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Warning: this post is going to be lengthy.

I’m going to start out this post by referencing a question raised by Melissa in the last segment. She asked “how do you decide what the appropriate settings should be in the moment? Say I’m shooting outside on a bright day, how do I know how low I should set the ISO or how low of an f stop?” Very, very good question. I’m not trying to coach anyone on aesthetics here, but lets shift our thinking a little bit. We can be reactionary photographers, or we can be proactive photographers. To be reactionary, all we need to do is lock the cam into “auto” and let the camera evaluate the situation and make all of the calls. Or….. we can be proactive when see a photo-worthy subject, and think to ourselves “how can I make this shot awesome by interjecting a bit of my own style into the way I shoot this?” Depending on how we answer that question is how we would know which way to skew the settings. If you aren’t quite sure what your personal style is when it come to photography, don’t sweat it. I’m sure that it goes without saying, that one’s style is a very dynamic thing that will constantly change and expand with time, experience and practice, etc.. For those who are having a hard time figuring out where to get started, imitation is always a good place. Think of some of the photos that have recently caught your attention. Decide what it is about them that makes them appealing. Then, practice recreating the appealing aspects in your own work.

Now that we know all of the variables involved in achieving a proper exposure, let’s put that knowledge to use. Let’s play out the scenario described by Melissa, as well as a lower light scenario. Since we are discussing shutter speed in this post, we will address the questions in that context.

Shutter speed in bright light—

We are shooting outside on a bright day. We have a great subject that we want to be proactive about and capture an interesting image of. We decide that we are going to make the aperture defer to our shutter speed. For those shooting with SLR’s there is actually a setting that will accomplish this for us. On Canon cameras, it is “TV” mode. I apologize for not knowing Nikon’s shutter priority mode. But I know that Nikon also has one. Nikon ppl, please put the name of Nikon’s shutter priority setting in the comments. In shutter priority mode, the camera will automatically try to adjust the aperture to gain the proper exposure, based on the shutter speed that the photographer has chosen.  But, the photographer will still have to manually select the ISO (unless the camera is on auto ISO [which I strongly discourage]). Since we are shooting outside on a bright day, lets start by dropping the ISO down to like 100. That way we know that we are going to get a nice buttery image with zero noise.

Ok, so we are set on shutter priority mode, with the ISO at or near the lowest setting. Do we want to show motion, or do we want to freeze time? It is going to be a lot easier to freeze time in bright daylight, since our aperture only goes so small. So lets dial up the shutter speed to 1/1000″ That should be fast enough to freeze most motion that humans are capable of. Since it it bright daylight, we shouldn’t have a problem underexposing. This is a great setting for jumping or hair whipping pics–

The image above was shot by John Holman, who is friends with the gentleman (my amigo Zach) jumping over his bride in the photo. Let’s check out the EXIF data (fn.1)  on this image.

So, we can see here that John was using a custom program geared towards action, giving priority to shutter speed (sounds pretty similar to Canon’s TV mode). That was a smart move. The shutter speed was 1/800″ and the aperture of f/10 was probably automatically selected by the camera based on it’s light meter. Here is a quick quiz. If John was shooting in TV, and would have had the ISO set to 100 instead of 400, and the shutter speed set to 1000 instead of 800, would the camera have adjusted the f-stop to a higher or lower number to try to get the same exposure?

Motion blur is also possible in well lit situations, but it is more fun in low light, so let’s cover it there. When you learn to do it in low light, you will be able to capture it in any kind of light.

Before we move away from our brightly lit scenario, there is one more idea that I would like to throw out, while we are talking about shutter speed. Why not underexpose? This in an effect that can be very cool. People who see the image will know that it was shot in bright light because of the way that the light is hitting the object in the image. But the photo will be interesting, because instead of being bright and blown out, it will look almost like night time. Here is an awesome example of that–

I wish that I could say that those were my images. Alas, they belong to Enrique Badulescu. Granted there is also some serious post-production work done on these, but it is a good example, no?

