6.4mm vs 17mm

[Pmolan]

Canon Vixia S10 camcorder at 6.4mm

http://molan.smugmug.com/photos/724337205_eHEai-M.jpg

50D at 17mm
http://molan.smugmug.com/photos/724337190_rDnse-M.jpg
(note the camcorder in the lower right)

Who creates these standards? ???

[JeffreyG]

The sensor sizes in those two cameras are very different. A larger sensor (larger format) will give a much wider angle of view at a given focal length than a smaller sensor.

So as you can see, 6.4mm on your tiny format digicam is a mild wide angle lens, just a touch wider than normal. On the 50D, 17mm is a wide angle lens. 6.4mm on a 50D would be crazy wide.

[SkipD]

Actually, the 6.4mm focal length on the S10 camcorder is barely a wide-angle lens. Its 35mm equivalent focal length is 43.5mm while the 35mm equvalent of the 17mm on the 50D is approximately 27.2mm. As you can see, that's quite a difference.

I don't know how to determine the actual dimensions of the "1/2.6 inch" size of the camcorder's sensor, but using the 35mm equivalent numbers I calculated that the S10's sensor is roughly 3.5mm high and 5.3mm wide. That's TINY compared even to the 14.9mm by 22.3mm sensor in the 50D. A 35mm film camera's frame is 24mm by 36mm.

[frankchn]

I don't know how to determine the actual dimensions of the "1/2.6 inch" size of the camcorder's sensor, but using the 35mm equivalent numbers I calculated that the S10's sensor is roughly 3.5mm high and 5.3mm wide. That's TINY compared even to the 14.9mm by 22.3mm sensor in the 50D. A 35mm film camera's frame is 24mm by 36mm.

Wikipedia says a 1/2.5" sensor is 5.76mm * 4.29mm. A 1/2.7" sensor is 5.37mm * 4.04mm.

[Pmolan]

I never really thought about sensor size. I guess I overlooked this because its a "Hight Definition" camcorder.

Its crazy that this 6.4mm is very close to 50mm on my 50D.

[Wilt]

I never really thought about sensor size. I guess I overlooked this because its a "Hight Definition" camcorder.

Its crazy that this 6.4mm is very close to 50mm on my 50D.

That is simply because the FOV captured has a direct relationship to the size of the sensor/film frame. If the FL of the len is about = diagonal measure of the frame, it captures about 50 degrees (diagonal) of the scene in front of the camera.

6.4mm(lens):4.1mm(diag) = 1.56

17mm(lens):26.9mm(diag) = 0.63

so the 17mm lens on your APS-C camera is a bit 'wide angle' in its AOV than the camcorder 6.4mm 'telephoto'. where about 1:1 would be 'normal'

[The Moose]

You're also forgetting that High Definition in the video world is 1920x1080 pixels. Therefore a larger sensor, like that on a 5D2, is unnecessary for the application and the market for that specific product. At the same time, the 5D2 was lauded as a video camera because of its larger sensor :)