Tuesday, January 11, 2011

Basics of Manual Camera Settings–Part 4–Stops and Metering

So, now that you know what all the things do, it’s good to know how they relate to what you see and how that helps you take good photos.

In camera metering is fairly easy.  I’ve seen a couple different types of meters.  Here are some drawings that illustrate both what they look like and how bad I am at drawing.

Some meters have a scale where the middle line indicates what the camera thinks will be a properly exposed scene (cameras base exposure on a percentage of gray, so they usually won’t expose all black or all white scenes well, I’ll explain how to compensate in a minute).  An alternative to the scale is example 3, where there will be a needle that bobs around.  Finally, some meters will tell you what f-stop you should be exposing for based on the film speed setting you are using.  These can have both meters, or numbers that light up.

The idea is to change settings until the needle is in the middle/the lit number corresponds with what you have set.

There are a couple ways to do this.  Example 1 and 3 show over exposure (your settings will make the photo too bright).  Either close your aperture (bigger f-stop number), increase your shutter speed or lower your ISO – in this case, 1 stop in example 3 and 1/3 stop in example 1.

So, what are stops exactly?  Stops are full measurements of ISO, aperture or shutter speed.  They are an equal distance from each other as far as exposure is concerned.  In ISO and shutter speed, each stop is twice as much as the one before it.  1/4 second to 1/2.  100 ISO to 200.  In aperture, it’s pretty much the same thing, except there’s a lot of math involved.  Square roots of 2 or something.  I don’t think it’s something we need to know, so here’s the short version.  Full aperture stops are: 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22 and 32.  There are others, but these are most common.

How do stops relate to each other?  If you move your shutter speed one full stop faster, you can move your aperture one stop wider and have the same exposure.  How is this useful?  If you have a light meter or your camera meter says to expose at f4 for 1/1000th of a second, you can increase depth of field by exposing at f5.6 for 1/500th or f8 for 1/250th.

To make this easy, here’s a craft tutorial for a stop slider!

Step 1, draw lines to separate out 15 equal spaces.  Now do it the other way so you have rows of squares the length of the paper.  I know these pictures don’t follow what I’m saying, but trust me and do it this way instead.


Leave the far left spaces blank (I didn’t and had to re-do it.)  Start writing in your f-stops (see above) starting with f32 and ending with f1 (which is backwards from this picture.  This craft was an epic fail last night, I redid so so much…).  In the second row, write your shutter speeds starting with 4 seconds, up to 1/1000th.  (4”, 2”, 1”, 1/2 OR 2, 1/4 OR 4, 8, 15, 30, 60, 125, 250, 500, 1000).  Now skip a row.  Write your ISOs, left to right, 25, 50, 100, 200, 400, 800, 1600, 3200.


Cut the top 2 strips out.  Leave 1 blank space on each side of each row, then cut the excess off.


Cut out 2 windows below the ISO row.


Fold the back around, then staple (or glue or whatever) the back shut and along the edges of each window to create little holes.


Insert your 2 strips from before.  Now you’ll have a handy slider.  Using ISO as your starting point, slide the 2 rows to match with settings from camera or a light meter.  Now you can move any 2 rows to the left or right and have the same exposure.


In this photo.  1/15th, f4 at 400 equals 1/30th f2.8 at 400.  1/4, f8 at 100 equals 1/8, f8 at 200.  And so on…

So, now that we know what metering and stops are, we can look at ways to use them.

Remember when I mentioned your light meter works with a certain percentage of gray?  That means if it sees something black, it will try to make it look gray and over exposed.  This is where you can shift a couple stops to over or underexpose a photo so that it works for your subject.

Another genius thing to do is bracket.  Take one shot normal, one shot 1 or 2 stops over and another 1 or 2 stops under.  Some cameras even have auto bracketing (with 3 clicks of the shutter, it will automatically shoot one normal, one under and one over).

I hope all that has helped your use of manual camera settings.  You should be well on your way to getting out of auto mode and into manual mode.  At least try using Tv or Av if you don’t feel like metering.  That way you can set the shutter speed or aperture and the camera will do the rest. 

Finally, always ALWAYS set your ISO in digital!!!  Use the lowest ISO your photo will allow!

Happy shooting,

Shasta Betty

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