It should be noted that there are different strengths of UV (Sometimes called haze) filters, as there are skylight filters. Tiffen, just for an example, has several UV filters that they offer:
UV Protector - Protects lens from dust, moisture, scratches, and breakage. Haze 1 - Reduces excessive blue haze caused by UV light by absorbing 71% of UV. Recommended for all-around UV control. Haze 2A - Absorbs all UV light; reduces haze; maintains color and image clarity. Best for high altitude and marine scenes. UV 17 - Created for the photographer who wants to absorb most but not all UV light. It absorbs slightly less UV light than the Haze 2A. Warm UV - combines the benefits of the UV 17 with the Tiffen 812 Color Warming Filter for added warmth. Other companies may have similar variations in their filter lineup. B+W has several variants of the UV or Haze filter. In some situations the "minus blue" filter may be a better choice for eliminating the blue found at high altitudes and in other environments, but not all companies make such a filter, which is a yellow filter that falls within a particular range. Not every yellow filter has the same characteristics. One B+W "UV" filter is the KR6, which is suited for daylight with a high percentage of blue (midday in the mountains during the summer), and which is recommended for color film.used in situations where an extreme blue tone is to be expected. Not only does it block ultraviolet light and reduce blue tones in the shade, but it also penetrates light fog. The bottom line is that it's easy to slap a UV filter on your lens and believe you're getting a certain result, such as the results provided by some of the above and similar filters. Unfortunately, many people believe a UV filter is a UV filter, or that all skylight filters are the same. Such is not the case, and the clever photographer chooses his or her filter with careful thought to the desired results. As for cleaning Multi-Coated filters, the two best cleaners that I;ve come across are the ones sold by The Filter Connection (I think it's their MC formula) and the cleaner sold by ClearSight. Both do a remarkable job with no streaking or leaving of residual haze or film, as another perennial favorite, ROR, cab do if not carefully applied. Shel > [Original Message] > From: Mark Cassino > Hi Boris - > > I did a simple test with Hoya HMC filters vs Pentax SMC - I took them out > into the sun and tried to see how much of a reflection I could bounce off > the filter onto a dark wall. The SMC filter was noticeably better in this > test. > > Does it mean anything? I don't know, but I use a filter on my A* 200 macro > to protect the front element, and I figure it's penny wise but pound foolish > to slap an inferior filter on an excellent lens. > > In regards to protective filters - I only use them when there are identified > risks that could damage the lens. Like little children and food (it's nice > to be able to just smile at a little tyke who just put his greasy finger on > the _filter_ in front of your camera lens, as opposed to traumatizing him by > snatching the camera away....) For macros in the field I use a protect > filter because it's easy to poke the front element of a lens when you are > poking around in brush etc - and when you have the lens set to close focus, > you don't always see potential hazards in the finder. Bus absent an > identified risk, I don;t use a filter unless I need the filter effect. > > It's also important to take into consideration those situations where a UV > filter or Skylight is truly valuable for it's optical effect. I think > there's a tendency to view these filters as merely being protective, but > they will actually improve sharpness, cut haze, and help color saturation > when shooting outdoors, particularly if you are shooting distant subjects, > in bright sun, in situations with high humpty, dust, or smog. > > I don't know why, but I've found cleaning multicoated filters (Pentax, Hoya, > and Sigma EX) to be very difficult. Maybe because you can rotate it and > really examine the glass, and any little imperfection is more apparent. I've > found Kodak lens cleaning paper to do the trick - after thoroughly cleaning > with a microfiber cloth, a few wipes with a single sheet of paper does it. > > - MCC > > - - - - - - - - - - - - - - - - - - - - > Mark Cassino Photography > Kalamazoo, MI > www.markcassino.com > - - - - - - - - - - - - - - - - - - - - > ----- Original Message ----- > From: "Boris Liberman" <[EMAIL PROTECTED]> > To: <pentax-discuss@pdml.net> > Sent: Monday, May 30, 2005 9:32 AM > Subject: Questions re Pentax made lens filters > > > > Hi! > > > > For some time I've been using el cheapo (Cokin plastic et al) > > protective filters on my lenses. Some time ago I stopped doing so. > > Then recently I found that some of my lenses are now dusty inside. > > Then on eekBay I found that there are Pentax made lens filters. Some > > of them are even SMC. > > > > Are they worth it? How do they compare to other manufacturer's filters? > > > > Finally, but please don't let it be a flame, if not Pentax, what are > > the protective filters that match optical quality of lenses such as FA > > 50/1.7 or M 50/1.4 that I have? > > > > Then of course as usualy I may be nuts again... I mean may be filters > > have nothing to do with dust inside lenses... > > > > Thanks. > > > > -- > > Boris > >
