Exposure Triangle in terms of the 1:1 ratio and Exposure Triangle in terms of the 1:1 ratio in another situation
How to demonstrate what you would change in aperture, iso or shutter speed to adapt to different circumstances.
24 Sunday Apr 2016
Posted Exposure Triangle
inExposure Triangle in terms of the 1:1 ratio and Exposure Triangle in terms of the 1:1 ratio in another situation
How to demonstrate what you would change in aperture, iso or shutter speed to adapt to different circumstances.
23 Tuesday Feb 2016
Posted Exposure Triangle
in04 Saturday Oct 2014
Posted Exposure Triangle
inBelow are answers to the recent quiz that speak to the ability to move between ISO, Shutter speed and Aperture to change these relationships.
If you were in a situation where your camera metered Iso 200 at f4 at 1/1000 s but you wanted greater depth of field, what would you do? What would the new settings be.
In these cases, remember the one stop reciprocity between the elements of your exposure triangle. You know that you want a greater depth of field (towards f22), and you know that your shutter speed is quite fast. If you don’t have to change ISO you might leave it, since the lower the ISO the less grainy/ pixelated your image will look.
So, if you moved your f stop up one to 5.6, your shutter speed would come down one stop to 1/500 and ISO remains the same at 200. Following this logic, your next fstop would be f8 and your shutter speed would have to let it more light, so going down to 1/250 with ISO same. Next it would be f11 and shutter speed would have to make up for the less light entering through the lens, and become 1/125 with ISO remaining same (200).
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If you were in a situation where your camera metered Iso 200 at f 4 at 1/60s and you were at a sports event and wanted to capture motion what would your new settings be.
If you are already almost entirely opened up with the aperture (as you are here), and you need to increase your shutter speed you would have to start thinking about ISO. In this case, the ISO increases by one stop by doubling in number, so from ISO 200 to 400 is one stop. And this would allow you to retain f4 and increase the shutter speed to 1/125. If you then decided to increase the shutter speed again you would need to increase the ISO by one stop; ISO 800 f stop 4 and shutter speed could increase to 1/250. If you wanted to get to 1/500 shutter speed, increase the ISO again to 1600 and retain the fstop of 4.
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If you were in a situation where your camera metered Iso 200 at f22 at 1/30 s
and you wanted to record motion with no blur what would your new settings be.
In this case you are again trying to capture motion, so you could do something similar to above (increase the ISO) or you could, in this case, also increase the amount of light coming in through the lens. You could start with opening up one stop to f16, and then your shutter speed would be 1/60 with ISO constant. Then you could go to f11 and 1/125 shutter speed with ISO constant. Then you could go to f8 and get up to 1/250 shutter speed with ISO constant. Then f5.6 and 1/500 with ISO constant, etc.
You can also work between elements, so adjust ISO for one stop and aperture for another stop. They all have a one stop reciprocity effect on each other.
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18 Monday Aug 2014
Posted Exposure Triangle
inShutter Speed is one of the three pillars of photography, the other two being ISO and Aperture. Shutter speed is where the other side of the magic happens – it is responsible for creating dramatic effects by either freezing action or blurring motion.
1) What is Shutter Speed?Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it can help to freeze action completely, as seen in the above photo of the dolphin. If the shutter speed is slow, it can create an effect called “motion blur”, where moving objects appear blurred along the direction of the motion. This effect is used quite a bit in advertisements of cars and motorbikes, where a sense of speed and motion is communicated to the viewer by intentionally blurring the moving wheels.Slow shutter speeds are also used to photograph lightnings or other objects at night or in dim environments with a tripod. Landscape photographers intentionally use slow shutter speeds to create a sense of motion on rivers and waterfalls, while keeping everything else in focus. In summary, high shutter speeds freeze action, while low shutter speeds create an effect of motion.
2) How shutter speed is measured
Shutter speeds are typically measured in fractions of a second, when they are under a second. For example 1/4 means a quarter of a second, while 1/250 means one two-hundred-and-fiftieth of a second or four milliseconds. Most modern DSLRs can handle shutter speeds of up to 1/4000th of a second, while some can handle much higher speeds of 1/8000th of a second and faster. The longest shutter speed on most DSLRs is typically 30 seconds (without using external remote triggers).
3) Fast, slow and long shutter speeds
Fast shutter speed is typically whatever it takes to freeze action. For me, it is typically above 1/500th of a second for general photography and above 1/1000th of a second for bird photography.Slow shutter speed is considered to be the slowest shutter speed that you can handle without introducing camera shake. Some of the newer Nikon lenses such as the Nikon 70-200mm VR II have special “vibration reduction” technologies within the lens that can handle shutter speeds of up to 1/10th of a second (depending on photographer’s technique), hand-held!
