“Light is the basic ingredient of photography. Photographers learn to love the light, to look for and anticipate great light. Some photographers learn to create the light they want…”
These notes were made to accompany a presentation I made at Bromsgrove Photographic Society in November 2025.
What is a Speedlight?
A Speedlight (also called a flashgun or strobe) is a small(ish) battery-powered flash gun designed to be mounted on a camera hot-shoe, in order to provide a convenient and portable lighting solution for photography when the available light is not enough for the photograph you want to take.
Speedlight was originally a Nikon brand name, where Canon used Speedlite. Sometimes people use strobe to refer to a studio flash – which is a much bigger, more powerful, and less portable version of the same concept.
For the purposes of this article I’m going to use the term “speedlight” to refer to any portable battery-powered flash designed to be mounted on your camera, “built-in flash” to refer to any flash that is an integral part of the camera, and “studio flash” to refer to larger units, usually mains powered, that are designed to be mounted on their own lighting stands. The line between speedlights and studio flashes can be blurred at times, with some smaller studio flashes being battery powered and mountable on a camera (at a pinch) and some larger speedlights being powerful enough to be mounted on lighting stands and used in studio settings.
Why use a Speedlight?
A speedlight has one basic function – to add light to a scene, in a controlled fashion, either to replace or to augment the available light in the scene as the light source for the photograph you want to take.
If your main light source is ambient light, and the speedlight is adding a bit extra (typically to brighten areas that would otherwise be too dark), then we usually call it “fill flash”.
If flash is the main source, and the ambient light makes little or no contribution to the exposure, then I’m going to call that “flash as main light” – there doesn’t seem to be a generally accepted term for it even though it’s a pretty common mode. Sometimes it might be called “full flash” or “auto flash” but these can be confusing, as it’s not necessarily either!
You might want “flash as main” because there is no ambient light to speak of, or you might want it because the quality of the ambient light is not what you want. Another possible use-case is when you want to freeze motion – by providing all the light for the exposure from the flash in a very short burst, any subject motion will not be reflected in the image.
While the above might suggest that these are the only two options (and on some simple setups they might be), in reality there’s an infinite number of intermediate options where the ratio of ambient to flash light varies from all flash to 50:50 to all ambient and anywhere in between. Hopefully all will become clearer later…
Are Speedlights still needed?
Back in the days of film, where 400 ISO was considered fast, noise reduction did not exist, and yet people still wanted to take photos indoors, flash was often the only way to get any sort of of photo at all.
These days with modern digital sensors and noise reduction techniques, it’s possible to take photographs in virtual darkness just using ambient light and still get useable results. Shadows can be lifted in Photoshop rather than filled in with flash light. Do we still need flash?
There are still limitations to what you can do in inadequate light – if you want sharp, high quality images of subjects that are not necessarily completely still, when the ambient light isn’t reaching all the parts you want, when the ambient light is constantly changing, or coming from the wrong direction, or if you want to stop a speeding bullet in mid-flight. And fill flash can be much quicker and easier to apply (and give better results) than trying to pull up all the shadows after the event.
How does a Speedlight work?
A speedlight works by rapidly discharging the electric charge stored in a device called a capacitor through a xenon-filled tube, at a precise moment (normally determined by a signal from the camera). The electricity passing through the Xenon tube creates a very bright flash of light, which lasts for a very short time – the exact time depends on the flash gun and the flash power. If the flash allows the power output to be adjusted (either manually or automatically), this is done by cutting off the power to the xenon tube after the required amount of light has been output. Very cheap or very old flash units will always fire at full power, meaning the entire charge on the capacitor is dumped through the tube each time the flash is fired.
Note that the capacitor in a flashgun caries a sizeable amount of electrical charge, at a high voltage (300-400V is typical). This can deliver a very painful shock if you touch the terminals without first discharging it. Do not mess around inside a flashgun unless you know what you are doing.
The fact that the control of the light output is done by abruptly interrupting the flash once the required light has been output has a couple of potentially interesting side-effects. Firstly, less powerful flashes are shorter than more powerful ones (which can be significant if you need the shortest possible flash duration, such as for freezing very fast motion). Secondly, because the capacitor is only partially discharged by a flash that is at less than full power, the flash can be ready to fire again more quickly.
Studio flash power control
Note that some studio flashes control power output differently – effectively by selecting how much power to store up in the capacitor, and dumping it all each time. For such flashes, lower-powered flashes may actually be slower than higher-powered ones.
