Digital Photography Revealed

White balance adjustment means to adjust the illumination in a picture to white. To accomplish this you must have a neutral in the image like a gray card or a white wall. Software can correct white balance, but not all software solutions are equally good.

The first thing you want to take care of, when you begin to edit your pictures, is white balance. White balance refers to the color of the light and assumes that the best light color is white. Some shots, like sunset or candlelight, do not have white light, but in general an impression of white light is desirable. Some use Photoshop\’s auto levels to set white balance, but that is not ideal, since auto levels just sets the darkest pixels to black and the brightest to white without looking at the mid tones. But what if the lightest pixel in your photo is not white? Or what if you do not have pure black in the photo? (Most images have black areas, but the palest pixels are rarely pure white).

When correcting white balance, the mid tones are the most important and to help set the mid tones correctly one adds a grey card to the photo when taking the picture. A grey card is a sheet of cardboard or plastic colored an exact mid tone neutral gray. Ideally one has three cards: a black, a gray and a white. Photoshop\’s levels adjustment panel has three eye droppers for picking color: one for white, one for gray and one for black. By clicking the gray color picker on the gray card, one can adjust the mid tones to neutral gray. One can only include a gray card in the picture if one intends later to crop the image.

If one does not want a gray card in the image, or if one doesn\’t have a gray card at hand, one can later use specialized software that scans the image and calculates the color of the light and sets it to white. There are problems with such applications: what if there are no neutral areas in the picture to calculate the color of the light from? Some applications do not need a neutral in the photo, but most do to get a good result.

If you work with RAW images, you will have discovered that the RAW converters generally come with a control for color temperature, which means a control to adjust the photo cool or warm. But what if the color of the light is greenish as when you have taken a picture in fluorescent light? The cool-warm control is good for regular incandescent light, but not for fluorescent.

Color correction controls are rarely good for correcting white balance, because the color correction will not just neutralize the gray card, but will also color the photo in an undesirable way: usually the blacks get toned or the whites or both. In short one needs some neutrals in an image to set white balance. A white wall or a sheet of white paper will do well; at best add a gray card for the mid tones.

This article is based on this article about White balance and this one White balance

Vignetting (V) is a common photographic problem. Most lenses and certainly all compact cameras show it. It is most visible at the corners as a radial loss of brightness due to lowered exposure. Vignetting can be used as an effect to draw attention to the central subject of a picture, but in general it is undesirable. There are in fact two aspect to vignetting: The common underexposed corners and the bright centre, called the hot spot.

There are several causes of vignetting: 1. Mechanical. 2. Optical. 3. Natural. 4. Pixel.

Mechanical vignetting can be caused by three things: too many filters stacked on the lens, a too small lens hood attached to the lens, or by secondary lenses. All three may reduce the light at the corners and darken them. The size of the aperture determines if the darkening will be abrupt or gradual. Small apertures create a more abrupt vignetting.

Optical vignetting is inseparable from the lens itself; it is caused partly by the combination of several lens elements, partly by the fact that the lens itself has a considerable length. Another name for optical vignetting is artificial vignetting. The length of the lens is a problem because when the lenses are used with a wide open aperture, the edges of the lens will occlude part of the aperture from oblique incoming light, thus shading the edges of the image. This kind of V is most pronounced in zoom lenses and wide angle lenses. The light in the lens is also reduced radially because the rear lens elements are shaded by the front lens elements, thus causing vignetting. One can often cure optical V by reducing the aperture two or three stops. Very large front lens elements tend to reduce this kind of vignetting and are typically used in wide angle lenses. Lastly, the contrast of the film or sensor plays a part: the stronger the contrast, the more pronounced the vignetting.

Natural vignetting, or natural light falloff as it is properly termed, is not caused by the lenses or mechanical issues, but is a natural light falloff proportional to the angle the light reaches the film or sensor. Technically the falloff is proportional to the fourth power of the cosine of the angle of the in falling light on the film or sensor. Lenses in compact cameras are particularly prone to such falloff. So are wide angle lenses. Telephoto lenses show the least falloff. At large apertures both optical and natural vignetting are present. The combined effect is often called illumination falloff or radial density.

