www.ukbutterflies.co.uk

hi, i own a canon eos 400d, 18-55mm lens and 70-300mm lens. i also have extension tubes and a 2x teleconverter.

i am considering getting either a flash gun or a 100mm macro lens.

which is most usefull and have you got any good suggestions as to which models are good

I have a 400D and a 300mm IS zoom lens plus a 100 macro and a canon 430 EX flash gun so it should be easy for me to advise. However it depends on what you intend to use them for. I like to take pictures of butterflies and dragonflies using natural light whenever possible but when I'm trying to take 1:1 snaps with the macro lens (small insects or parts of insects) and I want to use a high F number to get maximum DOF then the flash comes into its own although it works best if defused.
Hope this helps
Dave

it works best if defused.

You wouldn't want it going off unexpectedly would you?

Seriously - give serious thought to the 150mm Sigma lens - see many previous posts on this forum.
As far as flash is concerned, with a shortish lens, the on-camera flash will be useful (it works even with a 180mm lens on a 30D, but I think the flash sticks up a bit higher on this).
I have the amazing MT-24 EX Twin Flash - but I find it hard to justify the cost! Cheaper ring flashes are available, but give a wierd flat lighting.
As for extension tubes - the shorter the lens, the greater the effect.
Lots of decisions to make here - it's one of the things that makes photography such fun - deciding on kit.
Good luck.
Roger Harding

Ditto on the Sigma 150mm Macro 2.8.

Gruditch

i think i'll go for a flash gun, because i do a lot of photography at 2-8x manification.( i use a lens bought for £2 and a reversing ring, £7 from hong kong.)

i can't afford an expensive flash gun, im a 14 year old professional photographer who sells cards and postcards to local shops @ £1.20 each.

my list is as follows: Metz 36AF-C
Sunpak PZ42X
Jessops 300AFD
Sigma EF-500 DG ST

any suggestions as to which is best.