Automatic exposure using flash – called E-TTL mode on Canon speedlites and similar on other manufacturers flashes, is an interesting beast. The TTL part of the name means “through the lens” and refers to the fact that the camera is metering actual light from the flash, reflected from the subject and coming through the lens to determine the exposure. But the light that is measured is not from the actual exposure – it’s from a separate pre-flash that takes place just before the shutter is opened, too quickly for you to detect it as a separate flash. By measuring the amount of light reflected from this preflash the camera can determine the flash power required, and communicate that to the flash.
Pre-flash problems
This pre-flash can cause some problems. If you have slave flash units (such as studio flashes) that wait until they “see” the flash from the master before firing themselves, they can be triggered prematurely by this preflash. In such situations you should be using manual mode on the master flash. Also, subjects with fast blink reflexes may blink in response to the preflash and have their eyes shut for the main exposure.
Older flashes work differently
Older flashes worked differently to this – they used a light sensor on the flash to turn off the light after a certain amount of reflected light had been received. The advantage was that no communication was needed between the camera and the flash (though it did require that you set the camera aperture to match the flash maximum power and film speed, using a table usually printed on the back of the flash).
Flash and Exposure
Two exposures at once
It is often helpful to think of an image taken using flash as being composed of two separate exposures combined into a single image – one exposure coming from the ambient light, and the other coming from the flash.
We all know how to control the exposure from ambient light, using shutter speed, aperture, and ISO in the classic “exposure triangle” to give the image we want (or by delegating the selection of one or more of those settings to the camera in one of the automatic modes).
The exposure that comes from the flash is also affected by the aperture and the ISO, but it is NOT affected by the selected shutter speed. So long as the shutter is open at the moment that the flash fires, then all the light from the flash will be captured in the exposure. It doesn’t matter how long the shutter is open before or after the flash fires – the flash exposure is unaffected. The exposure from the flash is also affected by another setting that does not impact the ambient exposure, namely the flash output power.
So to summarise, ISO and aperture affect both ambient and flash exposure, shutter speed affects only ambient exposure, and flash power affects only flash exposure. Using this knowledge you can manipulate the contribution of each to the final exposure independently.
For example, if you want “fill flash”, select ISO, aperture and shutter for a standard ambient exposure, and set the flash power low to contribute just a little bit to the darker areas of the scene. If you want “flash as main” with (almost) no ambient contribution, then select the ISO, aperture and shutter speed to give a very under-exposed ambient exposure, and use a higher flash power to provide all the light you need.
Maximum flash sync speed
Note that I said above that shutter speed does not affect the flash exposure. This is true, with the caveat that the shutter must be FULLY open when the flash fires. Focal-plane shutters, which operate using a pair of curtains moving across the sensor, do not fully open the shutter at all when operating above a certain speed (the second curtain sets off to close the shutter before the first curtain has reached the far side to open it). If you try to use a flash above this shutter speed, your flash will only illuminate that part of the sensor that was not covered by a shutter curtain at the time. The maximum shutter speed you can use before this starts to be a problem is known as the maximum flash sync speed, and will depend on the camera. Modern cameras can often manage 1/200-1/250s, older ones would require 1/60 or below. Leaf shutters do not have this limitation and can sync at any speed.
Auto modes and Flash
Because there are effectively two independent exposures, there are also two independent decisions about exposure mode to be had. Your camera can be in manual mode, but using automatic exposure for the flash. They can both be in full manual mode. They can both be in full auto mode. Or the camera can be in auto mode with the flash in manual.
If the camera is in auto mode, it is liable to attempt to expose the scene for the ambient light and ignore the fact that there may be flash added to it – in other words, any flash is going to act as “fill-in flash”. If the camera is aware of the presence of the flash, it will restrict the shutter speed to ensure it is less than the max sync speed, and will also communicate with the flash so that the flash can operate in TTL mode, can narrow the beam to match the focal length of the lens, and so on.
If the camera is in manual mode, then you can set the ambient exposure to whatever you want (typically a few stops under-exposed, to allow the flash exposure to dominate). The flash can still operate in auto exposure mode so that exactly enough light is provided for the flash exposure to be correct.