Pixel vignetting is of course only relevant for digital cameras. It is created because most sensors have an angle dependency of the in falling light. Light hitting the sensor at a right angle produces a stronger impression than light hitting at an oblique angle, thus the corners become underexposed. Digital cameras often have a built-in compensation for this, used when converting the RAW image data to tiff or jpg. If one works with RAW images, one will have to do post-processing to remove pixel V.

What is vignetting in photos and how do you avoid it? Source: vignetting in photos.

In the good old days, back in the darkrooms with photo paper, there was a black and white system called multigrade. Multigrade paper was available in six grades and each grade produced images with more or less contrast. Today software provides contrast adjustment, but not all contrast adjustments are equal or equally good.

What is contrast anyway? One (noun) definition of contrast could be: \”The state of being strikingly different from something else, typically something in juxtaposition or close association.\” It can also be defined as (verb): \”To set in opposition in order to show or emphasize differences.\” This means we in photos have three different kinds of contrast: contrast of luminance, contrast of color and contrast of saturation. Most software offers a single contrast slider that edits all three at once.

Software usually alters contrast by simply altering the difference between the middle value (128) and the individual red, green and blue values; like this: R= (R-128) * contrast + 128; and likewise for green and blue. But what if the image is generally dark or pale, then this method will fail. A better method is to use the average values of the images R,G and B channels, like this: R=(R-RAverage)*contrast + RAverage. And so on for G and B. The drawback of this algorithm, in both cases, is that photos tend to become overly saturated and colorful when raising contrast. Similarly contrast reduction makes the image look like you have placed a semi-transparent gray film over it.

Luminance contrast needs special attention. One can use the above algorithms after converting the image to luminance (L) values. The R, G and B channels are not equally bright, so luminance is not just the average of the three. Green is brighter than blue and red and red is brighter than blue. Therefore one usually uses a weighted conversion like this: L = R*0.299 + G*0.587 + B*0.144. This algorithm is used in the YIQ colorspace. Photoshop has a checkbox in their contrast adjustment panel called: \”Use Legacy\”. The problem with this method is that the image becomes pulled towards the primaries R, G and B if you enhance contrast and pulled towards a uniform mid-gray if you reduce contrast. It is not very useful.

However, there are several ways to enhance luminance contrast. First one can simply expand the range: if Lmax is 200 and Lmin 50, then one can for example expand the range so Lmax is 255 and Lmin is 0. But what if Lmax and Lmin already are at the extremes? Then one will have to pull the existing near mid tone L values towards the extremes. This leaves two situations: one will normally lose the mid tones that way and split the picture; alternatively one can use dedicated software that can preserve mid tones while pushing L values towards the extremes.

There exists dedicated applications for luminance contrast adjustment. If one wants to do it in Photoshop, you will have to convert the photo to Lab mode, make the L channel alone active and adjust contrast for that. Remember not to use Legacy or the photo will tend towards either black and white or uniform gray. When adjusting contrast, remember not just to look at the extremes and the contrast in the image, but keep an eye out for the mid tones.

References: contrast and contrast. This article, Problems of Contrast in Photo Retouching has free reprint rights.

Recently I obtained a Nikon D3200, as I\’m a bit of a novice on the subject of Digital SLR photography. The digital camera included an ordinary 18 to 55mm lens, that is ideal for almost all day to day use. Although I immediately found disadvantages while taking photos of countryside, animals and insects or even my children from a distance.

In that setting the next measure may be to take a look for an optic which has a whole lot additional zoom capability. Nevertheless, there are such significant variations in tele photo lenses so it becomes tough to choose exactly what is most beneficial. From zoom range to aperture and also image stabilization there\’s a great deal which usually has an effect on the price tag and affordability of the optic.

For most leisure photography lovers it\’ll depend upon the cost. You are likely to hand over between a couple of $ 100 to several thousands. Dependent on the full focal size and range, along with the maximum aperture, price ranges will begin to go sky high, but there can be a number of sensible choices for a tighter budget.

1st you ought to be certain that you really want a telezoom optic. The primary reasons for getting one are usually if you either cannot or don\’t wish to get closer to the subject of your photograph. A typical example is capturing wild animals, where every movement in the direction of the topic will result in it to move or maybe fly away. Another situation is taking pictures involving young kids. A lot of these in general produce best if your small children are not aware of your camera, hence getting away genuinely will help.

