Brotherly photoshoot (critique needed)

[Zach]

Hey guys my brother asked me to take some Portraits of him, and of course I was glad too, this was some good experience for me too since I don't take many portraits (not by choice, I just don't know anyone) so I got to work and below are a few I took, and no photographers were harmed in the taking of these photos.

need Critique for these, don't worry I can take it haha

P.S. [these shots were taken with the canon 40mm pancake]

1 very light post work done here.

my brother by zachary T., on Flickr

2 again just light work done.

IMG_7975m by zachary T., on Flickr

3 cropped, 2 photos merged to get pistol barrel and eyes in focus.

Untitled-1m by zachary T., on Flickr

4 cropped, converted to B/W, low-key effect added, again 2 photos merged for eyes and barrel.

Untitled-2mmm by zachary T., on Flickr

5 The Experiment easy to tell what I've done here mostly just for fun.

test 2 by zachary T., on Flickr

a tripod was only used for number 5