Personally I mostly shoot in manual exposure mode on both flash and camera, when I am using flash for macro shots. The ambient exposure is irrelevant to me in such cases – I set the shutter speed at the max sync speed, the aperture to wide open (if stacking, as I usually am) or whatever is needed to get the DOF I need, and the ISO as low as I can. I set the flash (actually, three flashes operating together) according to the distance between be and the critter – usually between 1/32 and 1/128 power, and I fire a focus-bracketed burst. If it it is not quite as light as I want, then I increase the flash power – but no higher than 1/32 otherwise it can’t recycle fast enough for my burst. If I still need more light I increase the ISO.
If I was using TTL flash then (a) I would not have any way to limit the power to suit my required recycle speed and (b) the additional communication (and preflash) required to implement TTL flash metering would slow down my bursts considerably. I have shot enough images now that I can generally guess the required flash power and ISO without having to try various options.
Flash Exposure Compensation
Just as you can ask your camera to adjust up or down the exposure it gives for ambient light shots, using the exposure compensation setting or dial, you can ask it to apply similar adjustments to the flash part of the exposure, versus what its metering system suggested was correct. If the flash is too dominant (in TTL mode), dial in some negative flash exposure compensation.
Light fall-off
The amount of light that falls on a subject from your flash decreases as the subject gets further way – if the subject is twice as far away it only receives a quarter of the light (this is called an inverse square relationship). The net effect of this is that speedlights become rapidly less effective the further away your subject is (though the effect can be mitigated a bit by concentrating the flash into a narrower beam, using a fresnel lens mounted on the front of the flash)
Flash meters
A traditional light meter isn’t helpful when you are planning to add flash to your exposure – at least, it’s helpful for the ambient part of the exposure, but not the flash part. You need a meter that is designed to measure, and capture, the light reading for the very brief period of the camera flash.
Such meters were invaluable when working in a studio with film. These days, its usually easiest just to check the back of your camera, adjust, and repeat…
Flash techniques
Bounce flash
One way to avoid the harsh shadows that direct flash can create, and also to avoid any of the issues associated with having the flash source right next to the lens, is to bounce the light from the flash off a reflective surface rather than firing it directly at the subject. Most often, this reflective surface is the ceiling or a wall, but it could be a piece of paper, a portable reflector panel, or even the light clothing of a nearby person.
To use bounce flash, simply swivel the flash head to point at the surface you are wanting to bounce off. In some circumstances you may also want to block any light that might spill out of the flash directly towards the subject, though often a little bit of direct light is actually beneficial, helping to create a catchlight in the subject’s eyes.
When using bounce flash, the range of your flash will be reduced (so having spare flash power is important), and the light will be much more diffuse, which will give a softer image without harsh shadows.
If the surface you are using as your bounce target is not white, then the light that reaches the subject will have picked up a colour cast. If used deliberately, this can be useful, but most often you will want to use a white surface. Fortunately white is also the most common colour for ceilings!
Bounce flash outdoors
If you get TOO much into the habit of using bounce flash, you may find yourself on autopilot pointing the flash up to the ceiling even when shooting outdoors. The sky does not make a good bounce reflector…
Diffusers
Used to make the light from the flash (and thus the shadows that are cast) less harsh. You can buy plastic domes, you can cut up milk cartons, you can shoot through bits of cloth… Diffusers are particularly needed for macro work, when you are not bouncing the flash and the flash head is quite close to the subject – otherwise you tend to get bright specular reflections off the shinier parts of your subject. The design of diffusers makes a big difference to such photos and is the subject of much debate among macro photographers. Many make their own, including me…
For non-macro work, such as portraits, light sphere diffusers (as popularized by Gary Fong) seem to be quite popular, for situations where bounce is not practical or a harder light (but not as hard as bare flash) is wanted.
Dragging the shutter
“Dragging the shutter” means shooting flash with a longish shutter speed, such that the ambient part of the exposure shows motion blur. The flash part of the exposure will be short and free of motion blur, so the overall effect is of the subject moving into place (or out of place). See also the rear-curtain sync setting, which will affect the appearance of shots like this.
Dragging the shutter – motion blur and sharp image combined.
Overpowering the sun
Shooting portraits outdoors in bright sunlight is usually less than ideal. If you take a photo against the sky either your subject turns into a silhouette or you get a blown-out sky. The technique called “overpowering the sun” involves reducing the ambient portion of your exposure enough that the flash part can compete (at least as far as lighting your subject is concerned). Lots of websites and tutorials about it online, and it’s not something I’ve really tried, so I’ll just summarise my understanding of it.
