That's pretty amazing on a budget. It looks like you're getting dangerously close to true macro size with that set up.

What lenses are you using specifically and what's the sensor size on your camera. I was thinking about saving for a macro lens, but if you're getting that sort of result out of cheaper equipment, I'll probably put that off for quite a while.

Terry
Great shots, the bug is a Sloe Shieldbug (Dolycoris baccarum) . I used close-up filters for years before I bought the wonderful Canon 60mm Macro for my 40D. They always worked better on prime lenses than zooms and I think any lack of sharpness is due to the zoom lens, and would not be improved by the Canon 2 element version. For slightly more money you could get a second-hand 50mm f1.8 lens, which I used to use in the negative days. It's a great lens for portraits as well as macro with a CU filter, and should focus faster than your zoom.
One word of warning - photographing insects is addictive!

Brian

Terry
I used the 100mm for a time, but the problem was that at least 33% of shots were out of focus or had camera shake - you really need a tripod for it, and one is essential for longer lenses. With the 60 hand-held virtually every shot I take is sharp (as long as they stay long enough). I never really get the feeling that I scare the insects into moving - they stay or go in their own time . Don't forget that with a modern DSLR you don't need to fill the frame, 1/2 or even 1/3rd is good enough for the web or an 8x6 print (using QI ), and shots with the beast a mere speck can be good enough for an ID. Here's one I shot recently, although I didn't know I had it until I got home



and another



I've got more on my website but I haven't touched this bit of it for a year and I've just noticed that the  thumbnail page has gone t*ts-up, but if you click on one of them you can click through the large pics.

http://www.secalis.co.uk/CWood/index.html

Brian

It is a pity no one makes a stabilised macro lens, perhaps there's a technical reason.
Sigma also make a less expensive 105mm macro lens which would be better from the hand holding point of view.

The very close bug picture shown was at 300mm and it was very difficult to frame and focus; with 150 mm it is much easier so I wonder if a combination of that with a +4D close-up lens would work better.
I get definite chromatic aberration with the +4D simple lens, that's why the Canon 2-element item may be much better.
Terry.

It's most likely because IS shouldn't come into play. IS isn't normally supposed to be active when the camera is on the tripod. I've noticed sometimes if I've got my tripod completely extended that the IS will kick in a bit, but under normal circumstances if you're needing IS then you're probably beyond hope of macro work.

Plus macro lenses are expensive enough as is, throwing in something as expensive as IS when there's so much else that the money could go to providing in a lens is a waste.

Getting a 105mm macro isn't a bad idea, it's just a question of what one is trying to shoot and how much one values the extra working distance that the longer lenses provide. Probably the main reason I'd need the longer lens is to keep the shadow out of the area. But, I'm not sure how good of an idea natural light macro really is.

That's a good point though, if I do go that route, I'll probably splurge the extra $20 and get the 100mm f2.8 that Canon makes, from what I gather it's a better lens. I'm kind of curious why people seem to like the 150mm Sigma more than the more expensive 180mm f3.5L that Canon makes at the top end of their range.

That'll probably be the last of me thread jacking this thread. I'll have to look into it elsewhere, but I think that it looks like a good option if one can make due with one of the lower priced diopters, otherwise, if you start paying more than $150 or so, getting a 100mm macro starts to look really attractive.

Finale:
Brian said I know, been there done that.
I've just recently dug out my old macro slides from the 1970's and scanned them.
They can be seen here: http://www.pbase.com/tjm04/macrofilm
But one sample is below, a Lacewing Fly at 8 x magnification.


Terry.

I know this is late, but I never thought to use my 70-200 for macro.
I just know I will learn something from this forum   

Great examples
Ya Me