How about long shutter speed? Long shutter speeds are typically above 1 second, when you have to use a tripod to get acceptably sharp images (for low-light/night photography or to capture movement).
4) How to set shutter speed
Most cameras handle shutter speeds automatically through in-camera metering. When the camera is set to “Auto” mode, both shutter speed and aperture are automatically selected by the camera. When you shoot in “Aperture Priority” mode, you set the lens aperture, while the camera automatically sets the shutter speed.
There are two ways to manually set the shutter speed:
a) By setting the camera to “Shutter Priority” mode, where you set the shutter speed and the camera automatically selects the aperture.
b) By setting the camera to “Manual” mode, where you set both shutter speed and aperture manually.
5) How to find shutter speed
Do you know how to find out what your camera shutter speed is set to? It is typically very easy to find the shutter speed. On Nikon DSLRs that have a top panel, the shutter speed is typically located on the top left corner:
If you look through the viewfinder, it should also be the number on the bottom left side of the screen. On most DSLRs, you will not see the shutter speed as a fraction of a second – it will typically be a regular number. When the shutter speed is slower than or equals to one second, you will see something like 1″ or 5″ (the ” sign indicates a full second). If you still can’t find the shutter speed, set your camera to “Aperture Priority” mode, then look into the viewfinder and point at a really dark area. Remember the numbers in the display, then switch to a very bright area and see what number changes. The number that changes is your shutter speed.
18 Monday Aug 2014
Posted Exposure Triangle
inIn traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films – 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.
In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain.
Higher ISO settings are generally used in darker situations to get faster shutter speeds. For example an indoor sports event when you want to freeze the action in lower light. However the higher the ISO you choose the noisier shots you will get. I’ll illustrate this below with two enlargements of shots that I just took – the one on the left is taken at 100 ISO and the one of the right at 3200 ISO (click to enlarge to see the full effect).
(you can see larger sized images of both shots here for the 100 ISO and here for the 3200 ISO)
100 ISO is generally accepted as ‘normal’ and will give you lovely crisp shots (little noise/grain).
Most people tend to keep their digital cameras in ‘Auto Mode’ where the camera selects the appropriate ISO setting depending upon the conditions you’re shooting in (it will try to keep it as low as possible) but most cameras also give you the opportunity to select your own ISO also.
When you do override your camera and choose a specific ISO you’ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example – if you bumped your ISO up from 100 to 400 you’ll notice that you can shoot at higher shutter speeds and/or smaller apertures.
When choosing the ISO setting I generally ask myself the following four questions:
If there is plenty of light, I want little grain, I’m using a tripod and my subject is stationary I will generally use a pretty low ISO rating.
If it’s dark, I purposely want grain, I don’t have a tripod and/or my subject is moving I might consider increasing the ISO as it will enable me to shoot with a faster shutter speed and still expose the shot well.
Of course the trade off of this increase in ISO will be noisier shots.
Situations where you might need to push ISO to higher settings include:
18 Monday Aug 2014
Posted Exposure Triangle
inAperture is measured in “f-stops”. Increasing the aperture by a full stop doubles the amount of light entering the lens, while decreasing the aperture by a full stop halves the amount of light entering the lens. These full stop aperture measures are as follows:
f/1.4 … f/2 … f/2.8 … f/4 … f/5.6 … f/8 … f/11 … f/16 … f/22 … f/32
These numbers actually represent fractions, therefore the bigger the number the SMALLER the aperture. As such, f/22 represents a very small lens opening (SMALL aperture) while f/1.4 represents a very large lens opening (LARGE aperture) .
Therefore, as you move one stop up the scale, say from f/5.6 to f/8 (DECREASING the aperture), you are decreasing the exposure by one stop. Conversely, as you move down the scale, say from f/22 to f/16 (INCREASING the aperture), you are increasing the exposure by one stop. Also, many of today’s digital SLR cameras graduate the aperture setting by 1/3rd stops, allowing greater control over exposure. This therefore means that if you wanted a full stop change in aperture, you would turn the aperture dial three “clicks”.
As with shutter speed, aperture is rarely used in isolation. Any change in aperture will likely require a change in either shutter speed or ISO. For example, if you increase the aperture by one stop (which increases the amount of light/increases the exposure), you will likely have to compensate with faster shutter speed (which decreases the amount of light/decreases the exposure).
Also, as with shutter speed, aperture is not only a tool to set exposure but more importantly it is a creative tool as well. When you want to affect your depth of focus, aperture is the adjustment you will make. If you wish the entire scene from the lens right out to the greatest distance you can see to be in focus, you would decrease the aperture by setting it to a high number such as f/22. Conversely, if you only want a small portion of the scene in focus with the foreground and background blurry, you would increase the aperture by setting it to a small number such as f/2.8. Read more about depth of field techniques here …..