Filter Question newbie

I have an old canon 35mm eos which has a filter holder that screws on the lens and I have some filters that slide in to the holder, this doesn't fit my 350d.

Do the new types just screw on to the lens or do I need to get a filter holder that fits my kit lens, and I intend to get the sigma 105 macro, 24-70 f2.8 and the 100-300 f4 so will the filters I get fit all these or will I need to check each lens and get different size filters or filterholder or are there adpters to convert.

Sorry for all the dumb questions

Thanks

Mike

First check your filter holder. Many (Cokin, for instance) take adapter rings for different lens diameters. If yours is one of thes, you'll just need to get an appropriate threaded adapter for your existing one. Rectangular filters come in standard sizes; the Cokin "P" accepts about 75 mm filters, but there are several other filter holders which will also take this size.