Using auto extension tube on standard lenses for macro purpose

[MEPER]

Here the 35mm extension tube is back on the 50-250 DX kit zoom. Lens set to 130mm and full aperture. I think the lens is better corrected for CA in at "mid zoom" setting.
At 50mm at full aperture the lens did not perform very well. Maybe if I stop down a couple of stops. Did not try that.

I used the AF to focus. It was not shortest distance but quite close to it.