[BrianR]

The internet age's standard example of headshots vs focal length: Untitled Document

Note that 'portrait' to some people is synonymous with 'headshot' which is one reason why you're pleased as punch with a 3/4 length portrait taken at 31mm on APS-C even though someone else may say using a 31mm on aps-c is committing a 'portrait' sin. It's likely the perspective distortion he's complaining about, and your focal length and framing won't do funny things to a persons face like it would if you moved in closer for a headshot with the same lens.

Also, there's no hard cut off of 'greater than 85mm or bust, it's a gradual change in perspective as you adjust the focal length (and distance to maintain the same framing). It's also dependent on subject and viewer taste.

[DeadJohn]

Here are some more examples how wide angle lenses can distort portraits:

Effect of Lens Focal Length on Portraits - Personal View Talks
Anna Wu Photography
The Ideal Focal Length for Portraiture: A Photographer's Experiment

[calsan]

People confuse the terms 'distortion', which is a type of aberration, with 'perspective', which isn't.
They wouldn't do that if they had done old school technical drafting.

Perspective changes with distance from the subject. That's it.

This close perspective is what people find unattractive in portraits, as your subject's nose will appear to fill much of the frame (being close), while their ears are hidden around the side of their head. Basically, people like a 'flatter look' because it matches better the distance they are used to seeing other people. You don't stand 20cm away from someone when talking to them, but if you did, their nose would look big!

It's the same with a building, if you stand right in front of the door, you only see the door, but with a wide angle lens you can stand on the door mat and fit in much of the building, but the building will look more natural photographed from across the street with a longer focal length. Buildings don't complain about their doors looking too big, however.

[stevebrot]

The shorter the FL the more exaggerate objects closer to you and longer lenses instead gives a flattening perspective.

Sort of, though not really. The exaggeration is solely a factor of distance. This may be demonstrated by doing a stitch of multiple images from a long macro lens.

What a longer focal length gives you is the ability to frame tight at a distance.


Steve

[stevebrot]

People confuse the terms 'distortion', which is a type of aberration, with 'perspective', which isn't.
They wouldn't do that if they had done old school technical drafting.

Perspective changes with distance from the subject. That's it.

This close perspective is what people find unattractive in portraits, as your subject's nose will appear to fill much of the frame (being close), while their ears are hidden around the side of their head. Basically, people like a 'flatter look' because it matches better the distance they are used to seeing other people. You don't stand 20cm away from someone when talking to them, but if you did, their nose would look big!

It's the same with a building, if you stand right in front of the door, you only see the door, but with a wide angle lens you can stand on the door mat and fit in much of the building, but the building will look more natural photographed from across the street with a longer focal length. Buildings don't complain about their doors looking too big, however.

Thank you for explaining this in exquisite practical detail.


Steve

[RAART]

I am shooting Pentax however your Canon friend knows what he is talking about. Some called it perspective, some compression and some people distortion. I called it Lens Compression and Perspective. It is just lens characteristics however the longer lenses give you that desirable flattering look. As I come to Pentax from Nikon and two of the best Nikon portrait lenses are 105 F2 DC and 135 F2 DC (DC - defocus control) however my mostly used Nikon portrait lens was 180mm 2.8 followed by 105mm 2.0 and sometimes 300mm 4.0 for really tight head shoots. Just remember that I used those lenses way back in the 90's when I made my money with photography and all film cameras were FF but I never used any lens under 105mm for portraiture. If you calculate crop factor for the Pentax APS-C bodies you will find out that 105mm is in a fact 70mm on crop bodies where Pentax has DA70mm Ltd. and you can take it from there for the other focal length.

Here is more info on this matter (google is your best friend): https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=...nd+perspective

[MartinsB]

I was talking with another photographer and he said that he really dislikes shooting portraits below 85mm because "you get a distortion where it makes things closer to the camera look bigger, and things farther away look smaller." This is the first time I've ever heard that explanation.

That 85mm limit usually refers to head-shoulder portraits.

For comparison, I shot this at 31mm and I don't see any of the effects he is speaking of:

31 on APSC has the same field of view and hence perspective distortion as 46mm on FF.
You did take a full body portrait. Head-shoulder part in that shot has field of view like from a telephoto lens and therefore perspective distortions are not apparent. That's why 50mm on FF are OK for full body portraits.

[Rondec]

It really depends very much on how close you are to your subject. If you stand really close to your subject with a 30mm-ish lens on APS-C their nose will look bigger than if you would stand farther back and use a 60mm lens. Some people want their nose to look bigger, but seems like most would rather not have that effect.

