Digital Photography: How wide is wide?

Since the advent of reasonable priced digital SLR cameras like the original Digital Rebel from Canon, there has been one big achilles heel in the consumer digital SLR arena. Often loved by long range shooters, but much maligned by those who want to get far out, the Nikon, Sigma, Sony, Pentax, Canon and other brands have a crop factor of varying degrees.

What is a crop factor you ask? Well, the sensor that records the image is much like the film that records an imagine in traditional film SLR cameras. The only difference is that the sensor is smaller than a piece of 35mm film. This means that the edge of the film that would be capturing an image, on a digital camera doesn’t exist, so it doesn’t capture.

For my Canon 40D, the ratio of crop factor is 1:1.6, so a piece of 35mm film is 1.6 times larger than the digital sensor. The focal length of the lens is calculated by this crop factor to give you a 35mm equivalent zoom range for the lens in question.

If you are shooting wildlife or any other activity that means you need a long zoom lens this is great. It means that your 300mm zoom lens is now the equivalent of a 480mm lens on a full frame digital SLR or a film SLR.

The downside is that if you are wanting to go truly wide angle, the once wide 28mm lens is now the 35mm film equivalent of a 44.8mm lens. In other words, not that wide at all.

Luckily for us, outside the OEM lenses, Tamron and Sigma are both starting to make really good digital only lenses that allow you to get these ultra wide focal lengths on consumer digital SLRs. The lens I just purchased is a Sigma 10-20mm (16-32mm in 35mm equivalent) and boy is it wide. To give you an idea of how wide it is, take a look at this photo I took today. Keep in mind that when this photo was taken, I was less than 5 inches from my own hand. At that range on my 28mm, well, that lens wouldn’t have even been able to focus on it, but beyond that, I would have no photo beyond my palm, I wouldn’t see my whole hand, much less the surrounding environment.

That’s wide man! And for a lens that can be had for $500 by B&H Photo, it’s really quite a steal considering what ultra wide lenses go for in the upper end. As you can see from this photo it’s very sharp and gets great color.

I will surely be shooting many more photos with this leading up to the vacation I purchased it for, so keep an eye out on my flickr feed and decided if you also need to go WIDE.

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