Tag Archives: getting to know your camera

getting to know your camera # 5

Photographing Movement 2 – Panning Camera With Subject At A Variety of Shutter Speeds
speeding cylist in the lea valley park

Nikon d50; 24mm lens; 1/15th sec

Having completed the static camera exercise with people on foot, I decided to try cyclists for the next one where I was to pan with the moving subject and observe the difference between different shutter speeds. I moved onto a wider lens (a nikkor 24mm 1:2.8 ais) to allow for the faster moving subjects to come into shot, be picked up by me and then followed as they passed through the centre of the shot.

It worked quite nicely, but I was out of the shade and in blazing sun and there weren’t enough passing cyclists. So I crossed the Lea to the tow path of the navigation, settled myself down on a bench and swapped lenses for an even wider Zenitar 16mm 1:2.8, giving a 35mm equivalent of 24mm, as the cyclists would be passing much more closely than before.

(I know that 1/40th of a second (4) is faster than 1/30th (5), but pretending it isn’t preserves alternating directions of movement)

Once again, the strength of the light and the limitations of my camera’s ISO settings meant that much slower than 1/15th sec burnt out too much.

General Observations on the Exercise:
  • Below 1/10th of a second, it is hard to track your camera with a quickly moving object
  • Timing the start of the exposure is critical if you don’t want the subject to approach or depart at an oblique angle
  • Approaching obliquely (3 & 4)  is vastly preferable to departing obliquely (none, for that very reason)
  • The distance between the camera and the moving object decreases as it approaches, reaches a minimum when the object is parallel to the film plane/sensor and then increases again. Therefore the moving object slows down as it nears the centre of the frame and the accelerates away. This means that the further away from the midpoint you open the shutter, the more the rear of the object will move at a different speed from its front. This gives interesting distortion  effects (clearly seen in 4, where – I think – it enhances the sense of speed)
  • The closer to the camera the subject passes the more exaggerated the effect of this.
  • The closer to the camera the greater the relative sense of movement for static objects: the pictures here have three planes – the cyclist; the chain fence by the canal; the far side of the canal with the moored narrow boats – and the furthest loses its enhancing sense of movement first, then the railings, and finally the cyclist. At a 1/100th sec the background is still blurred and streaky; at 1/250th sec the chain is blurred by the background is coming to a halt; at 1/1000th sec all movement is frozen
  • The rim of a wheel is travelling faster than the hub: the later pictures (1/100th onwards) show spoke detail at the centre of the wheels, but blurs at the rim. At 1/1000th everything is static
  • If you manage to keep part of the moving object sharp (here, with cyclists, the face is key I think) the image is a good one (see 3, for a successful sense of movement with my pan remaining steady on the cyclist)

Different parts of the image all combine to create a sense of movement. Everything does not have to be blurred (and indeed something frozen is definitely required). The differing levels of blur are created by distance, relative speed and steadiness of pan. As with the previous exercise, some experimentation is probably required to establish the correct combination of these for the effect you want.

getting to know your camera # 3 – focus at different apertures

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All three photographs were taken with a Nikkor 50mm 1:1.8 AF-D lens on my Nikon D50. Focal length equivalent of around 75mm on a full frame camera. ISO was set to 200. Shutter speed varied according to the aperture.

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f1.8: A very narrow depth of field; almost everything except for a narrow band down the centre of the image is out of focus; moving out from the focussed strip the quickly becomes very blurred indeed.

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f6.3: A wider area of brick is in focus, stretching with a greater increase to the right of the image, where the wall was further away from the camera. The entire image is now readable as brick.

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f22: The strip widens again, and – unless you look closely – most of the picture seems clear, if not completely sharp. This time the increase seemed evenly spread on either side of the original in-focus area, which suggests maybe I knocked the point of focus off to the right when I was changing the aperture.

Nothing to add to this really; the smaller the aperture the greater the depth of field. It’s always interesting to do exercises like this and see in practice what the theory says…

getting to know your camera # 2 – focus with a set aperture

For this, I made more than one series of photos, trying to get different relationships between the in and out of focus areas, and to try different types of subject matter. In all cases, I used a 50mm lens at f1.8 on my D50.

First I tried framing something with no obvious subject that demanded focus – a section of my neighbours’ privet hedge, focussing on different areas of leaves, working from left (near) to right (far):

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None of them particularly wows me, but the third, with a narrow in-focus area to the right of the frame is the least interesting with the nearer, out-of-focus leaves creating a sense that I’m pressed up against something, trying to see beyond it. It might work if there was an obvious “thing” that was partly obscured, giving some sort of spying/surveillance feel to the shot, but here there’s nothing to suggest that sort of narrative. The second (focussed on the middle of the frame is okay, but unengaging; the first comes closest to working by dint of having an identifiable, in-focus subject (some foreground twigs) and also, I suspect because I am conditioned to scan pages (and pictures) from left to right and here I don’t start off with an area of no focus before settling on an in-focus area to the right of the page.

