I know that 67 105mm f2.4 is 55mm f1.4? lens but what's the exact focal length if I use adapter for 35mm FF camera?

[Adam]

what's the exact focal length if I use adapter for 35mm FF camera?

Nothing changes. It would still be a 105mm F2.4 lens, in other words a short telephoto.

Nothing changes. It would still be a 105mm F2.4 lens, in other words a short telephoto.

105mm on 35mm then?

[texandrews]

105mm on 35mm then?

Ummmm, I don't think so. On 6x7 a 105 has a 36.5 degree FOV, and 36.2 degrees on FF is a 55. See this handy-dandy chart: https://www.pentaxforums.com/forums/54-pentax-lens-articles/93714-field-view-...d-645-6x7.html

[aurele]

I know that 67 105mm f2.4 is 55mm f1.4? lens but what's the exact focal length if I use adapter for 35mm FF camera?

the P67 105mm f2.4 when use on a 6x7 body provide a FOV of 36.5 degrees, and can be comapred to the FOV of a 55mm f1.2 in 35mm terms.

If you use and adapter to use the 105 f2.4 on a 35mm body, you will have a short tele of 105mm then.
The Focal lenght don't change when you change format. only the field of view change, when you change the format.

the P67 105mm f2.4 when use on a 6x7 body provide a FOV of 36.5 degrees, and can be comapred to the FOV of a 55mm f1.2 in 35mm terms.

If you use and adapter to use the 105 f2.4 on a 35mm body, you will have a short tele of 105mm then.
The Focal lenght don't change when you change format. only the field of view change, when you change the format.

...and to be clear the aperture will also be f/2.4. To clear this a little more if shooting the 105 f/2.4 fully open on a 6x7 camera and you want the same look shooting with a FF camera you will have to use a 55 f1.4 lens (f/1.549 to be exact) fully open and stand at the same spot when shooting.

When putting the 105 f/2.4 on a FF it is a 105 f/2.4 lens only with a larger image circle than needed.

[Adam]

105mm on 35mm then?

Yes. Focal length = 105mm, max. aperture = F2.4, regardless of the camera you mount the lens on.

The only thing that changes is the narrower field of view that you get on smaller sensors. The smaller the sensor the narrower the field of view, since it sees less of the frame.

Adam
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[jbondo]

105mm is 105mm, period.

I use the 6x7 105 2.4 on FF often. (Canon 6D) It's quite heavy, so you may not be inclined to tote it around. It has minimal vignette. It has excellent quality of bokeh. It's a very good portrait lens on FF 35mm.