What are the most important factors that need to be kept in mind while purchasing a manual flash gun?

Question

What are the most important factors that need to be kept in mind while purchasing a manual flash gun?

Answer 1

To me, a "manual flash" means a simple non-TTL flash. When shopping for those, the five essential things to look at:

• Hot-shoe compatibility. Sony/Minolta systems use one layout, all the other manufacturers use what's considered a "standard" hot shoe with central triggering pin.

• Guide Number. This will tell how much light the flash can spit out in a pop. More is better. Different manufacturers may use different ways of measuring GN; while mostly it shows how far it would reach with an f/1.0 lens and ISO 100 imaging surface in meters, some manufacturers (e.g. LumoPro) show the same distance in feet so you'll have to divide those numbers by 3.28 to compare. Also, check what options you have for dialing down the power. More options will give you more flexibility in how you can use the flash.

• Ability to tilt the flash head up and down so you can bounce from ceiling for softer light.

• Ability to swivel (turn) the flash to both sides; how far? This will let you bounce the flash to a side to create directional light, and gives more freedom of placement when using built-in optical slave sensor (if the flash has one).

• Triggering voltage when buying an old second-hand manual flash - there are models that used voltage too high for modern cameras and might fry them. Research the flash model and ask the seller before buying one.

There are some other optional features that may or may not be important for you:

• Connectivity options, such as built-in optical slave (when triggered with a TTL flash, it should be able to ignore preflash) or whatever plug you need to connect to your radio triggers or an external optical slave.

• A zoom head and/or built-in diffuser to adjust beam width (as a bonus, a tighter beam will provide more reach).

Answer 2

By saying "manual flash gun" I assume you mean a speedlite kind of electronic flash with manual controls. Modern flash units pack a lot of goodies and provide excellent chance for customizing your lighting setup. I am familiar with the Canon lineup so the examples below are of Canon flashes but they apply to other brands as well.

The first factor to consider, would be the flash's power (measured in Guide Numbers). For a hobbyist use, most of the time you don't need the most powerful units. This means that, depending on your typical shooting conditions, you don't necessarily need a 580EXII but can easily do with 430EXII (I do not mention the other, cheaper ones, b/c you asked about a manual unit). Anyway, the more power levels you can set in your flash, the more flexible you will be with setting up your shoots. Going from full to 1/128 can be useful sometimes but most of the time you don't go that low in the output settings. But, have at least 4 steps of settable power, which make a difference between full lighting of the subject and some strong fill-lighting. For more delicate work you will want finer control.

Then come the other set of features. Manual flashes tend to have a zoom setting as well. This will let you control the spread of the beam. It is one thing lighting one person for a portrait work and a different thing lighting a group. Some units also offer additional diffuser to spread the beam even further at the min zoom settings.

If you shoot a lot of on-camera Speedlite photos then E-TTL (I-TTL for Nikon) is invaluable. It means that the flash exposure is determined by the exposure metering of the camera and you can shoot automatically.

Tilt and swivel are almost always very handy as it lets you avoid direct flash lighting of your subject. This will let you aim the flash at the ceiling/wall to have a relatively huge light source, casting very soft and flattering light.

For some types of photography, like daylight and action shoots the High Sync Speed feature is important. It will let you fire the flash when the shutter speed is faster than the Sync Speed (usually 1/200-1/250 sec). This is crucial for freezing fast moving subjects.

If you are doing off-camera lighting then you can fire the flash with a cable or some (optical or radio) slave. Canon and Nikon have integrated wireless control where your built-in flash or an external transmitter/speedlite serves as the commander to control the setup and firing of the slave unit. A combination of wireless and TTL is awesome. If your camera doesn't have this functionality then virtually any flash/camera can be paired with a cable but there is no TTL in this case. Radio control will let you put the flash in a softbox, where there is no Line of Sight for optical slaves.

Another factor is the weight. Pro units become very hefty. If you own a small camera then a pro unit will make the combination look pretty weird, and more important will introduce some imbalance in the whole setup. My Canon S5-IS P&S equipped with my 580EXII flash really look like a flash with a camera mounted at the bottom... For extended shooting sessions you will feel the hand fatigue holding and balancing the big load.

Lower in importance are factors like integrated bounce card (easily added by a rubber band and a piece of white paper). External power connector may be important if you shoot very fast or for extended sessions. AFAIK, only pro units offer these power packs.

Syl Arena's Speedliting.com has some good information on the techniques and equipment for flash photography (Canon-centric, though, but applies for other brands as well).

Answer 3

A few quick thoughts

cost

It's first on the list because if you can't afford it, well: you can't afford it ;)

power

How much light does it put out?
Is that enough to light your subjects at the distance you want to shoot?

reliability

It's worth hitting the reviews for this one, but in this day and age, your strobe should trigger every single time without fail.

recycle time

If you're shooting slowly this won't be so important.

settings

I can't think of the right term here (edit, someone? anyone? Bueller?), but how many stops can you turn the power down? Also, does it turn down in full stops? half stops? thirds of stops?

triggering

How do you get it to flash?
E.g:

• hot shoe (normal)
• pc jack (the funny connectors that most manufacturers use)
• normal jack (a 1/8" jack like you use for your ipod)
• slave flash (i.e. it goes off when it sees another flash go off
• IR
• radio

build quality

Will it fall apart the first time you drop it a couple of feet?

weight / size

You're presumably plannig to hump this around.
How difficult will that be? Will it fit in your bag?

gels

Does it have a way to easily attach colour correction gels?