when I went to Helgoland I wasn't really sure what to see or plan any images. But I learned one think 500/4 and 1.4x TC can be to much or open room for details?
EXIF: D7100 & AF-S 500 f4D & TC14EIII
700mm, f8, 1/1250s, ISO 320, -1ev
1.3x Crop active = 1400mm
I'm OK with such a tight crop especially with nice details like this, I just wish you did not have the light coming from behind the subject. I think you also had room room to stop down more by raising the ISO. Fun image.
Lovely details on this one. There are some tight portraits that really work, and this one does. However, I would clean up the left top corner with a slight crop or brush and crop some off of the bottom to just under the black portion of the bill to tighten up a little more.