“The art of art, the glory of expression and the sunshine of the light of letters, is simplicity.” – Walt Whitman

He was mainly shooting photos in locations where there was plenty of ambient light available to make a proper exposure with his camera, and I suspect that the unspoken subtext to his question was that he was wondering if there was any particular reason for him to spend the money to buy an external flash for his camera (or even to use the built-in “pop-up” flash).

Here’s what I told him:

There are two main reasons for people to use flash when making photographs:

1. There’s not enough ambient light to make a photograph without flash, or
2. The ambient light that’s there is not to your liking, and you want to modify or replace it with “good” light of your own.

Most beginners only think of reason #1. (It’s dark, so I use flash.) Simply adding more light quantity, without giving consideration to its qualities (such as its hardness, color, direction, and relative brightness), typically results in the dreaded “person in a dark cave” portrait.

A more experienced photographer will use flash to supply the light that he wants, where and how he wants it, either alone, or in addition to the existing ambient light.

Personally, I use flash most often when I’m shooting outdoors, in full sun, which is a situation where most amateurs wouldn’t even consider using flash at all.

In full sun, you have plenty of light, but it’s almost always very hard (the sun may be huge, but it’s 93 million miles away, and casts very hard-edged shadows). Also, full sunlight rarely comes from a flattering direction; it’s almost always overhead, which gives people raccoon eyes, and hides their faces in shadow if they’re wearing a hat. Also, full sunlight gives your images more contrast than any camera can capture in a single frame.

Adding flash from my camera position allows me to fill in those shadows without erasing them completely. This way, I can reduce the contrast in the scene to the point where my camera can actually record detail in the shadow areas, and I can avoid raccoon eyes and see people’s faces up under their hat brims. The flash also adds a bit of “sparkle” to the eyes, in the form of a “catch light” reflection.

Outdoors, I’m not generally looking to overpower the sun with my flash. I usually prefer to use flash that doesn’t call attention to itself. Instead of making the scene look “artificially lit”, I simply tame the shadows, and bring them under control.

It all boils down to control.  Using flash, you’re able to take control of the lighting in your images, and are no longer at the mercy of the ambient light.  To a photographer, that’s a very good thing.

The argument centered on the made-up term “light depth of field”.  (For the record, I find this term silly; even worse, I find it misleading.  I won’t be using it again, and I suggest that you forget it was ever mentioned.)

The context of the discussion, however, is both useful and instructive to examine.  The key issue in that context is:

Given the inverse square law, how do you determine the minimum distance away from your subjects to place a light, in order that the exposure variation across those subjects due to falloff stays within acceptable limits?

It sounds complicated, but it really isn’t.  There’s a smidgen of math involved, but it’s nothing harder than very basic high school algebra.

For those who’ve forgotten, let’s go over the inverse square law:

The intensity of light falling on a subject at a certain distance from a light source is inversely proportional to the square of the distance from the light source.

In layman’s terms, when you double the distance, you get the light intensity.  Triple the distance, you get the light intensity.  Move n times further out, you get times the light intensity.

We photographers like to deal in “stops” of light.  Each “stop” is a doubling or a halving of light intensity.  Put in math terms, the intensity difference in stops is the base 2 logarithm of the ratio of the intensities in foot-candles or lux.

And now, a little bit of high-school math:

Don’t worry — I’ll do the math for you.  You can feel free to skip to the end, if you just want the answer….

First, we describe the setup.  We have a light source (“L”) that is a certain distance (“x”) away from the closest subject (“C”).  A second subject (“F”) is further away.  How far?  Subject F is “y” distance past subject C.

Something like this:

L -------------------x----------------- C ----y----F

So, the distance from L to C is x, and the distance from L to F is (x+y).

If a light intensity falling on C (“x” distance units away from L)  is “i” lux, then that same light falling on F at “x + y” distance units away has an intensity of  , which is a change of stops.

