light meter

All posts tagged light meter


Imagine if you will a beautiful sunny day. You’re walking along, have your camera of course, and come upon a beautiful place to snap a shot. You get all ready to shoot and then it hits you! Uh oh, you left your light meter at home! This is terrible, how are you going to set the proper exposure for your sunny day photo? In fact not only did you realize you left your light meter at home, you remember that it’s really the light meter you’ve only been thinking about buying, you don’t even own a light meter yet!

Fear not, it turns out there is a way that you can set a close to perfect exposure on a nice bright sunny day without a light meter. This is excellent news for those of you who left your light meters at home, or haven’t gotten around to buying one yet (you know who you are out there). Enter…the Sunny 16 rule! It’s not just a record title by Ben Folds.

The Sunny 16 rule can be used as a guide to set a near perfect exposure when shooting on a sunny day. Here’s how it works. First switch to Manual Exposure mode on your camera. Not sure about Manual Exposure Mode? Just check a few blog posts back for our series on Exposure Modes. Next set your aperture to f/16 (that’s the 16 part of the Sunny 16 rule for those of you who were curious). Then set your shutter speed to the nearest full stop reciprocal of your ISO (what did he just say, did he just curse me out?).

Relax, reciprocal simply means to take the inverse of your ISO setting. So if your ISO is set to 100, then the reciprocal is 1/100. If your ISO is set at 200 then the reciprocal is 1/200. Hang on a minute though, I did say the “nearest full stop” to the reciprocal right? This is true, there are many cameras that only let you set your shutter speed to full stop settings, 1/100 and 1/200 are not full stop settings so you may not be able to use those on your camera. This is why we use the nearest full stop to the reciprocal. So if your ISO is set to 100, the reciprocal is 1/100 and we would use a shutter speed of 1/125. This is because 1/125 is the nearest full stop to 1/100. If our ISO is set to 200, the reciprocal is 1/200 and we would use a shutter speed of 1/250 because that is the nearest full stop to 1/200. Here is a list to refresh your memory about the full stop values with regard to shutter speed.

Shutter Full Stop Values: 1s, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000

So what is ISO? ISO is basically a setting of how sensitive the sensor in your digital camera is to light, or how sensitive your film is to light. The difference between the 2 is that with a digital camera you can change your ISO with the touch of a button, in a film camera you actually have to put a new role of film in. Most digital cameras set the ISO automatically for you, and use ISO 100 or ISO 200 most of the time, of course it is possible for you to change this setting, and then you would take the reciprocal of whatever you currently have your ISO set to. As a rule of thumb though on a bright sunny day you would typically use a low ISO of about 100 or 200, this is because there is plenty of light around you so your sensor or film doesn’t need any extra sensitivity.

That’s all there is to it! So the next time you find yourself shooting on a bright sunny day and don’t want to drag that light meter out of the camera bag you can use the Sunny 16 rule to make sure you have perfect exposure almost every time. It’s May, the weather is beautiful, go put the rule into practice and shoot some bright sun scenes. As always feel free to post the results or comment.

Here is a photo using the Sunny 16 rule, as you can see a very nicely exposed photograph, ignore the funny looking guy on the Segway, he thought he was in the 3 o’clock parade.

Properly Exposed Photo Using the Sunny 16 Rule, f/16, 1/250, ISO 200

We’ve finally made it to the end of our 5-part series on exposure modes. We finish with the king of all creativity, Manual Mode. This is the mode that lets your knowledge of photography and creativity shine through. Manual Mode is the one where you basically tell the camera to “shut-up” and let you do the driving.

Are you in a dark room where the camera is telling you it’s too dark to make  a proper exposure? No problem, Manual Mode will let you take that photo. Do you want to take a photo with a very deep depth of field and also freeze the action, but don’t have enough light? Switch to Manual Mode, and give it a shot, you’re not paying for film!

Ok ok, so Manual Mode is not a magical cure for exposure problems, but it does allow you to go out of your camera’s, and possibly your, comfort zone to take some photos that the camera might not allow you to take while in one of the other exposure modes.

Let’s review a bit…we’ve already learned about the other 3 exposure modes..

Programmed Auto Mode (P-Mode) your camera does all the thinking. Aperture and shutter speed are set for you automatically.

Aperture Mode (A-Mode) you set the aperture and the camera determines the shutter speed for you.

Shutter Mode (S-Mode) does just the opposite, you set the shutter speed and the camera sets the aperture value.

By now I’m sure you have guessed that in Manual Mode (M-Mode) you’re flying solo. You’re responsible for  setting both the aperture and the shutter speed yourself. That’s a big responsibility! Are you ready for it? Can you handle it? I think you can.

