For 1.5 frame, is 50mm better than 85 for portraits?

What's the prefered FL for head/shoulder portraits on a 1.5 frame
camera, such as Nikon? I feel that on FF the 85 provides for the best
facial impression (or even a 100 for that matter) but I have not
experimented much on the new system.

DeanB wrote:
: What's the prefered FL for head/shoulder portraits on a 1.5 frame
: camera, such as Nikon? I feel that on FF the 85 provides for the best
: facial impression (or even a 100 for that matter) but I have not
: experimented much on the new system.

Actually if you are wanting to get the same function as a 50mm lens on a
35mm film camera you would want a 32mm lens. True, if you don't mind
standing much further away a longer lens can be used to get the same
framing of the subject. But if you are trying to get the same framing from
the same distance from the subject you need a 32mm lens. The main
difference would be a difference in Depth of Field. But that can be
corrected with a change of Aperture (and a change of shutter speed to
match).

Randy

==========
Randy Berbaum
Champaign, IL

On Mar 17, 11:44 pm, Randy Berbaum
wrote:
DeanB wrote:

: What's the prefered FL for head/shoulder portraits on a 1.5 frame
: camera, such as Nikon? I feel that on FF the 85 provides for the best
: facial impression (or even a 100 for that matter) but I have not
: experimented much on the new system.

Actually if you are wanting to get the same function as a 50mm lens on a
35mm film camera you would want a 32mm lens. True, if you don't mind
standing much further away a longer lens can be used to get the same
framing of the subject. But if you are trying to get the same framing from
the same distance from the subject you need a 32mm lens. The main
difference would be a difference in Depth of Field. But that can be
corrected with a change of Aperture (and a change of shutter speed to
match).

Randy

==========
Randy Berbaum
Champaign, IL

What about the distortion by such a short focal length? Agreed the
50mm will get you the same crop as an 85 at full frame, but I dunno
about the actual facial distortion of using such a smaller FL.

On 17 Mar 2007 20:43:47 -0700, DeanB wrote:

What's the prefered FL for head/shoulder portraits on a 1.5 frame
camera, such as Nikon? I feel that on FF the 85 provides for the best
facial impression (or even a 100 for that matter) but I have not
experimented much on the new system.

If you prefer those focal lengths, divide them by 1.5 to get the
equivalent lens focal lengths when used with Nikon's DSLR bodies.
I've read that the "multiplier" is actually closer to 1.52, but such
a small difference is insignificant. This would require focal
lengths of about 56mm and 66mm to provide the equivalent FOVs and
focal lengths of the 85mm and 100mm lenses used with film or Nikon's
as yet hypothetical FF camera. The inexpensive 50mm f/1.8 Nikkor or
the somewhat more expensive f/1.4 version would make good portrait
lenses, and you might want their wider apertures to reduce DOF if
all that you have is the common 18-55mm kit lens. Nikon's 18-70mm
is a better lens and covers both of the FOVs that you prefer.

On Mar 18, 2:36 am, Randy Berbaum
wrote:
DeanB wrote:

: What about the distortion by such a short focal length? Agreed the
: 50mm will get you the same crop as an 85 at full frame, but I dunno
: about the actual facial distortion of using such a smaller FL.

Distortion (of the type you are reffering to) happens when the field of
view varies one way or the other from the "normal" lens. This normal Focal
Length (FL) for a 35mm film camera is aproximately 50mm, with a horizontal
Field of View (FOV) of about 40 deg. If the image taken with a different
sized sensor and an apropriate FL lens gives an image that has that exact
same 40 deg FOV there should be no difference in distortion purely
attributable to the wider FL. It is true that it is more difficult to
accurately manufacture a wider lens and so slight manufacturing error
distortion could appear. But manufacturing is becoming more accurate all
the time and so such abberations on all but the most extreme FLs should be
nearly indistinguishable from an older 50mm film lens. Even with an
extreme fisheye lens, if you cut out a piece from the very center of the
lens that represented the "normal" image the distortion would be much
less than you would expect.

IMHO

Randy

==========
Randy Berbaum
Champaign, IL

Randy - I don't mean chromatic aberation. What I am getting at is the
subject's nose appearing larger and closer to the lens as you reduce
the focal length. In 35mm world the perfect FL is 85-100 mm, and there
are opinions on which of those is best too. Go too far back with a
telephoto and the subject appears too flat.

DeanB wrote:
What's the prefered FL for head/shoulder portraits on a 1.5 frame
camera, such as Nikon? I feel that on FF the 85 provides for the best
facial impression (or even a 100 for that matter) but I have not
experimented much on the new system.

Well, if you like 85 FF, 85 / 1.5 = 56.666667 will give the equivalent
field of view on a 1.5x camera. I do in fact find my 58mm lens very
nice for portraits.

In article .com,
"DeanB" wrote:

On Mar 17, 11:44 pm, Randy Berbaum
wrote:
DeanB wrote:

: What's the prefered FL for head/shoulder portraits on a 1.5 frame
: camera, such as Nikon? I feel that on FF the 85 provides for the best
: facial impression (or even a 100 for that matter) but I have not
: experimented much on the new system.

Actually if you are wanting to get the same function as a 50mm lens on a
35mm film camera you would want a 32mm lens. True, if you don't mind
standing much further away a longer lens can be used to get the same
framing of the subject. But if you are trying to get the same framing from
the same distance from the subject you need a 32mm lens. The main
difference would be a difference in Depth of Field. But that can be
corrected with a change of Aperture (and a change of shutter speed to
match).

Randy

==========
Randy Berbaum
Champaign, IL

What about the distortion by such a short focal length? Agreed the
50mm will get you the same crop as an 85 at full frame, but I dunno
about the actual facial distortion of using such a smaller FL.

Use the longest lens you can...if you want the look of the 85mm, then
use the 85mm...film or digital...A 50mm lens on a digital gives the
equivalent of 75mm on a film camera, but its as if the 50mm was used
then cropped and enlarged...so all the characteristics of the 50mm lens
still apply. So yes you will get the same facial distortions. I hope I
am explaining it correctly. Now if you dont have the room to step back
a few feet then you will need a shorter lens.

JR