Not long ago I wrote several posts about the Leica SF 24D mini flash. During that time I was using a Leica M9 and the results were quite satisfactory. Now I wish to do some more testings of this mini flash on the Leica M to see how it performs.
Let me briefly introduce the Leica SF 24D again. It is a portable flash, with an overall dimension of 66 x 109 x 40 mm (WxHxD). Without battery the weight is just 180g with the two lithium batteries included, it is roughly less than 200g. In a word, it does not add any significant extra weight if you want to carry it in your bag for everyday use. Here are some major features:
- No bounce flash
- Guide number (at ISO 100/21°, in m/ft) at 50 mm: 20/65; with wide-angle diffuser 14/46; with telephoto diffuser 24/78
- Operating modes: TTL/GNC (Through-the-lens/Guide-number controlled), A (Auto) or M (Manual)
- Recycle times: approx 0.5-5s
- Power supply: two lithium batteries, type DL 123 A, CR 123A, no re-chargeable batteries are accepted
The main dislike of most people to the Leica SF 24D is that the battery type is not the common AA type. You should understand that using the type CR 123A batteries aims at reducing the size of the flash. But these lithium batteries are more expensive and not commonly found in stores such as supermarkets. I have hoped that rechargeable batteries may work but later on I found that they are not compatible. It is highly important for you to get some more spare batteries if you are going to shoot with flash in big events. In the instruction manual, it says a new set of batteries is capable of providing up to 370 flashes at full light output. Not a bad figure. The number of flashes may probably be increased if you always use automatic mode.
I have done some testing using TTL/GNC and A modes using the Summicron-M 50 mm f/2. No matter which mode you use, you need to match the aperture value on the lens the same as those on the flash. In this test, the exposure was set at aperture priority mode. The distance of the subjects was 1 meter. These images were taken in PNG format and no touching was done during converted to jpeg format for posting.
The image taken with no flash fired:
These two images taken with aperture f/4:
These two images taken with aperture f/5.6:
These two images taken with aperture f/8:
These two images taken with aperture f/11:
From the images, it is not difficult for you to find that optimal exposure cannot be achieved easily because the flash metering was deceived by the objects. The best exposure was probably at f/5.6. In this case, it was the white wall that deceived the flash sensor at the front of the flash. However, we can always use the exposure compensation on the flash to achieve the desirable effect, such as setting a little bit overexposure in the A mode and underexposure in the case of TTL/GNC mode. In the event of TTL/GNC mode, we can set in 1/3 EV increments; whereas in A mode, we can only set in whole EV values.
As you can see from the above pictures, the colour balance in TTL/GNC mode is more acceptable and close to the image taken with no flash fired. For example, the colour of the flask on the right is also “whiter” and the colour of the flower is also brighter, which are in common with those in the image taken with no flash. Of course there is no difficulty for us to modify the image in Adobe Lightroom or Photoshop in a few steps. Personally I prefer using TTL/GNC mode.
The final judgement is yours. I have no regret having the Leica SF 24D as my choice of flash.