Project - Exercise 2 - Focus at different apertures

Exercise:  Focus at different apertures

The second exercise in the Focus Project.  The brief here was to find a subject similar to the one in the previous exercise.  Each photograph was to be framed identically using a tripod and the focal point was to be the same for each image. 

This was a very good exercise for me.  I finally started to get the light bulb moment around the reciprocal relationship between f-stops and shutter speeds.  I have struggled with this in the past.  Because of the exercise and the overcast conditions I was forced to think methodically about what I was doing.  Another little obstacle I overcame today was my shyness when out in public with my camera and tripod.  As I twiddled with my buttons on my camera and scribbled notes in my little black book people walked past with their dogs and I just gave them a big smile and a hello.  After all they have no idea how good or bad I am!!

Back to the exercise:  All three images were taken using a tripod, focused in the middle of the tree line and on ISO 400 setting due to the low light.

The first image was taken at f4 with the shutter speed at 1/60 sec. 

The second image was taken at f11 with the shutter speed slowed down to 1/6 sec.

The third image was taken at f22 with the shutter speed slowed down to 1 second. 

I feel that I failed a bit with the third image.  It looks too light to me.  I didn't quite see that until I had the images on the computer.  I am using the histograms more during my shoots. I can now adjust the aperture and shutter speed when in Manual mode which is a massive learning curve for me. As with all learning processes more practice is needed before it is totally consolidated but this was an excellent exercise for this. 

I have printed these images off as part of the exercise.  There is  an obvious difference between the first and third image, partly due to my over exposing the shot by opening the shutter for a little too long (1 second) which let too much light in.  The difference in relation to the first image is  also due to the difference in f-stops.  f4 means that the aperture is open at its widest setting for this lens, letting more light in.  f22 closes the aperture down which decreases the amount of light reaching the sensor. This is why the shutter speed needs to be altered to accommodate and rebalance the changes in light.  So when the aperture is open the shutter can be speeded up and when the aperture is closed down to a smaller opening the shutter speed needs to be slowed down to let more light in. It is best to use a tripod if possible when the shutter speed is slowed down in this way to avoid camera shake.

On closer inspection of the printed images the area of best focus is different for each one.   In image one the area of best focus is narrower than in image 2 and image 3 has a much wider area of best focus than the first two images.  This is because the aperture effects depth of field as well as the amount of light that it allows in through the lens and onto the sensor.

I intend to go out and practice this exercise more.  Making myself work out the relationship between aperture, shutter speed and ISO is good practice.  I am happy that I have been able to let go of the security blanket of the semi automatic settings at last!