[MadMathMind]

On APS-C, the FA77mm is superb with beautiful colour rendering, especially for portrait.

Full stop......

Yeah, for headshots, the classic ranges on FF are like 85mm, 105mm, 135mm, and a pro uses a 70-200mm zoom.

For APS-C, the Pentax equivalent was the DA*50-135 f2.8 zoom. The DA*55, DA70 and FA77 are examples of headshot primes for the cropped sensor.

But for anything other than headshots, you need to be like a mile away. It's a big problem: you don't get strong bokeh/isolation unless you're reasonably close. But you have to back up sooo far with anything over 75mm on APS-C that you lose that bokeh unless you shoot at f/2, and even then it's not as strong. But the PDAF system loses accuracy as you get further away (because measuring distance becomes more error prone), so you're more likely to end up out of focus. For the precision you need to focus at f/2 with a long lens, that's not so good.

More likely will be two or more people at an event, or in a street scene or an individual at half-body, sitting, or full-body, or in their work or home environment, etc, so it's a foolish portrait photographer who doesn't also pack their 24-70 zoom on FF (or 17-50 on APS, et al).

Just to provide reference, I have to shoot all of my boudoir with a 55mm lens. Even in my home, with a reasonably large bedroom, there's simply not enough room for a 77mm (K-1) for much other than head and shoulder shots. Something shorter than the classic portrait lenses is indeed needed.

[Sandy Hancock]

I have made memorable portraits with focal lengths from 21-300mm. It all boils down to how you want to frame your subject, and how much of the surroundings you want to include.

Lighting, timing, focus and rapport with your subject are much more important than focal length. Suggesting any particular single focal length as the "proper" one is ridiculous.

[Edgar_in_Indy]

I always hear that the most recommended focal lengths are in the 70-100mm range....like the Sigma 85mm, Pentax 70mm, 77mm, etc.

But is this for Full Frame sensors and APS-C is "better" at 50mm?

I think you could say (for APS-C) that the portrait range starts around 50mm.

[pres589]

Seems very situational. Some options may be the Sigma 30 1.4's, FA 31, DA 40 or 40XS, FA 43, any 50 you can mount, DA 55, Biotar / Helios 58's, or DA 70. Maybe the FA 77. Perhaps one of the 85's. Et cetera.

[Canada_Rockies]

I own and very much like my DA* 16-50/2.8. That's 24-75 in 36 mm terms, and I find it just fine for the few portraits I take.

[emalvick]

This is all with respect to APS-C

Having used a 17-50 (Tamron) to shoot some portraits in the past and then with the DA 21 mm, the distortion makes portraits less than ideal if you are too wide. The 21 mm isn't so bad, but it is definitely at a lower limit. I occasionally use it indoors at parties to shoot people.

I do find the 31 mm makes a decent portrait lens, and I use it quite a lot with my daughter (9 mos. old) as I can get close and get some nice shots.

If I am actually trying to shoot portraits in a planned / posed way, I would probably agree with others and use around 50 mm on up and adjust my position to make it work. I do shoot more for the setting rather than the person as your position can make the person relatively the same, it's just how much of the scene behind the subject that matters. I often take portraits in a garden, and this really gets to matter, and so I often try to shoot wider (and then closer to the subject) to get a nice background along with the subject. The nice thing with the 43 and 77 lenses is that at f/1.8, you can still get a decent blur without having to be too close. In fact, I still often shoot at f/2 or 2.4 just to make sure my subject is sharp enough (thicker dof).

Finally, one of the better "tricks" (which I know isn't really a trick) is to make sure your subject has some separation from the background. It makes it easier to get the dof right and blur the background right.

[BATMON]

Having used a 17-50 (Tamron) to shoot some portraits in the past and then with the DA 21 mm, the distortion makes portraits less than ideal if you are too wide. The 21 mm isn't so bad, but it is definitely at a lower limit.

This is what i thought, as I hardly shoot below 35mm.

[Saltwater Images]

The straight goods. Wide angle (21mm) isn't flattering for portraits. It makes things look wide - hence wide angle (people and faces will look fat).