Next I took a subject where the planes we more obviously distinct – a swing in a playpark – and focussed on the textured matting beneath the swing (far) the swing itself (middle) and one of the supporting ropes (near):

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There is something to look at and treat as a subject in each of these , with the texture of the in-focus area helping to settle the eye, but the middle picture with the swing in-focus between two out-of-focus planes is probably the most easy to project into some sort of three dimensional space while the other two are less complex, consisting of something on top of, or in front of an in-focus object. This preference is probably enhanced by the strength of the blue and red versus the more muted colour of the faded red rope and the green matting.

My final go at this exercise involved setting the focus on different people in front of me on the long escalator down from the 2nd level at Tate Modern:

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Again, all three work in the sense of giving subject status to the thing in focus with the least successful being the one where that subject is not doing something (the one on the right, which was in fact the first to be taken). The centrally focussed picture with the man kissing his girlfriend is  probably the most comfortable to look at; the one on the left with the young man looking off to the upper right of the frame is also good, but there is an element of tension introduced by the man on the up escalator  (who I wasn’t really aware of as I took the picture) who is equally in focus and looking up into the frame, causing the eye to move back and forth over the central out of focus couple.

In all three series there is a sense that the thing in focus needs to be worthy of the attention before the picture works. Where this happens, the viewer is placed into a relationship with the subject that locates both of them within three dimensional space. Further to this, there is also a sense that other elements – colour, contrast, the possibility to construct a narrative – can support or undermine the effect of where the area of focus starts and stops. Lastly, there comes a point where the in-focus area can be too close to the edge (the third swing picture with the focus on the rope is a good example) where your eye is drawn out of the picture, away from the centre and other side of the frame.

So Soon?

It was a spectacularly lovely morning with the sun beating down from a cloudless sky, and I realised as I set up the tripod for the first exercise of the day, that my D50 was beginning to show its age when it came to its ISO range. Not able to go lower than 200, meant that anything slower than 1/30th of a second was beginning to burn out. This was fine for the two exercises (and anything slower than 1/15th second ran the risk of the moving subject disappearing totally, like it was Paris in 1830-something) but if I ever want to do something like this for people to see, I need to either get a camera that can do lower ISO speeds or – far less exciting – buy some ND filters. There are various things that argue for a new camera – the 3000 x 2000 pixel image isn’t that big any more; I got it in 2006 so it’s obsolete by now; it’s nice to have new gear – but I hadn’t expected to be thinking quite so seriously about upgrading for a year at least…

And then there’s the issue of the two spots that are apparent on the sensor when you shoot something tonally flat, like the sky:

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I can clean the sensor (or pay for someone else to do it), and I can clone them out when they’re annoying, like here. But, ugh. So soon…

getting to know your camera # 1 – focal length and angle of view

A straightforward exercise and something I’m surprised I’ve never actually done before. For it I used my Nikon D50 body, Nikkor AF-D 35-70mm f2.8 zoom at both ends of its range and a Zenitar 16mm f2.8 to give a final, wider version of the view. I was interested to see that – when looking through the viewfinder with the other eye open – sizes didn’t match at a focal length of 35mm (the normal/50mm equivalent for my camera’s sensor) but did when the lens was zoomed in to about 50mm. While the angle of view was correct for the 35/50 equivalency, optically the perceived size was correct only with a tighter focal length. Presumably this means that my “sensor size” (the retina of my eye) is closer to the frame size of 35mm film and while it is seeing a narrower angle through the viewfinder (approximating to a 75mm lens on a film camera) the visible size of the objects seen remains the same. Certainly, a couple of days later, trying a 50mm lens on a film SLR, it was still the 50mm lens that gave the same perceived size in both eyes. Now, it would be worth trying this with a medium format SLR and a 50mm lens, just to check whether a 50mm lens – acting as a wide-angle this time – would show objects the same size in the viewfinder as they appear through the other eye in reality.

Anyway, here is a composite of the three shots I took, with the tighter angled pictures scaled down to the equivalent size in the widest and then pasted over the original with the frame’s edges outlined:

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When I returned with 3 A4 printouts, I was just able to get my hands far enough away from my face for the 70mm picture to match the size of the original, the 35mm picture was ‘right’ with a slightly obtuse angling of my elbows and the 16mm picture would have needed to be too close to my face for me to focus.

Of course, I forgot to take a tape measure with me, but – back home with a ruler and relying on muscle memory, or whatever it’s called – I was able to estimate the distance at which the prints matched up in size to the view as being 70cm for the tightest and 35cm for the middle one. The widest was impossible to gauge, but it seemed to be almost right when the paper was around 10cm from my face; from the other two, it presumably would have been about 16cm given that (for an A4 print) focal length in mm equals arm’s length in cm…