Ok everybody knows
35mm is not the most flattering focal length for a portrait and by portrait I mean somewhere from chest and above... and of course it gets worse as we get closer to the subject. So if I find myself in a situation that that 35mm is the only lens at hand and want to still make it work do you think one way would be if I go much farther back and shoot the subject knowing that later I am going to crop it much tighter? Would that help with less distortion?
Ok everybody knows
Yes, to a degree. The distance helps perspective, but the cropping can remove many pixels of image size.
The key for portrait perspective is to stand back a bit. The camera standing back at least about six feet, and 8 or 10 feet is considered better in the formal studios. What focal length this could use for a desired field of view would depend on the camera sensor size. Use the focal length that gives the desired view when standing back, but it is the distance that fixes perspective (enlarged noses, etc).
We guys may not ever notice the problem, and the ladies may not realize exactly why they don't like the picture, but they will like those standing back a bit better. It's more like their idea of their picture.
For the 35 mm film format, the 105 mm lens was considered classically good for head and shoulders portraits, because the focal length required standing back at a good distance to see the view.
But not all portraits are head and shoulder, some are chest and up, or waist and up, or some might be even full length standing portraits, or even group shots. It is OK to use a shorter lens for the wider view, as needed, but standing back at least about six feet is still important. I prefer 8 or 10 feet, which is necessarily a longer lens.
You didn't mention sensor size, but most cameras today use a smaller sensor with shorter focal lengths to still get the same view. That's fine too, but standing back at least about six feet is still important. The right lens is the one that gives the desired view from the proper distance.
Standing back and zooming in as desired for the view is fine, no problem. It can still be just a head shot if desired, but the key is standing back a bit.
Standing back and then cropping for the field of view you want will help the perspective, but cropping costs many pixels, the image may not print as large then as you would like.
I disagree. Make your limitation your weapon!
There are many, and I mean many types of portraits. A wide angle lens can give you another perspective, so USE IT!
You have more room for the surroundings, use them. You have potentially more difference between sizes of planes, use them.
Personally... I love wide angle! I know 35 mm is not really a wide angle, especially o smaller sensors, but you get the idea.
You actually can make awsome portraits taking advantage of the lens distortion.
But if you want to stick to a classical portrait, go and rent the proper lens for the need. Especially if it is a paid work. You have a problem if you sacrifice resolution to make a choppy crop.
Yes, it would help, and it would be a feasible way if you need to have a "classic" portrait (i.e. flat faces). There are two down-sides to using the "wrong" focal length for portraits:
Increased depth of field because of distance: Subject separation will probably not be as strong as with, say, a 100mm f/1.4 wide open.As @Michael Clark and @WayneF pointed out, DoF (depth of field) has to do with magnification, so if you zoom your 35mm shot to the same crop as a 100mm one would offer, the DoF would be the same (with the same aperture).
- Image quality post-cropping: You will have to crop a lot, so noise will become more visible.
- (Optional) It will be harder to spot minor "defects" in the progress of the shooting: Most likely, you will have to check every picture after taking it for closed eyes, misfocus,... - things that you can spot more easily with an optical viewfinder when using the "proper" focal length.
Still, if you have no other option and want a portrait with the "face-flatness" of a tele-lens, then increasing the distance at least a bit will be the best approach I can think of.