Project 3

This project aimed to demonstrate depth of field achieved with different apertures. Although I have done this type of experiment several times before, I always enjoy seeing the effects. As my DSLR is likely to go off for repair for a few weeks, this was my last opportunity to try this project.

My chosen subject for this project was Anthon Berg liqueur chocolates, lined up on my kitchen hob. Bottles are often suggested as suitable subjects, however I wanted to give this a bit of a twist. The labelling on the "bottles" are good demonstrators of sharpness of focus, which I would still have with the chocolates. I also wanted to add interest with bright colours and reflections. As these chocolates are small, I chose my Tamron 90mm macro lens. Macro photography naturally has a narrow depth of field, so I wanted to push this to the limits.

I have uploaded 4 photos ranging from f2.8 to f32. As a macro lens was used, even the image at f32 doesn't have full sharpness throughout the image. I chose to focus near to the end of the row at the top right, so the extremes of blurring could be seen at the start of the row on the bottom left. The images are shown in increasing f-stop.

I was very pleased with the results in this project, particularly the dramatic bokeh effects achieved at f2.8 and f11.

At f2.8, the limits of sharpness are restricted to 2 bottles and their reflections. I find the blurring quite dramatic and attractive in effect, and the image quickly becomes quite abstract about 2 bottles either side of the limits of sharpness.

At f11, the limits of sharpness extended to about 6 bottles, but again the blurring is quite dramatic, with the bottles becoming quite abstract in the foreground.

At f20, the limits of sharpness extended maybe another 2 to 3 bottles, but this image was not dissimilar to the f11 image. Although the camera was set to aperture priority, and therefore the shutter speed should have been adjusted accordingly, the image was quite a bit darker at this aperture. The bottles in the foreground remain recognisable as such, even though they are blurred.

Finally, at f32, I was expecting the entire image to be sharp, but some blurring did remain in the foreground, although the labelling could be made out. I have since learned that sharpness becomes compromised at very small aperture values, and most lenses have a "sweet spot" for sharpness around f8 to f11. I have yet to find circumstances when extreme small apertures are likely to be used.