Thursday, 6 March 2008

Photography Equipment

I am a bit of an amateur photographer having brought my first single lens reflex (SLR) camera with my first pay packet back in 1975. Prior to that I had used a 35mm camera recommended by a professional photographer as a good beginners camera.

Having carried my camera backpack round the world a few times and realising that I wasn’t using most of its capabilities, I decided to purchase a compact camera. Over the last week, I realised just how different the compacts are from a good SLR camera. My camera combinations are a Canon EOS 300D and a Canon SX100 IS. For the EOS, I currently have just two lenses but I also have a range filters including some for close-up photography. The SX100 IS is a nice camera and includes a 10 times zoom giving a focal length range from 36 to 360 mm (35mm equivalent). With the standard lens on the EOS, the range is focal length range is 18 to 55 mm (possibly 28.8 to 88 mm 35mm equivalent) and with the zoom lens 110 to 460 mm (35mm equivalent). For many applications requiring a zoom capability the SX100 IS will do the job but not always but at 18mm, the EOS has a wide angle capability that is missing from the SX100 IS capabilities. But in most situations the zoom capabilities of the SX100 IS are adequate.

During last week, I have wanted to take photos in an indoor velodrome. Cyclist are moving around the track at speeds of 30 kph or more and ideally you want a sports photography mode. The SX100 IS has a good range of shutter speeds and it can be set to shutter speed priority but sports mode. Added to that, the aperture range is limited with the consequence that without using the built-in flash, the shutter speed is too slow. The included photo shows the impact. Note that the camera defaulted to ISO 200, shutter speed of 1/100 second, and aperture of f/4. Increasing the ISO setting would have enabled the use of a slightly faster speed but I am not convinced that the camera would have done the job. The ISO setting relates to the speed of the film. A faster ISO speed means that les light is needed to capture the same image. As I didn’t have the EOS 300D with me, I couldn’t attempt a comparison but past experience in the evening at an outdoor velodrome tells me that it is easier to get action photos with the EOS and standard lens even in low light.

Another experiment today was with taking photos of insects. In this situation, I wanted to limit the depth of field so a combination of zoom and large aperture should do the trick. This was using the standard lens with the EOS. This proved much easier to do with the EOS than with the SX100 IS. First off the SX100 IS quickly wouldn’t focus on the subject when using the zoom so I had to move further away. The consequence is a greater depth of field than the EOS 300D. The focal length was under 10mm while the EOS photos were over 40mm. Theory has it that in order to reduce the depth of field, you should have a long focal length and the widest aperture possible. (reported camera settings were: shutter speed 1/200s, aperture f/3.2, ISO 80, focal length 6.7mm (40.2mm 35mm equivalent), macro mode)

When reviewing the photos, I realised that the default ISO was only 80 so I increased it to 400 and took some more shots. This time, I tried to ensure that I used a longer focal length. Notice the difference? (1/100s, f/3.5, ISO 400, 12.8 mm (76.8 mm), macro mode)

I have the EOS 300D set by default to an ISO of 400 but it was also easier to set a longer focal length straight off so that I was zooming in to get the effect that I wanted. Even though the aperture is smaller than the SX100 IS, the longer focal length of the lens while closer to the insect delivered the results that I was after. (1/500s, f/5, ISO 400, 42mm (67.2 mm)


Just to prove that most of the problem is the photographer’s techniques and not the camera, I attempted some silhouettes. This proved easier with the SX100 IS because it doesn’t have a view finder and could place the camera in a better angle. You have to use the view finder on the EOS 300D so it was more difficult to get in a position that got the photo that I wanted. Here is the image from the SX100 IS. This was taken in the evening light where the earlier photos were taken in overcast conditions. (1/640s, f3.5, ISO 400, 14.4mm (86.4 mm), macro mode)

While taking the earlier set of photos, a cicada landed on the deck next to me and since it behaved rather tamely and allowed me to get close, I took a number of shots with both cameras. Again, it was easier to get closer and obtain the focus I wanted with the EOS 300D but notice the narrow depth of focus band. Also it appears as though I got closer to the cicada with the EOS 300D than I did with the SX100 IS. This is more a factor of the ability of the camera or lens to focus at shorter distances.

The SX100 IS image (1/320s, f/4, ISO 80, 8.2mm (49.2mm), macro mode)

The EOS 300D image (1/800s, f/5.6, ISO 400, focal length 55mm (88mm))

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