Choosing a lens which will give you desired results for a particular portrait assignment is an integral part of being a photographer.
There are many factors to consider when making this choice. Do you prefer zoom lenses that allow you to quickly change between focal lengths, or do you lean towards prime lenses, which usually offer wider apertures at a single focal length? Are you a photographer who prefers standard lengths such as a trusty 24-70mm lens or perhaps a nifty 50mm prime? Or would you rather experiment with something a bit different, such as a 200mm macro or a 12mm super wide?
Shorter lenses can be used handheld without a tripod and not yield any motion blur from hand movements at longer exposure times. For example, a 30mm lens might not have any hand movement motion at 1/60 of a second, but a 150mm lens at 1/60 s might have some motion blur. You can read up more on this elsewhere, but for now, you might have to take my word for this example.
As with any creative choice you make, it’s not so much about a wrong or right answer, but rather working with a final set of parameters in mind. For example, if you were photographing corporate headshots for a fairly conservative client, such as a law firm, you might want to use a standard lens length such as 85mm. Instead, if you were photographing avant-garde garments for a fashion editorial, you might choose to include a few really wide shots, such as on a 12mm, to really create a sense of mood or lean into the feeling of the clothing. Finally, if you were photographing a wedding, having a zoom with you might better allow you to zip in and out of the action to offer closeup images of intimate moments along with wide shots that show off the overall action of the couple’s perfect day.
Lens Compression
One factor that often gets overlooked when choosing which lens to use is lens compression. This phenomenon is more noticeable when working on location. There may be a few instances where it might also need to be considered for studio photographers.
As an aside, I have shown an example with images I have taken below. This might be easier to consider if you do this exercise yourself, though. If you do choose to try this, you will need either a zoom lens or several primes. I have shown which focal lengths I worked with, but these are suggestions. So, if you don’t have an 85mm focal length, you might opt for something slightly longer or shorter. But for the series to work, you will need several focal lengths.
Lens compression refers to how compressed the image looks. To clarify, this means that lens compression is how close the background appears to the subject. The key word here is “appears.” In this phenomenon, the subject does not move.
In this example, I framed the first image on the 30mm lens. I made sure the subject filled up most of the frame. Next, I used a 55mm focal length; the subject did not move. Instead, I stepped back a bit so that the framing of the subject was similar to the first image. I continued this with longer and longer focal lengths. The subject did not physically move within the space for any of these images. Instead, as mentioned, I stepped farther and farther back away from the subject for longer focal lengths. The key to this series is that I made sure that the subject filled up a similar amount of space in each image.
You’ll notice that I didn’t consider the background in my composition. To reiterate, I made sure I composed the image with the subject filling up a similar amount of space within the image. So, when I had a longer lens, I stepped farther back. However, even though the subject didn’t physically move within the space, with each progressively longer lens the background “appears” to move closer to the subject.
Conclusion
It’s an important bit of information to know for the few cases where you might actually use it or need it, for example, if you were shooting a portrait of someone with a landmark in the background. If you wanted the landmark to appear closer and fill up the frame of the image, you might consider using a longer lens while taking a few steps back yourself so that the image is more compressed.
Alternatively, this technique might offer an avenue for more creative compositions. For example, if a subject were in front of a landmark such as a house, you might reconsider how you photograph such a composition. Instead of positioning the subject close to the house and using a short focal length that distorts both the house and subject, as short focal lengths tend to do, you may consider positioning the subject a fair distance away from the house and using a longer focal length lens. Thus, this would compress the image so that the house appears closer to the subject and neither the house nor the subject are distorted.
SySyPhoTo 