I wanted to do some macro and eventually micro photography cheaply using a digital point and shoot camera. I want to stick with a point and shoot even if a digital SLR is more suitable to take good pictures of tiny things. My objection to the DSLR is that it is much more bulky and heavy especially with an add on lens.
So my present equipment it a Canon Powershot A620 7 megapixel camera bought used from Ebay. It can focus an incredibly close distance of 1 cm which is 3/8" away from the subject. But I found that this close focus ability was often negated by the lens barrel bumping into the subject or objects around the subject.
I did some web surfing and found that there are several ways to improve the macro capability and shoot a longer distance away from the subject. Also good if the subject is alive and easily spooked to run or fly away.
There are add on close up filter lenses usually of +1, +2, +3 diopters. I don't know what this translates in power but I think this is like the magnifier reading glasses which use the same + designation for the strength of the glasses.
To attach the close up lens I also had to buy a cheap lens adapter to attach the lens to the camera. On a DSLR you can attach the close up lens directly to the normal taking lens.
I bought a cheap set of close up lens made by Bower from Cameta Cameras. The lens set is made in China and is a set of +1,+2 and +4 which can be stacked by screwing into each other giving a +7 power which seems to be equal to the magnification of the Canon macro when focused at 1 cm.
So here are preliminary quickly taken comparison photos of the stacked +7 Bower lens vs the Canon in camera macro at 1cm. The first photo is with the in camera macro at 1cm. The second photo with the Bower +7 diopter lens. The photos aren't very good because I was rushed but you can see that the Bower lens set does give the orchid more depth of focus so more of the flower is in focus while the in camera macro gives a very small plane of focus.
The rest of the photos are of the camera and lenses.
And a whimsical photo of a dead fly badly lit and focused.
Still not close enough but a start.