First, you need to set the ambient exposure so that it is slightly underexposed (or at least not overexposed, according to taste), while still keeping the shutter speed under the maximum sync speed. Because there’s only so low you can take the ISO this probably means you are going to have to stop right down (f/22 or so) or use ND filters to reduce the light.
Then, with this reduced aperture and/or darkened lens scenario, you need to put enough flash light onto the subject to light it. That is likely to need quite a powerful flash, possibly in the realm of portable studio lights rather than speedlights.
If you have a camera that can sync at faster shutter speeds, the challenges are somewhat reduced. One reason why medium format cameras with leaf shutters (which can sync at much faster speeds) were popular in the portrait photography business, perhaps.
Flash in the image
Sometimes placing a speedlight (triggered remotely) within the image can give an interesting effect. Hide it behind an object to make it look like that object is the source of light, or leave it visible if that works for the image you are after.
Practical considerations and common problems
Red eye
The classic “point and shoot” or “disposable camera” look, where subjects have demonic red eyes. Caused by light from the flash reflecting from the retina, the easy solution is to move the flash so it is a little bit away from the lens, and the reflection misses the lens altogether and is not captured. Anti-redeye settings on old cameras would give a sequence of flashes before the main exposure designed to make people’s irises close. Usually it just made them blink, which I suppose DID avoid the red-eye…
Thankfully anti-redeye flash modes seem to have been abandoned in recent cameras. If you DO get redeye and can’t move the flash further from the lens, it’s not that hard to fix in post.
Typical red-eye shot. Also note the flat, direct light and the dark background, also known as the …
Party flash look
Often accompanied by red-eye, this is where you take a portrait of your mates in a dark room at a party, and they look very bright and flat, with the background very dark. It’s caused by the ambient exposure being very low, the flash not lighting the background (because of inverse-square falloff), and the flash being next to the lens so that all the lighting is straight-on and there are no shadows to give depth to the faces.
Bounce flash will solve both problems, moving the flash a bit away from the lens will solve the “flat” if you still want the dark background.
Funnily enough when researching for these notes, I found articles on both “How to avoid” and “How to achieve” this party-flash look. So I guess it has a certain appeal to it in some cases, especially if you are trying to make your photo look like it was taken on a cheap camera in 1985…
Harsh shadows
A flash is typically a small, hard light source, and this can lead to very distinct shadows which may be undesirable. There’s two ways around it – make the light source bigger and more diffuse (using bounce flash or a diffuser), or make the shadows fall out-of-picture (for example, you can move your model away from a background that the shadow might fall onto, or you can move your flash directly above the camera so that the shadows fall behind the subject and cannot be seen by the camera).
Harsh shadow caused by flash being positioned to one side
Lens shadow
If you are using a camera-mounted flash with a long lens, the body of the lens might block some of the light from the flash from your subject – creating a dark shadow. The solution is to mount the flash further forward and/or higher up (or off the camera altogether)
Black backgrounds
If flash is the only source of light for your image, and the background is some distance from the subject so that the flash does not illuminate it, you can end up with a brightly-lit subject against a black background. This is particularly an issue in macro photography, for example of insects.
It can be a very striking look, but if it’s not the look you want, then remember that there is also an ambient exposure you can control, so brighten the ambient part of the exposure so that you get to see the background. Alternatively, a piece of card with a suitable texture on it held behind the critter can give a pleasant non-black background, or change your shooting angle to have the sky as your background.
Dark background typical of flash macro photos
Colour balance
As I have said (a few times now), a flash photograph consists of two exposures – ambient and flash. If the colour temperature of the light for these two exposures is significantly different then you can end up with an image that has no appropriate “white balance” setting you can apply to make it look right – different parts of the image require different white balances.
The colour temperature of the light from a speedlight is not too far from daylight, so there should not be too much of an issue when using fill flash outdoors, for example. But a mixture of flash and warm indoor light, or worse, a mixture of flash and the rather greenish light you can get from fluorescent tubes, can be a problem.
There are two ways to reduce the problem. Firstly, you can use a coloured gel over your flash to change the colour temperature of the flash to match the ambient. Or you can reduce the ambient part of the exposure to allow the flash to dominate to the extent that it is not a problem.
