New answers tagged focal-length
Everything is a trade-off. (i.e., "Good, fast, or cheap; choose any two.") Convertors are cheap, but they pretty much all introduce hard to control chromatic aberration. They also reduce the effective amount of light entering the lens. The former can be fun for artistic purposes, or if you can balance the chroma problems with a deft hand in ...
The focal length of the lens system with a teleconverter will be 300mm (from the lens) * 1.4x (from the converter). This will give you a lens system with a focal length of 420mm. Cropping of the image by the sensor from the full field of view to the APS-C size doesn't change the focal length... it just gives you the same field of view if you had a lens ...
Yes, that's correct. Shooting a 400mm lens on the Canon 7D with a 1.4x converter, my effective focal length is 400X1.6X1.4=896mm equivalent.
http://photographylife.com/equivalent-focal-length-and-field-of-view I have to contradict with the reply's to this post The only thing that changes is the field of view when you use a cropped sensor. But the angle of view is what causes the distortion. And it remains the same for a lens irrespective of the cropped factor.
Top 50 recent answers are included