What are the use of glass filter (for the digital cameras) especially the Black filter?

Question

Do I need that on my Canon 350D?

I am only using the provided 18 - 55mm lens. THANKS

Thanks! antoni.

THANK YOU SO MUCH!!! for exerting extra effort in sharing your knowledge. :)

Answer 1

Hi

the "black" one is a polarizer they are for removing glare and reflections and make blue skys richer and the clouds stand out more

example of polarizer shot

http://flickr.com/photos/martini2005/1841374596/ - its like a sunglasses effect

EDIT: you might mean ND filters, but i dont think so, if you are they are for reducing the light the sensor/film recieves so slower shutter speeds can be used

EDIT2: vance and Dr Sam have answered you well, Masons emotive answer proves he knows very little about photography, doubt he owns a polarizer or knows how to use one.......vance or sam for best me thinks


a

Answer 2

For digital photography you will use:

1. Neutral density filters (graduated and or single density) to control exposure.

2. Circular polarizer to control reflections. This is useful for a wide variety of situations where most people don't realize there are reflections. Landscape photographers use it to get greater saturation in foilage because the reflections of the leaves reduces it.

3. UV filter. This is rarely needed and many people just keep it on their lens to protect it. There is some debate about doing that and I personally don't use one for that. Mason mentions that digital cameras are shielded from UV at the sensor. That's true, but at high altitudes, say 8,000 to 13,000 feet, I find that I do get a blue cast with my Canon.

That pretty well covers the filters for digital. There are IR (infrared) filters, which Antoni mentioned, which is a specialized use filter to record images from the infrared light reflected off objects and various special effects filters.

Your 'black' filter maybe a neutral density filter, but it is more probably a polarizer. If people know about filters at all, they have probably heard of polarizers and seen pictures showing their effect. The can understand that and it makes them a popular filter.

Without meaning to offend anyone, most people don't understand enough about photography to want or need a neutral density filter. For instance, you may want to use a slow shutter speed to get a blurring in moving water such as a waterfall. You want a specific shutter speed so the blurring isn't too much. You also want a shallow depth of field, which means a wide open aperture. This would be a good situation for a ND filter. If you know how exposure works, this will make sense. Maybe 3-5% of all people taking pictures ever go to that amount of planning to their shots.

I am going to throw this in because one of the digital hotshots may/will say something like 'You can blur the background in photoshop, so you don't need the ND.' True, but the blurring in photoshop spreads the shadows into the lighter areas, whereas the optics of the lens spread the highlights into the shadows. It gives a very different look to the image, less muddy and cuts down the work that needs to be done in photoshop. Point for the old fashioned technology.

Oh, another use for a UV filter, you can spread Vaseline (or similar) for special effects, put colored transparent tape on them and do other things for self made special effects. Clean them off and you can do it all over again. I find them more useful for that than anything but high altitude work.

Vance

Answer 3

The Black Filter is actually another name for UV filter (more basic photography that some people here should have already known). You may be familiar with the term 'Black Light' which is another name for UV light.

Black filters are beneficial for film photography but they have no use for digital photography since UV light doesn't affect digital sensors. The only use would be to protect the lens but I never use them because they only give more chance of lens flare.

Answer 4

Well, the "black" filter could also be an infrared, used to block out all visible light and show only the infrared. These filters call for long, tripod-ed exposures.

http://dpfwiw.com/ir.htm

Answer 5

Since you are asking about buying a general set of filters without telling us what they are, I will guess that you are looking at a "filter kit" from one of the manufacturers. These generally include three different filters.

Mason, since this asker is describing his filter as "black" and he doesn't know what it is used for, I am assuming that he is simply describing the appearance of the filter. If he knew the use of the term "black filter" for a UVA filter, he would not be asking this question. I will proceed with that assumption.

They always have one that is pretty much clear glass, such as a UV/haze or a Skylight filter. Many people like to use these as "glass protectors" for the front element of the lens. I have decided that, if it is valid to protect the front glass, I would prefer to do it with plain optical glass rather than alter the colors in my final image right across the board. I have found that even the "most plain" filters - other than optically pure glass - always influence the final outcome, so I will reserve their use for those times when I want those effects.

