I shot and downloaded a video some time ago using an R6ii with the 24-105 f4-7.1 lenses. Some of it was at 105mm, but not all of it. Is there a way in software to identify the focal length of a specific video frame?
Identifying focal length of a specific downloaded video frame
- Thread starter Salamander
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If the images are taken from the same working distance, then you should be able to use the relative field of view and some geometry to determine the focal length. https://www.edmundoptics.com/knowle...VqvZ8oRYrW7ErEoYTFnQZMggwdzMovJDacrfZheFqMsk8
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According to AI, this simplifies to finding the same object in both images (x fl and 105 fl) and measuring the pixel height in both images. Then you can determine your focal length by:
x = 105 x ( hx / h105)
x = 105 x ( hx / h105)
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You need to have a specific item both in the frame you *know* is at 105mm and in the frame you want to identify focal length
Assuming you're taking both frames from the same position, measuring pixel height between of the same item in both frames will let you infer the focal length of the second shot by a simple operation described above :
Focal length is x, so hx is height of the item in the frame to be identified. 105 is the shot you know is at 105 and h105 the height in said shot.
Assuming you're taking both frames from the same position, measuring pixel height between of the same item in both frames will let you infer the focal length of the second shot by a simple operation described above :
Focal length is x, so hx is height of the item in the frame to be identified. 105 is the shot you know is at 105 and h105 the height in said shot.
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