OK Roy...so the focal length is 560 for everyone..ok?.
I did take your advice and the first Google hit gave me the stuff included below.
However....my question still remains....a 5D will get a reach of 560 max and I will have to crop into the image to achieve anything like the image (FOV) that an APS sensor will get.
My point is that a 1.4x extender will get me nowhere near what I am seeing from Keith et al ??:C
Clearly I am new to digital photography as the last camera I owned was a 35mm Olympus OM4 and whilst I may not have the terminology down pat I'm pretty sure you know what my issue is
So in my attempt to learn from folks that are/have been doing DSLR bird photography using long lenses and talking about 560 or 896mm is puzzling.
I would really appreciate if you, or anyone else could enlighten me to what I am trying to ask?
For all I know I could be making a big mistake trying to stick a 1.4x extender on a 5D, so what would really be appreciated is some help rather than just a suggestion that I go Googling for focal length as opposed to FOV.
Thanks
Jamie
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http://www.millhouse.nl/digitalcropfactorframe.html
The field of view reduction of the digital camera is obvious.
This is also known as the crop factor.
A 25 mm lens on a DSLR camera is no longer a wide angle lens, but corresponds to a 37 mm lens on a 35 mm film body.
The D1X (and currently all other Nikon DSLR cameras) has a sensor size of 23.7 x 15.5 mm.
This sensor size is sometimes referred to as APS size.
As a result the effective field of view is 35/23.7 = 1.5 times smaller.
This is indicated in the picture below.