How To Use The Histogram Tool For Getting A Perfect Exposure

Looking on the back of the camera to see if you got a shot properly exposed can be misleading. The LCD may not be calibrated showing a too dark or a too light image. Or the sun hitting the LCD can be laying tricks on you.

Yet there is a tool, that is often ignored that can give you a very quick and good indication if you exposed correctly – The Histogram.

In a nut shell, the histogram is a graph that show how many pixels of each brightness level are present in a frame.  John Greengo of CreativeLive give a full back to basics course on photography, in this installation he discusses the Histogram in very easy to understand manner.

Generally, John mentions that you would want a histogram that looks like a mountain with a strong peak in the middle and a slope that goes out to either end. While specific captures may be unique, (such a capturing snow, or night shots), a strong peak on the right may indicate an over exposed image, while a strong peak on the left may indicate an under exposed image.

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Back to Basics – Contrast

contrastIn the last few weeks I’ve covered the basic exposure controls like aperture and shutter speed. I’ve also discussed the concept of depth of field as an important aspect of the subject in a picture. Continuing with the Back to Basics series, it is time to explore another important aspect of the picture – contrast. Contrast is the difference in tone in your picture. Specifically the difference between the brightest colors in the pictures (called highlights) to the darkest colors in the picture (called shadows). Usually talking about contrast goes hand in hand with talking about hard light and soft light. [Read more...]

Back to Basics – Depth Of Field

depth_of_fieldAfter discussing exposure in great detail, I would like to turn to a different kind of control – Depth Of Field (A.K.A. DOF). OK. Don’t jump – you are right. Depth Of Field is not a real control, but more of a result of how you used the aperture control.

In simple words Depth of field is the term you use to describe what is inside the focused area of your image and what is left outside of the focused area (and will stay home alone, and eat dry bread and drink stale water. Sorry Jewish mom syndrome…)

As I said before the control that has the most impact on depth of field is aperture. Bigger apertures tend to provide shallower depth of field. That means that if you open a wide aperture (say f/1.8) you will have a narrow location in your image which is focused. If you set your aperture to a small value, say f/22, you will have a huge focused area. The other two controls you can employ to control depth of field are Zoom focal length and camera to object distance. [Read more...]

Back To Basics – Exposure Demostrated

sunny day 16After talking so much about exposure and the controls you can use to, em.. well… control it, I thought I’d bring up some info that can help bring all the control info together.

As a solid base for demonstration, I chose to display and discuss a bit about a rule know as the “Sunny Day 16” rule. I guess that this rule is known to film photographers, and is of little use nowadays when all the cameras have built in light meters. But we can explore this rule and learn something about exposure from it.

The rule is simple: on a sunny day, set your aperture to f/16 and set your shutter speed to be as close to the ISO setting as possible. (There! All the three exposure controls in one coherent sentence. Pat on the back!). This is where this rule got its name – Sunny day 16. Image by Stefan Mendelsohn. [Read more...]

Back to Basics – ISO and exposure wrap up

isoIn the previous few articles, I have discussed some basic aspects of photography. The first subject to get a close look was exposure, and I have discussed two of the three components that control it: shutter speed and aperture. In this article, I will bring in the missing piece – ISO (or film sensitivity). After that I will conclude the exposure subject.

We have learned that the sensor (or film) can get the same exposure if we prolong the duration the shutter is open, but use smaller aperture (or shorten the duration that the shutter is open, while using a bigger aperture). If we want to be absolutely honest (which, at least for now, we do), we have to include the third part of the equation: film sensitivity (AKA ISO).

In short – ISO sets the impact that light will have on the sensor. High ISO will make our exposure brighter, while low ISO will make our exposure darker.

So how can we use ISO to produce better photographs? [Read more...]

Back to Basics – Aperture

Aperture tutorialAperture is one of the three main controls you can use when you are taking a picture. Along with shutter speed and ISO, aperture controls how light will hit the sensor (OK, old schoolers – hit the film).

In very simple words, aperture is the “size” of the hole the light goes through when it passes the lens. So large apertures will let more light go through then small apertures. Going back to the pipe allegory analogy, we can see the following: If we use smaller aperture, then to keep our exposure unchanged we have to use longer shutter speed, or higher ISO.

Sink image by Andrew Mason. [Read more...]

Back to Basics – Shutter Speed

shutter speedIn the previous article, I talked about exposure, and how it affects the final image. I mentioned that there are three controls the one can use to change the outcome of the clicking the shutter button: ISO, Aperture and Shutter speed. This article will focus on Shutter Speed. As I said, Shutter Speed is one of the three exposure controls. Luckily for this article, it is the easiest to understand. It simply controls the amount of time the shutter is left open for light to come in and hit the sensor.

I am saying sensor, but the old experienced folks may remember a time when the light was actually hitting film. Both the sensor and film collect light. The longer the shutter is open, they see more light – so the longer the shutter is left open the brighter your image will be. But shutter speed also affects other aspect of your image. Let’s try and have a look, but first let’s set the groundwork so we better understand each other. (Shutter image by brighterworlds) [Read more...]

Back to Basics – Exposure

Back to basics - ExposureThis is the first article of the Back to Basics series which tells allabout the basics of photography, and it deals with Exposure. Do you know that click sound that cameras make? It originates from a “flip” of a mirror that allow light to fall on the camera’s sensor (or for the old skool photographer – to fall on the film).

The effect of light falling on a sensor is called Exposure. That is because the sensor is exposed to light. (OK, great, so exposure happens when something is exposed. Big deal! no wait there’s more…) When the sensor is exposed, it gathers the light and depending on how much light is gathered it creates an image.

Exposure is relative and is comparable by something called stops. (or F stops). The main trick for understanding exposure is that “opening” or “closing” a stop, doubles or halfs the amount of light that falls on the sensor. Lets have a closer look. [Read more...]

Back to Basics

back to basicsIsn’t it fun to take a pile of PVC pipes and turn it into a studio? Or to take an old sheet and make it a first class photography backdrop? Some of those trash reused highly complex – space age technologies require nothing but two good hands, showing that no studio equipment is out of reach for the poor enthusiastic photographer. This is especially true when it come to mono-e-mono Vs. them high end gear guys.

Collecting all those DIY stories over the last year and a half or so, helped me realize that random stuff you find around your house good equipment is only half the key to taking good pictures. The other half is having good understanding of photography. Yet the third half is creativity or the ability to get creative. (yea, yea, I know that 150% of being a good photographer. But hey! if you really know it all you can get to be a 150% photographer… ) [Read more...]