Art of Photography

Rob Townsend


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Exercise – Panning with different shutter speeds

Brief:

Take a series of exposures of a moving object at various shutter speeds, following the subject by panning so that it is fairly sharp and the background becomes streaked. Note how different shutter speeds affect the image. Then look back at the photos in this and the previous exercise and note which ones are most attractive as a viewer.

Equipment:

Canon EOS 650D with EF 24-105mm f/4.0 L IS USM lens.

Method:

I positioned myself at a bend in the road on a busy coastal highway and took several shots of passing cars, bikes and joggers at different shutter speeds.

Results:

I took many more shots than are posted here! It took me a while to get into the swing of the panning action. I’m still not very good at capturing the subject sharp enough, but these are the best pictures to demonstrate the learning points.

A cyclist moving past me and a shutter speed of 1/30 sec produced a reasonably pleasing sense for movement, although the cyclist isn’t very sharp. There is enough difference in the motion blur to give the sense of movement:

1/30 sec

1/30 sec

I took some car shots at 1/40 sec exposures and got a few images where the cars were pretty sharp and the background showed plenty of streaking:

1/40 sec

1/40 sec

1/40 sec

1/40 sec

I moved up to 1/50 sec for the next batch. At this speed I captured a pair of joggers, another cyclist and another car. The cyclist one is the sharpest, and the feeling of movement is accentuated by the cars moving in the opposite direction:

1/50 sec

1/50 sec

1/50 sec

1/50 sec

1/50 sec

1/50 sec

Stepping up to 1/60 sec I captured the following shots of cars; I found the black car to give more movement, possibly as it is moving left to right, which is how I think I naturally read a photograph:

1/60 sec

1/60 sec

1/60 sec

1/60 sec

Finally I took some shots at 1/80 sec, but found it didn’t give as much of a sense of movement in the background streaking; the one example I thought showed a sense of motion was this of the Mini, where the jogger walking the dog provides the visual clue to the movement.

1/80 sec

1/80 sec

What I’ve learned:

As mentioned, I didn’t find this an easy technique to master! Once I’d discarded the outtakes, I found images that looked OK at shutter speeds from 1/30 sec to 1/80 sec. The most reliable range was probably 1/50 sec to 1/60 sec. What seemed to make a difference were various factors: how steadily I moved the camera; the speed of the moving object; the distance I was away from the moving object; the focal length.

The one in this set that most pleases me is the cyclist with the oncoming traffic at 1/50 sec – it is the sharpest subject yet it doesn’t look ‘frozen’ as both the background and the wheels clearly demonstrate the movement. Of the others, the joggers at 1/50 and the first cyclist at 1/30 are also appealing; in these cases I think the very slight blur of the subject, accompanied by the stronger blur of the background, gives the best sense of motion.

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Exercise – Shutter speeds

Brief:

Take a series of exposures of a moving object that fills the frame with various shutter speeds, from the fastest available on the camera to a very slow one. Observe the differences and the speeds at which the image is sufficiently sharp and in focus.

Equipment:

Canon EOS 650D with EF 40mm f/2.8 STM lens, tripod.

Method:

I set up my bike upside down and spun the front wheel to the fastest speed I could by hand. The camera was set up on a tripod and manually focused on the centre of the wheel to ensure consistent framing and focus. I started at the slowest shutter speed I could without blowing the highlights (1/10 sec) and worked up to the fastest shutter speed (1/4000 sec).

Results:

With the shutter speed at 1/10 sec, 1/25 sec and 1/50 sec the movement blur is so much that the tyre appears to be completely smooth and the spokes aren’t visible. Markings on the tyre are rendered as smears. The white reflector attached to the spokes gets progressively shorter as the shutter speed increases.

1/10 sec

1/10 sec

1/25 sec

1/25 sec

1/50 sec

1/50 sec

When the shutter speed was increased to 1/100 sec, 1/250 sec and 1/500 sec the texture of the tyre tread is increasingly revealed, and the spokes start becoming visible first vaguely and by 1/500 are quite well defined. There is still a blurriness to the lettering on the tyre though.