One typical highlight of today\’s optics is picture stabilization. This gets extra important the further you magnify whenever the digital SLR is handheld. The longer the focal length is set, the more trembling from the hands is exaggerated. Yet today\’s technology has found an incredible answer to the problem, which Nikon refer to Vibration Reduction (VR). It is strongly recommended to purchase an optic with this kind of highlight.

The next thing to take into consideration would be the telephoto range. A few of inexpensive devices will probably be restricted to 55-200 mm or maybe 55 to 120mm, and for many individuals this can be quite acceptable. Having said that, if you\’re searching for more significant focal length, you very well may have to go for a 300 or even 400mm lens. Always remember though, that the lengthier the telephoto range the larger and more pricey the optic will likely be.

Another alternative would be to fully replace a kit lens, like the normal Nikon 18 too 55 mm, and go for an excellent 18 – 200 mm model. They are normally a bit more costly than the usual 55 to 200 mm option, however it does reduce the inconvenience of switching in between lenses.

As a final point, the highest aperture might be of interest. With 200 mm many of the cheaper lenses come with a maximum aperture of five.6. This would obviously limit the shutter speed, which is often somewhat of a dilemma anytime shooting mobile subjects for instance wild animals. Specialist photography enthusiasts would in these circumstances go for a 200mm lens with an aperture of about 2.8, yet you would need to be ready to spend approximately ten times as much as for the cheap intro level versions.

There are various entry level Nikon DSLRs and making a decision may be rather puzzling. For some very good advice approximately two quite well known Nikon Digital SLRs be sure you click here for more information.

Chromatic aberration is an important photographic phenomena to grasp. It might sound difficult, but it is easy enough. Imperfections in the lenses create the fringes, that are seen as magenta and blue-green fringes. It comes in two varieties: 1. The individual colors do not focus on the same sensor plane. 2. The individual colors produce images of different size. In the following article we will look in depth at the phenomena of chromatic aberration and how to avoid or solve it.

The first thing to grasp is refractive index, so let us briefly explain what that is. When light passes through a medium, for example the glass of the lenses, the angle of the light changes. Light hits the lens at 90 degrees, but leaves the lens at 80 degrees (just an example). Unfortunately different wavelengths of light have different refractive indexes. For example blue could leave the lens at 79 degrees while red might leave at 81 degrees. This difference will create thin magenta fringes known as longitudinal chromatic aberration. The sensor focuses on the green channel and chromatic aberration causes the blue and red to be slightly out of focus, which creates the combined magenta fringes.

Transverse chromatic aberration arises when light does not enter the lens at 90 degrees, but from a different angle. Here the individual colors focus on the same sensor plane, but not at the same spot, thus the red image will be larger than the green and blue image, and blue smaller than red and green.This also creates colored fringes, but now both a magenta and a blue-green one. It is in the interest of lens manufacturers to avoid chromatic aberration, but since it is in the nature of light, it is hard to eliminate.

The two types of chromatic aberration produce different kinds of fringes. Longitudinal aberration produces magenta fringes around objects and is spread evenly throughout the image. Transverse aberration is absent at the center of the image, but grows in intensity towards the image corners. Longitudinal chromatic aberration is most pronounced in wide aperture lenses. It can be reduced by using a small aperture. Transverse chromatic aberration is most pronounced in telephoto lenses. There are numerous lens designs. So called achromatic lenses have minimal chromatic aberration and are very popular. Superacromatic and apochromatic lenses almost eliminate color errors, but they are not common. Chromatic aberration can be seen on film, but is most pronounced on digital images. One explanation is that the sensors are more sensitive to ultraviolet and infrared light, which are at the outer edge of the spectrum where aberration is most pronounced.

Chromatic aberration can be fixed with software. By sharpening the red and blue channels, one can somewhat correct longitudinal chromatic aberration; the green channel is used to focus the image and is sharp. Transverse chromatic aberration is satisfactorily corrected by radially enlarging the blue channel image and radially reducing the red channel image.

