So, you want to become a photographer? One of the fundamental elements to learn is that of exposure. Exposure is a key element in successful photography and it is something that needs to be understood and mastered to get consistently great photographs. There are many tips and tricks photographers can apply to increase the chances of getting the perfect exposure time and time again.
Low light photographers may sometimes find themselves in the situation where their camera’s internal metering system may struggle. In these circumstances there are things photographers can do in order to get a correct exposure for the image they want to take.
The first thing to try is to open the lens as wide open as it will go. This will give the meter the most light gathering opportunity which should help kick start it to life. If the meter gives a reading then it is simply a case of back tracking to the required aperture, remembering to double the shutter speed along the way. For example, say you get a reading of 10 seconds at f/4., but you want a picture at f/16. The required exposure at f/16 is 2 minutes 40 seconds - 10 seconds at f/4, 20 seconds at f/5.6, 40 seconds at f/8, 80 seconds at f/11 and 160 seconds at f/16.
Alternatively, you can increase the film speed setting, i.e. the ISO, instead of opening up the aperture. Whilst the light meter may not give a reading at ISO100 it may well do at ISO 400, ISO 800 or even higher ISOs. Once a meter reading is obtained the method of backtracking can then be used, with the exposure being doubled every time the ISO is halved. For example, your camera gives a reading of 10 seconds at f/4 on ISO 800. At ISO 100 the correct exposure will be 1 minute 20 seconds – 20 seconds at ISO 400, 40 seconds at ISO 200 and 80 seconds at ISO 100.
If the above methods seem overly complicated an alternative is to meter of a white surface and then dial in 2 stops of positive exposure compensation. If you can’t fill the frame with a white subject during metering then change the settings to spot metering. Metering off a white subject is often all that is needed to get your light meter working.
If your light meter is working but you are still unsure how to get a correct exposure then an alternative is to meter off a black object or from the dark shadows and dial in 2 stops of negative exposure compensation. Once again, if you can’t fill the frame during the metering process change the settings to spot metering.
An alternative to the above is to hold a gray card in the same type of light as the subject and take a meter reading from that. Gray cards have the 18 per cent reflectance for which camera meters are calibrated, therefore they work very well. Gray cards are readily available so getting hold of one should not present too many problems.
If the subject is a portrait or nude the meter reading should be taken directly off their skin. Once the reading has been taken you need to increase the exposure by 1 stop to 1.5 stops for Caucasian skin and reduce the exposure by 1 stop to 1.5 stops for dark skin.
If there is a dominant light source in the frame turn around and take the meter reading without the source in view. Alternatively, place your finger in front of the lens and take a meter reading.
If, after considering all the above, you are still struggling to decide how to get the perfect exposure you need to bracket the shot. Bracketing is simply taking multiple shots of the same subject at different exposures and choosing the preferred one after the shoot. Whilst some may see this as cheating it is often the only way to get the best shot, and it is better to take several shots and get the perfect one than to take a few of which all are no good.
Whilst learning photography, especially the basics, it is worth doing a bit of research. There are many great books on exposure and the theory of exposure and these are recommended to all photographers. Alternatively, there are many online photography courses to help begginers learn the art of photography and these are also well worth investigating if you want to take your images to the next level.