The kits always have a polarizing filter. This may be the "black" filter that you are talking about. The effect is quite obvious and sometimes dramatic. When light is reflected, the light rays become "aligned" by the surface fromwhich they are reflecting. They are not coming at you in a million random directions as they are when they are bouncing off of all things in nature, but they are "polarized," which means "all in the same alignment," by the reflecting surface. The most common use for a polarizing filter is to "see through" glare when you are shooting a picture through a glass window. Practically everone here has done that. Another common use is to cut the glare from a body of water so you can actually see the water instead of all the shimmer and sheen that wipes out surface details. Even light in the sky is polarized, because it has not been broken up too much by reflecting off of something. Have you ever worn "polarizing" sunglasses? If you have, you know that it's not simply a matter of putting some dark plastic between your eyes and the sunlight. The lens is "polarized" in a direction that is perpendicular to the usual path of the sunlight, so it blocks it even more efficiently than it would if it was simply a dark piece of plastic. Let's carry this one step further. If you tilt your head sideways while wearing polarizing sunglasses, they allow more light to pass and hit your eyes. It doesn't matter if the "target" is the back of your eyes, film or a digital sensor, if you reduce the amount of light, it will have an effect on what you or your camera "sees." A polarizing filter will allow you to "darken" the sky and make clouds stand out more in your images. I actually recommend a polarizing filter as the FIRST filter that someone should buy, as it is by far the most useful - especially in digital photography where so many "virtual filters" are easily applied in post-processing.

There is a chance that the "black filter" is a neutral density filter. I've seen them in kits, too. This is of value in any camera, but especially in a lower line digital camera where you may not have very many adjustments (especially as far as lens aperture goes) to control how much light enters the camera.

Another filter that is often in kits is called a "color enhancing" filter. The purpose of these will vary depending on the manufacturer who selects the kit. Some are "warming" filters to add some "pop" to your colros. Some are biased towards portrait work and render "more pleasing skin tones." This third selection is kind of a potpourri and it depends on the manufacturer or retailer.

Now...

What do you need with a Canon 350D?

I'd get a plain glass filter from Canon, Tiffen, or Hoya if you believe that you need lens protection. I'd get a polarizer as the most useful filter you can buy - even for a digital camera.

Here's my stock "filter" answer for you:

I've got a UV filter on my 18-200 lens and (oddly enough) a Skylight filter on my 17-55. I think I was going to compare to see what the difference was and I never paid much attention to this. I never had filters on my lenses before I got into the high-price spread of pro level lenses. I guess I have fallen for the idea of protecting the investment. You can also get optically pure plain glass filters, which I am now startin gto buy instead of the UV or Skylight filters. I didn't think that either the UV or the Skylight make much difference, but I did a comparison recently, since someone else asked about this and I have changed my mind.

"This is a sample image for those who ask whether a UV filter will alter the colors in a digital camera image. Download the image, cut a small section out of the top half and drag it to the same section in the bottom half and see what you think. The photos were taken about 15 seconds apart in subdued sunlight, so I think the lighting was virtually identical for each. There was no post-processing at all so you can make a fair comparison."
Nikon D200 - ISO 100 - 18-200 VR lens @ 112 mm - f/5.3
http://www.flickr.com/photos/7189769@N04/441244796/

Here is another sample comparing a Skylight filter and a UV filter - either one of which is supposed to be "neutral" when placed on your lens for protection. Okay, there may be a difference in the color of the lenses themselves, but they are both Nikon lenses, so I'd hope they are not too far off from each other. The difference in color is obvious, especially in the sky. Anyone who says that digital sensors are not affected by UV light needs to see this comparison.
http://www.flickr.com/photos/samfeinstein/1793551691/

I also own a circular polarizer for my 17-55 lens. I bought this for a specific job where I had to shoot through a glass display window and then shoot some photos in an exhibit that were under glass. I have used it only a couple of times other than that job, but I always had a polarizer for my film cameras. It's nice to use on a sunny day or especially if you are doing any shooting near water. Talk about "not cheap." Price a circular polarizer from Hoya for a 77 mm lens!

I used to have ND filters for the film camera also, but so rarely used them I gave them away. I can see how a split ND2 or ND4 would be nice at times, but I never tried one.

Answer 6

Paging Dr. Sam and fhotoace. Please give another answer (if there is any).