I take pictures of Art for my eBay Site  SensationalTropics .  Many times I ask myself, "What is the best f/stop to use to get the best picture.  I set my camera, a Canon Powershot A570 IS, to the Av setting.  The setting allows me to change the aperture settings while the camera adjusts the shutter speed. The  two pictures below show the result.  In both cases the light is the same,  The first picture was taken with an f/stop of 2.6.  This picture shows clear crisp colors.  The second picture was taken using an f/stop of 8.0, this picture shows fussy borders.  The light is a 500 watt halogen shop light.  Is it possible the fuzziness is the fact that with F 8.0 the shutter had to be open longer and that caused the fuzziness?


Figure 1: F 2.7


Figure 1: F 2.6


Figure 2; F 8.0


Next I take a look at the possibility that my free-hand (held camera with my hand) is the reason for the blur.   With two 500 watt shop lights, a white waste basket as my light tent and camera suppot and two more 50 watt bulbs right next to the waste basket I took the following two pictures.


Figure 3: F2.6 with a camera rest.


Figure 4: F8.0 with a camera rest.

It is clear the second is better.  I retook the top one three times trying to get it to match the clearness of the F8.0 picture. 

What is the conclusion?   If you hold the camera in your hand and and there is risk of shake, use the lower f/stop. (2.8)  If your light is good or you have a rest for the camera use the higher (8.0) f/stop.

Harlan A Nelson
SensationalTropics

Art and Jewelry