Getting the Perfect Exposure Everytime

11/10/11

What is exposure ? Whenever you click a picture, you do not capture moments, but you capture light. The art of manipulating light via your DSLR is known as Exposure.

Getting Exposure perfect now a days is a piece of cake for most of the modern DSLRs. All thanks to the ultra sophisticated Metering Systems our cameras are fir it. But then also, which metering system to use ? Spot? Matrix? Weighted? All these questions arise when you first time start photography.

Many people ask me, what were your exposure settings, which metering mode you used? Which mode were you in? The answer to all this is "I don't know"!
Really, I don't know. When I take pictures, the scene is already in my head, all the values and settings pre determined and the settings i dial in, i forget. Thats because now, its become a part of me.

I am not that good a photographer, nor am i a pro. But still when it comes to photography, it gives me an adrenaline rush!

Anyways coming back to getting the exposure right every time !

Well, first of all I would suggest you be in Aperture Priority every time you click pictures ( most of the time you will be using the aperture priority mode, say 99%) and that holds true for 99.99% of portrait work.

Well, using a priority mode on your camera, makes exposure so easy.

First of all, lets talk about the parameters which affect exposure. The Exposure triangle!

1) shutter Speed
2) Aperture
3) ISO

Shutter speed is the amount of time the shutter is open for. It is measured in seconds. Say 1 second, 1/5th of a second, 1/100th of a second and so on.
( Quick Tip : For handheld photography, always make sure your shutter speed is more than 1/60th of a second. This is reduce the risk of image blur and always give you crisp images despite the minute shakes of hand )

Aperture is the opening in the lens which allows light to pass through it. Aperture is measured in "f-stops".
A inverse law applies when it comes to aperture settings of the camera, i.e., a smaller aperture number means a larger opening of the aperture hole and a larger number denotes a smaller aperture opening.
For example, f/2.8 will allow more light to hit the image sensor than f/11 would.

Third and the last is the ISO. ISO is the sensitivity of the sensor inside the camera. It measures how sensitive the sensor is to light. And, higher the number, higher the sensitivity.

But you would ask me, how do these 3 things work together to give you perfect exposure?

Okay, lets take a situation where there is good lighting and you are in the open, say on the road and your subject is a man playing the guitar on the streets.

As i said before, be in Aperture priority mode, the mode where the user decides to set the aperture and the camera sets the other variable, i.e., shutter speed automatically.
So when you want a good and deep depth of field, you will dial in the maximum aperture your lens allow, in my case, f/1.4.
This means there is immense light entering the camera and hitting the censor.
So, to compensate for so much light, the cameras meter will reduce the shutter speed.
Say the shutter speed reading come out to be 1/200th of a second. This is the perfect exposure.

Now, there maybe situations where you want to keep the aperture max, and you may be getting a low shutter speed reading, say about 1/5th of a second. But as i said, there is a possibility of camera shake if your hands are shaky. What do you do?

Well, increase the ISO ! because, as i said before, ISO is the sensitivity of the sensor. Increasing the ISO will increase the sensitivity of light hitting the sensor and therefore the effect of this would be a rise in shutter speed. When you experiment with ISO, stop increasing it once you are well above 1/60th of a second.
This is because ISO has its own short comings. ISO produces noise, or electronic dust which you can see in your final image as dust particles if your ISO is way too high !

But now a days cameras like D7000 work very well on high ISOs as well.

Before digital SLRs came into being people used to estimate the perfect exposure settings in their head according to the type of film they had inside their cameras.

But of course modern technology has made every person to become a good photographer and that is why the photography industry is seeing a huge influx of new and novice photographers like me !

anyways,
enough for today, need to sleep !

do message me if you want me to answer specific questions.
and leave me an email on archit@tunitextiles.com if you have any feedback or any questions about the above article.

Thanking you,
Archit Sureka.