REVIEWS - Accessories - Leica SF-40 Flash versus Leica SF-64 Flash

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Leica SF-40 and Leica SF-64


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Weight Comparison

Leica SF-64 Weighs ~240g More

Size Comparison

Leica SF-64 Almost 2X as Tall

Size Comparison

Shown on a Leica M Monochrom Typ 246

Size Comparison

Flash versus Available Light

Rear Controls

Sexy versus Minimalist

Off Camera Flash

Nikon SC-17 TTL Cable

Nikon SC-17 TTL Cable

Leica TTL and HSS Support

Added Weight

Four AA Batteries Required

Four AA Batteries

Adds Approximately 121 Grams

Odd Shape

Does Not Fit Easily in a Camera Bag

SF-40 Soft Case

4x4x4 Inch Cube Eats Bag Space

Leica 35mm Summilux-M ASPH FLE

Leica M-246 • F5.6 • 1/125 • ISO 3200

Model Number 14624 14623
Announced October 2015 October 2015
Produced By Nissin Metz
Supports TTL Yes Yes
GN Output 131' @ ISO 100 / 105mm 209' @ ISO 100 / 200mm
Power Output 1/1 - 1/256 1/1 - 1/256
Recycle Time 0.1 - 4.0 seconds 0.1 - 4.4 seconds
Flash Duration 1/800 - 1/20000 sec 1/180 - 1/18000 sec
Compensation (FEC) ±2 EV, 1/2 EV Steps ±3 EV, 1/3 EV Steps
Zoom Range 24-105mm, 16mm Panel 24-200mm, 12mm Panel
Head Tilt 0º to 90º -9° to +90°
Rotate 180º Left / Right 180º Left / Right
First & Second Curtain Yes Yes
High Speed Sync (HSS) Yes Yes
Power Source 4 AA Batteries 4 AA Batteries
Off-Camera Terminal None Yes, PC Terminal
USB Port No Yes
Weight 203 grams 429 grams
Weight with Batteries 323 grams 549 grams


I occasionally use the Leica SF-40 and Leica SF-64, so this article is a casual comparison of the two flashes. The main difference between these two flashes is output power, with the Leica SF-64 providing ~40% more output relative to the Leica SF-40. With power comes a heavy price - the Leica SF-64 is roughly 2X heavier and roughly 2X taller. For most photographers the 2X difference will drive their decision. And rightly so, having over 500g atop a Leica M makes for a lousy handling experience.

A Leica SF-64 is unequivocally large on Leica M body, but what about a Leica SL Typ 601? The Leica SF-64 flash looks more in-scale with the Leica SL Typ 601; however, the overall package in terms of absolute weight is quite extreme. The SL kit set-up shown to right weighed in at 2685 grams - almost 6 pounds! The SL kit makes the Leica M Monochrom with the Leica 50mm F.95 Noctilux-M ASPH look diminutive. Okay, so lets assume weight is not the primary decision factor, then what is difference between these two flashes?


As already stated, the key difference is output power, but the most visually apparent difference is a big, sexy touchscreen on the Leica SF-64. It is a bit showy, but also informative. With the Leica SF-40, much is done on the belief the flash and camera will do the right thing. For example, there is no visual cue as to whether or not the flash is in High Speed Sync (HSS) mode or what focal length the flash has zoomed to. In contrast, the Leica SF-64's rear display shows all the information, so no guessing needed.

On the other hand, the Leica SF-40 is direct with no menu diving or touchscreen taps. Want TTL mode? Okay, just turn the dial to TTL and adjust in the amount of FEC desired. My biggest niggle with the Leica SF-40 is not knowing whether the flash has entered HSS mode or not. A simple firmware change like a steady TTL light (on the rear control) to indicate TTL and the same LED rapidly blinking to indicate HSS TTL would be nice. I do not worry so much about whether the flash has zoomed to the correct focal length, I just assume it has.


Wireless flash capabilities have advanced considerably. Nowadays Canon, Nikon, Sony, etc. have a wealth of hot shoe based wireless commanders with TTL capabilities to control multiple flashes. But not Leica... The SF-40 and SF-64 can be triggered by the flash burst of the on-camera flash. Or, they can be triggered wirelessly by a Yongnuo RF-602N set-up. In either case the flash output power has to be set manually and there is no TTL or HSS mode.

After some experimentation, the Nikon SC-17 TTL Cable (now discontinued) proved the most reliable and flexible option for off-camera flash. The Nikon cable is MUCH cheaper than buying Leica's Multifunctional Handgrip M and Leica SCA Adapter Set for Multifunctional Handgrip M. That duo costs over $1000 (at retail) vs a used Nikon cable for ~$20 from Ebay. I did try the current Nikon SC-28 TTL Cable. The contacts did not line up well and it worked intermittently at best. I also dabbled with the Nikon SC-19 Extension Cable and AS-10 Hot Shoe Adapter. Used in conjunction with the Nikon SC-17, this set-up adds ~12' feet of extension cable. Unfortunately, I could not get this set-up to work. So my $.02, stick with a used Nikon SC-17 TTL Cable and don't tempt fate.


Both flashes require (4) AA batteries. I use Panasonic's Eneloop Pro AA Rechargeable NiMH Batteries, rated at 2550mAh. These batteries have held up well thus far (had them a year or two now). Before I was using Ansmann 2850 mAh batteries, but they stopped taking a full charge after a year of use and became very unpredictable. Generally, I get ~300 clicks out one charge of the Eneloops.


Flash guns like these are not known for their warm, soft, lovely light. In my experience, dialing up the ISO and easing off the flash output goes a long ways towards softening the look. I would be hard pressed to say whether the SF-40's or SF-64's output is better; though, the SF-64 has alot more horsepower. The SF-64 also has a larger reflector, so its output seems broader.

Leica's TTL performance bounces back and forth between over and under exposed. Outdoor fill in daylight has proven very difficult (shooting aperture priority mode). This is why I keep harping about the Leica SF-40 not indicating whether it is in HSS mode or not. Auto ISO seems to confuse the Leica TTL calculations, so turning off auto-ISO helps to a degree. There are been various firmware updates for the Leica M's and Leica SL which are supposed to have improved flash performance, but for me it all still feels pretty random.

I have quasi given up on Leica's TTL, and usually put the camera in M mode and throttle the ISO and flash output until I get an exposure balance I like. This trial and error approach takes ~5 shots to get a scene dialed in. For more on the Leica SF-40 with the Leica M Monochrom Typ 246, check out this post from earlier this year.


If planning to occasionally use a flash, the Leica SF-40 is probably a good choice. The flash is not too big, is pretty easy to use and performs well once the exposure settings are dialed-in. If planning to use a flash on regular basis, despite the big size, I would opt for the Leica SF-64 just because it seems more predictable in its output and provides better feedback. And if pushed to make choice on which outputs better light, I would probably side with the SF-64. Regardless of which flash you pick, be prepared for a learning curve period.

end of review flourish

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