Focal lengths of 35mm SLR:35mm Cine lenses

Shooter

Shooter

Veteran
Bit of a debate running here...

We are trying to compare and relate focal lengths of 35mm SLR lenses to 35mm Cine lenses.

Anyone got a link to a comparison chart or the formula?
 
Do you mean crop factor for a certain cine gate compared to full frame still 35mm?
A focal length is a focal length. Let's say your talking about a Super 35mm gate?
The simple formula is to multiply a lens on SUper 35mm body by about 1.4x to get the equivalent field of view on still 35mm.
Super 35mm nor Academy has the same proportions as Still SLR. So the crop factor formula isn't perfect since horizontal and vertical proportions are different.
 
O.K... fov or focal length whatever...

Considering that we are discussing this in the 35mm DOF Adapter Forum where it is possible to mount both SLR and PL Cine mount lenses to the same device. (assuming one has suitable mounts)

We are trying to determine the equivalent 35mmCine lens to a SLR of X focal length.

In the same vein we could ask the equivalent to a 16mm cine lens.
 
On your 35mm adapter ground glass, a given focal length lens whether or not its SLR or PL mount will give you the same field of view.

What might present a problem for you is that most PL mount cine lenses don't have the image circle coverage that a still camera lens has. A PL mount lens if designed for 35mm MOVIE gates will have a smaller circle of coverage and so you may experience some vignetting.

That's why for example, you won't be able to put a PL cine lens on the future RED Scarlet Full Frame, and have it cover the whole sensor. Still SLR lenses are superior in this regard: they have greater coverage.
 
So you are telling me that if I use a 50mm lens from a set of 16mm lenses, I get the same FOV as I would with a 50mm lens from a 35mm cine set and a 50mm SLR lens?
 
are you trying to maintain academy framing on the film plane? same zoom setting on the camera , no matter the lens? or zooming for academy with cinema lenses, and full frame 35mm for SLR lenses?

I think, someone will correct me if I'm mistaken, and maybe I'm repeating the above info a different way, but I think a 50 is a 50 is a 50, if your maintaining the zoom setting for all lenses. and if I understand the pana link that cordvision posted, to match a different film gate size, or different zoom level on your GG, film plane, the focal length of the lens will be different to match given image, overall FOV.

does that make sense, at this point I'm back to confused. good luck

Maybe this will help, it should even though it's a RED test.

http://www.reduser.net/forum/showthread.php?t=13760
 
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I am talking about maintaining the same frame size (gate aperture size).


BTW - the test link is very interesting thanx. I could not establish if he was moving the camera when he changed from Cine lenses to SLR lenses although some shots seemed to show different frame sizes.
 
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he does go on to say that he was a bit lazy in making sure to put the camera in the same place.

I just had more written, but in the process I've made myself unsure again. someone else please, I'm frightened!:crybaby:
 
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oh wait, I think I had it right, a 50mm slr is = to a 50mm cinema lens, if you have the cam zoomed in the same amount, same gate. but if you zoom out for the complete FOV of the SLR, you now have the equivalence of a 33mm or 35mm cinema lens.

which makes the the SLR lens more versatile.

someone please correct me if I'm completely off
 
Shooter said:
So you are telling me that if I use a 50mm lens from a set of 16mm lenses, I get the same FOV as I would with a 50mm lens from a 35mm cine set and a 50mm SLR lens?
Click to expand...
That is correct, as long as u use them with the same dof adapter and if u don't change the zoom setting of ur camcorder. (16mm lens might not cover the whole GG)
 
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