Use a combination of wide apertures, long focal lengths and close viewpoints to take a number of photographs with a shallow depth of field. (Remember that smaller f numbers mean wider apertures.) Try to compose the out-of-focus parts of the picture together with the main subject. Add one or two unedited sequences, together with relevant shooting data and an indication of your selects, to your learning log.
Wide apertures create shallow depth of field, especially when combined with a long focal length and a close viewpoint. In human vision the eye registers out-of-focus areas as vague and indistinct – we can’t look directly at the blur. But in a photograph, areas of soft focus can form a large part of the image surface so they need to be handled with just as much care as the main subject.
Don’t forget that the camera’s viewfinder image is obtained at maximum aperture for maximum brightness and therefore at the shallowest depth of field. Use the depth of field preview button to see the actual depth of field at any particular aperture. (This is especially useful in film cameras where you don’t have the benefit of reviewing a shot immediately after you’ve taken it). It’s surprising to see the effect that a single f stop can have on the appearance of an image.
At the point I got to this exercise it was a wet and cold day so I decided to try some still life shots indoors. I used a Sigma 105 mm macro lens to get the long focal length and a good shallow depth of field. The camera was placed on a tripod and I placed a piece of white card as a reflector to the left of the items in order to try and bounce light back on to the objects. I first of all experimented with shooting the stamens of lilies as below:
Focal length 105 mm. 1/60 sec, f2.8, IS0 100
The focus point is around the centre of the stamens and it can be seen it drops off towards the front of each.
A similar shot but unedited is:
Focal length 105mm, 1/25 sec, f2.8, ISO 100 (Img 7042)
In this image the focus is on the centre stamen.
I then tried some still life photos – this one with the 24-105 mm lens attached:
Focal length 73 mm, 1/30 sec, f4, ISO100
Despite being on the tripod the image is not sharp where I would have wanted, i.e. the yellow pepper and seeds sharp with the focus dropping off for the red and green peppers. The background does show the shallow depth of field. It can be in macro work that several photos are needed with differing focus points and then stacked in Photoshop for overall sharpness.
The following week the weather seemed better so I headed to a local wildlife park with the idea of photographing some of the inhabitants with a shallow depth of field. Of course the best laid plans can go awry and this is what happened towards the end of my photoshoot – hail – even the ducks were swimming for cover! These photos were all hand held with my Canon 6D and 70-300 zoom lens (I had assumed that I may need to zoom in to get far away animals) – there is some camera shake in some photos.
On a more serious note I did get some good wildlife images for those animals brave enough to be out in the cold:
Focal length 210mm f5.0, 1/250sec Focal length 300 mm, 1/125 sec, f.5.6
ISO200 (Img2) ISO 500 mm (Img 4)
Focal length 275 mm, 1/1000 sec, f.5.6 Focal length 275 mm, 1/125 sec, f.5.6
ISO 800 (Img 6) ISO 400 (Img 9)
Focal length 300 mm, 1/85 sec, f7.1, ISO 800 (Img 11)
In looking at these 5 images they all have a relatively shallow depth of field although the last is getting more to a middle range aperture. Due to the gloomy conditions the ISO was set quite high and there is some noise apparent particularly in Image 6 which has been cropped.