I’ve been discussing filters for a while now, and I guess I need to go back one step and explain what a filter is and what it can do.  In photography, a filter is a camera accessory consisting of an optical element that can be inserted in the optical or light path. The filter can be a square or rectangle shape mounted in a holder accessory, or, more commonly, a glass or plastic disk with a metal or plastic ring frame, which can be screwed in front of the  lens.

Filters allow added control for the photographer of the images being produced. Sometimes they are used to make only subtle changes to images; other times the image would simply not be possible without them. The selection of the proper filter is actually far more important than any choice of lens or camera. The filter has a large and real effect on your image. Lens brand and sharpness does not.

The negative aspects of using filters, though often negligible, include the possibility of loss of image definition if using dirty or scratched filters, and increased exposure required by the reduction in light transmitted. The former is best avoided by careful use and maintenance of filters, while the latter is a matter of technique; it usually will not be a problem if planned out properly, but in some situations does make filter use impractical.  Worst case is that the light degradation is inevitable and is something I have to live with when using some filters.

Photographers classify filters according to their use. If you are aiming for cleaner, sharper pictures with less haze, photographers would pick up UV Filters which absorbs ultraviolet rays.  In fact, most photographers leave a UV filter on their camera lens at all times to protect the lens from dust, moisture, scratches, and breakage.

There is what are called Sky Filters - which reduce blush tones in outdoor shots.  We do not have to worry because this keeps skin tones natural and free of reflection from nearby objects.  It can also serve as a permanent lens protector.

Protector Filters are filters which protect your lenses from expensive front element damage which could be caused by dirt, knocks or scratches.

And you can choose also polarizer filters.     The circular polarizer and moose filters  are essential for outdoor photography; deepens intensity of blue skies; reduces or eliminates glare.  Circular Polarizing filters are used on auto focus cameras.  When using non-auto focus camera, use linear polarizer filters and linear focus.

The Neutral Density Filters are devised to reduce the amount of light without affecting the color.  This also eliminates overly bright, washed out images. This is also great for video.

One special kind of filter is the HOYA HMC Ultra Thin Filter.  This is a series or set of high end filters designed to avoid vignetting problems which occur with wide angle lenses.

Filters are commonly used in black and white photography to manipulate contrast. For example a yellow filter will enhance the contrast between clouds and sky by darkening the latter. Orange and red filters will have a stronger effect. A deep green filter will darken the sky too but will lighten green foliage and will make it stand out against the sky. Also see diffusion filters, which are used to reduce contrast.

Yes, filters are needed even if you use a digital camera and edit with Photoshop. Polarizers and grad filters need to be used before the lens and are not well, if at all, simulated electronically. Digital cameras are excused from most of the color conversion filters, since you dial these in as white balance settings. I still use a mild warming filter (81A) on all my digital cameras since I prefer the look I get, even with the WB adjusted warm.

In an earlier post, I mentioned that the first accessory I buy for a camera is a UV filter.  This is mainly for the protection of the camera lens.  Even now now with a UV neutralizing factor built-in with today’s digital cameras, rendering a UV filter unnecessary to filter out unwanted UV rays, I still use one for the protection.

Ultraviolet light is something we can’t see. However, your camera can see it. From an optical standpoint, a digital camera is not as vulnerable to ultraviolet light as film, but a UV filter can cut down on “purple fringing” and/or blue hues that occur in film and some digital cameras. Also, the use of an ultraviolet filter can protect your camera lens.
With the ultraviolet filter, we can achieve improved contrast and color saturation when shooting sunny landscapes, marine and mountain scenes. This filter specifically reduces the effect of ultraviolet light and atmospheric dust.

To maximize the use of the ultraviolet filter, experts have provided us seven steps on how to use this high-end.

Step 1.  Write down the diameter of your camera lenses or take your camera and lenses with you to buy the filter.

Step2. Purchase an ultraviolet filter for each of your camera lenses or opt for a filter system. In this case, you buy a filter-holder for the camera and interchangeable rings that fit your lenses. This is good for people who change filters often.

Step3. Screw the ultraviolet filter onto your camera lens.

Step4. Protect your camera lens from breakage, scratches, dust and moisture by leaving an ultraviolet filter on your camera lens whenever you’re not using a different filter, even when storing it.

Step5. Use a blower brush to remove dust and sand from your camera lens and filter.

Step6. Breathe on the filter or lens, and carefully wipe away any fingerprints or smudges with a lens tissue.

Step7. Take your photos as you normally would. The filter blocks the ultraviolet light.