We’re looking to find out how far away to put our light in order to get the light falling over our subjects to be even within a certain number of stops, when the group is spread out over a certain distance from the closest to the furthest subject.  In other words, we’re looking for “x”, given the number of stops and “y”:

If y is a positive number (which it will be, as we’ve laid out the diagram), then the number of stops will be a negative number, indicating that the light is getting dimmer the further away that we go.  While mathematically accurate, most photographers aren’t used to be thinking in negative numbers.  To make the equation more useful, let’s flip the fraction over, which will reverse the sign on the logarithm.  That way, we can specify the number of stops down as a positive number, rather than having to think of it as a negative number of stops up.

Now, we just need to solve for “x”.

And, finally….

There is our answer.  It’s a bit ugly, but it’ll tell us what we need to know.

If the closest subject and the furthest subject are y feet apart, and we want the exposure across the group to be consistent within “stopsdown” stops, we can calculate the distance x in front of the group at which to place our light.

As an example, if we want at most a variation of 1 stop from front to back across a group of people, and the distance between the closest and furthest people is 3 feet, then our light has to be approximately:

in front of the group.

If we want to limit ourselves to 1/2 stop of variation across the same group, we need to place our light further away:

in front of the group.

The Bottom Line:

The further away your light source is from your group, the less variation in light intensity you’ll have across the group due to falloff.  The overall intensity will, of course, be lower.  That’s not in question.  However, the important thing to remember is that there will be less variation of intensity across the group.  You’ll have more even — although dimmer — light.

If you know how much variation in light intensity you can tolerate (in stops) and you know the size of the group (from front to back, as seen from the perspective of your light source), then you can fairly-easily calculate the minimum distance to your light source.

To make this easy for those of you without a scientific calculator, I’ve pre-calculated a few factors that you can use in the following equation, just by multiplying:

The photos from NSL 2011/ROCstock 33 are now online for your viewing and purchasing pleasure.  Click on the “Browse and Buy Photos” button in the left sidebar to get to the CrayonPhotos.com online store.

If you are one of the people who won a free 8″ x 10″ print in one of the raffles held during NSL/ROCstock, please contact me via email with your address, and the number of the picture you’d like to receive as your free print.  (When you’re looking at the preview of an individual image, the picture number appears right underneath it, in the format “NSL11-xxxxxxxx”.)

National Association of Rocketry President, Trip Barber, presents a plaque to Rocketry Organization of California President, Rick Dickinson, in appreciation for hosting NSL 2011.

After five days and four nights in the Mojave desert, I’m back home, and recovering from one of the best “working vacations” that I’ve had in quite some time.

As I mentioned in my last post, I was on-site at the NAR‘s National Sport Launch in Lucerne Valley, CA, this past weekend.  I arrived last Wednesday evening, and didn’t get home until nearly 9:00 PM on Sunday, exhausted but happy.

I did, however, leave out one small detail that many of my readers are probably already familiar with: I’m actually the current President of the Rocketry Organization of California (ROC), who were hosting the event.

Rocketry is my hobby, and I’ve been an active member of ROC for well over a decade, now.  As in most hobbies, there are clubs, and the folks who hang around and help out with the clubs’ activities over time tend to get handed more and more responsibilities.  I’ve been on the ROC board for a while, now, and last year, they voted me in as President.  It’s a lot of work, but very rewarding.

In any case, that explains the picture at the start of this post.  I was very pleasantly surprised by Trip Barber, the NAR President, on Sunday morning, when he took the microphone at the launch control table, and called me up to present me with a plaque in recognition of my role as Event Director for this year’s NSL.  It was a pleasure doing it, and the thanks really ought to be shared among a large number of volunteers.  (But, all the same, I’m going to keep the plaque myself!)

I have just started to process the many photos I took at NSL, and I’ll post them in my online store as soon as I’ve gone through them, probably in about a week or so.  In the meantime, here are a few liftoff shots to whet your appetites:

Liftoff of Jim Wold's "Naked Fat Man" rocket on a Kosdon by Aerotech K700 motor.

