Owning a Sony camera, I didn’t want to splash out on their extortionate TTL flashes, so I opted for this manual speedlight (the KF-570II), and I’m glad I did.When turned on for the first time, the display said 1/128. That means it’s flashing at 128th of its full power: once I understood that and pumped the power to 1/1, it was crazy just how bright it was.It’s a manual flash, so you need to have your camera on manual and experiment with exposure to get the right results. Set your white balance to flash, for a start!I’ve really enjoyed getting back to basics and feeling like a proper photographer with this flash, and really thinking about lighting: as I work in film, I tend to use film lights for my photography too, so it’s a challenge to visualise how an image will look taken with a flash when it’s not on all the time.This one has a motor inside to move elements about depending on your zoom range so that you can go from 18mm to 180m.My Sony needs to have a shutter speed of 200th, otherwise I get a black line halfway down the image: some flashes let you go to 800th, I think. One important thing to remember though, is that shutter speed is almost removed from the equation when considering exposure if you are using a flash: the burst of light is so fast, that whether you use 1/200 or ¼, you will likely get the same exposure as the flash only lasts 1/200th of a second.If you are in a space with strong ambient light then of course, a longer exposure will result in more light from other sources, or an image with a bit of artsy post-blur, but be careful when mixing light sources that you don’t end up with orange or blue casts.Playing with the flash power, ISO and f stop you should be able to get perfect exposure, and using the angled head to bounce light or use the attachments to soften it, you can get some very flattering shots indeed.One big plus: in the description it says you need to let it cool for 15 minutes after taking 10 flashes. I thought that was mad, and it’s not true: that is referring to an option it has to flash 10 times in a split second to get a series of shots if something is moving past you quickly, which would all end up on the same shot (such as a BMX racer doing a jump - you’d get the bike at 10 points across the same photo). Besides that quite specialised use, you can flash away merrily as often as you like and not worry at all about overheating.This is an awesome piece of professional kit, and with a digital camera to check exposure and perfect lighting, this can only make me a better photographer.