The NIKON Thread (Talk About Nikon Stuff here)

[Gil Schwartzman]

I have a question for all you folks in the know... still learning...

I ordered a pack of lens filters today, just as something to play around with. It has a warm filter, a polarizing filter, and a UV filter. I figure if nothing else, they will serve as a way to help protect my lens. But, doing a bit of research on what filters actually do, I am a bit confused. The warming filter is sort of self explanatory, the others, not so much. The polarizing filter, I can see what it does through examples online, but I can't seem to find a solid answer as to why it does what it does. Hows it work? Also, from what I saw, the polarizing filter made for some nice shots. It made me wonder what the point of the UV filter was. I was under the impression that a UV filter was basically just to help in keeping the sun out of your lens shooting outside, but offers no real visual enhancement, whereas the polarizing filter makes for some nicer looking colors. I guess my question is, in what scenario would I want to use the UV filter over the polarizing filter?

[jmmtn4aj]

Polarizer - Wikipedia, the free encyclopedia

UV filters were made for film cameras in film days when UV light would interfere with the exposure, causing fogginess and such. With digital it doesn't affect that much, if at all any more. Most people with digital cameras buy UV filters simply for the protection of their lenses.

People normally keep the UV on all the time until they want to use a polariser (or any other filter), then they remove the UV filter and place whatever onto the lens, and remove than and put the UV back on when they're done. The UV is meant for protection after all.

[ServinginEcuador]

Gil,

A polarizing filter is for one of only a couple of circumstances. I'd try and explain it, but there are simply too many articles that are better. I copied some links that are easy to understand at the bottom of this post.

UV filters are used 24/7 on lenses simply to protect them and block any large amounts of UV light from messing up your exposure. UV can't be seen with the naked eye, but still strikes your lens and if the lens isn't coated will end up messing up your exposure. This line of thinking started with film cameras, and with modern CCD and CMOS cameras isn't as big a problem. It can add a bluish tint to photos if it's allowed to get to the CCD.

Found this online:

Polarizing Filters

These deservedly popular filters, also known as polarizers, use the inherent polarization of atmospheric scatter, glare and other unwanted reflections to remove such photographic pests selectively and prospectively from the light entering your camera. If you shoot much outdoors, the ability to mount a polarizer is reason enough to invest in a filter-capable camera and the required adapters.

Used properly, polarizers can darken the blue of the sky, highlight clouds, suppress unwanted highlights and improve general color saturation by suppressing atmospheric scatter and color-robbing reflections off water, glass, sunlit foliage, vehicles and even bald heads. (In wide-angle shots showing lots of sky, however, you may get better results with a GND.)

Polarizers are admittedly more complicated to use effectively (and to know when not to bother) than one might hope, but once you develop an understanding of the ways in which scattering and reflection add polarization to light in the photographic environment, polarizers become very simple. Digital rangefinder users often complain that they can't see their rear LCDs well enough in bright sunlight to adjust a polarizer properly under TTL (through-the-lens) control. But as long as you're after maximum effect (as is almost always the case), you can easily learn to adjust a polarizer reliably without TTL control.

Polarizers always require substantial exposure compensation. In strongly polarized ambient light, a polarizer can easily cut to 3-4 stops or more. In the absence of polarized light—or when set at 90° to the prevailing target polarization or target directions—most polarizers end up acting as 1- to 2-stop (0.3-0.6) neutral density filters.

To my mind, there are no polarizer advantages unique to digital cameras, but digital cameras with limited dynamic range can benefit greatly from the selective suppression of excess contrast discussed next. Due to the limited UV sensitivity found in most digital cameras, polarizers also provide a welcome and effective alternative for haze control at favorable camera-sun angles.

Polarization Primer

Scattered light, glare and other strong reflections can degrade photographs in many ways—e.g., by diluting colors, by obscuring or distracting the viewer from important image details, or by forcing suboptimal exposure compromises. Luckily, nature tends to tag such "bad light" with varying degrees of polarization, and that marker provides an easy way to suppress the "bad light" while capturing the good.

Most of the primary light sources encountered in photography—the sun, moon, indoor lighting, flash lamps—are unpolarized, meaning that the electric field fluctuations accompanying the light are oriented equally and randomly in all directions perpendicular to the light's direction of travel. If all the light's electric fields were oriented in the same direction, we'd say it's linearly or plane polarized. Other types of polarization—e.g., circular and elliptical—are seldom encountered by photographers outside their cameras.

Unpolarized light typically acquires polarization through absorption, scattering or reflection.

The Reflection Method

This method uses a strongly polarized reflection as a reference.

* Find a flat, shiny tabletop, countertop or water surface with bright reflections. Don't use a curved surface like a car fender here.
* View the reflections obliquely through your polarizer at an angle near 35° above the reflecting surface. This special angle (Brewster's angle) will insure that the reflections are maximally polarized by the bounce. (If yours is a circular polarizer, be sure to hold it with the male threads toward you.)
* Keeping this aim, rotate your polarizer until the reflections are maximally suppressed. The polarizer's blocking axis will now run parallel to the reflecting surface and perpendicular to the reflected light's direction of travel to the camera.

Links:
Filter options for digital cameras
Using a polarizer effectively without TTL control

[Happymonkey]

Not to mention the two types of polarizing filters you can get, linear and circular.

[Towert7]

Well, I just ordered myself a Nikon 35-70mm F/2.8D lens. I really want to see how this works for people shots, as I plan to do a lot of people shots now. I have high expectations of this lens, even if it's a 20 year old design.

Should be interesting to see the types of pictures I get from it.

[bloodydoorknob]

The Nikon 35-70mm F/2.8D is a superb midrange zoom lens. I found it to be great for portraits, but on a dx camera, it could use a little more on the wide end for those big group shots (weddings).

[Towert7]

Ah, that's great to hear!
Yea, the 1.5x was a little concern to me. I have a 35mm fixed and the angle is acceptable for getting a few people in.

At the moment I'm still building up my experience, so I don't need the 1000-1600$ lens quite yet. ^_^

[lan]

I thought about that lens also but settled on Tamron 17-50, and 50 and 85 mm primes.

[OverlordXenu]

I just got a used F100, and Adorama shipped it without a body cap...

Anyway, the mirror, insides, and outside are filthy. Example below...
http://i28.tinypic.com/5xo56w.jpg

NOTE: The above is a somewhat large pic (1600*1200) and I was not the one that touched the mirror.

How in the hell do I clean the mirror et al.? I have some alcohol swabs, 91% isopropyl alcohol, and some cottons swabs, but I don't want to leave fibers all over the place. At least, on the inside optics et al. What about the outside? Would the alcohol be too harsh?

Thanks guys. Photo-fi FTW!

(I have no tripod, so excuse the blurry pic...)

Edit: Anyone have any recommendations for B&W and color slide film?

[Towert7]

Well thankfully the junk on the mirror will not affect the final picture quality (since the mirror flips out of the way of the film). Still, that looks like a pain when viewing it. And to be honest.... if the mirror looks like that, chances are other parts of the camera aren't much cleaner. Might be worth it to just bring it to your local camera shop and have them give it a good cleaning if it's cheap.