Nice exposure and subject. The BG complements the subject as well. I agree that the white strip is distracting. I might have experimented with different shooting angles to try to minimize the foreground a bit. As is it is a little overpowering.
Hi Thijs. Good sharpness and a nice background. Yes, the white is distracting - you might want to tone that down some. I would also suggest cropping from the bottom to reduce the visual impact of the OOF foreground. Another option might have been to use a higher f/stop (since you were using a tripod and if the newt cooperated) to get the legs and tree more in focus. :)
Hi Thijs, agree with comments above and would have suggested a higher F stop for more DOF. Would have liked to have seen more of the legs in focus. Good you chose to put the subject on a diagonal but as stated the large oof area is distracting.
Nice use of lighting and backround...
Thijs, the newt and the BG look nice and clean. You already know the white area needs work and I agree with Steve that removing some of the OOF area in the FG would be a good idea. When in the field, I think taking a step to the left and using a smaller aperture might have resulted in a better shot. Newts are generally cooperative (dumb and slow :)) subjects so you may have been able to move it to a better location to remove some of the OOF area in the FG and without that white section. Just a few things to think about the next time you come across one of these little guys.
I like the sharpness of the eye and skin texture captured. A little higher shooting position may also have worked but the one chosen gives an interesting perspective. Agree with the comments on a narrower aperture to increase DOF. The white area may be easily cloned over.