What Flash?

[Frey]

I am thinking of doing a course (I am a real novice) and have been told I would need a flash gun. I have Canon 300D and 500N. Are there any that will work on both cameras, I can't afford to buy two and I probably can't afford the most expensive either! Can anyone tell me what my best options are, please.

[rent]

you probably want something with E-TTL so any of canon's EX line of flash would work. the 220EX is ~US$110, the 420EX, ~$170.