Use of different focal lengths
This blog is going to try and cover the fundamentals of lenses, explaining when to use them and why. If you have any questions after reading this then please get in touch via:
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I too took some photos at different focal lengths (see the below slideshow), between 10mm and 135mm, to emphasise how certain focal lengths are generally better than others for portraiture. This topic has brought up lots of comments and I have edited this part a number of times to try and get the best brief explanation, without going off on too big a tangent! To break it down to fundamentals, the thing that affects perspective is distance, the distance between the camera and the subject. The focal length you choose affects the framing of a subject. With the series of photos below, I tried to keep the framing the same for all the focal lengths; the thing that changed was the distance between the subject and me. At 10mm I was a mere few cm’s from the subject’s face (awkward), while at 135mm we were a few metres apart. This longest example (135mm) shows a flattening effect, where the content seems compressed. This occurs because of greater distance between the subject and myself. Making the depth of the face (e.g. from the nose to the ear) proportionally less compared to the distance between the subject and the lens… The opposite is true for the wide-angle photos. Take the 10mm example again; I am so close to the subject that the depth of the face makes up a larger distance than the distance between the lens and the nose, making the perspective exaggerated (also note how you can see the shadow behind the model with the wide-angle shots but you can’t with the telephoto portraits because of the narrower angle of view).
In full frame or 35mm film terminology, 50mm is deemed the ‘standard focal length’, as it is close to our eye’s central angle of view. This means that a 50mm lens produces a perspective very similar to what we see. Because the sensors in Fujifilm X-Series cameras are generally 1.5X smaller than full frame sensors (APS-C sensor size), this standard focal length equates to a 35mm lens, like the XF35mm F1.4 R. This is quite complicated to explain (it could be a whole other blog!)… So much so that I have spent hours editing these paragraphs, but hopefully you get the gist of how different focal lengths affect the perspective of a picture. There are some very informative comments about this topic at the bottom of this blog if you want to find out more.
Wide-angle lenses can create exaggerate perspectives which produce amusing (which is good as it’s engaging) portraits, especially with animals!
Apertures
Before we go any further, lets just check you understand the fundamentals of using apertures. If not then check out my previous blog that helps to explain how different apertures affect a picture (plus there are cute labrador puppies!).
Putting both together
Now that we understand how different focal lengths and apertures affect the look of a picture we can look at how to combine the two. First of all lets think about portraits: If you want to isolate a subject generally you are going to want to use a standard or telephoto lens with a low F-stop, such as the XF35mm F1.4 R, XF56mm F1.2 R or the imminent XF50-140mm F2.8 R OIS WR. For the image to the left I wanted to try and isolate the woman from the background as it was very busy and distracting, and while it isn’t entirely clean it is made better as a result of using F1.4 for a shallow depth of field.
If you want to capture an environmental portrait generally you would use a wide-angle lens and depending on how much of the environment you want to make out in the background you’d range the F-stop between F2 and F11.
Both of the pictures above were taken with the X100s (I love using it for these kinds of photos). The left image is at F2 and while you can make out the room the clarity of it is poor. Compare that to the right image where the use of F11 results in the mountain behind the boarder being sharp.
Prime vs. Zoom
This is very much a personal preference, there is no right choice. It depends on lots of factors, from space and weight restrictions to financial limitations. Because prime lenses have a fixed focal length, they tend to be smaller, lighter and have larger minimum apertures (F1.2-2.8) compared to zoom lenses. While zoom lenses have the convenience of effectively including many different prime lenses, generally these have more restricted apertures (F2.8-5.6). For me, it depends on the situation. I prefer prime lenses because of the greater depth of field control. As well as this I believe that the fixed focal length makes you think more about your photography, particularly composition. However, the convenience of zoom lenses in situations that are changing quickly can be invaluable as you don’t have to change lenses as often to obtain a variety of photographs. When conditions are unpleasant this is vital in order to protect the sensor. A point to consider is that the XF18-135mm F3.5-5.6 R LM OIS WR plus the recently released XF50-140mm F2.8 and XF16-55mm F2.8 R WR (hopefully arriving in the first quarter of 2015) are all weather sealed making them ideal partners for the X-T1, creating a weather sealed system.
If I am working in relatively controlled conditions where it is easy for me to change lens regularly then I try to use prime lenses.
But if conditions are not suitable for continuous lens changes or a situation is quickly evolving and I need to be on my toes the zoom lenses are what I grab.
The zoom lens examples above are all wildlife examples (which are often taken in difficult conditions where a situation is quickly changing) were captured with the telephoto half of the XF18-135mm F3.5-5.6 R LM OIS WR. The reason why I chose these examples is because I wanted to show what can be done with F5.6 as the maximum aperture, showing nice bokeh in the images where I’ve tried to keep the attention on the subject. Now imagine what will be possible with the new XF50-140mm F2.8 R OIS WR! Can you tell I’m a bit excited about it…?
What lens for the occasion?
The main reason I first moved to the Fujifilm X-Series was the prioritisation of high quality lenses. With the announcement of the X-Pro1, the first lenses available were the XF18mm F2 R, XF35mm F1.4 R and XF60mm F2.4 R. These are all high quality, lightweight prime lenses that, together, offer a wide focal length range package. From there the lens road map laid out Fujifilm’s intentions to create a strong lens collection covering a wide range of uses.
Generally lenses are associated with a particular genre of photography based on their focal length. For example wide lenses such as the XF14mm F2.8 R and XF10-24mm F4 R OIS are intended for landscapes and long lenses like the XF55-200mm F3.5-4.8 R LM OIS are for wildlife and sports. But rules are made to be broken and your lenses don’t necessarily have to be used to fit those stereotypes. The photograph below was taken with the 14mm lens, generally intended for landscape photography, however I used this lens to capture this macaque foraging for stranded marine life amidst a sunset scene.
The important thing to remember with your lens choice is to think “what do I want to convey?” On this occasion I wanted to show the scene as a whole. In the landscape shot below I focused on the distant hills over a bay with the setting sun using the 55-200mm lens, which is usually associated with wildlife and sports. This helped to emphasise the golden glow which wasn’t as prevalent with a wider-angle view.
Conclusion
Hopefully you now understand that lens choice can have a huge impact on your end result. If you understand the principles of focal lengths and apertures then you have a grasp on what lens to use and why. Remember that lenses are tools designed to help fuel your creativity. For me, a lens that I am very much looking forward to is the XF50-140mm F2.8 R OIS WR. This lens offers the versatility of a zoom but with a constant aperture of F2.8 it gives very good depth of field control. A lens such as this has many uses and I’m sure it is going to be a big hit with photographers from all genres.
A good exercise to try would be to force yourself to use one focal length next time you go for a walk. No matter if you’re using a prime or a zoom lens, try and restrict yourself. The purpose of this is to understand what you can capture with certain focal lengths so that in the future you will hopefully be more decisive with what focal length to use in a given situation. Remember that you can change the end picture dramatically through different apertures. Why not give it a go and then share with us the variety of photographs you managed to capture with the same focal length. Or you can change it up and use one aperture but change your focal lengths. Share your results with us and if you have any questions please get in touch via the contact details at the top.
Until next time, happy Shooting!
Ben Cherry