In theory, UV filters add clarity by cutting UV scatter in high UV environments—e.g., at extremely high altitude (well over 10,000′) or in long shots over water, but most digital cameras are too UV-insensitive to benefit here. Post-processing can suppress or sharpen a hazy blue channel to good effect, particularly in B&W work, but an effective UV filter (most like a haze) might allow you to improve clarity while preserving blue channel data in your color images.

Ask any portraitist or advanced (amateur/professional/hobbyist) photographer and they’d tell you that the hardest subject to take a picture of is a kid.

There are several reasons for this.  The most obvious is that kids have short attention spans.  Another reason is that it’s hard to give directions to kids, as a rule, they don’t follow.  Worse is if the kid is old enough and likes to ham it up before the camera.

However, one viewpoint I can present for this is that the photographer doesn’t have the time to take the shot.  For all the photographer’s preparations, the kid will not cooperate.  Composition is an exercise in dynamics.  In this context, taking pictures of kids is like taking pictures of a fast-paced sports event, or of a photojournalism assignment.  Just a little bit more frustrating because you want to finish the shot as soon as possible.

Patience is a virtue.  Specially when it comes to kids as photo subjects.  Seriously.  The best way to take a kid’s picture is to wait. and wait very patiently.  The alternative is to keep on shooting.  There’s got to be a good shot in there sometime.  When using film there seems that there’s not enough film in the camera.  And it’s a good thing digital cameras came along.

An old rule of thumb for professional photographers, is that out of three rolls of film (each of 36 shots), you’ve be lucky to have one very good picture.  That’s roughly one shot in a hundred.  With careful composition, and lots of patience, this number can be trimmed down to one good picture for every roll.  If you’re not picky, you can just choose one out of every ten. This is particularly true of kids.

However, when using a digital camera and playing with those numbers it just makes lots of sense to keep on shooting.  Of course, when you do that, there would be less composition, more pictures which are off-focus and blurred, you might not have the depth of field you want, and other problems.  The numbers would go up just to find that one picture.  And then you go back to the original problem:  how many pictures of ears and napes does it take before you get that one good picture with the distinctive facial expression?

Me, I’d rather wait, and wait patiently, with the camera aimed at the subject, taking the shot inside my head before taking a picture.   I have found that this is more fun than the shotgun approach.

Most cameras have flash units.  This is a matter of necessity for the most part as most people are not comfortable shooting in low-light or natural light settings.  In fact, most casual photographers don’t know how to take pictures without the flash, and worse, they don’t realize that a flash is very much important in harsh lighting conditions.  It’s a common enough problem, mainly because the regular casual photographer is not really concerned about the small things, but only about the big picture: did the subject appear in the picture?

A flash is an attachment to the camera to provide much needed focused light on the subject.  Normally this is mounted on top of the camera.  And there lies a story about making the shot better, if only the flash was at the BOTTOM of the camera. I’ll explain this in another post.

The nature of the flash is that it provides an instant of bright light to illuminate the subject.  The light lasts just long enough for the image to appear on film, or to be captured by the scanning element/sensor of the camera.  And since this is focused light from a single source, the shadows would appear emanating outward from it.

There are strategies to make the light more diffused or for it to appear from a different direction.  But as long as you’re using a camera-mounted flash, the light will hit the subject and the shadow would be behind it.

If the subject is too close, usually less than 10 feet, there would be uneven highlights.  It it is too far, usually more than 15 feet, then it would be a bit darker.

[An aside, notice that when in an arena, there are lots of flash from the audience when taking pictures of the performers or sports players?  The cameras are automatically set for flash, usually the picture will turn out fine.  But this is not due to the camera's flash unit.  This is because the subject is already bathed in light and the flash is not needed.]

For the most part, the ideal camera mounting is a ring flash.  This is a ring of flash elements mounted around the lens.  The purpose is to have the center of the picture and the flash one and the same.  There would be no shadows.  However, ring flash elements are expensive.  It’s quite rare to find a ring flash cheaper than $300.  However, these really are great accessories.  A side-effect is that if the background were too near the subject, there would be a halo-effect.  Not an altogether bad side effect.

My cameras all have filters.  That includes the (almost permanent) UV filter, which is always the first thing I buy after getting a camera.  Besides that, one of the most understated filters is the polarizer.  I know lots of guys with expensive gear, but no polarizer.  And is hampered when shooting the cityscape and sunset from his 37th story office.

