Filter Ring Stepping

Filter Ring Stepping
Will lenses made for Slr Cameras fit my 55mm non Slr Camera. Do SLRs have a different mount,or have threads to

I have an Olympus SP 510 UZ/ 7.1mp/10 zoom. I purchased the conversion tube to give me a 55mm thread. I seen on the internet with, and with, that there were alot of cheep prices on the SLR lenses made for different Model cameras. I plan on buying a 75mm-300mm zoom lens,so will the SLR Lenses fit my camera if it says; Accepts 55 or 58mm Filters. I know I would have to but a step-up ring, if I got a 58mm lens. Also, I have another question about; I seen prices for a 75-300mm Cannon SLR lens for 119.00, is this an auction site,or is there a catch to it; like a high shipping fee.

I fear we are talking about many, different realities…
The zoom lenses for SLR becoming cheap because of the digital boom. But if it says it’s accepting so and so filters, that mm value goes for the FRONT of the lens, the backside is specifically fitted for the different brands – Nikon/Canon/Minolta/etc. So, unless you get a conversion ring which says “converting Olympus mount to Nikon/Canon/Minolta/etc. you will not get lucky.
And check carefully the maker of those zoom-lenses; usually, it says SOMEWHERE, that lens made “for” Nikon/Canon/Minolta/etc. not “by”…i.e. we are talking about a 3rd party supplier…
Good luck!

Digiscoping. Attaching a camera with a filter thread to an Olivon spotting scope