Recipe for Hand-held Shutter Speed

The image says it all, but let’s be sure we understand it all, because this is an important one.

Pretend you’re looking through a pair of binoculars with about a 7 power magnification at a bird in your front yard.  It jiggles around a little bit as you try to hold it still, but you can make out the bird well enough, and the jiggling isn’t too bad.  Now imagine that the bird flies down the street and lands in another tree there.  You bring out a telescope with a 200 power magnification and try to hold it on the bird.  You’re disappointed to find that without resting the telescope on some solid object, there’s no way you can hold it still enough to see the bird.  The reason for that is because when you increased the magnification of the bird, you also increased the magnification of your movements and shaking.   What can you do?  Either get the telescope on a tripod, or find some way to cut “a thinner slice of time”.

Lens length is how magnification is measured in photography lenses.  The longer the lens: the greater the magnification.  Therefore the longer the lens, the thinner the slice of time that’s needed to eliminate motion blurring… thinner slice of time of course means faster shutter speed.

A “reciprocal” in math is the number that when multiplied with the orginal number equals one.  So if you’re shooting with a 300mm lens, your MINIMUM shutter speed should be 1/300th of a second.  For a 500mm lens it should be not slower than 1/500th, and so forth.

And by the way, about the “never slower than 1/60th”?  Okay, but why not hold yourself to a higher standard and say “never slower than 1/100th”?

How to Blur Backgrounds

Learning how to blur backgrounds is better said:  Learning how to manage my “DOF – Depth of Field”.

Have a look at the picture of the text above.  This image has a very shallow depth of field because only one line of text is in focus.  There are three factors that contribute to this effect, and it’s important to know each one.

  1.  Aperture – Recall that aperture is one of the three light management devices in our cameras, and that it refers to the adjustable opening inside our lenses.  The size of the opening is expressed as “f-stop”, and the numbers start from a low of 1.8 and rise to usually about 22.  The important thing to know and remember about these f-stop numbers for this tutorial is that the lower the numbers, the wider the opening, and the shallower the depth of field (hence the greater the amount of blurring both before and after the DOF).
  2. Lens Length – Lens length is expressed in millimeters, and is the way magnification is expressed in camera lenses.  The rule to know in the context of blurring backgrounds is that the longer the lens, the shallower the DOF and the greater the amount of background blurring.  Note that when we say lens length, we’re not talking about how long the actual lens body is, but how many millimeters of length has been designed into the lens.  That is, the effective length of a zoom lens for instance, is the number you have the lens set to, not how long the lens actually is.
  3. Focus distance – Finally, the farther you are away from your subject when you zoom in on it, the greater the DOF compression, and therefore the greater the blurring effect you’ll realize.  This is often convenient, as the farther away you are, the more you’re likely to zoom your lens to magnify the subject, and together they’re working toward the same end.

The bottom line then is, for the greatest DOF compression and the greatest background blurring, Choose the lowest aperture number, and the longest lens, at the greatest distance practical.

Parenthetically, often new camera owners are disappointed to find that they’re not able to blur backgrounds at all.  Most kits include a very short zoom lens that tops at 55mm.  Can you see what their problem is?

How to Photograph Moving Water

Learning how to photograph moving water involves a study of your camera’s shutter speed.  Let’s slow this tutorial down to the speed of the slowest walker for a minute:

Your camera’s shutter is one of the three “light management controls”.  It’s the faucet in our “How Do Cameras Work” session.  When the shutter opens, light flows into the camera.  It continues to flow until the shutter closes again.  The shutter’s “speed” is measured by the time it remains open.  In the pictures above, the shutter speed in the right picture is 1/125 of a second.  The shutter speed in the left picture is expressed as the decimal .4, or 4/10 of a second.  1/125 of a second is less time than 4/10 of a second, so the one on the right is said to have a faster, or a higher shutter speed.  Sometimes people are confused by that because they think that increasing the shutter speed means more light comes in, but it’s the other way around.

Think of shutter speed as “cutting a slice of time” with your camera.  In the picture above, the slice of time on the left is thicker than the one on the right, and the water was able to move more during that slice than the thinner slice on the right.

Don’t be discouraged if math isn’t your subject and you find these numbers hard to work with.  Consider keeping a list of “recipes” for various shooting situations with you when you go shooting.

While we’re here, notice that the brown wall on the very right edge of both of these images is exactly the same in both.  That means that the exposures are the same, which means that when we changed the shutter speed to get the two effects, one or both of the other two light controls (aperture or ISO) had to move in the opposite way (let in more or less light accordingly) to keep the exposure the same.

Recipe for a Product Shoot

The assumptions for this shoot are that the subjects aren’t moving, that you’re shooting from a tripod, and that you have control of the lighting – more or less.

