Stop, stop, stop

February 09, 2015  •  Leave a Comment


Last day of the BIG THREE



ISO is set in response to how the sensor will register the available light. Tv (time value) is how fast or slow the shutter opens and closes. Fast lets in less light. Slow lets in more light.

Today, it is the final point in our BIG THREE. We have aperture. This is the size of the opening in which the light passes.

It is best when we imagine the settings as fractions so 22 is 1/22 and a very, very small opening. Like squinting on a very bright day. While 22 is very small, 2.8 would be a very large opening and allow in lots and lots of light.

All lenses have a sweet spot in aperture. This is where they produce the best and most clear photos.

For most lenses, the sweet spot is around F/8 – F/11. We will often hear the aperture settings referred to as stops.

Portrait photographers LOVE the little F stops.  F 2.8 and F 1.4 are selected to produce a photograph with very soft background.  Portrait photogs like to call this “creamy.” Technical photographers will tell you this is a shallow “depth of field.”

On the other end of the scale is the f/22 and higher. The bigger number F stops are used for photographing  landscapes. By selecting the smaller opening, you get a larger depth of field, which is great when you want the people in the foreground and say mountains in the background to ALL be in focus.

Beyond getting a correct exposure, your style of photography and your desired depth of field are two items considered in determining the proper F stop setting. 

Today’s assignment is focused on the artistic use of an F stop.




Choose the Av setting on your camera (Aperture value).


You will need your camera and a subject .

Stand the person in front of a distant object such as a house or building.


1.       Set the aperture to F/2.8 or the lowest possible setting you can get on your lens, which may be F/4. Focus on the person and take your photograph.Take one photo of just their head and shoulders. Now step back and take a second photo which captures their entire body.

2.       Do not change anything about the subject or background, but do change your aperture to F/8 or F/11. Take a second set of photos.

3.       This time change the aperture to the highest setting, which is the smallest hole, F/18 or F/22. Take your third set of photos.


Compare all photos and make notations so you can remember which setting produces which results.




Look at today’s blog photo. Can you guess the settings?




Aperture:                           F 2.8

ISO:                                        200

Shutter speed:                 1/2000 of a second




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