Help me with these definitions

wxwax · January 16, 2006

Some bright spark had the idea of making a glossary of digital photography terms. And of giving me the project. :wxwax

The idea is to explain in layman's terms what our weird words mean. Layman's terms? I'm the man for the job. :1drink But the problem with being a layman is that I don't know much.

So I need your help. Check out the list I have so far. What mistakes have I made? What needs to be added?

Think of this as your charitable contribution to the cause. Not tax deductible. I don't think.

wxwax · January 16, 2006

Brightness
The amount of light your image is putting out, or reflecting. The overall lightness of your piccie. A well-exposed photo has good brightness, without being overexposed. Also, think of the color in your image as being broken down into three components – brightness, saturation and hue.

Burning and Dodging
Lingo from the old darkroom days. Dodge means to make a portion of your shot brighter. Burn means to make a portion of your image darker. Can be applied to Shadows, midtones and highlights.

Contrast
Having distinct bright and dark portions in your image. As opposed to a more uniform, or grey, lightness. The brighter the brights and the darker the darks, the more contrast you have. Contrast is generally considered a good thing, makes your shot “pop.”

Crop
Literally, cut off a part of your image. Imagine taking a pair of scissors and snipping off parts of a photo print. Usually done to help the composition or to remove distracting elements.

Exposure
How much light has been allowed into the camera to make your image. Underexposed means you let in too little light and everything’s too dark. Overexposed means you let in too much light and everything’s too bright. Digital cameras don’t have as much dynamic range as film so are more sensitive to over- and under-exposure.

Dynamic Range
Your camera’s ability to handle a wide range of light, from bright to dark, in the same image. Digital cameras have a narrow dynamic range, far more narrow than film used to make prints. That is to say, they have a hard time handling extremes of darkness and brightness in the same picture. For example, bright sunlight with a deep, dark shadow.

Panorama
Several shots arranged to give a larger perspective than is possible with a single image. Usually the photographer pans their camera along the horizon, taking images that overlap one another. The shots are arranged side-by-side in the post-production process.

Red Eye
What happens when a flash is at the same angle and close to your camera lens when you take someone’s picture. Their eyes seem red in the image. Can be fixed in post production. Or by using a flash that’s not as close to the lens.

Sharpen
Make the edges of things in an image more distinct. When you sharpen a photo, you make the focus seem clearer, or sharper. You also see detail more clearly. This is a post-production technique.

Anti-aliasing
Removing the tiny jagged edges in the curved lines of your digital images. Your digital photo is made of millions of tiny pixels. They’re square. Squares don’t make good curves. Corners stick out. Anti-aliasing smoothes out these corners so curves look even, not jagged. Cindy Crawford thanks you.

Color profile
Computers are dumb. They need to be told how to handle color. The instructions are called a “color profile.” Because life is complicated, there is more than one kind of color profile in the world. Each has its own uses. It’s a good thing to know what color profile your camera and your software are using, when you post-process your images.

Feathering
Making a sharp edge seem softer in your image. Usually used when making a selection in post-production. You often soften its edge so your selection blends-in more naturally with the background.

Gamut
The number of colors your eye can make out is your eye’s color gamut. Gamut = range. Your eye is the top dog when it comes to color gamut. Your camera, your computer monitor, your software, your printer – they all have their own color gamut, or range. And all of them are more limited than your eye’s. All hail the human eye.

Gaussian Blur
Makes your image blurrier, or out-of-focus, usually for dramatic effect. Imagine holding a piece of gauze in front of your eyes. It makes what you’re looking at a little blurry. If it doesn’t, go see your eye doctor. You can get the same effect with computer software in post-production. Most programs have a filter called Gaussian blur, that allow you to control the amount of blur. By the way, Gaussian has nothing to do with gauze – it’s actually a math thing. And therefore incomprehensible.

Masking
Literally, putting a mask over a part of your image. It’s a technique used in post-production. When you want to change only a part of your image, you “mask” the parts you want to protect. That way your changes are only applied to the parts you don’t mask.

RAW
A way of saving your photo so that the camera does as little processing to the image as possible, before storing it. This gives you a lot of flexibility in post-production to change your photo’s exposure, saturation, sharpness, contrast and more. Normally, your digital camera’s processor will control all of this to make your picture look good. Expensive digital SLR’s give you the option to tell your camera not to.

Resolution
The number of tiny little pixels that make up your digital photo. The more pixels you have in a given space, the more detail you have. Detail is considered a good thing. A lot of people use the words resolution and detail interchangeably.

Unsharp mask
This is the post processing filter you use to make your digital photo sharper. It’s also a perfect example of making things more confusing than they need to be. You’d think they’d call it the “sharpen” filter. But nooooo.

Histogram
A handy graph that shows you how the light in your image is distributed, from light to dark. It will also show you if you’ve exceeded your image’s dynamic range. Digital SLR’s can show you a histogram for each photo, so you can adjust your exposure while you’re shooting. Good photo editing software does too, so you can better control your photo’s brightness and contrast.

