Unfortunately, this is not true... A crop from a noisy sensor is a noisy crop. DPReview has a very enlightening blog post showing that more pixels does not produce a better image even if you downsample. Same thing would apply to crops. A long telephoto lens on a small sensor with a lot of megapixels is a formula for bad pictures. If you are looking for a long TF shots, do yourself a favor and get a real SLR camera.