Getting noisy photos?

Recently... this question popped out... noisy photograph. An aspiring photographer just bought a brand new Sony NEX-5N camera and happily started shooting in a family function.

The result was horrid... at least to himself... blurry and noisy pic. So he asked for help.

A look at his photos... yep... those are photos with lots of noise (grains that might look ugly)... and some of the picture had very blurry subjects. So I asked for exif of those pic.

Well... the ISO setting are wayyyy too high... most of them are shot at ISO3200 and one or two are shot at ISO6400. I was like, wtf? Then I look at his aperture setting and shutter speed... most of the aperture setting are at f8 to f11... and shutter speed are hovering around 1/6 to 1/10.

So you see the problem here?

There are a couple... so let us go into the fact first.

Environment

   

First... the lighting in the environment of the shoot is pretty bad... it was night, and outdoor... not properly lit and people are moving around. There are a couple of kids running or moving pretty quickly...

Thus with this type of environment... it is no wonder that the photographer had to set his ISO high, in order to give him adequate shutter speed. However the second problem came up... he set his aperture too small... this is an obvious case whereby he do not understand DOF in relation to the distance between himself and his subjects. With a small aperture, less light will enter the lens and hit the surface of his sensor at a given time. So he would need to open his shutter longer and so lengthen the shutter speed.

All these added together... to give a rather noisy photo and if subject is moving fast or even slowly, you would get blurry pic... and not to mention with a longer shutter speed, the photographer is inviting effects to his shots due to shivering or shaking of his own hands.

So how to we remedy?

1) Know your environment first.

    a) What is the lighting condition?

    b) Are we shooting indoor or outdoor?

    c) If we are shooting indoor, what is the environment like - low ceiling? What is the color of the ceiling?

    d) If shooting outdoor, what is the lighting condition? Well lit or in daytime?

    e) What subject are we shooting? running kids, animals, models posing, adults that don't mind to be still for a while?

Only by establishing the environment that the shots are to be taken, could we determine what equipment to use or take (this would include, external flash, tripod, monopod, lenses, softbox, bounce card, etc).

2) Know the relationship between ISO, shutter speed and aperture.

They are related... but first lets take them apart and look at them one by one.

a) ISO - this is a value whereby the sensitivity of your sensor was being measured, the higher the value the more sensitive your sensor would be to light. So the higher the ISO-value the more sensitive the sensor is to light. However, the catch is... the higher ISO-value, the more noise will appear in your photo. So in practice, I normally don't like to go past ISO-800... although in recent photoshoot... I have been shooting at ISO3200 or even ISO5000 (and make full use of the grains in the photo to my advantage - that will be cover in later discussion).

b) shutter speed - this is the speed whereby your shutter is opened and exposing your sensor to the light that enter from the lens. The longer the shutter is open, the longer your sensor is exposed to the light. However if there is any movement (be it yourself or your subject) during the time your shutter is opened, it will be recorded in the camera and so you will have blurry picture.

c) Aperture - this is directly related to DOF (Depth of Field). DOF is the distance between the nearest and farthest objects in your picture to remain focused. Herewith, there is a rule of thumb

    "The larger the aperture, the thinner the DOF and the smaller the aperture, the deeper the DOF"

So if you open your aperture wider (small F-value) the lesser area of your subject will be in focus, all other will be blurry and the smaller your aperture (big f-value) more of your subject and the background will be in focus.

Okay, now we put these three variable together and see what we got.

If your close your aperture smaller - less light will be allowed into the lens, so less light will hit the surface of the sensor, and in order to get the photo properly exposed, you would need to open your shutter longer so that the sensor could be allowed to receive more exposure. However that would result in shakes and shivering in yourself or your object and so it will cause a blur shot (motion blur of yourself and/or your subject). So one would have to increase ISO value... this would make the sensor more sensitive and so it will need less time for exposure... however noise will step in and ruin your otherwise great photo.

So in this manner, we would like to use as low an ISO as possible, yet increase shutter speed... this mean your aperture had to be opened wider. However if you open your aperture too wide, you would have too thin an DOF thus you might only get certain part of your subject in focus.

So the first thing is... you must know the relationship between your distance to your subject and the aperture value. A good way to start was to open your aperture to around f4 or f5.6... it should give you enough distance between yourself and your subject whereby most of the subject or all of the subject will be in focus.

  

Next with an aperture of around f4 to f5.6... your speed will still not be enough to freeze the action of running kids or moving adults. So you need to rise your speed... note that we do not want to increase ISO value though, so the only way is to increase the lighting in the area.

How to do it? Flash... either a direct flash or external flash, with tilted head so that the light don't go directly on the subject. I like to use bounce flash.... but at time, you cannot because there is no where to bounce your flash... so you can use a bounce card or stuff like that.

  

Also note that for alot of camera, there is a limit in shutter speed if you are using flash (for Canon it would be 1/250)...

  

So up till now, we know how to remedy the problem in that aspiring photographer's shots. But in detail... like how to shoot flash and stuff like that, I would need more than a few pages (will discuss later).