is a little larger, but has some attractive built-in features: tilt-swivel head, built-in diffuser, and analog controls as opposed to the LCD of the SF-24D.
Right away in TTL mode it was apparent that the pre-flash/flash cycle of the SF-40 was a lot quicker than the SF-24D. In an attempt to relay just how noticeable the difference is, attached are two videos. They demonstrate quite clearly how much quicker the SF-40 operates.
From a real-world prospective, the SF-40 pre flash/flash cycle is almost indiscernible while the SF-24D is quite noticeable. It’s easy to imagine that with each generation of flashes, the controls and speed have improved so it shouldn’t be a surprise to find the SF-40 significantly faster.
Video shows the SF-24D flash pre-flash and flash cycle. This was shot, slo-mo on an iPhone 6s. The time between flashes is 2.38 seconds.
Video shows SF-40 flash pre-flash and flash cycle . As before, slo-mo on iPhone 6s The time between flashes is .85 seconds.
The SF-40 is three times faster in the pre-flash/flash cycle.