Lightning Photography
by Chuck Doswell

NOTICE: All photographic images included here are copyrighted and are not to be reproduced by any means without my expressed permission. E-mail me at cdoswell@earthlink.net for information about their use. See here for more information.

These images have been scanned from original slides, with some digital enhancement (touch-ups of dirt on the slides when scanned, and some enhancement of the original scanned images to make them look more like the original slides). I do not alter my images digitally to put in things that were not originally in the image or remove things that were originally in the image, and I do not make digital composites. I am personally opposed to such image manipulations unless they are admitted to clearly and obviously. 

Photographing lightning is special. Not all storm chasers are into lightning photography, but to me (and some others) there is no better way to cap off a successful storm chase day with a successful lightning night. Learning lightning photography is not easy, since it is tough to get proper exposures. There are several different techniques for lightning, but they depend on having some proper equipment:

• Good quality camera, with a "B" (bulb) setting for extended exposure times
• Good quality film (see below)
• Steady tripod
• Cable shutter release

Basic Dark Sky Lightning

Assuming that you have this, the simplest form of lightning photography is done well after sunset, with a dark sky. In essence, you find a part of the sky where lightning is happening, aim your camera that way, focus on infinity, set the f-stop, open the shutter with the cable release, and close the shutter after lightning happens. In effect, the lightning takes its own picture, while you wait with the shutter open. After some amount of lightning happens (or not, as the case may be), you close the shutter, advance the film, and shoot again (or not, as the case may be) ... the amount of lightning that you choose to include in your image depends on the circumstances. In most cases, one vivid cloud-to-ground (CG) strike is sufficient, but your goals may be to include more than one strike. Experience will tell you what gives you the most pleasing results to your eyes. When the sky is dark, therre is no limit to how long you can wait with the shutter open ... although you may get some "strobing" (see below) or perhaps some distant artificial light will become intrusive with very long exposures. The choice of an f-stop is perhaps more difficult ... more on that later.

Artificial Lights

 

There may be some lights somewhere in your view. You may or may not wish them to be there, but unless they are spotlights (or car headlights) aimed into your lens, you can do long exposures (on the order of a several minutes) without having them ruin the photograph. Your first job is to obtain proper exposure of the lightning. If the flash channel is visible, the most attractive photographs (in my opinion) show a lot of branching, so if you want such pictures to be exposed so as to reveal as much branching as possible. This makes it possible for artificial lights to become intrusive.

Assuming you don't want artificial lights to intrude noticeably in your image, having them in view limits the length of time you can wait for a flash with the shutter open. Even bright moonlight can be a problem if you have lengthy time exposures, as illuminated clouds will move (and, therefore, blur) during the time your shutter is open, when you hold it open long enough. Of course, you might want such blurring in your images ... the choice is up to you, as the photographer. If the lightning is happening inside the cloud (intra-cloud, or "IC" flashes), illuminating it from within, such lightning can be attractive but it is not as bright as flashes showing the channel, so you'll have to give it more exposure (a smaller f-stop, equivalent to a wider lens aperture); probably on the order of a full stop of additional exposure, compared to shots done with a visible, bright lightning flash channel.

The "Strobe" Effect

On very long exposures, with lots of intracloud flashes, the clouds may move visibly in the frame, giving a sort of "strobe" effect. In the example, the tower to the left of the cloud-to-ground flash is strobed once.

One thing is almost certain: you will use a lot of film attempting to get good lightning photographs! Until you become familiar with the process through experience, plan on having fewer than 20% of your exposures turning out worth keeping. Film is cheap, so don't be afraid to use it in learning your technique. As you gain experience, you will get better at estimating the exposure from the situation. I use Kodachrome 64 (ISO 64 speed) for most of my dark sky lightning work; if the flash channel extends through most of the frame when the frame is horizontal ... for a 35 mm camera using a lens with a 50 mm focal length, such lightning is relatively close! ... a starting point for exposure is in the f4-f5.6 range. Not all flashes are the same brightness and I am always in the position of having to guess what exposure to use. The preceding is just a point of departure, and nothing more.

Given all the factors that influence the process (distance, brightness of the flash, film speed, exposure time, etc.), it is difficult to be definitive. For daytime lightning, I prefer Fujichrome Velvia (ISO 50 speed), which means roughly 1/2 stop more exposure for the same scene shot with K64. For lightning that is farther away, more exposure is needed ... if it's very close (see below, on safety), less exposure is called for to get the right image. There are no hard and fast rules, so experience is going to be your best guide. NOTE: if you use filters a lot, especially polarizers, either remember to remove them before starting your lightning photography, or be sure to account for them when you estimate your exposure setting.

