Sunday, 19 September 2010

Using the Lumix 20mm as portrait lens

A portrait lens has two main properties. First, the focal length is fairly long, so that you can take a picture of a face at sufficient distance to avoid distortion. Second, the aperture is large, so that you can focus on a face and have the background out of focus.

Typical high end portrait lenses for film based cameras are 85mm f/1.4. The focal length corresponds to around 42-45mm for Micro Four Thirds. Many zoom lenses available for Micro Four Thirds will give you this focal length option. However, the largest aperture of these zoom lenses is generally much smaller than f/1.4.

One prime lens which comes close is the Lumix Leica 45mm f/2.8 macro. However, while this lens has a larger aperture than the zoom lenses, it is still far from f/1.4, and I am sure some will find it limiting for portrait usage.

Another lens comes close in the aperture department. It is the Panasonic Lumix 20mm f/1.7 pancake. However, this lens is quite a bit wider than most portrait lenses. So can you use it for portraits?



Let's take a look. When talking about portraits, let's say that we mean a picture in which the face fills the majority of the frame. When using the Lumix 20mm pancake lens, this is what we get, when going close enough to fill the face into the frame:



As you can see, the face is distorted. The nose and chin looks too large. This is due to getting very close to the face. The distortion is not a property of the wide lens. The distortion is related to the distance to the face. The closer the distance, the more distortion. With a longer focal length, you can stand at a longer distance when photographing, to avoid distortion.

So let's try a longer focal length. Here is the same face filled into the frame using the Lumix 45-200mm f/4-5.6 at 45mm:



The effect is very clear: 45mm is sufficient to get a proper perspective. The nose and chin now looks natural, and not artificially large, like in the picture taken at 20mm.

This picture was taken at 1m (3.3 feet) distance, which is the closest you can get with the 45-200mm lens. This is probably no coincidence. I'm guessing Panasonic designed the lens so that it could be used to take a headshot at the shortest focal length.

It is also interesting to see that the out of focus discs (bokeh) are about similar sizes in the two images. This means that f/4 at 45mm gives about the same background blur as f/1.7 at 20mm, when filling a face into the entire frame. Of course, the 20mm image was taken at a closer focus distance.

In a previous paragraph, I said that the distortion is related to the distance to the subject. So the solution is very simple: When using the Lumix 20mm pancake lens, take a step backwards. With the same distance as in the 45mm image above, the perspective should also be the same. Here is the outcome when using the 20mm lens at 1m (3.3 feet) distance:



In this example, there is no apparent distortion. However, the downside is of course that the face only fills a part of the frame. Also, the background is less blurred, since the focus length was larger.

The Lumix 20mm lens is very sharp. Especially in the centre region. So what you can do, is to crop the centre out of the image. Here is what I get using that method:



Of course, you might want to include a bit of background, and not crop as tightly as I have done here.

Conclusion

So can you use the Lumix 20mm lens for portraits? Yes, but don't stick the camera in the face of the subject. At a distance of about 0.7m (2 feet) or more, the face distortion should not be noticeable. If you need to, you can crop off a bit of the borders, to get a closer portrait.

Of course, you could take a so called "environmental portrait", in which you don't just shoot the face, but include some more of the person, and some elements around him or her. In that case, it makes good sense to use the 20mm lens. In fact, I'd say the Panasonic Lumix 20mm f/1.7 pancake is a perfect lens for environmental portraits.

Here is an example environmental portrait taken with the GH2 and the 20mm f/1.7 lens.  The image parameters are: f/2, 1/60 second, ISO 1600.


You could even use the Lumix 14mm f/2.5 wide angle prime lens for environmental portraits. As long as you keep a distance to the face of around 2 feet or more, you should not get any excessive distortion. On the other hand, if you photograph a sitting person head on, his knees will look abnormally large this way, due to the perspective.

18 comments:

  1. Nice Post, you talk about Panaleica 45mm, that you made an excellent review. Now you test lot of lens, for you, what is now the best m4/3 portraits lens?
    Thank you

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  2. I think that the Olympus Four Thirds 50mm f/2 macro (not Micro Four Thirds) is probably the best portrait lens at the moment. However, it will not AF on the first series of Panasonic m4/3 cameras. And for other m4/3 cameras, the AF is slow.

    For studio use, the AF speed is probably not so important. But for more causal use, it can be a problem.

    At the current date, the best portrait lens for m4/3 is probably the Panasonic Leica 45mm f/2.8. However, it is expensive, and still a compromise with the f/2.8 aperture.

    There is rumour that a new fast prime will be announced soon from Panasonic. And Olympus has a 50mm prime in the making. So you could consider to wait some months and see what pops up. Perhaps a more suited lens will become available.

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  3. Great post. Love the 1.7 and will keep this in mind when taking photos. Thanks.