Veronica Kirk's Level 2 Certification Flight Lifts Off

Rocket launch at Lucerne Dry Lake

Come join CrayonPhotos.com at the National Association of Rocketry‘s annual National Sport Launch this coming weekend, June 10-12, 2011, in Lucerne Valley, CA, where we’ll taking pictures of amateur rocketeers and their rockets.

Hosted by the Rocketry Organization of California (ROC), this three-day event brings together young and old rocket flyers from all over the country.  There should be over a thousand people gathered over the weekend in the middle of Lucerne Dry Lake’s vast flat expanse.  FAA approval has been granted to allow rocket flights up to 19,000′ above ground level, so expect some spectacular sights.

We’ll be posting pictures from this weekend’s festivities once we get back in town, so if you can’t make it out in person, please check back next week to see what you missed!

I’d like to offer my sincere thanks to all veterans for their service.  You put your lives on the line so that the rest of us can enjoy the benefits of freedom.  We don’t thank you enough for your service, and for that I apologize.

Thank you, again, for being willing to make the ultimate sacrifice.  You honor us  with your service.

But, with the number of naive photographers with their first DSLR who seem to see wedding photography as an “easy way to make some money” with their brand new camera kits, I thought it made some sense to look at the minimal entry requirements, from a camera equipment standpoint.

Weddings combine the technical aspects of fashion and portrait photography with the high pressure and tight time-lines of corporate event photography.  You have to produce elegant portraits of brides in delicate white dresses standing next to grooms in black tuxedos, while preserving detail in both, under challenging (and often variable) lighting, and working on-the-fly with no chance for a re-shoot.

I know that in a previous post, I said that “your camera doesn’t matter“, but I have to wonder what the groomsman in the background of this photo will be able to produce with the little disposable camera that he’s using?  I suppose that there are some minimal standards necessary for entry into this particular photographic specialty.

So, what do I consider the minimum requirements, equipment-wise, to shoot a wedding?

First, you need a good camera.  It doesn’t need to be the latest, greatest, most expensive camera, but it needs to have a few important features that your average “point and shoot” camera won’t have:

• Fast, reliable focusing.  Things move fast at a wedding.  If you can’t quickly and reliably get your shots in-focus, then there’s no point in you even being there.
• Easy manual control of aperture and shutter speed.  As I already said, things move fast.  Dials and knobs will beat menus and buttons for quick adjustments eight days a week, and twice on Sundays.
• A way to mount and trigger an external flash unit.  Usually, this means a “hotshoe” on top of the camera.  You will need to use flash, especially when outdoors, to fill in overly-dark shadows.  A built-in flash will just not “cut it”, in terms of power, battery life, or (more importantly) position.  You need to be able to get the flash up a ways over the lens, in order to avoid red-eye, and to avoid casting shadows from the lens and/or lens hood.
• The ability to use interchangeable lenses.  For portraits, you’ll want medium-long focal lengths.  For the dance floor, you’ll probably want wide-normal focal lengths.  For ring and flower shots, you may want a macro lens (or at least a lens that focuses fairly close).  Generally speaking, you’re not likely to find a good quality single lens that does “everything” — at least not well.

In most cases, these requirements mean you should probably be using a DSLR.

Then, you’ll need another one.  You MUST have at least one backup camera.  A wedding is a (hopefully) once-in-a-lifetime event.  There are no “do overs” if you drop your camera and break it.  You don’t get a “mulligan” if your shutter dies and refuses to fire any more, or if your autofocus suddenly decides to stop working.  Make it the same brand, so that your lenses are all interchangeable between bodies, and so that the control layout will be familiar to you.  (It doesn’t have to be the exact same model, but if it isn’t, you need to make sure you’re just as familiar with its controls and quirks as you are with your main camera.)

(If you’re smart, you’ll have a third camera, as well, so you’ll still have a backup when you continue shooting after one of your cameras dies.  “When”, not “if”:  Murphy was an optimist.)

Now, let’s talk lenses.