Even if you don’t think you’re quite ready, I implore you to try Manual Mode. Nothing will teach you about exposure settings and the relationship between aperture value and shutter speed faster than being out there on your own making your own exposure settings.

Plus, if you make a mistake, you might it’s a part of life, because you’re shooting digital it costs you nothing to try, and it’ll be our little secret if it doesn’t turn out quite right the first time. If you’re shooting film however, you may want to borrow your friend’s digital camera to try it out. You’ll most likely be going through a lot of frames, plus the digital camera allows you to get instant feedback, instead of having to wait for the film to be developed to see what worked and what didn’t.

The toughest thing to shooting in Manual Mode is picking a starting point. When choosing your aperture and shutter speed where do you begin? It can be very overwhelming. Sometimes when shooting in Manual Mode professional photographers will use a light meter. A light meter is a hand-held device that measures the light in the scene around you and gives you values for what your aperture and shutter speed should be.

Now wait a minute…that sounds just like what your camera does when it is in P-Mode. Well you’re right, your camera has a built-in light meter which is how it determines the proper exposure values for the scene you are shooting. So what do you do when you’re new to Manual Mode and your light meter is in the shop? Put your camera in P-Mode and press the shutter down half-way.

This is going to give you an exposure reading. In P-Mode the camera will use it’s built-in light meter to “read” or “meter” the scene and tell you the aperture and shutter values that it comes up with. So now armed with this new information we can switch back to Manual Mode and plug in those values we just got from the camera’s built-in light meter. You now have an excellent starting point for setting up your shot in Manual Mode.

You know these values are going to give you a relatively decent exposure to begin with, so now you can start getting creative by varying either the aperture value or shutter speed to achieve your desired results. Want a shallower depth-of-field? Go ahead and dial in a larger aperture value, just keep in mind that you’ll need to adjust your shutter speed to keep your exposure well balanced.

A good rule-of-thumb to remember is that for every full stop of aperture value you increase or decrease you should also change your shutter speed by a full stop to maintain the same Exposure Value (EV). We learned about this a while back when we discussed reciprocity.

So for example, if our light meter (built-in or hand-held) chooses an aperture of f/8 and a shutter speed of 1/125 and we want a shallower depth-of-field. We can change our aperture value to f/4. That is a change of 2 full stops. So in order to keep the same Exposure Value (EV) we will need to raise our shutter speed by 2 full stops bringing us to a shutter speed of f/500.

This is because when we make our aperture value larger by a full stop we are letting in double the light. Since we changed our aperture from f/8 to f/4, 2 full stops, we are now letting in 4 times the light at f/4 than we did at f/8. So to compensate we use a faster shutter speed by 2 stops from 1/125 to 1/500. This causes 1/4 of the light to be let in at 1/500 than we had at 1/125 which cancels out the 4 times more light coming in from our aperture value.

How do I know that is 2 full stops you ask? Well I have included a chart at the end of this article that shows the full stop values for both aperture and shutter speed. Some high-end cameras will let you change your aperture or shutter speed in 1/2 or 1/3 stops as well, but all cameras will let you dial in full stop values.

Manual Mode also comes in very handy when shooting with flash, especially external flash. A full discussion on shooting with external flash is a topic for another blog post, but we’ll touch on it briefly. When shooting with an external flash the cameras light meter may not take this into account. Therefore it might choose a very slow shutter speed automatically for you because it is metering the available light in the scene. The light meter may not know that an external flash will be used. This is the perfect time for Manual Mode.

By shooting the scene in Manual Mode you are able to tell the camera that you would like to use a faster shutter speed. We know this still will result in a good exposure because the flash is going to provide quite a bit of light to our scene. Shooting in Manual Mode let’s you choose the shutter speed and also the aperture value that will work for your flash lit scene.

There are some people who are perfectly content taking all of their photos in P-Mode and letting the camera do all their thinking. Most of the time this yields decent photos. However, you cannot truly begin to explore the creative possibilities of photography or take your photos to the next level until you turn that dial and try shooting in one of the other 3 modes.

Maybe you feel Manual Mode is a bit too much for you to try right now, but Aperture Priority Mode or Shutter Priority Mode are just begging for you to give them a shot. They let you start taking control of the exposure in your photos without having to fly solo. And as with most things, there is no better way to fully understand your cameras exposure modes than to get out there and shoot as much as you can!

I hope you’ve enjoyed this multi-part series about exposure modes, even if the end was a long time coming. Feel free to ask questions, leave comments, and share your creative photos. Until next time.

Exposure Value Chart

Chart of full stop values and Exposure Values (EV), Courtesy of thecrosseyedbear on Flickr http://www.flickr.com/photos/thecrosseyedbear/2124175721/