1.800€ vs 300€ "Compact" Flash

It was a long decision process whether we should buy one of those Quantum Qflash units or not. Why did we even think about it? Among other reasons, one was that we have never been satisfied with Canons TTL results (Through The Lens - the camera measures the flashlight hitting the subject and the flash stops emmitting light as soon as there is enough - theoretically because a lot of conditions have to be met). In our earlier times we shot with Minolta and the flash exposure was almost always spot on, even though the devices have a technological disadvantage of about 10-15 years. That also kept us from upgrading our Canon 550EX to the newer versions 580EX and 580EX II that provided similar TTL results in our experience. With manual flash settings we had quite OK results with both.

Well, now how does the Canon 550EX compete with the much more expensive Qflash?

We made our first impression at our dealer Slach, where we could try one of these units before we purchased it. Some shots (especially one against strong sunlight) conviced us and after we evaluated the shot in our office, we went out again with the money in our pockets and brought the baby to its new home.

In the first part of this hopefully continued test (as freelance photographers we have to deal with our time as you might imagine), we just compared the sheer power of these two units...

 

The following table shows the measured f-stops in 1m, 2m and 3m distance. Before you dive into it, let me explain the rather complicated table.
On Canon System Flashlights you can adjust the zoom (what you can also do with the Qflash if you have the according accessories) and that way focus the light. A zoom setting of 50mm matches approximately the standard reflector that ships with the Qflash, so these two values are easy to compare. To illustrate that, compare it to a torch. A focussed light of the same wattage is much brighter, but illuminates a much smaller area than a flood reflector.

Even though the values for 24mm zoom on the Canon 550EX and the Wide Angle Diffuser (QF67A) appear in the same row, you must not compare them because the WA Diffusor illuminates the area of a 12mm lens on a full frame sensor.
The last column btw. shows the combined power of the two units.

A short note regarding the values - especially for those who have never dealt with a lightmeter. These units measure the light in full f-stops (e.g. 4; 5,6; 8; 11; 16; 22) and additional in 1/10th increments of these f-stops. Since the f-stop is a ratio between the lens diameter and its focal length, there is no other way to indicate f5.6 and 3/10th than 5,6 - 3. You can´t say 5,6,3, can you? I hope that explains it well enough.

So what´s the conclusion for the first part of our test? The Qflashs power is about 150% of the power of the 550EX. Hmm - not enough to justify 6x the price you might say - you could achieve that with 2x 550EX units fired together. Well if that was the only advantage I´d probably agree. But there is much more. One big advantage is the power of the Qflash when illuminating a full frame sensors frame with a 12mm lens attached. At least for those of us who use that advantage.

But there is much more - see you in part II soon!