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Basics of Flash Photography

See Reviews:

Neewer VK750 II    Yongnuo YN-565EX

Aperlite YH-700N    Neewer NW985N.

Part 2: A large chart of specs of a couple dozen speedlight models (the next page)

Comparing flash power level with Guide Number Ratings

Menu of the other Photo and Flash pages here


Beginners Guide to Select a Hot Shoe Flash

This article is about choosing a speedlight for the hot shoe. Not specifically, but rather about the big questions, to help think about what you need.

The flash can be used on the camera hot shoe, either as direct flash or as bounce flash, either as the single main light, or as fill flash, possibly to lighten harsh dark shadows in bright sun. The flash can be used off-camera, maybe in umbrellas, maybe multiple flash units, maybe for studio portraits or for tabletop or macro work. Or the speedlight can be used to stop fast motion of water drop splashes or hummingbird wings.

The first big concern is "How will you use the flash?". What do you need it to do? For any time the light is dim or harsh of course, but there are several options, and so much that can be done. The question is: Will you? What features do you need?



Did we mention speed?   A speedlight capturing a punctured water balloon. 105mm DX, ISO 400, f/16, 0.8 second shutter (actually, it was manual Bulb shutter... open shutter, poke the balloon, flash triggered by "pop" sound, close shutter, which the Exif says took 0.8 second).
Flash up close (3 feet) at 1/64 power level so the Nikon SB-800 flash duration is 1/30,000 second.
Or pictures of the kids with routine bounce flash at half power, speed would be maybe 1/1000 second.
Which is the reason camera flashes are called speedlights (can freeze very fast motion).

This was in normal daylight patio shade ambient (not bright, but far from dark). The big point here is that ISO 400, f/16, 0.8 second was insufficient exposure of the ambient light. That picture would be dark without the flash (so no motion blur is seen from the continuous dim ambient). But the flash was close, and bright, and very fast, and instantly froze the motion of the collapsing balloon and water.

The first main question will be about using Manual flash mode, or TTL flash mode? Many of us use both for different duties, and optimum would be a speedlight that can do both. But beginners with no flash experience absolutely need a flash that can do TTL for them.

TTL Control:

Terms: Note the term TTL has a few different meanings. We do say TTL generally (just meaning any automatic Through The Lens metering), but there are different designs, and for today's Nikon DSLR (those since 2003), we always specifically mean iTTL flash units (which we likely call TTL). The term TTL also specifically means older film TTL, no longer compatible. So "TTL" depends on the usage context, any general automatic Through The Lens metering, or specifically the old TTL version used with film cameras - or it may actually assume iTTL. The context generally defines it, and we get used to the confusion. :)


Broad generalities about some feature groups of camera speedlight flash models:


Old flash models

Used flashes can be a good buy, but old TTL flash models for film cameras cannot do TTL on digital cameras. TTL flash is simply quite different between film and digital cameras. Nikon also had a different early digital D-TTL flash system, no longer compatible. The current Nikon DSLR do only iTTL. Canon DSLR do their ETTL. If the flash is older than 2003, there is no possibility that it can do Nikon iTTL. The only Nikon iTTL flashes are SB-300, SB-400, SB-600, SB-700, SB-800, SB-900, SB-910, and SB-R200 (the three digit models). Older Nikon flashes with only two digits, like SB-24, SB-26, or SB-80 cannot do today's iTTL. However, those old ones can still do Manual flash mode very well with current cameras (most were a fully powered class). And several may also have a non-TTL Auto mode that can meter itself, and can do automatic flash exposure that way. The old ones can't do the current CLS hot shoe communication however, so you inconveniently have to manually enter the f/stop and ISO into the flash unit menu, so Auto mode will know the camera's target goal (Manual mode does not need that, you only set power level). Nikon offers this Compatibility Guide for combinations of older and current flash and camera models, showing the features that will be available. Nikon manuals are online here.

(Too much detail, sorry) Connecting some old flashes to the camera can have special concerns. All flashes do put a voltage on the trigger contact on the flash foot or the PC connector, called sync voltage. The camera shutter shorts that voltage to trigger the flash. The ISO spec allows 24 volts, but today, this is normally around 5 or 6 volts. But some old flashes might put a couple hundred volts there, dangerous to digital circuits. All Nikon DSLR cameras are rated to withstand 250 volts (see manuals: at Optional Speedlights, or search PDF for "250 V"). The later Canon DSLR are rated 250 volts now (earlier EOS said only 6 volts). And some other cameras are low rated, so the concern about digital sync voltage damage comes up. The only way to know what you have is to measure it yourself, with flash turned on but not connected, and simply measure the DC voltage on the foot center pin to the metal foot frame (Other articles). Touching that pin to measure it can slip and cause it to flash, which is fine, that's how it works, but do expect this possibility, and aim it away from your eyes, and do not lay it face down on a surface that the flash tube heat will scorch (definitely can happen). If there is excessive sync voltage on a nice studio flash unit worth keeping, get a $50 Wein Safe-Sync to protect the camera. If is an old cheap speedlight, the $50 is much better spent towards a newer unit. All of the old Nikon speedlight flashes are a safe voltage, but old Vivatar and others, possibly not. Measure the voltage before connecting them to the camera.