Longer lenses (larger focal lengths) will help "frame" distant lightning, but remember the following things when you use those longer lenses: If the lightning is far away, the intervening dust will tend to shift the color more toward the red, as in this example.

If you find this "redshift" troublesome, it can be compensated for with filters, but the use of filters will necessitate more exposure (larger apertures = smaller f-numbers). Tungsten light-balanced (indoor) film can also reduce this reddening effect, but will give regular (not distant) lighting exposures a very bluish tint. You may or may not find the resulting blue cast pleasing.

• Lightning is not very predictable. If you zoom in on a small portion of the sky, you are decreasing the probability of having a lightning strike occur within your frame. Of course, you always can get lucky ...

The visible part of a typical lightning flash runs down the lightning channel one or more times. Flashes that illuminate the channel only once are often called "staccato" flashes.

They tend to be visibly bright and brief, often leaving a vivid afterimage in a dark-adjusted eye. These photograph quite well, typically revealing a lot of branching. Multiple flashes along the same channel usually do not reveal as much branching, apparently because the second and later flashes run mostly down the main channel and do not re-illuminate the branches. Hence, staccato flashes are more photogenic, in general, at least in my opinion. You have to be very lucky to catch a stacatto flash in the daytime (see below).

Recently, some gadgets have been developed for fully electronic cameras (with an electronic shutter and shutter release button) that can detect lightning flashes and trigger the shutter in time to catch the flash. In principle, this might make capturing daytime staccato flashes easier ... except that they can be triggered by in-cloud flashes, as well as CG strikes. Based on the experiences of some friends of mine, it's not obvious yet that this is going to represent a great improvement in catching daytime staccato flashes.

A way to pick the right part of the sky, but with no guarantees, is to observe the lightning for a while without attempting to photograph it. new flashes to ground near a developing shaft of precipitation often are followed by several more in about the same area. As a storm dissipates, lightning activity shifts into its anvil, with streamers flashing sporadically (not frequently) through the anvil. In general, it is easier to capture frequent lightning than occasional flashes; the latter often do not seem to follow any simple pattern that enables you to anticipate where the next flash might be.

Advance the film quickly when completing a shot, and be ready as soon as possible for the next flash. There is considerable frustration in having a spectacular flash occur as you are advancing film!

Once you get to the point where you can get 80% "keepers" from your dark sky shots,you might want to advance to the much more challenging daytime lightning (i.e., lightning shots while there is still light in the sky). The idea is to get both the lightning and the surround scene properly exposed. It's more fun (i.e., challenging) and the images can be quite dramatic, but can consume huge quantities of film quickly ... your success rate can be pretty low.

There are several ways to obtain a shot that is properly exposed for the existing, ambient light and the lightning.

You can get lucky, and have the flash occur during a regular daytime shot. Of course, I've never had this happen, but it is at least logically possible. Good luck!

You can stop down the lens (large f-numbers), thereby requiring longer exposure times for a properly exposed shot. This increases your chances of getting lucky (as in method #1). One way to enhance your capabilities here is to use a neutral density filter to cut down on the exposure (a typical lens-mounted polarizer can work well for this purpose). You should be aware of the potential for reciprocity failure in long exposures - reciprocity failure is a color shift associated with the film characteristics that varies from one type of film to another. Another problem with this is that the lightning may not be all that much brighter than the ambient light, depending on a number of factors; the result may be that the lightning simply doesn't appear, or only appears as a dim, barely visible thin channel that is not very dramatic (branched). The brighter the ambient light, the more likely a bad result will occur. This technique works best as the daylight is fading.

For non-staccato flashes, if you have reasonably fast reflexes and trip the shutter as soon as you see the first flash, a subsequent flash may illuminate the channel while the shutter is open. Once again, non-staccato flashes often do not reveal much branching.

If you have the right camera equipment, use a gadget that fires the shutter electronically when it detects a lightning flash (see above).

