hi there! im using canon 1000D and tried to use fisheye lens but was wondering why i cant get full 180 degrees of angle..is it due to the crop factor of my sensor or what??
hi there! im using canon 1000D and tried to use fisheye lens but was wondering why i cant get full 180 degrees of angle..is it due to the crop factor of my sensor or what??
Michael Lim
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how many mm is ur fisheye? for 16mm fisheyes, you normally wont notice much on a 1.6crop sensor.
try using a 10 or 8mm fisheye
Last edited by wdEvA; 6th January 2009 at 04:11 PM.
I just helped some friends buy the Canon Digital Rebel XSi. When shooting with a camera that is not full frame, like in your case, multiply the focal length by 1.6. So if you are shooting with a 15mm fixed lens your camera produces and image that is at a focal length of 24mm. 15mm x 1.6 = 24mm I hope this helps you.
google it for more [crop factor]
or click this if you need spoon feeding
http://www.kenrockwell.com/tech/crop-factor.htm
The smaller sensor does crop the full image, but the 1.6x math does not apply to fisheyes, only linear lenses. Eg a 10mm linear lens on a 1.6x gives a 16mm linear viewpoint (=16mm on FF), but a 10mm fisheye does not give a 16mm fisheye viewpoint: it gives a cropped 10mm fisheye viewpoint. A full-image 16mm fisheye still gives a 180 degrees diagonal viewpoint. A fisheye designed to give 180 degrees diagonal viewpoint will do so for it's intended image(sensor) size, independent of its actual focal length.
Last edited by ST1100; 6th January 2009 at 05:10 PM.
interestingly, how do u measure the view angle in an image?
RIP CP5700, Nokia E61i 2MP Camera, SB-900
The lens will come with specs: horizontal view angle, vertical view angle, diagonal view angle.
Imagine an isosceles triangle. The focal length of the lens is the height of the triangle, the width, height or diagonal of the sensor is the length of the base (36/24/43 for FF). The top angle of the triangle is the view angle. Hope this makes sense.
Applies only to linear lenses.
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