4x5 ideal head shot focal lenght lens ?

Oh, and you did not say what size lens boards you have, but assuming they're 4" or so and your format is 4x5, here are some of the likely candidates for a good head shot portraiture lens.

240mm f:5.6 Apo Sironar S (Jock Sturges uses one on 8x10 IIRC, but not usually for head shots)

10" or 12" f:6.3 Commercial Ektar (Karsh used a 14" CE on 8x10)

240mm f:4.5 Tessar or Heliar. This is the largest f:4.5 lens you're likely to get on a small board, and it will take some custom work to do it.

9-1/2" (240mm) or 12" f:6.8 Dagor

250mm Fujinon Soft Focus

250mm Imagon in Copal or Compur #3

Cheers, Steve

When focused to the identical close distances for a head portrait, the angle of view for a large format camera narrows much more than a 35mm camera, thus making the common 'format ratio' formula less reliable. The equation is perfect at infinity, though.

This calculator includes a magnification factor: http://eosdoc.com/jlcalc/

Here's another way to think about this, if you want to sort out what is practical with the equipment you have.

A really tight 4x5" headshot has a magnification ratio of about 1:3 (image sizebject size).

Many 4x5" cameras have a double extension bellows, or 12" (about 300mm), some like Linhof have a triple extension bellows around 16-17" (around 425mm), and on top of that it is possible to add more extension on some monorails with additional standards or to use a "top-hat" extension lensboard, or to add extension tracks, or just to use a larger format camera with a longer bellows and 4x5" back.

On a camera with a minimum double extension bellows, you need 280mm extension with a 210mm lens, so you've got a little space to even get a little closer than 1:3, and subject distance will be about 2 feet.

240mm non-tele lenses tend to be designed for 8x10" and are in large shutters and may not fit on a 4x5" camera, but if it does, then it needs 320mm of bellows, and you only gain a few inches of subject distance over a 210mm. A 240mm telephoto design will work with a 4x5" camera and double extension bellows, if you have a 240mm tele you like.

300mm lenses can be more compact and a non-tele design will require 400mm of bellows at that magnification--pretty stretched out on a Linhof or other triple extension camera, but do-able, and subject distance goes up to about 3 feet.

360mm opens up the possibility of a few telephotos that can work on 4x5" with not so much bellows--not a common choice, but a Tele-Xenar of that focal length will give you 1:3 magnification at about 300mm extension, and subject distance of about 3-1/2 feet.

500mm non-tele will require about 670mm of bellows--most easily done by putting a 4x5" back on an 8x10" camera. A 500mm Tele-Xenar needs about 420mm of bellows, so it should just work on a triple-extension 4x5" camera, and subject distance will be about 5 feet. 500mm telephoto lenses are available for 4x5", but aren't that common.

Best to work with studio strobes for this amount of magnification.

Ian C said:

Here’s how to calculate the equivalent focal length in terms of a familiar format for a different focal length and format.

Let

F = unknown equivalent focal length for the familiar format

D = diagonal of the image rectangle of the familiar format

f = focal length of new format

d = diagonal of image rectangle of the new format

F = f*D/d

Example:

Determine the 35mm format equivalent of the Mamiya RZ67 210mm APO lens on the 6 x 7cm format.

Take the diagonal of the 35mm format as D = 43.27mm and the diagonal of the 6 x 7cm format as d = 89.25mm (The Mamiya RZ67 manual states that the format is 56mm x 69.5mm).

F = 210mm*43.27mm/89.25mm = 101.8mm = 102mm to the nearest millimeter

This agrees with the 35mm equivalent for this lens given by Mamiya here

http://www.mamiya-usa.com/rz67-pro-iid-lenses-210mm-f4.5-apo.html

Click to expand...

This would work OK when the aspect ratio of the formats are similar...645 vs. 4x5 vs. 8x10. It works horribly when you take the overly long 3:2 aspect ratio of 135 format and try to equate it to a 5:4 ratio format, which is the logic behind using the short dimension of the frame (which is the narrow dimension used in single portraits...nobody ever prints a 16x24 or 8x12 for a portrait...they print 16x20 and 8x10 for the frames that go on walls and desks. Simply by altering D to not be 'diagonal' but 'short dimension', the same formula still works.

Monito said:

This calculator includes a magnification factor: http://eosdoc.com/jlcalc/

Click to expand...

That is nice. Thanks for posting.