1/100 sec

1/100 sec

1/250 sec

1/250 sec

1/500 sec

1/500 sec

At shutter speeds of 1/1000 sec, 1/2000 sec and 1/4000 sec the image is getting increasingly sharp. At 1/1000 a very slight blur is evident on the ‘Continental’ lettering, but at 1/2000 and 1/4000 the image looks like that of an absolutely stationary wheel. The image is completely frozen at these shutter speeds.

1/1000 sec

1/1000 sec

1/2000 sec

1/2000 sec

1/4000 sec

1/4000 sec

What I’ve learned:

Shutter speeds of around 1/2000 sec will freeze movement to the point of appearing stationary. Deliberately slowing down the shutter speed can give a real sense of movement – the one at 1/100 depicts this best in this set, in my opinion. Choice of shutter speed is therefore dependent on the effect one if trying to achieve.


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Exercise – Focus at different apertures

Brief:

Take three photographs of a scene with depth to it, first at a wide-open aperture, then at a mid-scale aperture, then at a small aperture. Focus on the same central point. Observe the areas of sharpness in the resultant images.

Equipment:

Canon EOS 650D with EF 40mm f/2.8 STM lens

Method:

Very similar to previous exercise: I lined up a set of five condiments/jars from the kitchen cupboard, staggered in a slight diagonal line so that each was visible in the viewfinder. I chose the middle jar as the focus point and did the three shots at f/2.8, f/9 and f/22.

Results:

With the widest aperture, only the coffee jar in the middle is sharp, with readable text and defined edges:

f/2.8

f/2.8

With a mid-range aperture setting, the honey on the left and to a slightly lesser degree the salt on the right both fall into the sharp zone while the two items on the outside remain blurry:

f/9

f/9

At the smallest aperture the entire image is sharp enough to make out the text on all of the labels, and the wooden surface on which they are placed shows its grain pattern.

f/22

f/22

What I’ve learned:

This exercise was good for demonstrating a concept that I was familiar with, that of controlling the depth of field using aperture settings. The two extreme examples can have specific applications, such as bringing focus to one part of the image (widest aperture) as in a portrait or a macro shot, or drawing the viewer’s eye in through the image foreground->centre->background in more of a narrative way (smallest aperture), as you might for a landscape shot with a great deal of depth to it.


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Exercise – Focus with a set aperture

Brief:

Take three photographs of a scene with depth to it, at the same wide-open aperture but with the focus on three different positions.

Equipment:

Canon EOS 650D with EF 40mm f/2.8 STM lens

Method:

Very straightforward: camera on tripod, bottles lined up on tabletop, selected focus point first on foreground, then on middle then on background.

After doing it with beer bottles, I repeated the exercise with playing cards, just to see if the principles of where I preferred the focal point held true.

Results:

Bottles - near focus

Bottles – near focus

Bottles - mid focus

Bottles – mid focus

Bottles - far focus

Bottles – far focus

With this set of images I had a clear preference for the one with near focus. It just seemed most ‘natural’ that the foreground is sharpest and that objects further away would be more blurry. This seemed to help to imply the depth as it in some way mimicked the human eye. Also, there may be something in the theory that the eye reads a photo from left to right and settles on the lower right portion. This is why I tried the alternative set of images with the cards, as a comparison.

My second favourite was the one with far focus. This one seemed to lead the eye towards the sharper portion of the image and so had more implied movement, whereas the close focus one seemed more static, or ‘grounded’.

The least satisfying shot was the middle focus one. It just lacked interest. You look right into the middle of it and… that’s it.

As mentioned above, I did an alternative set with playing cards, to test the theory. I also wanted to make sure I wasn’t getting distracted by the subject matter…!

Cards - near focus

Cards – near focus

Cards - mid focus

Cards – mid focus

Cards - far focus

Cards – far focus

This set confirmed my findings with the bottles in that my preference is for the one with the sharpest foreground. Again it seems most ‘natural’ and needs least interpretation. In this instance, the sharp foreground covers both the left and right side of the finished shot, which makes me surmise that the focal sharpness is probably more significant than the absolute position in the frame.

