I shot this photo some years ago. I saw this chopper of our German federal police (Bundespolizei) in the air and thought I try to take a photo with my Tamron 70-300mm lens. Of course, I had to do heavy cropping and applied noise reduction to the image. But I think it’s not too bad. You even see the “Bundespolizei” logo on the tail of the chopper. Don’t ask me what kind of chopper it is. I have no clue about this.
Diary of Dennis 
Nice photo! I photograph our local Metro police choppers too.
I find it quite difficult as they fly pretty high here… even with my 70-300mm lens, it won’t work without maximum cropping. On the other side, I am quite amazed how good noise reduction works after you cropped the hell out of an image. Pretty amazing.