Lens:  Best glass you have in the 75-200mm range.  Research minimum distance from subject requirement and set your tripod accordingly.

Shooting mode:  APERTURE PRIORITY (Av on Canon cameras)

Aperture setting:  F8-F16

ISO:  100  (If neither the camera nor the subject are moving, why not choose the most noise-free setting?)

Shutter:  Any    (Let the camera decide, but remember that even road traffic can shake a floor sometimes.)

Exposure Bracketing:  Product shots like these are the perfect time to use AEB.  I routinely bracket everything when on a tripod and shooting still subjects.

Background details:  Pure white sweep if trying to avoid editing.  Otherwise various shades of white or gray if planning to cut out the background in post.  NEVER use colors unless required to.

Misc Notes:  Remember to check the website or other location where the shots will appear.  Be sure a decision-maker is on-site or available via email to approve shots.  Zoom to check focus before going to the next shot.  Use a gray card when colors are involved, and consider post-it notes to yourself in the frame when compositing multiple shots.

 

How to Photograph Blue Skies

You may already know how to photograph blue skies, but for everyone else, let’s see what these two shots can teach us:

Both images were taken of the same scene only a few minutes apart, and both are facing in exactly the same direction (north).  Notice the exposure and color of the dancers in both shots.  That shows that the skies in both images should also be identical, but they’re not.  The sky on the right is clearly superior.  The question is, how did that happen?  Here’s a hint:  There were NO settings changes whatever between those two photos, and nothing was done in post-production.

Did you notice that the shot on the left is vertical (portrait) and the one on the right is horizontal (landscape)?  That’s the reason the skies in these photos are so different.  What could explain that?  The camera was equipped with a polarizer filter that day.   Polarizers are used to accomplish two effects in our images:  One is to reduce glare from reflective surfaces, and the other is to allow blue light from the sky to pass through to our camera’s sensor, as in the shot on the right above.

Polarizer filters are characterized by having two filters connected together in such a way that you can turn them with your fingers and they remain joined together.  They do that because polarizers work their magic only if the filter is turned to a certain point relative to the direction of the sun.  I turned the filter until the sky was dark blue in the shot on the right, then forgot to re-adjust it when I turned the camera to vertical for the second shot on the left.

Portrait and Landscape… and Sabrina

In the movie Sabrina, there’s a scene where Sabrina (played by Julia Ormond) is photographing a property for her employer.  Her character had learned to use a camera from fashion photographers in Paris, and when she spotted a lighthouse in the distance, she lifted the camera to frame the shot horizontally.  As soon as the shutter released, she smoothly turned the camera ninety degrees to get the same shot vertically as well.  I smiled when I saw that, and wondered if Julia Ormond was that good a photographer, or was the gesture written into the script for her.  Maybe it was director Sydney Pollack’s suggestion, or even a tip from one of the cameramen on the set that day.  However it happened, it showed that Ms Ormond’s character Sabrina knew what she was doing.

The best way to learn how to shoot video is to spend time in front of an editing program turning footage into a finished story.  The same can be said for still images.   Who knows how an image will be used on a website, in print, or framed and hanging behind a couch?  Will the editor have to fill a vertical space, or will the image be used full width as a header or footer?  Finish editors appreciate having as many choices as possible, and when shots matter, as for a wedding or commercial shoot, you’ll be glad to follow Sabrina’s example by always thinking to get both landscape and portrait versions of each important shot.

Why Aren’t My Pictures Sharp?

You should recognize the three light management controls in the above list: Shutter, Aperture and ISO.  The list also shows the three “side effects” of each. Let’s start with the bottom one:

Motion blurring is the result of either the subject moving, or the camera moving, or both while the shutter is open.  If the shutter is open for a short time, the blurring is less. If it’s open a long time, the blurring is greater.   Think of shutter speed as cutting “slices of time”.   The thinner the slice, the less motion blurring you’ll see in your image.  Motion blurring can easily be confused with Focus blurring (below), except that motion blurring usually has a direction (imagine the camera moving from left to right or up and down), and also focus blurring due to camera movement should affect every pixel in the image the same.

Focus Blurring is the second culprit, and sometimes that can happen when we’re careless while focusing.  It’s important to know the exact POINT your camera focuses on each time, and that requires that you set your camera to focus on a point, rather than just a bracketed area.  Also, in the list above aperture’s side-effect is listed as DOF, or “Depth Of Field”.  This has to do with the part of your image that’s in focus, measured from front to back.   When foregrounds and backgrounds are blurred with sharp areas in between, it’s DOF.