In this example, I found both of the other variations lacking. This may be as the cards have a flatter focal plane, and the gaps between the objects are smaller, meaning less of a sense of depth than with the bottles.

What I’ve learned:

I was already aware of how to focus on one portion of an image to control depth of field and draw the eye, and I think when I do this I naturally tend to focus on the foreground anyway. I hadn’t however done an exercise like this before to do a direct comparison between different points of focus. What I have learned here is that one can choose to add a little more… interest? (interactivity? mystery?) into a photo by moving the focal point towards the rear of the scene, as this inherently makes the eye move into the image.


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Exercise – Focal length and angle of view

Finally getting started with the actual coursework. The first exercise under ‘Getting to know your camera’ is about focal length and angle of view.

Brief:

Take three photographs, one at a focal length that gives a ‘standard’ (equivalent to human eye) view, one at a wide angle and one at a telephoto zoom length. Print each one at A4 size. Hold them up at eye level to measure the distance from eye to photo where the image is the same size as the actual subject. Observe the differences between the photos taken at the varying focal lengths.

Equipment:

Canon EOS 650D with EF 24-105mm f/4.0 L IS USM lens

Method:

I found this slightly confusing at first but worked it out after checking how other people had done it (and some had the same initial confusion as me, which made me feel better). I set up the camera on a tripod on a low wall in the garden and pointed the camera at a terracotta garden ornament, positioned at the foot of a tree with a few daffodils for background detail.

As instructed I worked out what 50mm equivalent would be on my Canon crop-sensor camera – a crop factor of 1.6x means that I should select 31.25mm (this was the part that had me briefly confused; makes sense now though). As it turned out, the EXIF data said I actually took the shot at 32mm, which is pretty close.

Then I took the wide angle shot at 24mm (widest I could go as this is the only zoom lens I own, for now anyway!) and the telephoto shot at 105mm. Printed them out on A4 as instructed and then did the measuring part. I needed help from my long-suffering assistant* (*wife) for the telephoto shot as my arms weren’t long enough. Then I did some mathematical checking against the theory and was reasonably pleased that it stacked up!

Results:

32mm

32mm

This was supposed to correspond to the ‘standard’ 50mm field of view which on my crop sensor should have been 31.25mm (close enough). this gave a corrected focal length of 51.2mm.

To see the image and the subject at the same size I had to have this 350mm away from my eyes.

24mm

24mm

This is the widest view, 24mm or 38.4mm equivalent when corrected for the crop factor. Not too different to the first one really. Wish I had kept my old Tamron 18-50mm…

To see the image and the subject at the same size I had to have this 290mm away from my eyes.

105mm

105mm

This is the furthest extremity of my zoom lens, 105mm. Or corrected for the crop factor, equivalent to 168mm.

To see the image and the subject at the same size I had to have this 1150mm away from my eyes.

Some maths:

I did some maths to check whether my findings were in line with focal length physics (with thanks to Martin Proctor, who inspired me to dig out the formula). Simply put, dividing the (corrected) focal length by 50 (as 50mm is closest to a 1:1 subject:image view) gives the magnification factor.

So: 24mm (corrected: 38.4mm) should give a magnification of 0.768x and an expected viewing distance of around 269mm compared to my 32mm (51.2mm) distance – I measured 290mm, so not far off.

Similarly, 105mm (corrected: 168mm) should give a magnification of 3.36x and an expected viewing distance of around 1176mm – I measured 1150mm, again pretty close. I’m putting any slight variances down to the gusty weather and me not wearing my glasses!

What I’ve learned:

After many years I think I’m finally getting my head how focal length affects an image. The concept of the ‘standard’ view makes a lot of sense now. I wish I’d had a wider lens range for this exercise but I think I’ve managed to demonstrate the principles enough for me to grasp the key points.

References:

Korpella, R. (2013) How to convert focal length to magnification [online]. eHow.com. Available from: http://www.ehow.com/how_6823034_convert-focal-length-magnification.html [Accessed 21 April 2013]