Disclaimer: I'm a newbie. Old hands should feel free to rubbish the post, but it'll just prove how out of touch you've become
I have selected Canon Rebel XSi to buy based on my budget.
Xsi Body with 18-55IS, 55-250IS and EF 50mm f/1.8 II
now I have 500$ remaining on my budget.
which one should I buy in the below,that is very essential or that
covers wide range :
28-135mm f/3.5-5.6 IS -- 380$
EF 70-300mm f/4-5.6 IS -- 550$
17-85mm f/4-5.6 IS -- 450$
None of these do anything
that different to the lenses you've already chosen. As your budget is not squillions, I'd spend it on better stuff like...
and what am i missing in the kit? SD card,right?
Yup, an SD card or two. A cheap 4Gb one is enough for 300 RAW+Jpeg shots. No moving parts makes them reliable, so cheap mainly means slow*. The camera has a buffer (albeit small) so paying $$ for a fast card doesn't get you
that much benefit. If you're snapping sport or other fast stuff it could be worth the premium.
You're definately missing a tripod and camera bag. Neither is essential, but they're as close as you can get to it
A circular polariser and an ND filter might be nice for experimenting with. A UV filter to protect the 18-55 is recommended by some. Given the price of half decent filters I just got the cheapest - they'll do for learning with. I'll splash the cash on half-decent ones only if I'll get the use from 'em.
A hood for the 55-250 would be useful as well. If you're spending more than a day away from electricity a spare battery is an idea (cheap as long as you don't mind going 3rd party -but fewer electrons; likewise with the hood).
A wired remote is cheap. Again, 3rd party ones are half the price and do the same job. Along with the tripod this will let you do all sorts of cool stuff.
You might want to take the time to find a really good book on photography. There's a lot of rubbish out there - books on digital photography date fast, and film photography books miss out on quite a bit of interesting digital-specific stuff.
After that the only things you'll need are a blowy thing with a brush to get dust of the lens. A microfibre cleaning cloth is ace too - so much better at cleaning my glasses than the yellow cloth that came with 'em.
Right, so that's it. Be cheapy-cheap on everything but the tripod (search the forums for advice on how much to spend) and you are completely, totally and utterly set** whilst still within budget. Spend any leftovers on beer/flowers for the wife. Jobs a good'un.
I did like the suggestion of just spending the $500 on the flash+tripod thobut...
...and the suggestion to stick just the kit lens would mean you'd get ace at composition and all that other stuff you ignore when you've got toys to play with instead.
- Well, cheap prolly means less reliable as well, but 1 in a squillion chance of failure instead of 1.5 squillion is still pretty reliable.
until you need to get dust of the sensor...