Noise is sometimes mistaken for blurring, but really it’s a pebbly distortion that’s associated with high ISO settings.  Because higher ISO’s are used to get better exposures in low-light situations, shots after dark or in dimly lit rooms tend to be noisy.  Interestingly, noise in film cameras happens because of a chemical reaction in the film.  Noise in digital cameras happens because of electronic static from solar winds (the ISO adjustment is really just an amplifier, not unlike a volume control in radios).  Despite this difference between film and digital, noise looks almost exactly the same in both film and digital finished images.

 

The Illusion of Sharpness

Obsessions can be destructive things, but I’m happy to be obsessive about getting tack sharp captures every time I go shooting. Other things like color, exposure and framing are important too, but I’m especially careful about sharpness because sharpness is the one thing that can’t be meaningfully corrected in an editor later on. Let me say that again: You need to concentrate on the things that rob our photos of sharpness during capture, because none of the so-called sharpening tools can do anything to fix an image that was captured un-sharp.

Don’t get me wrong. I “sharpen” almost every image I use*, but until editing programs are able to know what the camera SHOULD have captured, all of our so-called sharpening tools create an optical illusion designed to trick the eye into thinking that our capture was sharper than it really was. Here’s how it works: An edge consists of dark pixels next to light pixels. The sharpening tools work by first detecting those edges, and then by darkening the dark pixels and lightening the light ones. Each tool may use a slightly different path to get there, but other than that, they all work the same way.

We’ll cover these in other sessions, but for now note that there are three things that can rob our images of sharpness: Motion blurring, focus blurring, and noise. Each one is caused by something different, and therefore each one has its own remedy (or remedies). The first step in solving a blurring problem therefore, is to determine which of the three is the culprit. Learn to zoom on your images in the review screen all the way to check for sharpness, and to not let your subject leave until you’re sure you’ve been successful!

*My preferred sharpening method is Photoshop’s High Pass filter technique  (to be covered in another session soon)

Should I Buy a Tripod?

Tripods are devices used to hold cameras still. If a camera moves when the shutter is open, there will be a certain amount of “motion-blurring”. The longer the shutter is open, the greater the blurring. If a shutter opens and closes quickly enough, then the blurring will be so small as to be not an issue at all.

You may or may not believe that Pablo Picasso was a great artist.  I didn’t think so myself until I learned that when he was a little boy he could paint the feet of pigeons better than his art-teacher father could.

You’ll read camera book authors who will tell you that their images have “soft focus”.  My cynical instincts always rise up when I hear that. “Soft focus” can be a euphymism for “I failed to get a sharp capture”, and I warn you to not fall into that trap yourself. Picasso had already proven that he knew how to draw what he saw before going abstract.  Before you pass your blurred images off as “artistic”, first be very sure that you know how to get “tack sharp” images in the first place every time.  Tripods are the first step toward sharpness for any photographer, no matter what they say about how still they can hold a camera without one.

It’s true that shutter speed can reduce or even eliminate motion blurring, and you should memorize and apply the rule for that every time you have to shoot without a tripod. We’ll talk about this again in another session, but here it is:

When shooting handheld, your MINIMUM shutter speed should be the reciprocal of your lens length, but in no case slower than 1/100th of a second. A reciprocal is the fraction formed when you put a 1 over the /…. so if you’re shooting through a 300mm lens, your minimum shutter speed should be 1/300th of a second.

See also The Illusion of Sharpness


How to Photograph People in Dappled Light

Getting great shots of people in full sunlight or full shade is one thing:  Getting them in dappled light is something else!  An experienced photographer will seek out any shady spot over high-contrast (“raccoon eyes”) sunshine, but the really experienced ones will be careful to exclude the the shade under trees, or anything else that lets spots of light shine through onto the subject.  Those spots are called “dappled light”.

So alright, the clients prefer a treed location, and the sun is ruining every shot, like the one above (don’t even think about fixing it in post-production).  What to do?  Can a white translucent diffuser disk be held over them to remove the spots?  If not, then you may have another technique that’s pretty much sure-fire… IF you have the equipment and skills to use it:  Speedlight flash.

The technique involves two steps:  First, turn the subject around so the dappled lighting strikes their back rather than their front.  That’s easy enough, but now the camera is shutting down in response to the bright light, which in turn starves the shaded side of your subject.  You can try adjusting the exposure with EC or any of the three exposure controls (shutter, aperture or ISO), but you’ll find that the contrast and colors of your subject will be disappointing at best.  The second step of this technique remedies that.  It’s to simply replace the light lost when turning them around with a gentle pop of flash as shown below.  Note:  Here we actually lowered the exposure using shutter speed in manual mode, then letting flash illuminate the nearby subject.