angle of field using 105mm telephoto lens

[AlikH]

Using an old 35 mm SLR camera with 105mm telephoto lens, what is the size and shape of the picture that you get? Does it depend on other factors? Thank you.

 

[john.margetts]

Using a film 35 mm SLR camera, the picture (negative) will be 24 mm by 36 mm regardless of the lens used.

www.johns-old-cameras.blogspot.co.uk

 

[wfooshee]

If you're asking for a comparison to modern cameras, it would be exactly the same field of view as a 105 on a full-frame dSLR (D610, D750, etc.) That's why full-frame is called full-frame: it's the same size as the 35mm film frame.

It would be be about the same field of view as, say, a 70-200 almost all the way back on a crop-factor dSLR (D3X00, D5X00, D7X00.)

 

[AlikH]

Thank you both. So John, when you say a 35 mm SLR will always produce a 24 mm by 36 mm, do you mean 36 mm width and 24 mm height?

 

[Designer]

Thank you both. So John, when you say a 35 mm SLR will always produce a 24 mm by 36 mm, do you mean 36 mm width and 24 mm height?

Yes, that is the size of the sensitized area of the film. The edges where the sprocket holes are does not have any of the light-sensitive emulsion that makes film film.

The projected image will be larger, and circular in shape, but all that light is simply not part of the image because it doesn't fall on any sensitized area.

 

[480sparky]

Using a film 35 mm SLR camera, the picture (negative) will be 24 mm by 36 mm regardless of the lens used.

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Not always. There are 35mm film cameras that are ½-frame.

 

[AlikH]

Does that mean that if I showed you an unretouched photo that was claimed to be taken with a 35 mm SLR camera with 105 mm telephoto lens, you could tell from looking at it whether it really was?

 

[Designer]

Does that mean that if I showed you an unretouched photo that was claimed to be taken with a 35 mm SLR camera with 105 mm telephoto lens, you could tell from looking at it whether it really was?

I probably couldn't simply from looking at a photo.

If you are trying to judge the angle of view of a 105mm lens, you could take a picture with a 35mm camera and a 105mm lens, and compare the unknown with the one that you took as the control.

Do you mind telling us why you need to know this?

 

[480sparky]

Well, a 105mm on a full-frame traditional SLR or DSLR will give you approximately a 21 x 14° FOV.

 

[AlikH]

It pertains to a very old photo. So, Sparky, you're saying that the picture itself would be 21 wide and 14 high? So, in other words, 50% wider than it is tall?

 

[480sparky]

It pertains to a very old photo. So, Sparky, you're saying that the picture itself would be 21 wide and 14 high? So, in other words, 50% wider than it is tall?

You're mixing up two totally, different units of measurement.

The FILM NEGATIVE measures 24mm x 36mm (unit of length). The camera/lens combination will record a 14° x 21° portion of the world around it (unit of angular measure).

You can't just measure an old photo and deduce the focal length used to create it.

 

[KmH]

Field of View Calculator - Rectilinear and Fisheye lenses - Bob Atkins Photography

 

[Dave442]

If you know the size of something in the shot and the distance to the object then you could probably calculate the focal length of the lens knowing that it was shot on 35mm film and you are looking at the negative (or a print that was done to the same aspect ratio - a lot of enlargements would cut off part of the image and you would have to factor that in). You probably don't know distance to anything in the image.

The 105mm and 135mm lenses were popular and it might be possible to determine if one of these mid range telephotos was used in place of the normal 50mm or a wide angle lens. An older image would not have been taken with a zoom lens so that helps to reduce the number of focal lengths. Knowing the type of camera could also help as some had lenses that were more popular than others among brands.

If the person claiming the focal length used for example also knows that the camera was only used with three or four lenses it would also help to narrow down the possibilities.

 

[AlikH]

Thank you all. I am going to try to find out what the focal length was. It was a Nikkorex 35 mm SLR camera. But regardless, the negative would have been 24 by 36 which means that it was exactly 50% wider than it was tall. That's what I'm getting.

 

[480sparky]

The size of the negative has nothing to do with what focal length was used.