Matching SUp focal length to photo

pgarch

Hi, I am doing some photomontages of a building in the landscape without any reference for SUp's photomatch.
The photo has a 35mm equivalent focal length of 17mm, I had hoped that I could set the focal length on SUp to 17mm and the focal lengths would match, they do not, Is there a way to match the focal lengths?

I tried matching the field of view and that does not seem to work either.

Thanks in advance Philip

l.frisken

well you could try and correct the photo using another program

pgarch

There is nothing wrong with the photo, its just wide angle, not sure why it needs corrected

thomthom

@pgarch said:

I tried matching the field of view and that does not seem to work either.

FYI: SU uses vertical FOV instead of horizontal.

pgarch

I managed to find a work around, I positioned the camera in Sup in the position the picture was taken and saved that view as it was the correct view only much smaller, I then imported the image into Photoshop and scaled it to the correct size and it seemed to work fine.

Anssi

Thomthom is almost right. The SU field of view numbers refer to the vertical angle of the lens, whereas in film cameras the angle is usually measured diagonally.
In digital cameras the manufacturers often quote focal lengths either as the real ones or then as "equivalents" compared to the FOV of 35mm film lenses. A 17 mm lens in a digital camera has a smaller FOV than in a film camera, because usually the digital camera sensor is smaller than a 24 x 36 mm frame in a 35 mm camera. It is complicated more by the fact that many digital cameras can take pictures in several aspect ratios, where a 2:3 ratio is in practice not perhaps the most common.

Anssi

Pixero

@anssi said:

Thomthom is almost right. The SU field of view numbers refer to the vertical angle of the lens, whereas in film cameras the angle is usually measured diagonally.
In digital cameras the manufacturers often quote focal lengths either as the real ones or then as "equivalents" compared to the FOV of 35mm film lenses. A 17 mm lens in a digital camera has a smaller FOV than in a film camera, because usually the digital camera sensor is smaller than a 24 x 36 mm frame in a 35 mm camera. It is complicated more by the fact that many digital cameras can take pictures in several aspect ratios, where a 2:3 ratio is in practice not perhaps the most common.

Anssi

Thomthom, I think we need a plugin to take care of this.

thomthom

It's in the plans to make a Camera plugin. Object representing the Scene tabs (selectable off course) with extra tools and dialogs to visually control them. But I need help to understand how cameras work when I begin on this.