Question Step-up / step-down adaptors

Hi all,

My existing lenses are all 77mm diameter, but I see that Canon's new wide
angle offering is 82mm (which I'm going to get).

I don't want a collection of 77mm AND 82mm filters if I can avoid it - is
there any penalty associated with just buying 82mm filters and using a
step-up adaptor when there's a need to mount them on the 77mm lenses?

Conversely, when a unit like the Variable ND is only available in 77mm, is
there much vignetting when shooting with an 82mm wide angle lens? I'm
assuming small amounts of vignetting when shooting wide-open, and negligable
amounts when stopping down???

Many thanks,

"Rita Ä Berkowitz" ritaberk2O04 @aol.com wrote in message
...

Ah, the new 16-35/2.8 II. Please post some pics from it when you get it?

Will do. I've got the new 1D Mk. III & 580EX Mk. II ordered, so I'll get
them out of the way first then see how healthy the retirement savings are
looking compared to budget!

Stepping rings are cheap and a good alternative to buying filters for
every
lens. Using an 82mm filter on all your 77mm is OK if you could live
without
the possibility of using the lens hood. This isn't a problem for filters
that you occasionally use, but can be frustrating for the popular ones.

Ah - hadn't thought of the lens hood issue - will probably have to go 82mm
for UV and polariser. Unfortunately the Variable ND only comes in 77 - and
I'm probably going to need the WA a lot of the time - so will have to see
how we go on that one. At present I'm stuck with a 24-70 F2.8L USM on a
20D - and I'm finding it's just not wide enough for a lot of the landscape
I'd like to shoot.

A smaller filter will work, but might vignette at the widest angle. Canon
has enough problems with light falloff and vignetting on the WA lenses and
I
wouldn't want to induce more by going cheap on the filters.

I understand that it's been an issue in the past - but perhaps not so much
of an issue now that they've gone to 82mm? In any case I don't mind tweaking
in PS.

Have you
checked B&H for this model in 82mm? Good luck.

Yes. I like Heliopan filters - and (off memory) B & H have the usual
suspects in 82mm.

Thanks for the info