Super Macro >=2x with MFD >=1ft @ a budget

Not sure what you mean by "focus by teetering". If you are changing the lens to window distance, that's not the same experiment.

 

If your distance from the front window to the ruler is only 1" and the lens to window distance is greater than 1", then your results are not surprising. The magnification effect is only significant if the front of the lens is close to the window and the distance through water is similar or larger than the lens to window distance.

With fixed magnification, the only way to move the plane of best focus is to move the camera+lens assembly. I do this by teetering back and forth. Do you move the plane of best focus by moving the camera+lens or by changing extension (= changing magnification)?

 

Lens to subject distance was approximately 2", lens to front glass distance was approximately 1", not that different from your setup.

In my setup the camera is fixed on a tripod and the macro lens focuses internally (I used auto-focus). So, camera lens to window and camera lens to subject are fixed. So, that accounts for the difference in results. Interesting.

Here is a photo of my setup (with water in the jar). l[ATTACH=full]1334721[/ATTACH]

From the picture this looks like whiskey tumbler to me?

This setup will always give a magnification because a round glass is used, when filled with water the glass-water surface will produse a lens like effect.

In addition, a normal drinking glass is not optically optimized, so the results may vary by just turning the glass a bit, or moving up or down.

The container had a rectangular cross-section and a flat front wall. Only the screw lid was round.