300mm equivalent in LF 4x5?

[GaryFlorida]

If 300mm is 6x telephoto in 35mm format, would it still be 6x in LF (4x5 format) just with a bigger field of view? I mean, the magnification would be the same right, just a wider field of view no? I mean from the same distance to the subject, the size of the subject on the film would be the same with the same focal length lens right?

 

[Ian Grant]

Yes, a 300mm lens will render an object the same size regardless of format (from the same view-point) but it won't be a 6x telephoto on 5x4, assuming 150mm is a standard lens for 5x4 it's only 2x that.

Ian

 

[GaryFlorida]

but I mean actual magnification on the film is the same though right? I dont mean the angle of view which is only greater because the piece of film is bigger so it captures more of the scene.

I mean if you are photographing a bald eagle at 100 yards withe a 300mm lens, whether its 35mm or 4x5, the actual eagle is going to be the same size on the film. With the 4x5 there will just be much more scenery around the eagle correct?

 

[wiltw]

Let's state it this way, with a 300mm FL optic on the camera and an 8' tall object which is 101' away from the camera

• On the 24mm wide 135 format frame the 8' tall object exactly fills 24mm on film, the full width of the 24x36mm image area
• On the 94mm wide 4x5 format frame the 8' tall object exactly fills 24mm on film, 25.5% of the width of the 4x5 image area

 

[Dan Fromm]

but I mean actual magnification on the film is the same though right? I dont mean the angle of view which is only greater because the piece of film is bigger so it captures more of the scene.

I mean if you are photographing a bald eagle at 100 yards withe a 300mm lens, whether its 35mm or 4x5, the actual eagle is going to be the same size on the film. With the 4x5 there will just be much more scenery around the eagle correct?

Yes, that's right.

 

[MattKing]

Of course, the 300mm lens designed for your 35mm film camera probably won't fill the 4x5 film - it will give you a sharp 24mm x 36mm image in the middle of the film, and the sharpness and illumination will fade outside that area, most likely to nothing a short distance outside the 24mm x 36mm area.

And you may find that the 300mm lens designed for your 4x5 camera might give you less sharpness and contrast in the 24mm x 36mm area in the centre, because all lens designs involve compromises, and the compromises necessary to offer 4 x 5 coverage with movements may result in different performance in the centre than a lens that is only required to cover a "miniature" format.

 

[David A. Goldfarb]

You live in Venice, Fl., so I'm guessing you're thinking of photographing birds with large format. If you can get pretty close, this may be interesting, to produce a very detailed image of something like the Venice rookery on 4x5". I've tried a little bird photography with my longest lens (360mm/5.5) and a 6x7 rollfilm back on my Linhof 4x5" Tech V using the rangefinder, and there aren't many keepers, but ratio of keepers to discards is low anyway, even with 35mm and a long fast lens, so you may consider it worth a go, particularly for egrets and herons that are willing to stand still for a while.

LF lenses of that focal length tend not to have very fast shutter speeds, though if you're using a camera with a focal plane shutter, like a Speed Graphic, you can get a high shutter speed that way.

LF lenses also tend not to be as sharp as 35mm lenses, if you were hoping to enlarge a 24x36mm section of a larger frame.

 

[RobC]

Field of view is what the lens sees of the subject and is pretty much fixed for any specific focal length regardless of the film format it is designed for.

Angle of view is the angle of the cone of light the lens projects inside the camera and onto the film. Angle of view is highly variable according to the lens design and is NOT dependant on focal length.

Changing the size of film format has precisely ZERO affect on either lens field of view or lens angle of view. BUT what it does do is crop a section from the angle view which effectively crops the field of view too.

Lens specification will tell you what the size of the lens projected image circle diameter is and the diagonal of the film format tells you how much of that image circle gets used by the film format. i.e. does it fit inside the projected image circle.

As pointed out above, a 300mm lens designed specifically for 35mm film format will have a much smaller angle of view than a 300mm lens designed for 4x5 format which will also have smaller angle of view than a 300mm lens designed specifically for 8x10 film format. But they will all have a similar field of view.

So check the lens spec image circle diameter to find out what you'll get on any specific film format.

Using a 300mm lens designed for 8x10 on a 35mm film format will effectivly crop the filed of view from whatever it is to something much smaller. i.e. you won't get the same effective field of view on the 35mm film format as you would on 8x10 film format because your film format has cropped it. BUT you haven't changed the lens angle of view or field or field of view, you have just cropped it by using a smaller film format.

Magnification on film will be the same for all three lenses, you will just see less or more of the subject depending on the film format and which film format the lens was designed for.

 

[GaryFlorida]

Field of view is what the lens sees of the subject and is pretty much fixed for any specific focal length regardless of the film format it is designed for.

Angle of view is the angle of the cone of light the lens projects inside the camera and onto the film. Angle of view is highly variable according to the lens design and is NOT dependant on focal length.

Changing the size of film format has precisely ZERO affect on either lens field of view or lens angle of view. BUT what it does do is crop a section from the angle view.

Lens specification will tell you what the size of the lens projected image circle diameter is and the diagonal of the film format tells you how much of that image circle gets used by the film format.

As pointed out above, a 300mm lens designed specifically for 35mm film format will have a much smaller angle of view than a 300mm lens designed for 4x5 format which will also have smaller angle of view than a 300mm lens designed specifically for 8x10 film format. But they will all have a similar field of view.

So check the lens spec image circle diameter to find out what you'll get on any specific film format.

Using a 300mm lens designed for 8x10 on a 35mm film format will effectivly crop the filed of view from whatever it is to something much smaller. i.e. you won't get the same effective field of view on the 35mm film format as you would on 8x10 film format because your film format has cropped it. BUT you haven't changed the lens angle of view or field or field of view, you have just cropped it by using a smaller film format.

Thank you for your insight. Just so we dont get too far off track, I dont know how or where exactly it was suggested to use 35mm format lenses on 4x5 format cameras but I did not propose that or wonder anything about that. Interesting information though.