Photography - Part 3 - Shutter Speeds

It's time for another "lesson" and this time, it's about shutter speeds. I will admit, I rarely am shooting on TV or SS priority modes. For me, I just don't have sessions that are geared for that as much. But, I can tell you where it's useful.

Sports. Taking those action photos of your kiddos out on the sports fields, in bright sunlight. ;)

I think the MOST important thing to know about Shutter Speeds involves camera shake in your photos. When your shutter speeds are too low, too slow, camera shake occurs. A good rule of thumb is to never use a shutter speed that is slower than the length of your lens. For example, if you have the 50mm lens, then you shutter speed should be above 1/50 of a second. In my case (I have a terrible case of the shakes) I need to keep my shutter speeds over "double the length of the lens" for the most part. With a telephoto lens of 70-200mm, you need to have your shutter speeds above 1/200 of a second.

However, if you can steady your camera (like on a tri-pod) you can create some FUN photos using really long shutter speeds (like 15 or 30 seconds).

(this was taken at our campsite last July, about 9pm or so, the purple/blue light and orange light in the center were created with glowing "necklace" things from 4th of July. The glowing light to the left, is the streetlight at the bathhouse. Look carefully and you can see the kids legs where the firelight from our campfire reflected off of them.) Canon5d camera, 24-105mm lens with focal length at 24mm, f/4.0, ISO 800, ss of 30 seconds


As you saw from earlier posts, shutter speeds double or halve according to changes in Aperture or ISO. All three are inter-related, and a change to one means a change to another. If you take a photo and think it's "slightly underexposed" you can move your shutter speed to a slightly slower one (next one down) and try it again.

But, I know many of you are thinking, when would or should I use the Shutter Speed priority mode? Well, think about taking photos out on the baseball field. It's a partly cloudy day with a brisk wind (bad for the lens with blowing dirt but we'll ignore that part of it for now). The sun is play "peek-a-boo" with the clouds, and if you are in AV mode and have your aperture set to 3.2 (fairly wide, but a little depth of field when shooting across the field). The SS will change according to lighting it sees each time. Well, you have ISO set to 100, with an aperture of 3.2 the shutter speed when it is sunny gives you 1/1000. Really fast, you breathe a sigh of relief...life is good. :)

Until the sun goes behind a cloud, and the shutter speed dropped to 1/250! Which, truthfully should be fairly good, but remember I shake a LOT! I needed it above 1/400. The image was of your son catching the baseball for an out!!! It's blurry due to slight camera shake, it's actually good enough for using in scrapbook, but it's not going to be 16x20 size!

*that's my criteria, a print MUST be able to go to 16x20 every time*

Okay, what should I have done? Or what did I do AFTER that shot?

I moved ISO to 200, set the SS priority to 1/500 (double what I needed) and the camera figures out the best aperture, which in this case would be 5.6. This aperture, across the baseball field, would still give us a good blurred background, but it also gives us room for that shot when the cloud obstructs the sun.


Canon 30d 70-200MM lens, 160 focal length, aperture 4.0, ss 1/1250sec (aperture priority actually...oops, but notice I have PLENTY of maneuver room in the shutter speed department) ISO200. Now, I did have exposure compensation at +0.33 meaning I made it overexpose by 1/3 of a stop (my 30d chronically underexposes). Notice here, I have aperture of 4.0 and all of JM is basically in focus (open it up in a new window to see larger), the fence and crowds in the stand are blurred with a nice bokeh. Crop leaves a lot to be desired doesn't it? Well, this is a 4x6 ratio, and a 16x20 would be a 4x5 ratio. I was looking for a good shot for a 16x20, as such I have to leave roughly 1 inch of room around the outside...this one worked out to be all at the top. JM moved within the area I had pre-framed.


So, in recap, you use aperture priority mode when you are most interested in controlling the aperture. You use the Shutter speed priority mode when you are most interested in controlling the shutter speeds so that they don't go slower than a specific amount.

Next post...next post is the illustration of how these 3 factors work together.

Assignment: Put the camera in shutter speed priority mode, set the shutter speed to be double your lens length. Go outside and play with different "lighting" areas - full sun, under your front porch (shade), beside a house on the north side (open shade), dappled lighting (my most hated lighting situation), and so forth. Watch what the apertures do. For best results of CLEAR photos, set the ISO for the shade on the front porch (I would suggest starting it off around 400).

Remember, ISO 1600 is NICE to get non-flash photos indoors. However, you trade it off in noise. If you underexpose the photo on any ISO level, you get noise in the photo as well.