Generally speaking, you’ll want “fast glass” (aka lenses with wide maximum apertures, f/2.8 or better).  This is for several reasons:

• Some churches don’t allow the use of flash during the ceremony.  If you want any pictures at all, you’ll be shooting in low light, which means wide apertures, slow shutter speeds, and high ISO values.  You need every last photon you can get, and wide apertures are the absolute best way to achieve that.
• Subject isolation through limited depth of field.  If you want to throw the background out of focus to isolate and draw attention to your subject, you’ll want wide apertures.  You might be able to “fake it” with Photoshop after the fact, but it’s always much better to get things right in-camera.  It generally looks much better, and it’s easier, too.
• Image quality.  Generally speaking, the wide-aperture lenses in every manufacturer’s lineup tend to be among the best they make, in terms of optical quality.  Making wide aperture lenses requires the largest, most expensive glass lens elements.  It only makes sense that manufacturers would do their best to make sure that these expensive lenses are truly “top of the line” in all ways, not just in terms of maximum aperture.

You probably won’t need extremely long focal lengths — you are shooting a wedding, not capturing tiny, elusive, and easily-spooked birds from a great distance.  But, a medium-to-long zoom lens will probably be your number one lens for the ceremony and formal portraits.  And, a moderately-wide-to-normal zoom lens will probably be your “go-to” lens for the reception.  If budget constraints force you to choose, put the most money into the medium-to-long zoom.  You’ll be able to use flash at the reception.

Again, backups are important for lenses, as well.  You probably don’t need identical expensive lenses as your backups, however.  Slightly slower lenses can act as backup for the more expensive fast glass.  Maximum apertures of f/4.0 are probably good enough for your backup lenses.  You can crank up the camera’s ISO another stop, and simply live with having to filter out more grainy noise in post-processing.  It won’t be quite as good quality, but it’ll be worlds better than nothing, and your skills will help to (partially) make up for the not-quite-as-good lens.

Finally, don’t forget things like flash units (at least two, so you always have a backup), and extra fully charged batteries and empty memory cards.  Most importantly, you should have lots and lots of time under your belt spent practicing with your cameras, so that you know all of their quirks, and can change settings quickly and intuitively to deal with changing conditions.

What equipment do I use?

I shoot Olympus DSLR cameras.  I’ve been shooting pictures with a variety of film and digital cameras for years, but I bought in to the Olympus DSLR system when I first got a DSLR.

I started out with an E-520 two-lens DSLR kit.  At the time, it was the absolute best “bang for the buck” DSLR kit available, by a fairly wide margin.  The “kit” lenses are both remarkably sharp, and the body includes image stabilization.  And, it was priced several hundred dollars cheaper than the closest equivalent Canon or Nikon rig.  It was a very good purchase, and I’m still quite happy with it.

Since then, I’ve added a number of higher-quality lenses and other pieces to my kit.  I shot my niece’s wedding last weekend with the following:

