What do you do when you need more light but you don’t want to use flash?
Decrease Aperture
Well, you can mechanically let in more light by decreasing the aperture. When you decrease the aperture, you increase the size of the “hole” light enters through, thus letting in more light. To let in more light by adjusting the aperture, you should lower your f number. The lower the f number, the more light can come in.
Decrease Shutter Speed
The second mechanical trick you can do to let in more light is to let the “hole” mentioned about stay open for a longer period of time. The longer the camera’s sensor is exposed to light, the more light it captures. However, the longer the shutter stays open, the more chance you get of blur being in your picture.
Look at the two pictures below. The first one has a faster shutter speed. It’s a darker picture. The second picture has a slower shutter speed. The shutter stays open longer and lets in more light. This picture is much better and not as dark. However, had my puppy been awake and moving around I wouldn’t have been able to increase the shutter speed because then she would have been a blurry fur ball.
- Shorter Shutter Speed (0.25 sec), Mid-Range ISO (500)
- Longer Shutter Speed (0.5 sec), Mid-Range ISO (500)
Increase ISO
So, what if you can’t decrease your shutter speed? What if your subject is moving? What if you don’t have tripod?
Easy, increaes your ISO. By increasing the ISO you increase the sensor’s sensitivity to light (and noise) making it possible for you to take low-light pictures without a tripod. The drawback to increasing the ISO is that the higher the ISO the more noise will appear in your image. But at least you get the shot, right?!
This third picture was taken at the same shutter speed as the first (the dark picture), but at a much higher ISO. I probably went a little too high (or a lot too high) on the ISO, but I wanted to really give you the idea of how increasing the ISO can really brighten up an image.
Shorter Shutter Speed (0.25 sec), Higher ISO (3200)