A different kind of chromatic error is the dreaded purple fringe. It appears along hard contrast edges when photographing something against a hard back light, or when photographing a light source against a dark background.The purple fringe invades the dark area. Purple fringes are sensor errors, whilst chromatic aberrations are lens errors. It is very difficult to correct purple fringes with software since it is really an overflow of light from one sensor to the surrounding ones, and is not a simple geometric error like transverse chromatic aberration. Also the original color is usually suppressed. Software can reduce the color of the purple fringe to a grayish tone. At best the local color is not completely eradicated by the purple fringe and can be reconstructed.

This text is a rewrite of this: chromatic aberration I and this: chromatic aberration II

When retouching photographs one should first look at white balance and contrast. White balance is usually the thing one should fix to begin with, then contrast.The reason for correcting white balance first of all is that you can\’t correct color contrast if the image has a color cast.

White balance concerns the hue or tone of the light in the image and sets white as a goal. White balance applications attempt to retouch the hue of the light to white and to do that, the software normally needs some neutrals in the image to find the suitable correction tint from. The whites can for example be a white wall or a sheet of paper or a dedicated white card. The grays are ideally a dedicated gray card.

White balance software comes in two varieties: automatic and manual. Manual correction comes as a temperature slider, which is fine for incandescent light, but not for fluorescent light or mixed light. When converting RAW images, one usually has a temperature slider. Some RAW converters also have three color sliders for red, green and blue. Fluorescent and mixed light can be somewhat corected with color sliders, but unfortunately color sliders usually tone the blacks and whites in an undesirable way. For automatic corrections, the software normally needs neutrals in the image, like a gray card and/or a white card. Some applications can dispense with that, but usually neutrals are needed.

There are three kinds of contrast: hue, saturation and brightness. Normally software only has a single slider for contrast that addresses all three aspects at once. A single slider usually results in an over saturated image and gaudy colors. The best software has two contrast sliders: one for luminance contrast and one for color contrast.

The standard way to manipulate contrast is simply by altering the difference between the individual R, G and B values and the middle value (128); like this: R= (R-128) * contrast + 128; and likewise for green and blue. This method is not suitable for very dark or very pale images. What about very dark or very pale images? In that case you need to change the algorithm to use the average values of the image\’s R, G and B channels, like this: R=(R-RAverage)*contrast + RAverage. And similarly for G and B. Using 128 attempts the same and merely assumes the picture has a full range of brightness values, in which case the average will be 128.

If the darkest and brightest areas are not black and white a different situation arises. If that is the case, one should also be able to expand the brightness range to reach black and white. Levels adjustment is meant for this type of correction. One can do this with Photoshop\’s levels adjustment like this: Convert the image to Lab. Select the L channel only and use Photoshop\’s levels adjustment on that channel only. Then convert back to RGB mode.

Read more about White balance and Contrast

White balance correction means to adjust the illumination in a photo to white. In order to accomplish this one must have a neutral in the image like a gray card or a white wall. Software can adjust white balance, but not all software are equally good.

The first thing you might like to take care of, when you set out to edit your photos, is white balance. White balance refers to the color of the light and assumes that the optimal light color is white. Some pictures, like sunset or candlelight, do not have white light, but usually an impression of white light is the best. Some use Photoshop\’s auto levels to set white balance, but that is not a good idea, since auto levels only sets the brightest pixels to white and the darkest areas to black without looking at the mid tones. But what if the brightest pixel in your photo is not white? Or what if you do not have pure black in the photo? (Most images have black areas, but the lightest pixels are rarely pure white).

When correcting white balance, the mid tones are the most important and in order to set the mid tones correctly one adds a grey card to the image when taking the photo. A grey card is a sheet of cardboard or plastic toned an exact mid tone neutral gray. Ideally one has three cards: a black, a gray and a white. Photoshop\’s levels adjustment panel has three color pickers for picking color: one for white, one for gray and one for black. By clicking the gray color picker on the gray card, one can set the mid tones to neutral gray. One can only include a gray card in the picture if one intends later to crop the photo.

If one does not want a gray card in the picture, or if one doesn\’t have a gray card at hand, one can later use specialized software that scans the image and finds the color of the light and sets it to white. There are draw backs with such applications: what if there are no neutral areas in the picture to calculate the color of the light from? Some applications do not need a neutral in the photo, but most do to get a good result.

When working with RAW images, you will have found that RAW converters usually come with a slider for color temperature, which means a slider to adjust the picture cool or warm. But what if the color of the light is greenish as when you have taken a picture in neon light? The cool-warm slider is good for regular incandescent light, but not for fluorescent.

