Challenges

Being objective about one’s equipment

It was a field trip designed to create a post about a photographic movement that began in the mid-1920s - New Objectivity. I'd seen it on TV recently. The documentary used as its example a German husband and wife who travelled around during winter (the light was more suitable) and photographed industrial buildings. There were rules to ensure that the result would be an objective rendition, not some artistically pictorial image of prettiness. As a field trip designed to create a post about objective photography, it ..

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It was a field trip designed to create a post about a photographic movement that began in the mid-1920s – New Objectivity. I’d seen it on TV recently. The documentary used as its example a German husband and wife who travelled around during winter (the light was more suitable) and photographed industrial buildings. There were rules to ensure that the result would be an objective rendition, not some artistically pictorial image of prettiness.

As a field trip designed to create a post about objective photography, it failed.

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The car park I use near work contains a lot of unhappy looking trees. Even in their peak, they look distressed. The leaves are full of holes. Around the base of each tree is a metal cage, variously mangled and bashed over the years.

These cages intrigue me. I want to document them before the car park is redeveloped.

So, with some of the features of New Objectivity ringing in my ears, I waited for an overcast Sunday morning and headed over there. “Overcast” because it creates an even light when viewing the trees from different angles and “Sunday” because there would be very few cars.

But the results were disappointing. Instead of the clarity and crispness required of objectivity, I got the soft and fuzzy of the picturesque. I strain my eyes when I look at the result, trying to force a degree of focus that just doesn’t exist. And, yes, I used a tripod and shutter release.

Example

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I’ve since learnt that the depth of field affects the sharpness of an image. I knew that depth of field affects which section of the image will look sharp when compared with other sections, ie it defines the area to be in focus. I did not realise that it affected the degree of sharpness in that focussed area.

In my desire to encourage the trees to stand out from their background, I selected F1.4 on my fixed 50mm lens. Mistake. Big mistake. 56 big mistakes. Not that I wasted 56 photos. This is, after all, digital. I wasted 56 squats that were required to look through the viewfinder. I’ve never done 56 squats before.  I have now.

So, there was no post about New Objectivity, just a lot of muscles objecting.

Instead, there is this post about getting to know your equipment …

Get to know your equipment!

Today, I experimented with my three lenses. There is the fixed 50mm mentioned above and the two zooms that came with the camera. The aim of the experiment was to compare the results of each F-stop.

Having selected an object with plenty of detail on a vertical plane, I set up the camera on its tripod and worked my way through each F-stop on each lens.

Test Subject

In order to see the differences writ large, I cropped the first, middle and last shots from each.

For the fixed 50mm, the F-stop range was 1.4 to 22 with a middle around F5. I realise F5 doesn’t sound halfway, but there are a 25 separate stops and F5 is number 12. In the result, the 1.4 is soft and dreamy and the mid-range is much sharper.  Then, for the 18-55mm zoom, the range was 5 to 32 with a middle F-stop around 11. Again, the mid-range is sharper.

Fixed 50mm lens:  F1.4   F5   F22
Fixed 50mm lens: F1.4 F5 F22

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18-55mm zoom lens:  F5   F11   F32
18-55mm zoom lens: F5 F11 F32

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However, there may be something else going on with the 55-200mm because the results did not fit this pattern. The manufacturer intended it to be used as a telephoto lens. Perhaps an experiment where the object is just a few feet away was not the best option? Or perhaps there was a variable I didn’t pick up on?

For the 55-200mm, the range was F4 to 22 with a middle around 9. Here, the first image appears sharper.  Perhaps not by much, but it seems sharper to me.

55-200 mm telephoto: F4  F9  F22
55-200 mm telephoto: F4 F9 F22

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Back to the car park

Armed with this new insight, it’s back to the car park … on the very next overcast Sunday morning.

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