which hot-shoe flash

[shot6]

Hi all

I am a newbie to the DSLR movement. I recently bought a Nikon d5000 and as I am slowly building on the accessories side I was wondering what criteria should I use when shopping for a flash.

All advice welcomed.

Thanks.

[inkista]

Basic features I'd look for would include:

Guide Number.
This rates the power/light output of your flash. The higher the number, the better (although the numbers can be deceptive. If you're comparing brand-to-brand, try and find reviews where some's actually measured the GNs). Think of the guide number somewhat like the max. aperture on a lens: you almost always want more. The more light you have, the more versatile the flash is going to be. The SB-900 has the highest GN of the Nikon flashes.

Tilt & Swivel on the head
Along with the power, the ability to point the head in any direction is useful, particularly if you plan on using the flash on-camera for bouncing. Being able to turn the head gives you a larger choice of reflective surfaces to use as your light source, and if you end up using optical triggering of some kind, gives you more ways to turn the sensor towards the master signal. The vast majority of flashes have only a 270° swivel capability (usually 180&deg to the left and 90&deg to the right). 360° is best. The SB-400 only tilts, it doesn't swivel. The SB-600 only does 270° swivel. The SB-700 and SB-900 both do 360° swivel.

Zoom
A flash with zoom capability in the head basically can move the flash bulb closer or farther away from the face of the flash head to narrow or widen the beam of light that comes out. This "zooming" can send out light to cover the same field of view as the given focal length of the lens you're using. The narrower and more concentrated the beam is, the farther the light can travel. The wider and more diffused the light is, the shorter the distance it can travel. So, aside from simply matching the lens you've got on your camera, it gives you another way to control the light's output and size/shape. If you have manual control of it. The SB-400 has no zoom capability.

Manual mode
Just like you want Manual mode on your cameras for control and consistency, you want the same thing on your flash. And if you plan on using the flash off-camera, this becomes doubly important because you may have no other way of controlling the flash's output level. The SB-400 has no Manual mode, unless it's on-camera.

iTTL
This may only be useful for on-camera flash, as triggering with iTTL can become expensive to do off-camera, or require a cable. But this is like having A or P mode on the camera. The camera and flash communicate with each other, and the camera can use metering with a "pre-flash" burst of light from the flash to automatically determine a good power level for the flash. This is really useful in changing lighting conditions and run'n'gun situations, in the same way that A/P can set your exposure settings for you very quickly on the camera.

CLS
This is a proprietary system of light-based signals between a commander unit on the camera and in the flash so that you can remotely command a slave flash off camera, with i-TTL and FP mode (high-speed sync). It's a terrific system, but is rarely found with full function outside of Nikon's own SB speedlights. The D7000 and up bodies have flash commanders in their pop-up flashes, but the lower models don't. And both the SB-700 and SB-900 are units that can be both commander and slave. The SB-600 can only be a slave unit.

FP mode
aka High speed sync. This lets you use shutter speeds faster than the maximum sync speed of your camera body. The way shutters and flash work means that without FP mode, if you try and use a really fast shutter speed (say, over 1/250s), you'll end up with black bars at the top and/or bottom of your photo. FP mode eliminates that, but eats up your flash power.

SU-4 mode / optical triggering
CLS and optical triggering are sometimes confused with each other, because they're both light-based ways to remotely set off flashes, but the difference is that CLS uses encoded signal bursts. A dumb optical trigger simply sees-a-flash then fires-a-flash. It's cheaper, and is more widely found on third-party flashes, but it can be an exceedingly useful feature to add a light into a studio setup without requiring an additional radio trigger, and can even be used with P&S camera built-in flashes. The SB-700, SB-800, and SB-900 include an SU-4 flash that does this same function. The SB-600 does not.

Sync Port
This is a way to externally connect something to trigger a remote flash. You can use a PC sync port to add an optical slave to a flash that doesn't have one, or use a radio trigger (some of which do not connect to a flash hotshoe), or a sync cord. The SB-800 and SB-900 have them. The SB-600 and SB-700 do not.

battery pack connection
Four AAs may last you months. They may last you a few hours. Depending on how heavily you intend to use your flash, you may want to be able to connect it to a larger power source that can last longer.

Now what you want in a flash, just as what you want in a lens, depends on a lot on what you want to shoot and how you want to shoot it. If you plan on slapping it onto the camera hotshoe and run'n'gunning events (say, weddings, parties) then you probably want to get a Nikon OEM flash (or maybe a Nissin) with all the CLS/i-TTL bells and whistles. But if you plan on using the flash strictly off-camera with cheap radio triggers that can't do iTTL, then getting a $160 LP-160 or $70 YN-560 might actually be a better way to spend your money. And if you plan on doing professional studio shooting, then foregoing that shiny SB-900 and just plumping for a Paul C. Buff Alien Bee or Einstein monobloc might be an even better way of spending your cash.

But for a first speedlight unit, I'd say get an OEM flash and as high-up the chain as you can afford, because that light can do double duty with both on-camera iTTL, and off-camera Manual. But for additional lights after, you really want to think whether or not you need those bells and whistles, and whether or not you really want a speedlight.

[shot6]

Thank you so much Inkista. This is exactly the kind info I was looking for.