I remember the old Polaroid sunglasses commercial showing a guy beside the pool looking at the girls swimming around.  The sunglasses clear the glare from the water, and sees crystal clear to the swimmers.  That is the basic principle of a polarizer.  This is a very subtle advantage when taking pictures of landscapes and skycapes.  It is particularly evident when taking pictures of the water or the beach.  To explain further, this all relates to that wonderful organ called the eye.  The human eye adjusts what it sees and translates accordingly.  This happens unconsciously and is an important hidden function of the human body.  It works, and that’s all there is to it.

On the beach we see the clear water, and what else is underwater.  With some automatic pre-processing it is a lot clearer compared to taking a picture of the objects under water.  The light which reflects from the underwater object gets diffused before escaping to the surface.  And there’s a lot light reflecting as it hits the surface of the water.  All of this makes for a murky image.

The polarizer is like a fine filter which only allows light coming in from a certain angle.  This resolves the glare and murky image.  The sky looks a lot more blue, a darker shade of blue, in fact.  Taking a picture of someone beside the glass window would lessen the reflection and show what’s out the window.  However, because it filters out ambient light, the resulting images are darker.  It’s usually not a good idea to use flash to solve this situation.  In which case, the only solution would be a tripod for long exposure times.  In my experience, I can live with it.

Yup, after the UV filter, the third thing I bought was the tripod.

This is for all the camwhores out there.  Pardon my french, but the most common camera pose nowadays sucks.  Yes, the most common camera shot is with a camera held at arm’s length and pointing at oneself.  I say it sucks because there is no possibility of composing and expanding the picture.

No offense meant to anyone who’s done that before.  I know I have.  On my wedding day, even.  And that was with a film camera.  But really, there’s only that very close shot and if you’re lucky, you occupy the whole picture.  If you’re unlucky, it might show an ear.  But considering that the digital camera might have a wide-focus lens, the ear only shot is a very slim possibility.

I don’t mean to say that I don’t like the shot.  I actually hate it.  First off, because in all probability, the lens is wide angle, the resulting picture would be distorted.  The face would be a bit fatter, and the nose wider.  As an aside, this is also what happens when you have an ID picture shot at an arcade booth.  I will not go into the psychological study of people who have no better things to do than take pictures of themselves.  To them I say, knock yourself out.

I would much rather use a tripod.  Or at least a camera’s timer.  If there’s no tripod available, you can always set the camera down somewhere and hope it doesn’t fall and take a shot at the sky.  Now if I only had a camera remote control, I would not have ran uphill those several times I went to some hill top spots.

Tripods are cheap.  At least these are much cheaper than the camera.  Come to think of it, I have two cameras of my own, and two tripods.  One camera and tripod set was bought twenty years ago.  I don’t use the camera as often as before, but the old tripod still gets a lot of use.  And I expect to be using it for a much longer time than my film-based camera.

And yes, I bought the tripod so I won’t have to take a picture of myself at arm’s length.

There is however, one exception to the camwhore-camera-held-at-arm’s-length-sucks picture. If a celebrity on the red-carpet was bantering with fans and shot the photo at arm’s length to show him and the fans, then that is way cool!

This is one trick I learned while I was still using film cameras.  Digital cameras are now a lot more common than film cameras, but I still use technique to tweak my pictures.  I’m actually surprised that a lot of digital photographers who use computers to enhance their pictures don’t know this.

The problem stems more from the white balance of a camera.  For most users this is set to auto mode.  And this results in pictures with funky colors, this fault is specially evident with skin tones.  The solution is to adjust levels using an image editor.  In most instances this would be Adobe Photoshop.  I use an open source software called GIMP which comes with Ubuntu Linux.  Either way, the method is the same.

After loading the picture in the image editor, go to “Levels.”  On Photoshop, it’s under the Image menu.  On GIMP, it under “Colors.” Among other things, the levels dialog box shows a graph of the gradation of color.  Say for instance, for red, the graph would show the amount or volume for a tint of red, from darkest red to lightest. On the Levels dialog box, there’s a drop-down menu for Channel (for “All”, red, green and blue).  For each of these values, you move the left and right slider so that the these sliders are at the edge of the graph.  This means that for the left slider, no graph values remain on the left.  And for the right-hand slider, it is at the right side limit of the graph.  Much like book-ends.  Repeat this for the red, green and blue values.

The resulting picture is more vivid and with better contrast than the original.  However, this is not needed for all cameras.  Some cameras have built-in levels which is computed while you compose the shot.  In most instances, there’s very little gain from this exercise.  Most specially for pictures with levels encompassing the whole spectrum.  Or if the camera white balance was set correctly.

Still, I take a look at the levels every time I load up a picture for enhancement or editing on Photoshop or GIMP.  Force of habit, I guess.

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