Don't confuse Field of View with Perspective. 40mm or 50mm are normal perspectives even though their Field of View differs on APS-C versus FF. A 50mm lens will always have a 50mm perspective even though the FOV is approximately 75mm on a crop sensor. The laws of physics don't change - a 50mm lens is a 50mm lens with a 50mm perspective regardless of sensor size.

70mm, 77mm, 85mm and 100mm lenses offer a perspective that is flattering for portraits - that is because these short telephoto lenses create compression distortion that makes people and faces look a little slimmer creating natural (not edited) enhancement. It doesn't matter if you use a crop sensor or FF - you still get compression distortion based on the physics of the lens.

The challenge with APS-C is having a lens that creates flattering compression distortion without having a Field of View that is too narrow. For me I find 70mm to be the right fit on my humble crop sensor.

Then again you can easily choose to ignore physics all together and shoot everything with a 21mm or 35mm lens and PortraitPro edit the images to death to create something flattering:-) There are a lot of ways to go!

[clackers]

The straight goods. Wide angle (21mm) isn't flattering for portraits. It makes things look wide - hence wide angle (people and faces will look fat).

More portraits are done at around that FL than any other, SI - it's what phones are equipped with.

The issue with selfies is they're taken at arm's length.

There are bridal portraits done with 14-24 and 16-35 ultrawide zooms.

- that is because these short telephoto lenses create compression distortion that makes people and faces look a little slimmer

There is no such thing as compression due to focal length, SI.

That's a myth, no matter how widespread.

[goatsNdonkey]

Another reason that short telephotos have been used for portraits (in the pre-Phartsmone age) is working distance. When people used to be shy about having their picture taken, it was useful for the photographer not to be shoving the camera close to their faces. In the old film era standard kit of 3 primes -- 28mm, 50 to 55mm, and 135mm -- the 135 was the "portrait" lens.

[UncleVanya]

There is no such thing as compression due to focal length, SI.

That's a myth, no matter how widespread.

I have read that if you crop to the same perspective the "telephoto" compression will show up even if shot with a shot made with a normal perspective lens. Which I find fascinating.

[clackers]

Another reason that short telephotos have been used for portraits (in the pre-Phartsmone age) is working distance. When people used to be shy about having their picture taken, it was useful for the photographer not to be shoving the camera close to their faces. In the old film era standard kit of 3 primes -- 28mm, 50 to 55mm, and 135mm -- the 135 was the "portrait" lens.

Yep, 135 became out of fashion in the APS-C digital age.

You then had to raise your voice above conversation level at its working distance.

The 50 becomes really good, a bonus for us buyers because they are available cheaply.

[NZ_Ross]

On APS-C the DA 70mm f2.4 Limited makes a very good head and shoulders lens. It is small and light and focusses fast on the K-3. This image from PNG was taken with the DA 70mm while I was walking through a reception. Quick focusing of the lens, and luck with the glance took care of the rest.

If you are wanting the classic 85mm equivalent field of view and fast lens bokeh on APS-C then the Voigtlander Nokton 58mm f1.4 is a very good lens. An example from this lens is here. The only issue with this lens might be that it is manual focus.

The FA 77mm Limited is also a very good lens for portrait on either APS-C or FF.

[Sandy Hancock]

Perspective has been discussed ad nauseam. It has nothing to do with focal length and everything to do with the distance from the camera to the subject and other elements in the image.

If you maintain an appropriate camera to subject distance with a wide angle lens there is minimal perspective distortion - you just get more in the frame. That can be a good thing if you want to give a portrait some context.

DA21 wide open.

[UncleVanya]

Perspective has been discussed ad nauseam. It has nothing to do with focal length and everything to do with the distance from the camera to the subject and other elements in the image.

If you maintain an appropriate camera to subject distance with a wide angle lens there is minimal perspective distortion - you just get more in the frame. That can be a good thing if you want to give a portrait some context.

DA21 wide open.

Always the voice of reason. Great shot.