Most flash units come with a gel or two designed for this purpose. Note that these can be useful even if ambient light contribution is not significant – for example, if you want your photo to look like it was shot in warm evening light.
What does that setting mean
HSS – High speed sync
As I mentioned above, there is a limit to how short you can make the shutter speed before you reach the point that there is no single time that the flash can fire and still illuminate the whole sensor.
HSS mode will mitigate this issue by replacing the single very-short flash that is normally output by a succession of smaller, shorter flashes that last for the entire time that the shutter is operating. The idea is that the maximum flash sync limitation is removed, but at the cost of reducing the “motion-stopping” ability of the flash, and reduced maximum flash power.
Don’t use it unless you need it. I’ve only ever used it by accident.
The term “high speed” in HSS can be confusing – it refers to high shutter speeds, and NOT to high speed subjects. If your subject is moving at high speed and you want to freeze that motion, HSS is NOT what you need. For that, you need…
High speed flash
A flash designed to have a very short duration – as little as 1/1000000s – might be used to freeze the motion of very fast moving objects. These tend to be specialised equipment – most speedlights will go no faster than 1/30000 or so, depending on the power selected.
Playing card split by airgun pellet, shot at around 1/1000000 second.
Rear curtain sync
As I mentioned earlier, for the “flash” part of the exposure, it doesn’t matter how long the shutter is open before or after the flash, while the “ambient” part of the exposure is taken from the entire shutter open period.
Normally, the camera will trigger the flash to fire as soon as the shutter is fully open – this is as soon as the first shutter curtain has finished its travel, hence the term “first curtain sync”. But there is also an option to trigger the flash just before the end of the ambient exposure, just before the second shutter curtain starts its travel. This is known as “rear curtain sync”.
If your subject is not moving, it makes no difference. But if it is, the effect can be quite dramatic. For example, if you take a photo of a moving car, with a 1s exposure and rear curtain sync, the car will be exposed by the flash at the end of its travel, with a blurred shape from the ambient exposure behind it. If you use first-curtain sync, the blurred image from the ambient exposure would be in front of the car. Generally in such situations, rear-curtain sync looks better, but it depends on the effect you are after.
This is front-curtain sync – the blurred motion comes after the frozen image. It would have looked much better with rear-curtain sync.
Zoom flashes
Many larger flashes incorporate a “zoom” feature with a lens in front of the flash head that moves in and out according to the focal length you are using, to concentrate all of the light output onto the area in front of you that will be covered by the camera frame. This extends the range of the flash without having to increase its power.
Generally the flash will automatically select the widest zoom setting as soon as the head is moved away from the “straight ahead” position, as zoom mode is not desirable when using bounce flash.
If your camera and flash are compatible and connected via a suitable hot-shoe of cable, the camera will communicate the focal length to the flash to set the zoom automatically. If not, you can set it manually.
FEC and FEB
FEC is Flash Exposure Compensation, described earlier.
FEB stands for flash exposure bracketing – taking a series of shots with different flash power so you can pick later which one you want best. About as useful as standard exposure bracketing is (i.e. not very, in my experience). Better to get the exposure right, then use that exposure for all your shots, than to end up with 3x as many images where 2/3 of them need to be immediately deleted because the exposure is wrong. Especially if it’s going to use up your flash batteries 3x as fast.
Multiflash
Fires the flash multiple times (at regular intervals) during the course of a long exposure. Used for special effects.
Channels etc
Other settings on the flash relate to communicating with other flashes in a multi-flash setup. They will control such things as what channel(s) to use to avoid triggering other photographers’ flashes or to have different groups of flashes using different settings, whether this flash should be a master or a slave, and so on. These settings are beyond the scope of what I will discuss here.
Buying a flash
Which system?
Most camera manufacturers sell their own range of flashes, which are designed to work with their cameras and which won’t work with anyone else’s. While the very basic communication with a flash gun via a sync cord or the centre pin of a hotshoe is pretty much standardized (see caveat below regarding old flashes), the layout and meaning of other contacts in the flash shoe is not, nor are the communications protocols between camera and flash. This means that you are locked in to your camera manufacturer for any automatic flash functionality beyond the basic manual flash modes. As a result manufacturers own brand flashes tended to be over-priced and under-specced.
Or at least, you were.
These days third party manufacturers such as Yungnuo and Godox have reverse-engineered the connections and protocols such that you can buy a flash from them that will work just as well as the OEM ones – often better – at a fraction of the price.