Color adjustment controls are rarely good for correcting white balance, because the color correction will not only neutralize the gray card, but will also tone the picture in an undesirable way: often the blacks get toned or the whites or both. In short one needs some neutrals in an image to adjust white balance. A white wall or a sheet of white paper will do well; preferably add a gray card for the mid tones.

Here you can read more about white balance. And here: white balance

Photoshop plugins, or Photoshop filters as they are also called, add functions to Photoshop. They are automatically loaded into Photoshops Filter menu. Most plugins focus on effects that are hard to duplicate in Photoshop.. Recently a number of plugins have been produced, that do sophisticated image retouching that would otherwise be impossible or very time consuming in Photoshop. Photoshop has since begun to offer functions similar to some of the old plugins, like lens correction and proper black-white conversion.

Installing plugins into Photoshop is pretty easy. Adobe Photoshop installs with a folder called Plug-Ins inside the Photoshop folder. Simply place the plugins there. Next time you launch Photoshop, the menu Filters will have your new plugins as an entry. If Photoshop was already running, when you installed the plugins, you will have to quit Photoshop and launch Photoshop anew. Actually you don\’t have to install the plugin into Photoshop\’s Plug-Ins folder. This is how to set Photoshop up to load plugins from any folder you like:

1. First make sure you have an alternative plugins folder. Create it where ever you like and call it what you will. 2. Start Photoshop. 3. Go to the menu Edit and open it. Go to the bottom of the Edit menu to Preferences. Open Preferences. 4. Go to the Plug-Ins Preferences. It may be called Plug-Ins and Scratch Disk, depending on your Photoshop version. 5. Activate Additional Plug-Ins Folder by checking it. 6. Click the button Choose to browse to your desired alternative Plug-Ins folder.

That\’s all there is to it! You now have an alternative plugins folder where you can store all your personal plugins. Exit the preferences and relaunch Photoshop. Next time you run Photoshop, the menu Filters should have all your personal plugins listed at the bottom.

There are generally two types of plugins: 1. Retouching plugins. 2. Plugins that add effects. Retouching plugins tend to manipulate what is already in the image without adding anything new. Effects plugins on the other hand add, well, effects to the picture. Sharpening, exposure or saturation would be examples of retouching. Lens flare, bokeh or raster would be examples of effects. The distinction is not always so easy. What about lens correction? Is that a retouch or an effect? If you correct barreling or pincushion, it is a retouch, but if you use it to create the look of a fish eye lens, it is an effect.

Third party plugin support was first introduced in Photoshop 2 in 1991. Three years later Joe Ternasky released Filter Factory for writing third party plugins. Three years after Filter Factory appeared, Alex Hunter released Filter Meister as an improvement over Filter Factory. Many of todays plugins are written in Filter Meister. Ten years after Filter Meister was released, a novel approach to filter development was released as Filter Forge. Filter Forge plugins require Filter Forge to run and they are not stand alone.

More about Photoshop plugins and here: Photoshop plugins

It?s not uncommon for domestic portraiture photographers to head outside on a nice day and take pictures of their model. As a photographer I believe that the studio can make people a little tense. The large lights and digital camera lens can make for a nervous experience. For shy people who want their image captured, a photographic studio may not be ideal.

Exterior sources of lighting such as flash is very vital even in open-air portraiture. You must take your speelite with you to fill any shadows that appear. A reflector is a helpful tool too. You can place the reflector under the persons face to photograph a very abstract shot, or, to simply get rid of shadows beneath the nose and chin. Recently I did a portrait shoot outside. It was of a young lady who sought shots for her collection. She was hoping to break into modelling. After some ideas back and forth it was decided that going to the park was an idyllic way to do the shoot.

Lenses for portrait photography Firstly, one of the most significant features of winning outside portrait photography is the lens you employ. Making use of the right aperture, focal length and depth of field are essential elements to an outside portraiture shoot. A fast photographic lens is the preferred lens by skilled portrait photographers. What is a fast lens? A fast lens is a lens that has a very big maximum aperture. This might be somewhere between 1.8 and 2.8. This will mean that you can allow a lot light in and use a fast shutter.

