Tutorials - ISO Settings

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Probably the easiest thing anyone can do to begin the process of taking better photos is to get to know your camera. The first step in doing this is to read the manual. When you take the time to do it, have the camera in your hand and follow along. You don't necessarily have to try to remember everything all at once and there are some things that may be of no interest or use to you. As you go through it those things will probably become easily identifiable.

Besides the easier settings mentioned in the previous essay, there are other menu settings that can go a long way to making better photos. This essay will be discussing ISO settings.

ISO settings refer to standardized settings that measure the sensors sensitivity to light. In the Before Time this was also used to measure the film speed meaning the film's ability to react to light. There isn't much need for the average person to try to understand the nuances of this but it can be explained in layman's terms to give us a general understanding of how this will affect our photos.

As mentioned in a previous essay, the only thing a camera does is capture light. If this is the only thing a camera can do then why does it have all of these menus and settings? The camera has three ways of controlling the light that enters the camera. As the light enters the lens it is first controlled by the "aperture" also called the 'F' stops on professional cameras. This is simply a diaphragm that expands and contracts to allow more or less light into the camera. A professional camera has the ability of controlling the opening of the aperture to get desired effects. This is a more advanced feature and the point and shoot camera doesn't have the ability to change the aperture specifically but it will be affected by the various settings it does have. In general the more light available the smaller the opening. The less light available the bigger the opening. I say in general because this can be manipulated for various effects called "Depth of Field" which is simply referring to what is in focus and what is not in focus. The point and shoot has limited abilities to control this but with a better understanding of the camera, it can be to some degree. This will be discussed in a later essay.

As the light passes through the lens aperture it then goes through the shutter. The shutter is simply a door that opens and closes to expose the sensor. Again the professional camera has control over the speed that it opens and closes, the point and shoot, not so much. The more available light, the faster the exposure. The less light the longer the exposure. As above, knowing how the camera functions, you can use the available settings in a point and shoot to try to maximize the potential for good shots by understanding how those settings affect the shutter. It is mostly common sense and logic as stated above. Bright light = fast. Low light = slow.

After the light passes through the shutter it then gets recorded on the sensor and this is where ISO comes into play. You can set your camera to its automatic settings and the camera will decide for you the optimum aperture, shutter and ISO settings it needs to take any given shot in any situation. For most people in most situations this is all good and it will give you a good shot most of the time. As we get better at photography though, we might try to push the camera further than it thinks it can go to try to achieve something more aesthetically pleasing than just a snapshot.

The ISO settings affect how fast the sensor will react to light that is hitting it. Typical values for ISO settings are 200, 400, 800 and 1600 going from slowest to fastest. The slowest setting of 200 is the optimum because it allows the sensor to gather more information (light). This setting will give us the clearest, highest quality image the camera can get. So why don't we use 200 all the time? Well you can if you override the cameras auto settings and set it yourself. Not every camera can do this but most will. As with everything though there is a price to pay. As the light gets lower and lower, the slow sensor will not be able to record the information unless you let in more light by slowing the the shutter speed. However slowing the shutter speed can result in blurry photos , as discussed in the blurry photo essay, unless you can mount it on a tripod or set the camera down and use the timer.

So, if we can stabilize the camera, we can use the 200 setting and capture crisp clean photos in any low light situation including near complete darkness. If we can't stabilize the camera we can choose a faster ISO setting speeding up the ability of the sensor to capture light. This will allow us to capture more images in lower light situations and may eliminate the need for a flash capturing only the natural available light. However, there is a price to pay. The faster we set the sensor, the less information (light) it is absorbing. This will make a less clear photo that will have more 'noise'. It will appear 'grainy' to use the old film reference. Sometimes the graininess is bad and sometimes it isn't. Getting the shot is usually preferable than not getting the shot and we don't really know what's going to happen so it is usually worthwhile to try to increase the ISO incrementally to see if we can get a good shot.

The little pictograms on your camera for night shooting, sports or whatever are all simply trying to anticipate your needs by optimizing the three things the camera does, aperture, shutter and ISO. As we get better at photography, we can use this knowledge to manipulate these settings to our purposes rather than letting the camera control us and increasing the ability to get more good photos in difficult situations.

In the first photo, I was walking on a trail in the Muir Woods when this little guy poked up right in front of me. He wasn't scared and didn't seem to care about my presence one bit. The forest is quite dark, I didn't have time to set up a tripod and I didn't want to scare it with a flash nor did I want to use a flash to begin with. The flash would have destroyed the natural light and would have been a far less interesting shot in my opinion. I took a photo but at 200 it was too dark. I changed the ISO and was able to get this shot. You can see that it isn't super crisp but the softness doesn't take away from the overall quality of the image in this instance. The drawback is it may not make a good print if it is enlarged too much. But I got a cute shot and that's what really matters.

In the photo below I was again not allowed to use a tripod which can be frowned upon in some places. The interior of the cathedral was very dark. I sat in a pew and did my best to stabilize my arms on the pew in front of me. However it was still too dark for a 200 ISO setting so I started to step it up until I got a passable shot. You can again see graininess that softens the photo but the natural light creates an ambience that fits the scene. A flash here would have captured almost nothing of interest. Most likely it would light the closest pillar and most of the rest of it would just be dark. The flash would also reflect light off of the windows essentially blocking the natural sunlight coming in and there would be no color or detail. Even if it did light up some of the interior, it would not have the same affect that is achieved with the natural light.