Filter fitting- 550D

[Jez O]

Can anyone tell me how a filter fits to my Canon 550D with kit 18-55mm kit lens (and 55mm-250mm lens) please.
It appears to have a screw thread at the end- does the filter screw in? Looks a bit fiddly if so.

I know I'll need a 58mm filter- looking to get a polarising and ND filter.

Cheers in advance.

[SamHH]

Yes, they screw in.

You can either get round ones that look like this:



Or square or rectangular ones that slot into a holder which screws onto the lens, like this:



Most sort of filters come in both varieties. Round ones are a bit simpler to use, square ones are better if you're going to be changing the filters from shot-to-shot or if you are going to use graduated filters (ones whose strength varies across the filter).

[dirtbiker]

Bear in mind that both the lenses that the OP mentions have front elements that move when focusing which will make a square filter holder a pain to use. If you're using a graduated filter or a circular polariser you will have to re-adjust them each time you focus. It's a bit of a pain but not the end of the world.

The screw in threads aren't as fiddly as you'd think but are prone to jamming if you get sand/dust in the threads so be careful with that one.

[LongQ]

Jez O said:

Can anyone tell me how a filter fits to my Canon 550D with kit 18-55mm kit lens (and 55mm-250mm lens) please.
It appears to have a screw thread at the end- does the filter screw in? Looks a bit fiddly if so.

I know I'll need a 58mm filter- looking to get a polarising and ND filter.

Cheers in advance.

If you go for the screw in type AND intend to stack them (ie use two or more filters at the same time) remember that there is potential for the filter to appear in the corners of the image as they will likely be at the edges of the angle of view.

You can allow for this by buying larger filters and an adapter (Step-up) ring where the adapter fits to the lens and the filters screw into the adapter.

The downside of that is that usually the lans hood will become useless with the filters fitted. On the other hand most lens hoods make using adjustabole filters (like polarisers) difficult anyway so the trade off might not be too great.

[Jez O]

Thanks all. Don't think I'm quite ready for stacking multiple filters yet, so that's something I don't need to worry about! Will a polariser also serve to cut out light purely for longer exposures in daylight, or do they do a massively different job?

[LongQ]

Jez O said:

Thanks all. Don't think I'm quite ready for stacking multiple filters yet, so that's something I don't need to worry about! Will a polariser also serve to cut out light purely for longer exposures in daylight, or do they do a massively different job?

Yes.

And yes.

A polariser will indeed reduce light throughput by up to 2 stops - and can be combined with an ND for a greater effect. (Which is why I mentioned stacking filters...)

But a polariser does have a different function to perform and so is not a direct replacement for ND filters as such.

[Killwilly]

The movement when focusing on both lenses mentioned by the OP is negligible, perhaps one or two millimeters at most. I use a Hoya circular polariser on both of my Canon kit lenses without problems.

Edited by Killwilly on Tuesday 13th September 07:46