From guaranteed sharp pictures every time, to stunning astrophotography photos, here are 7 lesser known photography tips and principles.
1. Shutter Sharp
This tip doesn't really have a name. I'm dubbing it Shutter Sharp. Shutter sharp is a simple calculation to determine the minimum shutter speed that will ensure a sharp shot every time, when shooting handheld on non image stabilized lenses. For this one all you need to do is set your shutter speed to double your focal length.
Shutter Speed = Focal Length x 2
So if you are shooting with a zoom at 250mm, your shutter speed should be 1/500th or faster. If you are shooting with a 100mm lens shutter speed should be 1/200th or faster and so on.
Getting the Most Out of Shutter Sharp
Many of you out there have an APS-C or smaller sized sensor. Make sure to note your sensor size and use this rule based on the Full Frame Equivalent given by your lens and sensor. On a Canon 7D MKII for example, you would have a Canon APS-C sized sensor giving a crop factor of 1.6x. In this scenario a lens at a focal length of 250mm would have a full frame equivalent of 400mm. Giving you a suggested shutter speed of 1/800th of a second.
[pmath size=14]800= 2(250 x 1.6)[/pmath] or 250 x 1.6 x 2 = 800
You can see it put into practice here, as well as 7 addition causes of blurry photos and how to fix them.
This is not a rule but a guide. It's possible to shoot at lower shutter speeds than shutter sharp suggests, but the likelihood of doing so is much less when you go against it.
2. Hyperfocal Distance
Hyperfocal distance is a way to achieve the maximum amount of sharpness (depth of field) on a given lens. This is most useful in street photography and landscape photography. Hyperfocal distance is:
The shortest distance at which a lens can be focused where the depth of field spans from exactly half that distance, out to infinity.
As there are no numbers in this base principle, it's best understood in practice. This is nearly impossible to do on modern lenses with no focal distance scale written on them like older manual focusing lenses.
Depth of field is exponential, so with any lens as you focus further away the depth of field increases. It increases more so forward than backward from the point of focus. At some point you will achieve focus where the depth of field spans from half your current focal distance out to infinity. That is your Hyperfocal Distance.
For example if you used a Nikon D4 with a 50mm lens, your hyperfocal distance would be about 35ft. It's at that focal distance that you would have everything in focus from about 17ft onward to infinity.
3. Sunny 16
This rule goes all the way back to the mid 1800's and can be used today to the same effect. The Sunny 16 is a method for obtaining correct exposure when shooting outdoors without any metering. Basically it sets the par for proper exposure in the sun, and with some knowledge of photography Reciprocity, this little tip goes a long way. It is as follows:
Correct exposure outdoors on a sunny day: f/16, 1/100th, 100 ISO
Getting the Most Out of the Sunny 16
Use the photographic Reciprocity Law below to match exposure to the Sunny 16 while getting the aperture or shutter speeds you want.
4. Reciprocity Law
The reciprocity law is probably the most significant of this list. Once you understand and apply it to your work, you'll find your abilities and confidence as a photographer broaden in ways you didn't know possible.
The density of a photographic image is directly proportionate to the density of light
Essentially this is a method of calculating exposure equivalence. If you can multiply and divide simple numbers by 2 as well as observe the aperture of your lens, you can calculate reciprocity. By knowing what setting changes are equal to one stop of light change, you can compensate for almost any gain or loss of light from one setting, by changing another. This knowledge will give you control of the image while maintaining proper exposure. You will do this by using aperture, shutter speed, and ISO.
Doubling or halving the shutter speed or ISO once equals a change in 1 f-stop. Increasing or decreasing to the next common aperture is also equal to a change in 1 f-stop.
Lets start in a scenario where The Sunny 16, is in effect, which is f/16, 1/100th, 100 ISO.
If you wanted more shallow depth of field in this situation, you could compensate the light increase of lowering the aperture by increasing the shutter speed. Changing the Aperture from f/16 to f/5.6 would add 3x the amount of light (3 stops) to your image. To compensate you would double the shutter speed 3 times equalling 1/800th, reducing 3x the amount of light. Both settings balance out and total light input to the image remains the same.
5. Inverse Square Law
This law is most closely associated with the use of flash or studio lights.
An object at a distance 'A' from a given light source, will receive 1/4th the illumination when distance is doubled to distance 'B'.
Therefore if you have a proper exposure and lighting, then move your subject twice the distance from the light source, it would require 4x the amount of light to achieve the same amount of light when it was half the distance it currently is.
6. The Astrophotography 500 [AKA 600]
If you haven't explored simple astrophotography before, I can tell you its surprisingly easy to expose an image long enough that the stars in your image have slight trails to them rather than being a pinpoint of light. Unless done to extremes this is undesirable. At long exposures the rotation of the earth can act as a sort of camera shake, as you are moving but the stars are [comparatively] not.
This is a simple mathematical calculation for determining the longest exposure possible before star trails begin to emerge.
Shutter Speed = 500 / Focal Length
Simply take the number 500 and divide it by the focal length you are using, the result is the maximum amount of time (in seconds) you can expose the image before star trails begin to emerge.
If you were shooting the night sky with a 24mm lens:
500 / 24 = 20.83
So this means you should shoot at about a twenty second exposure or faster to capture pin sharp star images. Some use the number 600 which gives a similar results, but I find 500 to be a bit more conservative and therefore better results.
Getting the Most Out of the Astrophotography 500
With the maximum shutter speed determined, you can then lock that in and use aperture and/or ISO to increase the light input for your image. In astrophotography you'll want to increase the ISO to its usable limits and the aperture to its minimum. The more light, the more stars.
7. Scheimpflug Principle
Austrian army captain and aerial photographer Theodor Scheimpflug (1865-1911) stated that:
"If the lens pane is tilted down, when extended lines from the lens pane, the object plane and the film plane intersect at the same point, the entire subject plane is in focus."
This principle shows its effect in swing and tilt movements of view cameras, and tilt-shift lenses. In landscape photography for example, this means that the lens can be tilted downward, so that the plane of focus is no longer perpendicular to the ground but parallel to it. This acheives focus from near to infinity no matter the aperture.