Shooting Wide Open
refers in photography to having the aperture open as much as a possible. The aperture can be regarded in a simple manner as a window. The bigger the window, the more light falls into the room. The aperture is measured using the so-called f-number. Every lens will have information about focal length and number(s) for the widest aperture. This information is usually printed on the lens. The f-number of an optical system such as a camera lens is the ratio of the systems’s focal length to the diameter of the entrance pupil (source and more reading Wikipedia F-number).
Since sensor/film sensitivity (ISO) and shutter speed also control the amount of light that can be “seen” by the camera, it really helps to sit down one afternoon and get your head around the so-called exposure triangle. Pragmatically, all you need to know is how to multiply and divide by 2 (saves time to be able to work in powers of 2) and know the true f-numbers (aka f-stops).
f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32
If you exposed a photo at f2.8, 1/60s, iso 100, and you shoot the same frame at f2, 1/60s, iso 100, it will be twice as bright. You might be asking, but why? f2.8 sounds more not less, and certainly not half of f2. Well, read the Wikipedia link above, or just accept it.
Nifty Fifty Prime Lens
I enjoy shooting some landscapes wide open using my 50mm prime lens. I use the Pentax SMCP-FA 50mm f1.4 lens. A few words on prime lenses. The have no zoom (obviously), as a result no moving parts in the lens and hence sharper. Cheaper, smaller, lighter and because you can’t zoom, you will have to move more. This makes you fitter both in a physical and photographic sense. 50mm lenses (referenced to 35mm sensor) are often called normal lenses. A normal lens is a lens that reproduces a field of view that appears natural to the human observer.
For example, if put your camera on a tripod, take a shot at 15mm, then at 50mm and at 100mm. The former (super-wide) will resemble best what you observed, all the stuff you can see with your eye, but things appear to be further away from you. The 50mm will show much less of what you can see, but the distance between camera and background seems natural to you. At 100mm you see even less of the entire landscape, and objects appear bigger than they are observing with the unaided eye.
From what I gathered, a true normal lens is not 50mm, but the focal length should be identical to the diagonal of your sensor. The diagonal of my full frame sensor is 43mm and Pentax obviously offers a 43mm limited lens. Can’t justify to purchase this lens yet…
Hyperfocal Distance & Depth of Field
Oh no, more stuff to read and get our heads around. The good news is that it is really easy, there are cool apps for it to sort out the calculations. Why should you read about the hyperfocal distance? Well, if you are shooting landscapes and you focus always at infinity, you are focussing wrong. The hyperfocal distance will depend on focal length and f-number. The depth of field, which has something to do with hyperfocal distance, also depends on focal length and f-number. These things are in great detail explained on Wikipedia. Go on and have a read and another read etc. After all, you are interested in photography, aren’t you?
Here’s a photo I made early in the morning of Will fishing. Well, it was before 0600 and he didn’t know I was making a photo of him, but no one can tell anyway. I know this is a photo of gentleman and legendary angler Will. But this is not about Will, it is about shooting wide open. I shot at f1.4, focussed on Will and knew what the result will look like. The hyperfocal distance for this shot is about 60m. Unfortunately, Will was roughly 50-70m away from me. Had he been only 10m away, I could have made a much more interesting shot. One were the foreground and background are not sharp, but only Will and ca. 3.5 m behind him.
Non-Typical Landscape Photography
Typically, in landscape photography, the idea is to present a photo where everything is sharp. You use a wide angle lens, small aperture (like 15mm, f16) and everything from about 0.5m to infinity are sharp. The more you practice, the more you know, the more options you have when making photography. In terms of shooting wide landscape, there is another technique that can create a wider aperture than physically possible with your lens. How about that, you have an f2.8 lens and you make a photo that resembles one taken at f1.8. Have a read on the Brenizer Method.
Here’s another photo of the afore-mentioned angler, as he is rowing out before 0600 for an early morning fish. I saw Will on my way home at work. That is Island-Living for you, get up early, row out, catch a fish, row back and go to work.
Have a good day, best wishes, Ben