I was going to keep dragging this post out, and write about choosing a shutter speed in low light. But since my attention span has expired, I can imagine that a reader trying to ingest all of this would probably also be struggling to pay attention by this point. So, instead lets do an assignment and chat about low light later.

Before we get to the assignment, I would just like to throw in a quick suggestion/technique. One of the coolest things about digital photography, is that it costs just as much money to shoot 100 frames as it does to shoot 1 frame. So, trial and error is our friend. Shoot as many frames as you need to. Term of art– “bracketing.” If we are documenting something that doesn’t allow us time to perfectly dial in the exposure before we start shooting, we can put it about where we think the setting should be– shoot a few frames; then adjust up a bit, snap a few; Adjust down, snap a few. This way we have our bases covered. If the initial guess was a bit off, no worries. We have belt and suspenders by exposing some frames adjusting up and down a bit. One of those shots is bound to be golden.

Here is the homework– Let’s find the sweet spot for freezing time with our shutter speed. Note, this is going to vary depending on how bright of light we are shooting in. So, let’s try it shooting outside during a fairly bright time of day. Set your camera to the shutter priority mode (“TV” for Canon). Start with 1/800″, and play around until you get an image that you are stoked about. Remember, depending on the ambient light, you run the risk of underexposing while using a high shutter speed. The camera can only compensate in f-stops up to the maximum aperture of the lens you are using. But you can always fall back on adjusting the ISO up a notch if you need to.

For extra credit, purposely underexpose in broad daylight. Still in shutter priority mode, run the shutter speed up all of the way, and drop the ISO all of the way. Depending on the ambient light (and your camera’s maximum settings), you may end up with some seriously dark frames at first. So between frames, gradually slow down the shutter a bit until you get an image that you are stoked about.

Link to your images in the comments, if you feel like sharing the results of your homework assignment.

Stay tuned for ideas with shutter speed in lower light situations (for which I’m planning a short action packed tutorial vid to accompany).

1. EXIF data is the information regarding the camera and camera settings that digital cameras automatically store in the image file. It can be viewed in most photo editing programs. Unless the EXIF data has been scrubbed from the file, you can even download images from the interwebz, and see what camera settings were used to capture the image.

View all parts of this series here.

Ok, so here we go. For the first part in this series, I have decided to discuss exposure (not the indecent kind).

Exposure is kind of the corner stone of photography. I mean, that’s what photography is– exposing film (or a light sensitive chip) to light. There are three variables that determine the exposure of an image (not counting post-processing). They are ISO, Shutter Speed and Aperture. The “exposure triangle” is a useful way that I have seen it explained before. I drew a little diagram with a marker of the exposure triangle. Please pardon my terrible penmanship, but I thought it was nicer than stealing someone else’s graphic, and faster than fumbling with Illustrator (not my forté)–

All three of these settings can usually be controlled manually on most modern digital cameras, even inexpensive ones. This allows the photographer to take total control of the way that the image is exposed. There are several sought after effects that can be achieved by manually dictating the way that your camera exposes the image. First, the very basics–

ISO

Historically, ISO was a number that was used to measure the sensitivity of the emulsion on film. The lower the number, the slower that the emulsion reacted to light, making it take longer for the film to expose. This same idea translates to digital cameras. The ISO setting on a digital camera controls the sensitivity of the chip. The settings generally range from ISOs 100 to 3200 (or more), depending on what kind of camera you are using. The lower the number, the less sensitive the chip will be, and the longer it will take to achieve desired exposure. Conversely, when using a high ISO  number the chip will be very sensitive.

There is another factor that should be taken into account when selecting ISO. The lower the number, the richer and creamier (term of art, hahaha) the image will be. The higher the ISO, the grainier the image will become. The graininess that occurs at high ISO settings is commonly referred to as “noise.” Some times images are shot to purposely include noise for aesthetic effect (our friend Kat in Charleston, last summer) . Most of the time it is not desirable, because it can muddle the sharpness of the image.

As a rule of thumb, I try to keep the ISO at 400 or lower. But depending on lighting, that’s not always possible.