Imaginative portrait photography ideas You can work out a multitude of creative portrait photography ideas simply by practising. Practising offers with something so incredibly precious: experience. As you start to gain extra practice in outdoor portraits you will see how outdoor light and direct flash work, the best way shadowed areas interrelate on peoples faces and most notably how you can improve next time.

Many of my most creative ideas come from not only getting official education in photography, but in addition, from observing the way light works. Lighting can offer you several good ideas about where to place a person, how to angle yourself to get the best portrait shots.

Outdoor portrait photography poses Posing depends on the gender of your model. There are various poses that a man will take to seem more manly. There are very special stances a female will take so she appears more feminine. Female models look good when the lines of her body are softened as opposed to accentuated. This includes turning on an angle, tilting the head and using the focus on the eyes. You can utilise a foot position alteration to emphasize a posture change.

High key portrait photography What does \”high key\” really imply? Well, if you examine the technical definition it is entirely about reducing the lighting ratio that is present in the scene. What this means, in English, is that the light is overly bright with just the main details in clear, sharp focus. This is wonderful fun and a terrific way to photograph appealing portaits. Can you make use of high key photography in gardens? Most certainly. As long as you have a powerful light source on one area of the persons head for example, you can utilise the flash on the other side. Be sure you secure focus on the eyes first so detail is maintained on the eyes.

Keep in mind that photographing outdoor portraiture photography is a great opportunity to have an attractive setting. A park, seaside or city street scene can increase the story of your photo considerably.

Amy Renfrey is a professional photography teacher. She shows you how to take stunning photos every single time, even if you have never used a digital camera before. Click here to discover/ how to take beautiful photos every time you press the shutter button.

A collection of tips on how to begin photography, makes the perfect starting point for a beginner to emerge and hopefully, begin taking better photos much smoother. You will find those tips right here, and hopefully they will help you enter the world of photography.

If you are presented with a low-light photo opportunity, you need to set the aperture, also known as the f-stop, properly. Adjusting the aperture will open it further, allowing for more light to flood the camera lens as you capture a photo.

Do you want to take a photo that features a rain effect? You can create this effect yourself with a spray bottle that you can mist over the subject to give the appearance of \”rain.\”

In your minds eye, picture the viewfinder as being segmented into nine equal parts, three horizontal and three vertical, like a tic-tac-toe board. Put the object you are photographing on one of the lines instead of in the middle.

Cropping is an easy way to improve your photos. A picture could be perfect, but what about that random person in the background? More commonly, a perfectly fine image may not be centered correctly. Fix these problems and crop the picture.

If you are taking any landscape pictures, there are three main things that you will need to have. They are a foreground, a mid ground, and a background. This concept is not exclusive to photography, however. Painters rely on the idea to add visual depth to their creations.

One of the first things you should learn is how sharpness affects your photographs. Sharpness usually appears in the center of your lens, where the focus should be. Sharpness then begins to degrade the closer it gets to the outer edges of the lens and the image.

Take some time to learn the focus-lock feature that is on your camera. Most cameras have auto-focus, which locks the focus on the object at the center of your viewfinder. If you want to place a subject off center, you can use auto-focus to your advantage. This is often achieved by gently pressing the shutter button while aiming the camera at the subject. With the button half-depressed, physically move the camera to frame your shot. Depress the shutter the rest of the way to snap the shot.

Resist the temptation to maximize the number of available shots you can get on one digital card; instead choose settings that will allow a far greater quality for output printing. These lower settings should only be turned on when the images you shoot are intended for viewing on the screen of your computer. The quality will suffer in any other display medium.

It can be difficult to take pictures in a low light environment. The photos have a tendency to blur. It is important to keep your hands, and therefore the camera, as steady as you possibly can when trying to take a photo in low light. Bracing them on a stationary object is the best way to go. Consider buying and using a tripod.

It can cause a few problems when taking a photograph because the photographs tend to blur in low light. When shooting in low-light, keep your hands as steady as you can. You might even want to place them on something when you are taking the photo. You might want to consider investing in a tripod.

With the above knowledge in hand, it will be much easier for you to take great photos. When you apply the skills and ideas you just learned, impressing others with your photographs is easy. With a little time and effort, you can even attain an expert skill level and start taking professional photographs for other people.

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