If you are looking for a flash, I can’t think of any reason to buy one from any other manufacture than Godox. They have a large range, full of features, at good prices, that work with all the major cameras. While Godox sell all of their flashes that connect directly to cameras in different versions (one for each manufacturer), all their flashes can communicate with each other so you can use a Canon-version Godox flash trigger to remotely fire an Olympus version Godox flash (or vice versa). so with a bit of planning you can share your kit across multiple systems.
I can particularly recommend the MF12 macro flashes and the TT860iii speedlight. Which of course work together seamlessly if desired.
How much flash power do you need?
Flashes used to quote something called a guide number – this was an indication of how powerful the flash was, and was measured in feet (or metres). A flash with a GN of 12 feet could give a correct exposure of a subject 12 feet away at ISO 100 and aperture f/1.0. Of course, you probably are not going to be shooting at f/1.0, but you can divide the GN by the aperture to give the effective range – so at f/4 your GN of 12 would give a good exposure up to 3 ft away at ISO 100. If you double the ISO, the range for a given GN will increase by a factor of 1.4 (the square root of 2), because of the inverse square light falloff rule.
Before the advent of any automatic flashes, the GN was all you got. You took the distance to your subject, the GN, and the ISO speed of your film, and used it to calculate an aperture to set your lens to for the correct exposure.
These days, the GN is generally used just to give an idea of the power of a flash. Higher GN values mean higher maximum power, but with some caveats. Firstly, to compare like with like, the GNs you are comparing must both be using the same units (metres is standard these days), and at the same ISO (100 is normal, but it’s wise to check). Finally, because many flashes have the ability to “zoom” by using a lens in front of the flash head to concentrate the beam when lighting more distant subjects, the GN becomes dependent on what zoom setting it is measured at. If two flashes quote the same GN, but one is at a longer zoom than the other, then the one with the shorter zoom is probably more powerful.
Is more flash power better? Only if you need it. More powerful flashes will be bigger, heavier, and more expensive. Also consider that you can double the power of a flash by using two flashes together, so sometimes two (or three) small flashes can be a more flexible arrangement that 1 big one – see my MF12 macro rig for example.
Besides power, other factors that might determine your choice of flash might be features such as zoom, remote triggering, modelling lights, multiflash mode, shorter recycle time, bounce heads… Bigger flashes do tend to be more fully-featured, but not all features are necessarily useful. Bounce head and remote triggering are definitely useful, and a short recycle time is nice. Other features may not be important to you – I have only ever used multiflash mode once.
Batteries
Until fairly recently all speedlights tended to be powered by AA batteries, and the choice of battery would have a big impact on how well the flash worked – in particular, how quickly the flash recycled and how long the batteries lasted. Flashes are quite hard on batteries – they require high currents in order to recharge the capacitor quickly – and some batteries are better at delivering that than others. If your flash uses AA batteries, do yourself a favour and feed it with Eneloop or similar batteries – rechargeable (but precharged) NiMH batteries.
Some more modern flashes use rechargeable Lithium Ion batteries – either built-in or removable, which give much better performance both in therms of recycle rate and number of flashes. AA batteries do have the advantage of being universally available though, where your proprietary Li-Ion battery may be hard and or expensive to source a spare. Built-in batteries are convenient, but you have to stop shooting and recharge when they run out rather than just swapping in a fresh battery.
Radio controlled flashes
When using multiple flashes that you want to fire together, or when using a flash that is not physically connected to the camera, some form of wireless control to connect the flashes is used.
Many modern flashes incorporate radio technology to facilitate this, and in some cases the camera will also have radio controller built in.
Older flash units used to communicate via very short coded pre-flashes, which meant they would only be able to communicate if there was line-of-sight between the flash units.
External radio control units such as “pocket wizards” can also be used to synchronize remote flashes.
In the Godox system that I use, a radio controller X1 is connected to the camera (this unit needs to be compatible with the camera system you are using – Godox sell versions for Canon, Nikon, Olympus, Sony, and Fuji) and communicates with the macro flashes (which are camera-system agnostic) via radio.
It’s not strictly true that the radio controller needs to be camera-system specific. If you are not using TTL mode and don’t require any communication from the camera other than “fire now”, then you can use a trigger with just the central hot-shoe contact (or the sync cable) connected, and the camera make/controller type is irrelevant.
