What is a wide angle on large format?

[Stanley Kubrick]

Hello, just wondering if somebody could tell me what millimetre numbers are used for the various different focal lengths in large format lenses for 5x4 cameras. As an example, a 50mm lens is the standard for 35mm film, 28mm is a wide angle lens. I know that a standard "50mm" lens on a 6x6 medium camera is around 80mm.

Thank You

[Kirk Gittings]

see this: http://photo.net/photo/lens-table

[goamules]

Or: http://www.largeformatphotography.info/matos-begin.html

[Bob Salomon]

The general rule is that a normal focal length lens is the diagonal of the format so a true normal for 35mm would be about a 44mm not a 50. A wide angle is the length of the short side of the negative or shorter and a long lens is equal to the long side of the negative or longer. For 4x5, 135 to 180mm are usually considered normal focal lengths. Shorter then 135 would be a wide and longer then 180mm would be a long lens. I intentionally did not use the term telephoto as that is really a design type and not just a longer focal length.

The exception to this rule, of course, are square formats like 6x6cm, 5x5" and so on.

[Stanley Kubrick]

Thats great, thanks a lot for all you're advice

[C. D. Keth]

If you want to know the equivalent lens on a format and you're familiar with another format, just set up a simple proportion equation.

To figure out what lens on 4x5 is like a 28mm on 35mm film, just set up the lens of each format over the diagonal of each format:

28/43=x/162

Solve that for X and you get 105mm.

[Tom Sobota]

"A wide angle is the length of the short side of the negative or shorter and a long lens is equal to the long side of the negative or longer"
Do I understand this correctly? Since the diagonal is longer than the long side, this would mean that the normal lens is always a long lens? Hmmm...

[Dan Fromm]

"A wide angle is the length of the short side of the negative or shorter and a long lens is equal to the long side of the negative or longer"
Do I understand this correctly? Since the diagonal is longer than the long side, this would mean that the normal lens is always a long lens? Hmmm...

No, you've just received some Internet nonsense.

In LF, the normal lens' focal length is the format's diagonal. In smaller formats, normal focal length is sometimes determined by convention, e.g., the quaint concept that the normal focal length for 24x36 (diagonal 43 mm) is 50 mm. Except when it is as long as 58 mm, as was the case before designers solved the problem of making 50 mm 6/4 double Gauss lenses that would clear a 35 mm SLR's mirror. Lotta BS and marketing nonsense out there.

[Brian Ellis]

A rough guide you can apply in your head is to multiply a 35mm format focal length by 3 to get the approximate 4x5 equivalent. As I'm sure you know, because the aspect ratios of the two formats are different there are no exact equivalents and 3 isn't the closest possible number to use but it's easy to use in your head and it's close enough for most purposes).

I wouldn't worry too much about diagonals or ratios and formulas for determining what's "normal." Different people have different ideas. FWIW I consider 210mm to be long normal, 150mm to be mid-normal, and 135mm to be wide normal.

[Tom Sobota]

No, you've just received some Internet nonsense.

In LF, the normal lens' focal length is the format's diagonal. In smaller formats, normal focal length is sometimes determined by convention, e.g., the quaint concept that the normal focal length for 24x36 (diagonal 43 mm) is 50 mm. Except when it is as long as 58 mm, as was the case before designers solved the problem of making 50 mm 6/4 double Gauss lenses that would clear a 35 mm SLR's mirror. Lotta BS and marketing nonsense out there.

Yes, I know. I was just reacting to a previous Bob Salomon's post in this same thread.