Newbie canon lens question

Hi Guys

I have just purchased a canon 20d dslr.
I have been looking at the lens prices on fleabay for a 300mm zoom/telephoto lens and find at the moment they are out of my price range.
I have noticed though that some lens for other makes of camera are within my price range and that adaptors are available to make them fit on to my camera.
I know I would have to use it in manual mode for focusing.
My question is. is it practical to do this if so what makes of lens should I look out for and which should I avoid.
Would this cause any problems using the camera.
I have also noticed even though the camera is supposed to be able to use all EF and EFS lens some sellers say not suitable for digitial cameras on their listings for EF lenses.
Why is this?

Hope someone can advise me.

Cheers Jim

What is your budget? The Canon EFS 55-250mm lens can be purchased quite inexpensively. It's not quite 300mm, but 250mm is pretty close.

As a newbie I wouldnt buy any lens that requires an adapter. There might be reasons to adapt lenses to your camera, but thats for later. Manual focusing isnt easy on a DSLR as they arent really made to do that well. As Scott says above, the 55-250 is a relative bargain, start there and have a good learning experience.

Thanks for the replies guys.
At the moment my budget is a max of £40 so you can see there isn't anything im my price range.

Cheers Jim

Jim, what lens do you have now? I understand the desire to have a longer lens, but I just dont think you are going to be happy with an adapted lens.

I would save up for a decent EOS lens. The Canon 70-300 IS, the Tamron VS, and the 55-250 all seem to get favorable reviews here. I have an older Sigma 70-300 (not even a DG), and it is often severely limiting. Wait until you can afford something decent with IS.

It currently has a 18-55mm EFS lens fitted.
I live in Shetland so wanted to use it for otters etc thats why I was looking for a longer lens.

jps71 wrote in post #14435067
It currently has a 18-55mm EFS lens fitted.
I live in Shetland so wanted to use it for otters etc thats why I was looking for a longer lens.

Your best option might be to rent a longer lens.

gonzogolf wrote in post #14435069
Your best option might be to rent a longer lens.

I cant think of any one in Shetland who would do that.

jps71 wrote in post #14435535
I cant think of any one in Shetland who would do that.

There are likely services elsewhere in the UK where they rent by post. Generally you are charged a rate for the 3 days, or week, that you actually have possession of the lens. Once your rental period is done you pack it back up and send it back by mail.

keep saving until you can afford an EF-S 55-250IS...there's no point to waste money on anything else...it'll just cut into the amount of time it takes to save for the 55-250IS

DreDaze wrote in post #14436577
keep saving until you can afford an EF-S 55-250IS...there's no point to waste money on anything else...it'll just cut into the amount of time it takes to save for the 55-250IS

Thanks for the info

I have decided to wait until I can afford a suitable lens.

Cheers JIm