What to buy
Well what do we need to consider?
- Mount type
- Colour consistent
- Exposure accurate
- Flash duration
- Mains or Battery
- TTL Support
- High Speed Sync
Budget: well in many ways this is linked to the other points so we will skip this for now but, more money means more features, more support etc. Budget, midrange and high end all have their pros and cons.
Mount type: many systems have the Bowens S mount, the other common ones are the Elinchrom EL and the Profoto. Soft attachments like soft boxes can generally. be adapted or you can get third party adapter rings to fix your Profoto soft box on to say an Elinchrom flash head. It gets more difficult with hard accessories like beauty dishes. Think long and hard about where you want to go too.
Colour Consistent: This is one of those things linked to budget. The midrange and higher end flashes tend to drift no more then 300k in use. If your only taking a few pictures not too much of an issue, if your taking a lot of pictures with a lower end flash unit, keep taking a custom white balance as you go along. Taking a white balance reading and shooting for a couple of hours and then in post production noticing your colours are off after an hour in the session can cause issues when your editing and will slow down your work flow. Be aware or buy better lights.
Exposure accurate: There are two aspects to this. Consistent amount of power while you work, which is essential, and consistent when you turn up the power turn the power down, this is less important but can cause a bit of frustration if your wanting to go down one stop, set the flash one stop less and its only half a stop down in power. It slows you down a little, but is not really and issue if you meter well after each change, remember as well some of the cheaper lights may change colour temperature if you change power output, so white balance reading after a power change may be required.
Flash duration: Do you shoot sport, want to freeze water droplets, the flash duration is what freezes the action. For general use most flash is fast enough. For some specialised use then you can get special flash heads with very short duration to freeze action.
Support: Cheap and even some midrange flash units do not have good manufacture support, the units are considered consumables, if they die after three years then buy a new unit. Some high end flash companies support their old heads that are now over thirty years old and will cost-effectively repair and turn it around quickly. They have dealers locally that can lend you loan units and give quick turn around.
Power: Generally in small studio’s you do not need a lot of power, 250ws or 500ws (watt/seconds) is enough. The issue with cheaper flash units is often too much power, some high end 1000ws units will turn down 1ws, cheaper 250ws will only turn down to 30-50ws. This makes them less flexible. You may need to buy a 250ws and a 500/1000ws head as well to give you options. Also look at some reviews on YouTube. Some higher end flashes that are rated at 250ws when tested could nearly reach output of cheaper 500ws lights due to the more efficient head design and better reflectors.
Mains or Battery: This is linked to power. On location, wedding receptions, event photography then battery is the way to go, in the studio then go for mains. Depending on the amount of power I have needed on location I have either used small speed lights or my more powerful Elinchrom Quadra units. With newer technology and better batteries you can make the case for using battery in the studio. There are some units. now that are battery powered but can run on mains as well.
TTL Support: Studio flash scares a lot of photographers, in fact flash period scares people. TTL flash is generally what you get with small speed lights, but more and more studio flashes are supporting TTL. TTL – Through the Lens metering means your camera and lights work together to try and make the correct exposure. As long as the scene is not too dramatic it generally works well.
High Speed Sync: If you are mixing daylight and flash then you often find your flash sync speed in your camera becomes a limiting factor. This is why high end medium format cameras for fashion photographers can sync up to 1/2000 and some 1/4000 or 1/8000 of a second. To over come the the limits of typical cameras slow sync speed the camera and light manufactures came up with HSS. The flash blasts lots of little flashes in the hope that some of the flashes correspond with the high shutter speed in use. It uses up a lot of power but can really help if you need it. If your looking at HSS then mains power or very powerful battery lights is the way to go.