I just checked and found that this is the seventh post covering exposure. It makes me wonder – how could I write so many posts to cover one topic?
I’ve wandered a bit – three separate posts on shutter speed?!? I’ll just say exposure covers a lot of ground and leave it at that. Today’s post will be the finale – unless I decide it would be useful to summarize the highlights of these seven posts. That could lead to a very long-winded post, indeed!!
Today we will explore small apertures which, unfortunately, are designated by large (not small) f/#s. For those inclined, this Resource Article explains f/#’s but let me cut to the chase.
The concept of f/# is very, very useful to photographers, astronomers, Department of Defense, …. you’d best just take my word for it. All you need to understand is this: no matter what camera, no matter what lens, an aperture setting of f/4 represents the same amount of light/exposure – always!! An f/4 setting on the Hubble telescope is the same as f/4 on your point & shoot. The apertures will be different in size but each will present the same amount of light to the telescope/camera. Check out the free article for details if you’d like.
The photo above demonstrates a classic use of small apertures (large f/#). Landscape photos are shot with small apertures to ensure the foreground, middle ground and background are all in sharp focus.
The entire scene is in sharp focus in both of these landscape vistas. In photography parlance this is called large depth of focus (DoF). Compare that to the shallow DoF typically used in portrait photographs as detailed in last week’s post.
Both of the vistas were shot at f/22 meaning the aperture was tiny. That tiny aperture necessitated a slow/long shutter which, in turn, meant a tripod was needed. A landscape photographer will sink a princely sum for a stable tripod – to the tune of several hundred dollars if they require a light weight version.
Tiny aperture, large f/#, large DoF shooting is also very common for macro photography as shown in the psuedo-macro flower photo. Once again, tripods are required when the tiny aperture necessitates a long/slow shutter.
A large DoF isn’t always necessary. Take a peek at the two photos from a trip Rebecca and I made to the Big Apple. Both were shot at f/3.5 – a near-wide open aperture. The DoF achieved was perfectly adequate for the fire station – there’s not much depth in the photo. In contrast, the same f/# in the subway portrait demonstrates a shallow DoF and a blurred background – just as planned.
By the way, if you’ve never been to Manhattan you’ve gotta go – what a great place to photograph and experience. The fire station shown above is located minutes from the World Trade Center just across the Brooklyn Bridge. On September 11, eight brave men from Engine 205 rushed into the building to rescue others. Follow this link and give tribute to those heroes that gave their lives in service of all of us.
OK – now I’m choking up …. sorry but it’s such a moving scene, location, experience. You’ve gotta go – take our word for it.
Here are a couple of other photos from NYC that demonstrate how to choose an aperture to tailor your DoF. The fire escape was shot at f/7. The statue at the Rockefeller Center was shot at f/20 by necessity. Pick your aperture based on your needs – no reason to shoot with a tiny aperture (e.g. f/20) unless you need a large DoF.
One more side note – when you visit the Big Apple be sure to check out the view at “The Top of the Rock” (i.e. Rockefeller Center). Look to the South for this view:
Turn 180 degrees and see this view of Central Park:
And, if you’re timing is good, walk down Broadway avenue and enjoy the wonderful variety in humanity – melting pot indeed!!
OK back on topic – here are two more photos exhibiting wide DoF achieved by shooting in aperture priority mode and choosing a large f/#.
The wind toys are another matter. For this photo I chose a small aperture to force the camera to choose a slow shutter speed. My reasoning – I wanted to show the spinning wind toy and it worked, at least for the distant toys. However, the large wind toy in the foreground was mostly lit by flash and hence, as discussed in this post, it’s spinning motion was stopped by the short flash exposure.
Another long post complete. I hope you were able to suffer through it and gain a bit of comfort with large f/#’s and DoF.
Feel free to comment or show off some of your own compositions that illustrate this tip. In the meantime, stay tuned because in next week’s post we wrap up this Exposure series. Better yet – be updated automatically by “friending” our Facebook site.
PS - This is one of dozens of photo tips in our continuing Tuesday Photo Tips series of posts. There are other resource articles on our site you may enjoy covering basic and more advanced photography topics. There are also tips covering topics such as preparing for family or infant/child portrait sessions. If you would like a topic covered just jot it down in a comment or send us a note.