The way method #2 works is this: meter the image (without lightning) at, say, a one second exposure time. From this, you obtain an f-stop value that will give a proper exposure. You can increase the length of time your lens is open by taking advantage of the reciprocity rule ... each time you stop down the lens (reduce the aperture) one full f-stop, you increase the exposure time by a factor of 2 and keep the same exposure. Thus, suppose your one-second metering gives you a reading of f4. Stopping down to f5.6 will mean you can expose for two-seconds, f8 means a four-second exposure, f11 gives 8-seconds, f16 gives 16-seconds, and so on. For daytime images, an exposure of more than about 4-seconds gets you into reciprocity failure with most films, so you can expose it for a little more time than the reciprocity rule requires. In the preceding example, a 4-s exposure could go for 6-s, an 8-s exposure could go for 12-s, and a 16-s exposure probably could go for 26-s or perhaps a bit more. Hopefully, this should become clear, with practice.

With method #3, you probably can get away with exposure times as short as 1/2 second or so. If need be, you can use a filter to get a proper exposure of the ambient light with these relatively long exposure times.

Basically, since the branches are not as bright as the main channel, it is difficult to capture a well-branched lightning channel photograph with much ambient light.

When trying for daytime lightning, I usually switch from K64 to Fuji Velvia film. With its warmer color palette, the ambient light aspects of the photograph are rendered more pleasingly (to me!) with Fujichrome than with Kodachrome.

Picture composition is a matter of personal taste, naturally. Rules are meant to be broken, but there are some things to think about. It is possible in some places of the plains to have lightning appear on a completely featureless horizon; this may or may not be what you want for your lightning images. It is getting to be impossible on the plains to avoid farmer pole lights (a never-to-be-sufficiently-damned illusion of security that is polluting our night sky with very ugly sodium and mercury vapor light), and any cities nearby will contribute, positively or negatively according to your personal taste. When aiming at any photographic subject, avoid the amateurish tendency to center the frame on the object of attention; specifically, be attentive to the location of the horizon line in your frame. You are photographing lightning, not a wheatfield (unless you are photographing a wheatfield illuminated by lightning), so you might want to push the horizon line well down in your frame (you are using a camera with a through-the-lens viewfinder, aren't you?). In most cases, you want to fill the frame with lightning to the maximum extent possible. However, rules are meant to be broken:

There is no way to take lightning photographs without risk. You are likely to be standing near a metal tripod, holding onto a metal cable release in a relatively exposed location in a thunderstorm. Think about it! Lightning need not strike you directly to be dangerous; it can travel along power and phone lines, metal fences, or even through the ground to you. Lightning photography necessitates taking some risks, but being foolhardy is not recommended. Some factors you might want to mull over as you ponder your safety decisions can be found here, provided by Dr. William Hark and here, as well, provided by Dr. Mary Ann Cooper.

Lightning is not very predictable. Please consider about the fact that you will not hear the flash that gets you! Roughly speaking, sound travels about one mile in five seconds, so if the delay between the flash and the thunder is less than five seconds, the lightning is less than one mile away. When that delay time is less than five seconds, you should be thinking seriously about getting out of any exposed positions (say with your tripod poked partway through a barbed wire fence running along a hilltop to get just the right composition). Generally, it is safe inside your car, and you may be able to use a window clamp as a tripod and so keep merrily snapping away in relative safety. You definitely do not want to be under a tree, but there may be shelter nearby where you still can obtain lightning shots in a relatively safe position. NOTE: being in a doorway or under a carport is NOT a relatively safe position ... being out of the rain does not mean you are out of danger from lightning.

Shooting while under thunderstorm anvils or near developing precipitation shafts can put you right near the first flash from that region of a thunderstorm. You won't hear the first flash in order to time the delay if it gets you! There is virtually no reduction of risk associated with using a non-metallic tripod, wearing insulated shoes, or any similar measures. A flash that has made it through thousands of feet of insulating air is not going to be prevented by a half-inch of rubber, or whatever.

Lightning strike victims may not be killed outright, but their hearts and/or breathing may stop. Having someone around who knows CPR would be quite handy in such an event! They may have a headache (or other lingering effects, some of which can be pretty awful), but strike victims given CPR in time will be around to try again (if they haven't lost their sense of invincibility to the point of giving up lightning photography entirely!).

Feedback? Suggestions? Corrections? Useful information? Send me an e-mail!

Further Reading:

Outdoor Photography Advice
Some Basic Elements of Photography
Some More Advanced Photgraphic Skills
Lightning Photography

GALLERY