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  4. I bought the 50mm Olympus lens for my GH1-camera, but they bought got stolen. I only got to use them together a couple of days, and I agree that it was a great lens for macro, but with the lack of autofocus it was not so convenient to take portrait pics etc. Perhaps I would have needed more time to have gotten used to it though.

    Anyway, I needed a new camera, and decided to go for G2, as I still have the 14-140mm lens from my GH1 kit lef ( luckily that wasnt stolen), and I also got the 14-42mm lens together with the G2. But I still want to get a proper portrait/macro lens, so I'm considering buying the 50mm one more time, or perhaps go for the cheaper 35mm one from same manufacturer (http://shopper.cnet.com/lenses/olympus-zuiko-digital-macro/4014-13038_9-31578057.html#info-5). Now that I have the G2, I will be able to autofocus with both lenses ( albeit slow), which makes it interesting. I want to take good portrait pics as well and not only macro, and for that I reckon the 50mm is the best one? Have anyone tried the 35mm one?

    As for the news about either Panasonic or Olympus launching a new portrait-lens in the upcoming months makes me want to wait for them as well, but the 35mm lens is only about 180 dollars, which is quite cheap.

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  5. Great article, thanks.

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  6. Another great article! Thank you so much for all the time and effort you put into this blog. Your articles are the best explained, best illustrated photography tutorials I've seen anywhere.

    Cropping the more distant 20mm headshot gives surprisingly good results. It's a good technique to have in your repertoire, and I'll definitely keep it in mind. This technique also nicely demonstrates one of the benefits of having a compact camera with a DSLR-sized sensor -- you can crop without worrying about noise problems!

    I'm planning to use the Olympus 50mm f/2.0 FT lens for studio portraits and the Panasonic 20mm f/1.7 MFT lens for environmental portraits. I'm very happy to own these two fine lenses, and I appreciate your giving them such good press. :)

    Thanks again for all your great work,

    Fred Chapman
    Bethlehem, PA

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  7. P.S. I just recommended your blog to all my contacts on Facebook, Twitter, and LinkedIn! I'd love to connect with you -- please feel free to send me an network invitation:

    http://facebook.fwchapman.com/

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  8. Thanks for your very nice comments. I don't use facebook, twitter and linkedin ... Perhaps I should.

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  9. Great post for those whoIndoubt how to frame aPortrait picture with the popular 20mm1.7 . From my experience , when taking horizontal picture , the max I can frame a person is half body , shoulder till face is the best distance , as for vertical picture , I can only frame till knee to give a pleasing result . I normally slightly tilt down the camera . However , I am really looking forward a 50mm and below f 2.0 lens for m4/3

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  10. I think a lot of people are anticipating a fast portrait prime for m4/3.

    The Samsung NX mirrorless system is soon getting an 85mm f/1.4 lens. This lens, while quite large, sounds quite useful.

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  11. Brilliant! I ordered the pancake few days ago.. so now I know how I'll b using it properly.. sweet
    I just wonder after reading this post:
    Do you always have to keep the minimum distance of 2 feet from any object , not just faces? I mean you 'll b getting distortion from every close up .. right?

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  12. You are right that keeping a short distance to the subject will cause perspective distortions. Even if you are not photographing people.

    But perspective distortions might not always be a problem. If you are photographing a flat subject, then they don't matter. If you photograph organic shapes, then perhaps the distortions are not visible.

    Feel free to experiment! Closeups of plants, flowers, animals, etc, might be fine despite perspective distortions.

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  13. If I am posting in the wring section, sorry, just seeking some advice on best 4/'s wide lens for Olympus e-series for shooting landscapes. Don't have a huge budget. Thanks

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  14. For landscapes, why not stick to using the kit lens? That is a low budget solution.

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  15. Thanks for msg!

    What do you mean by the kit lens? The 14-42mm? Is that suitable or is there anything better which gives a wider view? Ps only just starting out so all help appreciated!

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  16. Yes, the 14-42mm kit lens should be good for landscapes.

    For a wider view, you could look for the Olympus 9-18mm f/4-5.6 lens (the Micro Four Thirds version of the lens). It's not cheap, though.

    My advice is that you try using the kit lens first, and see how that goes.

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  17. Muchas gracias y felicitaciones por su explicación tan clara, que solo la dan las personas que saben mucho de un tema.

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  18. The last photo with the man wearing the tie looks underexposed. I've been old that 1/60 is the limit for handheld photography, but I would think that a tripod or some other stand for the camera would have allowed for an even longer shutter speed for better exposure.

    Since the ISO is already at 1600, I wouldn't want to bump it up higher than that, even on a good camera.

    Plus, if the lens goes to f1.7, why shoot this at f2.0 when it could clearly benefit from some more light and depth of field?

    Was it a conscious decision?

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