Normal eye focal length

ok so what focal length on a 1.6 crop factor aka the xti what focal length is the same as the human eye

such as if you were to have both eyes open one on the eye piece and one not when would it be the same

approx 35mm in focal length. Eye piece and eye will only "match up" if you get 100 view from your viewfinder.

Actually the 50mm FOV = human FOV is totally inaccurate. Barrie and ljfinger are correct, see this http://forums.dpreview​.com …rum=1018&messag​e=17075832

the world is FLAT!! I think it is safe to say, that at one time, before fstopjojo hit the planet, the 50mm FOV was considered human eye FOV.

Sorry Dante, I don't get this response. Is it a rebuttal to the argument in the link?

i have seen somewhere between 35 and 50mm - so on a 1.6 crop factor - you need - 22 to 32mm

original the standard lens supplied on a 35mm camera was a 50mm lens and considered to give the same perpective as the eye - although lots of different discussions occur on this subject.

what are you trying to achive.

No no, just a lame attempt at humor. I can NOT rebut that argument. I cant even read half those big words.

Cheers Dante. It's definitely an interesting read, and it helped clarify some of my own thoughts on the issue, along with some other good reads on the matter.

nothing i was just wondering because before i reas 50 but i thought the potn people would know

Look...I won't be arguing, but take a look around with your eyes. Look at something. Figure out how big the portion of that image that is in reasonable focus is. Now..take your camera. On average, on a 1.6x camera, at 30-35mm lens will show just about exactly that portion of the image. The magnification is almost exact, as nothing appears to change from changing between the viewfinder and your "naked eye".

I'm not saying that on FF, 50mm is the same as your field of vision with your eyes, but it's roughly the "in focus" part (for me, anyway).

I see furhter whith my eyes than my 17-85mm lens on 85mm on a 1.6 crop body. I'm amazed!

I never really got the whole "normal" argument. Why would that lens be better than any other? I think you should choose a lens based on what you want to shoot and how you want to portray what you're shooting.

Mark

For my vision, I have always found a 35mm lens on film to be the most natural looking perspective and field of view. On an APS size sensor that translates into 22mm.

I'm just answering about what the FOV was...not what lens is better for what. Whether one lens is "better" than another is very much a subjective matter.

If you're asking what the "normal" lens focal length for an APS-C camera is, the answer is approximately 31mm. The "normal" lens for a 35mm film (24x36mm frame) camera is approximately 50mm.

That really has nothing to do with the focal length of the human eye, though. It has more to do with the diagonal dimension of the film/sensor frame. Actually those diagonal values are a little shorter than the accepted "normal" lens focal lengths for the two formats.