• Olympus E-3 body with HLD-4 battery grip.  This is a solid, professional-quality body with incredible “never worry about the pouring rain” weather-sealing, image stabilization, and controls that I could use blindfolded.  With two batteries in the grip, I can shoot all day without running out of power, and it balances nicely with heavier lenses.
• Olympus E-520 body.  While it lacks the battery grip and weather-sealing, it has similar specs to the E-3 in most other respects.  It’s a solid performer, and I’m very familiar with its controls, as well.
• Olympus 35-100mm f/2.0 Super-High Grade Zuiko Digital zoom lens.  This is one of my favorite lenses.  It’s not lightweight, by any stretch of the imagination, but it produces beautiful images, and the constant f/2.0 maximum aperture across the medium-to-long zoom range is perfect for portraits, and for low-light shooting.
• Olympus 12-60mm f/2.8-4.0 SWD high-Grade Zuiko Digital wide-to-moderately-long zoom lens.  This is the perfect “all purpose” lens.  With flash, it’s perfect indoors.  It gets wide enough to get close, and long enough to step back a ways.  Image quality is excellent, and it’s super-versatile.
• Olympus 50mm f/2.0 Zuiko Digital macro prime lens.  I used this lens for close-up shots of the wedding rings, but it’s also a great backup to have on-hand for portraits and for low-light situations.
• Olympus FL-50 flash, and Metz 48 AF-1 flash.  I kept the FL-50 on the E-3, and the Metz on the E-520, because I own an external battery pack for the FL-50, and the E-3 was my primary camera most of the day.  Both flashes have similar guide numbers, so their flash power is comparable.  Both are compatible with the Olympus TTL metering system, so there was no real difference there, either.  So, I used the one with the external battery pack on the camera I used most often.
• Backup equipment.  In my truck, I had the following backup equipment handy, just in case:
  • Olympus E-1 DSLR body.  This is an older, lower resolution model, without image stabilization.  But, it’s weather-sealed like the E-3, and it’s better than not having a backup if one of my main cameras had died.
  • Olympus 50-200mm f/2.8-3.5 Zuiko Digital lens.  Not as fast as the 35-100mm f/2.0 lens, this one is still a great performer, and would have worked just fine if something had happened to the 35-100.
  • Olympus 14-54mm f/2.8-3.5 Zuiko Digital lens.  Not quite as versatile as the 12-60mm lens, but still a great performer with almost identical (and excellent) image quality.
  • Assorted extra batteries, memory cards, and other lenses.

Would a Nikon, Canon, Pentax, Sony, or other brand of DSLR have worked just as well, or maybe even better?  Perhaps they would have, for another photographer.

In my hands, probably not.

My experience with my equipment’s particular controls, quirks, and idiosyncrasies probably outweigh five-to-one any differences in the cameras or lenses, themselves.  If you don’t know your cameras cold, you’re just asking for trouble.  I know mine, and trust them to intuitively work as an extension of my arms and my eyes.  I know how to get them to perform at their best, and they help me to perform at my best.  Any brand can do that, as long as it’s YOUR brand, and you put in the time behind the eyepiece.

I have.  Have you?  If not, start walking….

If you read any of the camera review web sites or magazines, you’ll see that a lot of noise is made over noise.  From the articles I’ve read, it seems as though if you can’t shoot black cats in coal mines without flash and get perfectly clean, noise-free output, then your camera must be junk, and you need to rush out right now and spend multiple thousands of dollars to buy the next generation of über-camera before everyone else notices what an amateur hack you are.

Guess what?  They’re wrong.  All that noise about noise is, as Shakespeare put it, “full of sound and fury, signifying nothing.”

If you were to consider all of the many factors that go in to making a photograph that grabs your attention and draws you in, and rank those factors in order of importance, “absence of noise” would never even make the top 10.

Strong composition that draws you in to the subject would be right up near the top of the list. Emotional impact would also be at or near the top. The interplay of light and shadow, lines and curves, and the deft use of color would certainly all make the list.  Effective use of perspective, contrast, and control over depth of field are all important factors that contribute to making strong photographs.

The artistic vision, skill, and talent of the photographer are key.  The equipment isn’t.

Of course, if you put high-quality equipment in the hands of a talented photographer, that photographer is going to be able to work more efficiently, adapt more quickly to changing circumstances, and produce output of the highest technical standards on demand.  A talented chef could cook a gourmet meal with no more equipment than a hot plate, frying pan, and a Swiss army knife.  But, that same chef will be much more efficient working in a properly-equipped commercial kitchen, with all of the professional tools of the trade available.

Good equipment doesn’t make a good photographer; good equipment simply gets out of the photographer’s way, and allows him work more efficiently under a wider variety of circumstances.  Keep that in mind the next time you’re reading camera reviews.  Also, keep in mind the fact that camera company advertisements “pay the bills” at most of these web sites and magazines.

In a future post, I’ll share a little bit of detail about what I use, and why I choose to use the equipment that I do.  You can probably already guess the basics, however — my equipment simply gets out of my way, and lets me work efficiently to make good photographs under a wide variety of circumstances.