That said, I think most photographers understand this sort of distortion and if they use a wide angle lens like a 15mm on APS-C or 20mm on full frame, they will use for environmental photos that will position the subject away from the edges of the image and include environment as well. Most of the comparison shots of different focal lengths and portraiture for some reason show the photographer maintaining exactly the same framing and just moving closer and closer as the focal lengths get shorter and this is definitely problematic when you get to really wide angle lenses.

[LensBeginner]

Here are some more examples how wide angle lenses can distort portraits:

Effect of Lens Focal Length on Portraits - Personal View Talks
Anna Wu Photography
The Ideal Focal Length for Portraiture: A Photographer's Experiment

Third link:
"Notice the difference in what appears to be the size of the bushes. This is due to the compression that is created by the telephoto lens being shot at 160mm."
*cringe*

[stevebrot]

It is just lens characteristics however the longer lenses give you that desirable flattering look.

Ummmmm...No, not a lens characteristic.

I have a set of example photos, though I will have to dig them up to share. A longer focal length is incidental to getting the desired "flattening".


Steve

(...learned this stuff in art class in eight grade...)

[VisualDarkness]

Sort of, though not really. The exaggeration is solely a factor of distance. This may be demonstrated by doing a stitch of multiple images from a long macro lens.

What a longer focal length gives you is the ability to frame tight at a distance.


Steve

Ah, I missed a part:
"given the same framing of the subject"

[RAART]

Ummmmm...No, not a lens characteristic.

If you tell me that field of view and depth of filed i.e. for telephoto lens is not a lens characteristic, than I will be gladly taking back all I mention before

This is practical example and I hope that everyone will understand... You can use practically any lens for portraits, it doesn't matter the focal length, but every single focal length has unique characteristics. Take an DA35mm lens and take picture of the subject/person at let say f5.6. Than take an DA70mm or/and DA200mm lens and take the picture of the same subject and make sure that the framing of the subject is the same (Height, length, width, position, etc.).
You will get 3 pictures with the subject at the same place and position in every picture. Is something different there?
Yes, it is... Notice how background changed?
People tend to say that it is compressed, but lens did not physically compress anything or did the lens has some magical power that I did not notice? Simple, field of view changed and the impression given is the compression. Did something else changed there?
Yes you bet it did... The background is more blurred from lens to lens, even you took the shoot at the same f-stop, say 5.6
Why? Simple depth of field changed while longer focal length lens magnifies everything in the frame and since the subject is closer to you than background and both of them are magnified that may give you appearance of more shallow depth of field than it is and this is creating bokeh, that might be distracting or pleasant and you have to pay attention where magnified will appear in the frame.

I do not want go any more into details in regards of field of view and depth of field, otherwise it will be simpler to write a book and publish it.

Depth of field and field of view are unique characteristics of every lens including distortion (click to get explained this) which is also characteristic of the individual focal length of the lens...

Hope this is helpfully and explains more. No offence taken and hopefully none given!

[Tanzer]

Actually if you take the picture from the same distance using all three lenses at f/5.6, the DOF will be identical. Of course, you will then have to crop the 35mm and 70mm images considerably to get a similar subject framing as the 200mm, but once you do that, you will get the same background blur. <-- Edit: I think I might have overstated this.

This is largely academic because you would need to crop a lot to get a 35mm image to look like a 200mm, and you will lose a lot of resolution, so nobody does that.

Anyhow, the important criteria when choosing a focal length for portraits is to use one that allows you a comfortable working distance from your subject, while at the same time not requiring excessive image cropping or shouting at your model from far away. (The assumption here is that a "comfortable working distance" means a distance we are used to standing when looking at people in real life.)

---------- Post added 04-23-15 at 06:26 PM ----------

The exaggeration is solely a factor of distance. This may be demonstrated by doing a stitch of multiple images from a long macro lens.

Alternatively, this may be demonstrated by cropping a wide-angle image.

[BrianR]

Actually if you take the picture from the same distance using all three lenses at f/5.6, the DOF will be identical. Of course, you will then have to crop the 35mm and 70mm images considerably to get a similar subject framing as the 200mm, but once you do that, you will get the same background blur.

Same camera, same distance to subject, same aperture, but different focal lengths will give different depth of fields (and different framing as you say). Is there some parameter you're thinking of changing but didn't mention?

[stevebrot]

If you tell me that field of view and depth of filed i.e. for telephoto lens is not a lens characteristic, than I will be gladly taking back all I mention before

No argument there.


Steve