Filters up front or at the back of wide angle converter ?

[wolfgang_fener]

Hi,

Background:
I use a Canon S5iS and a Canon wide angle converter WC-DC58A. The converter screw into a 58mm LAHDC20 adapter.
I often use this adapter with a B+W (Schneider optic) 58mm polarizer and/or UV filter when I don't need the wide converter.

Question :
My problem is there's no thread at the output of the wide converter so I can't attach any filters there. Anyway quality filters of this size (>77mm) would be more expensive than the wide converter so that's not a wise option.

Except for possible vignetting, would the UV and/or polarizer filters work as well if installed behind the converter (in between the adapter tube and the wide converter) or is it mandator to install filters at the far end ?

[djwixx]

I don't believe there's a way to connect the filter to the adapter then the wide angle to that, or does the adapter have a screw thread, so the filter screws to that then the adapter screws to the filter? If so, there's nothing to say you can't do it, and it's certainly worth trying to save on the expense of a larger filter. Some people reverse lenses stack lenses etc. to get the required results, so nothing is mandated. If you can get it to work, try it and if the results are what you want then keep trying anything. Adding any extra glass has a potential to create vague problems, so be aware of the requirements of the filter and expose accordingly. Generally speaking a CL filter will result in a loss of 1-2 stops so you need expose to compensate. It looks like you're buying quality filters so that's half the battle won.

Depending on your setup (aperture and focal length) vignetting may already be present anyway, so I doubt the filters will add anything noticable to what you already have.

[wolfgang_fener]

I did a few tests last weekend.

It is impossible to fit a filter between the adapter and wide converter. There's some kind of protruding ring outside the wide converter back thread that prevent you to do this (I guess this prodtruding ring is there to proetct the lens, without it the lens would possibly touch the table if you where to put the converter on a table). I did a test shot holding the converter with one hand and there was way too much vignetting.

I see two solutions : grind out or saw/get rid of the protruding ring so you could srew the converter on a standard filter (which still may produce vignetting) or somehow fit a threaded ring (a step up ring maybe) to the wide converter to allow you to screw a large filter (which would cost more than the wide converter itself).

I'll just forget about it.

For me, this wide converter is only usefull to shoot group of people indoor with an external flash. For landscape, it only offers very limited use because you can't add filters. Glare may also be a serious problem depending on the position of the sun.

With the S5 and its accessories, you get what you pay for...