– The first one is battery duration. Although the battery indicator is not very good (it only has three lights indicating full charge, medium and low) I never run out of juice in any of my sessions. I’ve been using it outdoors and sometimes at full power and never got any battery issue. I’m thinking about getting an extra battery just in case for longer shoots but so far never really needed it.
– I also use the pack indoors for studio purposes. So the second reason would be the ability to shoot with the charger plugged into the wall and not have the battery ever running out. The Quantum X2 I was using previously couldn’t do that and running out of power was always an issue specially on long studio shoots. One thing about this is that the modeling light does run on the battery unless you purchase a special charger to let it get the energy from the wall.
– Third reason is output consistency. The quality of light and consistency is amazing. You can shoot a series of photos and all of them look exactly the same. That saves a lot of post production time on nearly every shoot.
– Fourth reason is ruggedness. Everything is well built and seems to hold up very well. I have used it on regular conditions so I still haven’t tested this properly but the overall feeling is good.
– This fifth reason might sound stupid but I’ve noticed it actually is true. This light looks a lot more professional than the smaller speedlights. When you show up at a shoot and you start setting up people notice this is not your average light. They feel that you know better what you are doing just by the looks. I know it’s dumb but I want to look as professional as possible and I’ve noticed this helps too.
One important thing about this pack compared to other flashes I’ve used is flash duration. If you search around you can read a lot of stuff related to the flash duration, but one that I found specially helpful was Brian Smith’s blog. The he explains how he made some tests and how the two different dials to change output alter the flash duration. I’ll quote that part here:
FLASH DURATION: I did these tests with both Acute 2 and old-school Acute heads and got similar results. I doubt the duration is different in the AcuteB heads. Profoto lists the full power 600w/s flash duration as 1/1000th of a second, but they have always measured «peak-to-peak» duration which is much shorter than actual. Using a flash meter, the actual duration when using either an Acute 2 or older Acute head both appear to produce a flash duration of 1/350th of a second. This means that shooting at full power at 1/500th will clip about 1/2 stop of output and at 1/1000 you’ll clip a full stop of output, so if you need to shoot at 1/500 or higher, you might as well trim the pack to 1/2 power. There are two ways to cut the output of the heads. The first is a 3-position switch for Max, -4 (1/4 power) and -2 (1/2 power) this trims power without lowering the voltage, so going down to 1/2 power this way cuts flash duration to somewhere around 1/800th of a second and even going to 1/1000 of a second only clips 2/10ths of a stop. The second way is a click-stop dial that allows you to trim up to 2 stops in 1/8th stop increments. This is more accurate, but it appears this also trims the voltage so the flash duration doesn’t get cut back as much, so just remember if you want the fastest flash duration, trim the power as much as possible using the 3-position switch – not the dial.
I found all these tests from Brian Smith quite interesting and I used the to figure out a way to sync my flashes a lot higher than regular sync speed. I’ll post on that later though.
One last thing to have into account and that I realized once I had the flash is the need of a bigger flash stand. I was using the normal ones you would use with Speedlights or any other smaller head. This head is heavy and off the center so if you don’t want your flash to tip over you need a bigger stand. This is not a dealbreaker for sure but you need to have it in mind for your purchase.