Of course it is all a matter of opinion and as such we will never agree. Fine by me and I respect your opinion.
To me, cropping pictures is OK even if plane parts are taken off. Basically the rule for me is:
- I want the aircraft centered in the picture
- I don't want to have a large part of the picture 'empty'
To show you what I mean the following at A.net. The first picture has the complete aircraft, from wingtip to nose. However, because of the angle, you get the plane on the right and the wing on the left. So, aircraft is not centered and you have a lot of 'empty' picture on the left.
http://www.airliners.net/open.file/1200769/L/" onclick="window.open(this.href);return false;
The next shot shows a little bit the same, with the plane in flight. Again, by keeping the whole plane in the picture you get an off balanced picture (the way I see it anyway).
http://www.airliners.net/open.file/1204906/L/" onclick="window.open(this.href);return false;
In this picture however, the picture is cropped and part of the wing is chopped off. In my opinion the picture is much better balaneced, as now the plane is in the center and there is not much 'empty' space.
http://www.airliners.net/open.file/1204173/L/" onclick="window.open(this.href);return false;
However, in the example ruudb gives, there is no need to chop of the tailend. This indeed looks like a 'bad' picture to me. If the whole plane was on it you will still have it centered without much empty space. So in that case I wouldn't have cropped it.
The way of course, to eliminate the problem all together is taking side shots. But only taking side shots gets too boring, so I just need to crop a little and actually, those pictures often look better to me than the side shots....
Yes, it is a matter of personal opinion....
Erwin