Vintage flashes – use extreme caution
Vintage flashes are available for peanuts on eBay and the like. You can hardly give them away, and they can in theory offer a lot of flash power for little to no expenditure. BUT, old flashes designed for use in the days of film when cameras were largely mechanical, and the flash contact inside the camera was a simple physical switch, may route the entire flash capacitor voltage through the flash contact. This 400v will very quickly, and very permanently, damage a modern electronic camera. Unless you are sure that the flash has a trigger voltage of 6v or less, DO NOT connect it to your camera. You can get an adaptor to allow you to use old flashes safely, but at that point, just buy a new flash. It will be much better, much more flexible, much more reliable, safer to use… Save the vintage flash for use on your vintage camera (you do all have a collection of vintage cameras, don’t you?)
How old does a flash need to be for the trigger voltage issue to be a concern? Hard to put an exact date on it, but if in doubt, any flash that supports TTL is going to be fine. Any flash that doesn’t, best to check. A quick google of the flash name and “trigger voltage” will probably tell you.
Other thoughts
Flash and nature
Is it ok to use flash on nature subjects? Well, I’m sure plants and fungi don’t mind, but what about mammals, birds, and insects? In my experience, subjects are no more bothered by a flash than they are by the sound of a shutter or the smell of a photographer – actually, rather less so. The flash doesn’t blind them or affect their night vision any more than it does for a human subject. If it’s too bright, right in their eyes, they will find it unpleasant just as you or I would, but you would also get a very poor overexposed picture. But you must make up your own mind what level of disturbance is justified to get a picture, whether talking about flash or any other aspect of nature photography.
A badger at night, with flash. The badger was completely unconcerned.
I use flash for many of my macro shots of insects, because there is never enough light when working close up. Using flash allows me to hand-hold without risking camera shake. My normal practice is to shoot bursts of 40-80 shots with focus-bracketing and a 0.1s pause between them to give the flash some recovery time – if I keep the flash power below 1/32 then the flashes can keep up. If the subject moves, I can select one or two frames from the burst where I managed to get good focus. If it does not move, I can focus-stack in the computer using Zerene.
I don’t often use flash for other nature subjects, because I prefer the look of natural light. I used to occasionally use a “Better Beamer” for bird photography which would provide just a little fill-in flash (and a catchlight in the eye) when shooting birds at a medium distance, but have not used it recently. I think the nature of birding opportunities in Florida were more conducive to its use than they are here in the UK.
Incidentally, if you are using a Better Beamer in a sunny climate like Florida, be careful where you put it down. It’s very easy to melt holes in the front of your flash if you leave it pointing at the sun, or worse.
Nature photographers using “Better Beamer” flash extenders
Why is it called a “hot-shoe”?
The “shoe” is the shaped channel on top of many cameras that can hold the “foot” of the flash for mounting purposes. A “hot” shoe has a contact in it to trigger the flash at the appropriate moment, while a “cold” shoe would provide a physical mounting point only without any control. Manufactures have added additional contacts for communication between the camera and flash, but the positioning and purpose of these vary from manufacturer to manufacturer.
In addition to the contact in the hot-shoe, cameras will have a connection called a “sync terminal” that allows a cable to be connected between camera and flash.
Ring flash
A ring flash is a specific flash designed mostly for macro work that will allow an even distribution of light onto a very nearby subject without hotspots. I have not used one, so I can’t really comment on their effectiveness.
Other lighting (not a flash)
Alternatives to flash lighting include natural light (push the ISO if it’s too dark), reflectors, or continuous lighting.
If you just need a little fill the using a simple collapsible reflector to bounce a bit of light into the shadows may be all you need. It’s certainly cheaper than a flash, but not necessarily more convenient – it might need another pair of hands to operate, for example, and have you ever tried folding one back up?
Continuous lighting has become much more popular recently with the advent of LEDs that can deliver bright light without generating excessive heat or using excessive power. They do still generate quite a lot of heat and use quite a lot of power though! The main reason for using continuous lighting is for shooting video, where flash is not practical. Other advantages of continuous lighting in a studio setting are that you see what you are going to get (and can meter without any special tools, or let your camera meter for you). But continuous lighting cannot compete with flash for its combination of power and portability, nor does it offer any “motion freezing” capability.
Other resources
https://strobist.blogspot.com has all the information you could ever want to know about use of speedlights for portrait photography.
Leave a Reply