Shutter Speed

Shutter speed is pretty obvious, right? It is the setting that determines how long the shutter is open, allowing the film or chip to be exposed to the light. Fast shutter speeds are great for freezing time (fashion week fall 2010), like when shooting sports or if you are shooting outside on a really bright day. Slow shutter speeds are cool for showing motion (a great example, shot by my good friend Zach Tolbert), or for when shooting in low light. Shutter speed settings can range anywhere from 30″ to 1/2500″ (or more). In layman’s terms, those numbers translate to thirty seconds (a super slow speed, for shooting at night or something), to one twenty-five hundredth of a second.

About 90 percent of the time, I find myself shooting between 1/80″ and 1/640″. Many times, this setting will show up on the camera menu display as a single number, not a fraction. For example 1/80″ will just be 80. Higher end cameras will also generally have a “bulb” setting. Bulb will keep the shutter open as long as the shutter release button is pressed down (or press once to open, press again to close). The “bulb” setting is what people use to get those crazy long exposures of stuff like the stars swirling in the sky, etc..

Something to keep in mind– To obtain sharp images, it is best to keep the camera perfectly still while the shutter is open. So, shutter speeds slower than 1/80th of a second while shooting hand-held (not on a tripod) might run the risk of blurriness caused by camera shake, especially when large amounts of caffeine have been ingested.

Aperture

The aperture is the diaphragm behind the lens, that can be adjusted to control the flow of light coming through the lens. The size of the opening is measured in “f-stops” and is generally expressed as a fraction, because… that is what it is. An example of how f-stops are written is “f/4” or “f:4”. The “f” part of the fraction is referring to the focal length of the lens (we will get more into that later). So for example, if I’m using a 50mm lens, then “f” is 50. If I’m using a 50mm lens set to f/4, then I know that the aperture size is 1/4 of 50 millimeters.

Ok, if all of that sounds a little too much like math class, then just remember that the lower the f-stop, the larger the aperture is, and the more light you are letting through. So f/1.4 is letting in a lot of light. F/22 is only letting in a little pinhole of light. As with shutter speed, the f-stop may appear as a single number (not a fraction) on the camera menu. So, f/4 might just show up as “4” or “4.0.” A helpful way to think of it might be to remember that the higher the f-stop number the more light you are stop-ping from getting to the sensor.

One important thing to keep in mind when choosing the appropriate f-stop, is that the aperture size also affects the depth of field. Depth of field is what determines how much of your image will be in focus. We will discuss this more later. For now, just try to remember that it is affected by aperture (or f-stop).

For those who are more visual learners (like myself), I’ll use an example that one of my grade school photography teachers used, and has stuck with me all of these years. Again, please pardon my less than stellar drawing skills and penmanship–

Ok, in the amazing graphic above, we are using the metaphor of filling a bucket with water, as getting the correct exposure of an image. Just like the exposure triangle, we have three main variables. How large is the bucket? Compare the bucket size to the ISO setting. If the bucket is small (if the ISO is a high number), the bucket will fill up fast. Conversely, if the bucket is large (if the ISO is a low number) the bucket will take longer to fill.

Shutter speed can be compared to how long we have the tap open for.

Finally, compare the aperture to how large of a hose we are using. If we are using a fire hose (large aperture), the bucket will fill up much faster than if we are using a garden hose (small aperture).

The object is to use the exposure variables to offset each other, when we are seeking a certain result. Let’s say that we want to shoot with the aperture wide open to create a really shallow depth of field (more about that later). But since we are letting all of that light in, we are going to seriously overexpose the image, unless we compensate by choosing a fast shutter speed and/or drop the ISO.

Now let’s say that we are trying to shoot a hummingbird and freeze it’s wings motionless in the image. So, we need to use a really fast shutter speed. Unless we have a really bright light source, we are probably going to underexpose the image if we fail to boost the ISO and/or open up the aperture.

Hopefully some of this makes sense. I’m sure that there are plenty of other photographers who have helpful insight on understanding exposure. So, please feel free to contribute in the comments.

Should I be giving assignments?

View all parts of this series here.