Thank you very much. The extension tubes have done more to broaden my photographic possibilities than any other single acquisition I have made so far. I kind of love making use of the old "obsolete" M42 lenses and accessories, and they certainly fit in with my po' boy budget. Were it not for them, I wouldn't have 1/5 the lenses I currently have. I've managed to fill my camera bag to overflowing for less than the price of one modern high quality autofocus zoom that would cover the same range. And I enjoy the extra "hands-on" involvement of manually focussing and setting the aperture. I even get a kick out of guesstimating settings on flash exposures and am inordinately pleased with myself when I get it right on the first try.
I've found the 55/1.8 is turning out to be a better lens when put to macro use than it is when used in its normal function. It has been a good utilitarian lens, though not outstanding. I wouldn't care to part with it at all now that I've seen what it can do for me in a macro role.
Just to clarify: The pen top was with the tubes, and the hatband was with a +3 macro filter.
Today I decided to see what they could do in combination. Here is a 100% crop of the IR mark on my Super Takumar 135/3.5.:
Next I'm going to experiment with adding my 2x teleconverter to the mix.