Just saying though, we spend hundreds on a fancy modern DSLR, which can do impressive TTL flash things, and it seems a shame to hang on to an obsolete old flash that cannot do any of it. But manual flash can still work, and does have its own virtues.


How To Start with Flash, First Time

Just a quick rough idea for beginners who have never used a camera with settings before. Wade in, a little experience will be very helpful. Speaking here of a DSLR and a hot shoe flash (which maximum power capabilities do vary of course). Note that the DSLR camera menu which sets TTL or Manual mode is only about the camera's internal flash, which is totally out of play when its door is shut. A hot shoe flash has its own menu, and totally ignores that camera menu (SB-300 and SB-400 are exceptions, they don't have their own LCD menu, so must use the camera menu, in camera models designed to recognize them).

For fill flash outdoors in bright sun, camera P mode is the place to start, and the Nikon TTL BL system can do balanced fill flash automatically. Fill flash can make a huge difference for picture of people in bright sun.

For an indoor subject, set camera A or M mode (Aperture Priority or Manual camera mode - a TTL flash is still automatic flash in camera Manual mode). Shutter speed 1/60 to 1/200 second, which doesn't matter to the flash (but see the Part 4 page). I am ruling out any camera Auto mode, which won't allow much control, and it will want to open the popup flash door, and it will use Auto ISO. Note that Auto ISO cannot be used with Manual flash (flash cannot respond to it), and it's a great idea to turn it off for TTL too. Auto ISO indoors will just make the orange incandescent lights be objectionably bright.

Indoor Direct Flash - Assuming a subject at about eight feet. ISO 100 and maybe f/8 aperture. Maybe f/5.6 for a lower powered flash, maybe f/4 for the cameras internal flash. Low ISO.

Indoor Bounce Flash - Assuming standing under a ten foot white ceiling. ISO 400 and maybe f/5 aperture (which includes a safety factor, and faster recycle, but small flashes may need ISO 800 for bounce). Don't stand too close for bounce, a normal 6 or 8 feet, but zoom in all you want. Aim flash head up at white ceiling, and pull out built-in bounce card, if present.

In all cases above, correct the results as necessary (as seen on camera rear LCD and/or histogram), adjusting Flash Compensation (TTL) or adjusting Power Level (Manual), and shoot again. If the Ready LED flashes three times immediately after the shot, that is the warning that the flash had insufficient flash power for the situation, and you should set wider aperture, and/or higher ISO, and/or move to a closer subject distance, or get a larger flash. Make it be perfect. First time will seem difficult, but a little experience makes it real easy real soon. Simply adjusting poor results as seen needed is the easy way to get perfect results.



Flash Features

If your camera model does not provide the Commander or Auto FP flash modes, then those flash features won't help (maybe on your next camera). That feature omission could make less expensive flash options be more attractive and justifiable. Nikon camera models which include the Commander also include Auto FP and FV Lock. Camera models without the Commander do not.

Opinion: In fixed situations (umbrellas, etc), I mostly use manual flash (and a hand held flash meter if multiple flash units). However, it seems obvious that indoors, everyone needs a good hot shoe TTL bounce flash (for example, to keep up with quick kids, or to do the walk-around pictures at the birthday party). And sadly, many of us need a kick in the rear to start thinking about getting better flash pictures (which bounce is). It is easy enough for anyone. For a Nikon camera, I don't necessarily imply Nikon brand flash, but my thinking is that the SB-700 is an easy choice today - especially true if you have a camera model described as "higher than low end", which can use the Wireless Commander/Remote and Auto FP HSS features the SB-700 provides. Higher price cameras like D90, D300, D7000 and up have these features too, but lower price cameras like D60 and D3100 and D5200 do not (no Commander, no Auto FP mode). The SB-700 is pricey, and its features may be overkill if you only use hot shoe direct flash aimed straight ahead (however it does also offer GN Mode, really useful for direct flash). But TTL flash mode is something essential, features you can really use, all the time. It can do walk-around TTL bounce, like at parties or to follow kids playing. It can also do manual flash mode, and has a great SU-4 slave mode that works wirelessly off-camera, like in umbrellas. The SB-700 also works as a wireless remote with the Commander (and if you have a Commander, you do want to see this feature). It should do anything you need a flash to do. I use a couple of similar but discontinued SB-800, about ten years old now, and they have been absolutely wonderful. But if you will never bother to investigate and use these better features, then a lot less flash might suit you too. But flash really is pretty easy - and never learning flash would be a real shame.

See Reviews:

Neewer VK750 II    Yongnuo YN-565EX

Aperlite YH-700N    Neewer NW985N.

Part 2: A large chart of specs of a couple dozen speedlight models (the next page)

Comparing flash power level with Guide Number Ratings

Menu of the other Photo and Flash pages here


Copyright © 2013-2016 by Wayne Fulton - All rights are reserved.

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