After getting my Nikon D800 back from being repaired by Nikon (a tale for another post), I attached my 1.4x lens extender to the D800 together with my 300mm f/2.8 lens to capture some soccer. With the 1.4x extender attached to the D800, the 300mm lens effectively becomes a 420mm. That's a focal length that's very useful for soccer. Given the extremely high 36 megapixel photo capturing ability of the D800, the ability to capture the far reaches of a soccer field while maintaining photo sharpness after cropping is useful.
Each of these photos were shot with the D800 and 1.4x extender attached to a 300mm f/2.8 lens.
Shutter speed 1/8000; Aperture f/5.6; ISO 900; Original Pixel Size 36.2 MP; Cropped to 7.8 MP
Shutter Speed 1/8000; Aperture f/5.6; ISO 800; Origianl Pixel Size 36.2 MP; Cropped to 8.4 MP