UV Filter For My Schneider APO 210

At the risk of starting another taste great-less filling argument over UV filter quality and types. I'd like to poll readers of this great site ab out the type of UV filters used, and whether I should even consider it an issue at all. Are multicoated UV's necessary, the Schneider's multicoated, is there such a thi ng as too much coating? Are there different types of coatings used and could the differences cause you more harm optically than good? I want,as most of do, to get the most of our lenses. I try buying the best I cou ld afford so I can concentrate my efforts on composition and technique. I've noticed however, it's difficult seperating hype from facts. I welcome your thoughts.

The new Heliopan SH-PMC multi coating is 16 layers (8 per side) repels moisture and dust to keep the lens surface cleaner and the top layer on each side is now much harder to reduce the possibilty of scratching.

Additionally the new coating reduces flare to a new low - more then 99.9% of the light striking the filter is passed to the lens.

All common filter types are supplied with this new coating and Heliopan uses onl y slim rings (with front threads) as standard. The slim polarizers do no have front threads. The Heliopan slim mounts will not vignette with lenses as wide as a 21mm on 35 or its equivelent on other formats

I use a B+W 021 light yellow filter as a UV filter. This is, of course, for when I really need to filter out UV light. I don't own a clear UV filter for lens protection. If I needed lens protection, I would use a Tiffen with no coating, so it would be easy to clean. I would not worry much about MC. My favorite lens, a G-Claron, is single coated and works fine. MC can get in the way, as it can be hard to clean (Formula MC is the only cleaner I know that cleans, rather than smears an MC filter), and it can wear off or be damaged.

I use all B+W's and like them very much... not the most expensive but very well made. Cheers

Editor: I've deleted a duplicated thread. Here were the answers posted.

Albert, I use Hoys SHMC filters and find them fine. I tried Heliopan once but found that the filter rim is much deeper than the Hoya and was concerned over possible vignetting with wide angles. As for too much coating, who knows? The Hoya are available at reasonable prices too. Regards Paul Answered by paul owen (paulowen_2000@yahoo.com) on March 04, 2001.

Today all common Heliopan filters, warming, cooling, black and white, etc. are supplied standard in slim rims only. As to "possible vignetting" did they? Answered by Bob Salomon (bobsalomon@mindspring.com) on March 05, 2001

I'll second the Hoya HMC filters as giving a very good price/performance ratio. They seem every bit as good as any B&W or Nikon MC filters. Unfortunately, Hoya seem to be reducing their range of HMC filters now. I don't see why you think you can have 'too much' multicoating. Multicoating isn't like coats of paint, where it can get runny if you apply too much. Lens coating works by easing the passage of light from air into glass. Ideally we would like a coating which gradually changed from a refractive index of 1 (air) to ~1.6 (or whatever the refractive index of the particular glass is) throughout its depth. Such a variable index material would be nice, but doesn't exist. The closest that we can practically get, is to build up microscopically thin layers of different transparent materials, one on top of the other, to simulate the effect of a variable index material. The more layers, the closer you can get to zero reflection across a wide spectrum of light. So, basically, no, you can't have 'too much' multicoating. For all you purists, I know this is a simplistic view of lens coating, but a treatise on wavefronts, electric fields, impedances and dielectric properties is a bit out of place here. Answered by Pete Andrews (p.l.andrews@bham.ac.uk) on March 05, 2001.