On the subject of lenses, I use a Sigma 150mm with a Canon 20D body. I used to use a Sigma 105mm until I “upgraded”. I would say that the main benefit of 150 vs 105 is not only the working distance, but principally that the 150 does not extend as it focuses and is silent, and the 105 used to scare off the subject sometimes, especially when close. I would say that if you’re thinking about which to buy, the 150 is probably better as you may well want to upgrade later.
Regarding hand-held, I am a convert to tripod. I used to think that hand-held was just as good (even though the combination of the 150 and body is around 1.5kg) but I was persuaded a couple of years ago to persevere with a tripod by a Dutch friend and expert photographer, Peter Groenendijk (
http://www.anythingbutcommon.nl/), who made the sensible suggestion of comparing my hand-held shots with shots using his tripod. You may not see the difference until you make the comparison.
So I used a cheap tripod, costing around £30, last year and was pleased with the results, even though it was tedious to have to extend the legs and snap six levers into place. But when you get a subject that is roosting or seriously nectaring, a tripod comes into its own. At the start of this year I bought a Manfrotto Neotec tripod, a superb but expensive piece of kit that allows you to just extend the legs and they automatically lock into place. Using this with a ball-joint to allow easy and immediate movement of the camera, to get the required angle fast. With practice, I found I could judge the positioning to get the right shooting angles quite quickly. I also became quite paranoid about the micro-shake of pressing the shutter button and invested a few pounds on a remote shutter release. I found when I got truly still subject, I could scale down on the shutter speed from 1/160 in stages down to 1/10 and get improved depth of field without the shake you would expect from such a long exposure. The Amanda’s Blue on this page (
http://www.butterfliesoffrance.com/2008 ... s_grid.htm 4th row, far right, click on grid photos to enlarge) was shot using this combination at a shutter speed of 1/25.
I would suggest buying a cheap tripod and sticking with it for a season or so. If you really can’t get on with it, it’s no great loss.