Layers
A magical way to edit your photograph without changing the original image. In a darkroom, when you make a change, you can only do it to the original photo you’re printing. But with some photo editing software, you can make an almost unlimited number of copies of your image. They’re all stacked on top of each other, in “layers”. And each layer has a single change made to it, like contrast or saturation. When viewed from above, the image you see combines all the changes from each layer. Even better, you can “turn off” a single layer, and see what it looks like to remove one of your changes. And you can “mask” portions of each layer. It’s a wondrous thing.

Sharp/Soft
Jargon for in-focus or out-of-focus. Sharp means in focus, all the lines and the detail are sharp. Soft means the opposite, everything looks soft, no sharp edges or detail. You can improve your piccie’s sharpness with “unsharp mask” or make it softer with “Gaussian blur.”

Hot
Jargon of over-exposed. A portion of your piccie is “hot” if it’s so bright it’s white and you can’t see any detail in it. This the worst sin you can commit – you cannot recover detail from a hot, or overexposed, portion of your image. This is where “RAW” and “histograms” come to your rescue.

Bokeh
Blur. When the subject of your piccie is sharp and in focus, and everything else is out of focus, the out-of-focus stuff is called bokeh. It happens when you set your lens to have a narrow “depth-of-field”. It’s a great way to draw attention to your subject. Bokeh is a Japanese word that means fool. As in “to fool”. I hope.

Shadows
The darkest parts of your image. Specifically, the darkest 30% of your shot. The relationship between your shadows, midtones and highlights constitutes the contrast of your photo.

Midtones
The tones that fall between shadows and highlights in your image. No kidding, huh? Roughly, the lightness that makes up the middle 30% - 70% of your image. The relationship between your shadows, midtones and highlights constitutes the contrast of your photo.

Highlights
The brightest, lightest 30% of your image. The relationship between your shadows, midtones and highlights constitutes the contrast of your photo.

Composition
It’s what you decide to include inside the frame of your picture. Composition is the order in which those things appear, their relationship to each other. The human eye finds some visual relationships more pleasing and interesting than others. Check out the “golden ratio” – it’s fascinating stuff.

Post-production or Post
Work you do to your image after it leaves the camera. With film, it’s what happens in the darkroom. With digital images, you use software in your computer. Photoshop is the current king of the post-production hill. Also know as post-processing.

Selection
A tool in your photo editing software that lets you outline, or “select”, a specific part of your image. You can then copy that selection and put it onto another photograph as a layer. For example, you can select a bone from one photograph, and add it to another photograph that shows a happy dog. Or you can make changes only to your selection, leaving the rest of your shot unchanged.

Filter
A way to add effects to your photograph. With SLR cameras you can put a filter in front of the lens to get an effect. The people who make photo editing software have taken the same concept and gone wild with it. You can make your photo blurry, make it sharp, distort it, all sorts of whacky things.

Saturation/Desaturation
The intensity of the colors in your image. More intense color = more saturation. If you desaturate your image, you are removing the color from it. A black and white image is completely desaturated.

Depth of Field
The amount of your image that is in focus. All lenses are capable of putting everything in focus. But you can make some lenses put only a small part of your overall image in focus. This is called a narrow depth of field. You need a lens that has a long focal length and a wide aperture to get the narrowest depth of field.
Here’s the technical language for it: “The amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in your photograph. Depth of field depends on the size of the aperture, the distance of the camera from the subject, and the focal length of the lens. The bigger the aperture, the greater the depth of field.”

Tone/Tonal Values
This can mean a couple of things. It can mean the color cast of your image – warm tones mean there’s more red in the image, cold tones mean there’s more blue. Check out the definitions for color temperature and white balance. There’s a second meaning, too. Tone can also mean the relative amounts of lightness and darkness of your piccie – the feel of it.

Golden Ratio
This is literally a mathematical formula that describes shapes that the human eye finds pleasing. For example, the shape of Cindy Crawford’s face matches the golden ratio. Lucky her. You can use the golden ratio to organize the elements of your photograph into a pleasing assemblage. Literally, the golden ratio is 1.61803, or the ratio of a diagonal of a pentagon to its side. Huh?

Warm/Cold
An image is considered warm if it tends towards being red. And cold if it tends towards being blue. It all has to do with color temperature and white balance.

Color Temperature
This is how the color spectrum in light is measured. It’s the actual temperature of different colors in light, as measured in degrees Kelvin. Red and blue are at opposite ends of the spectrum. Red is considered warm and blue is considered cold. The higher the color temperature, the more light is being put out.

White Balance.
A setting in your camera, or in your photo editing software, that makes sure white is displayed as white. When you have white set properly, all other colors in the spectrum will also be correctly displayed. If your image is too warm or too cold, chances are your white balance is wrong.

Color Cast
When the colors in your image don’t look like they should, when they have a tint. If your grass seems too red, for example, then you have a warm or red color cast. Usually this happens when your camera has the wrong white balance.

wxwax · January 16, 2006

OK, that's the list so far.

Any suggestions?

DavidTO · January 16, 2006

Wow. What a great start!

My thoughts (as unqualified as I am...)

Change "arranged side by side" to "stitched together" in the Panorama one.

Red Eye: the flash is bouncing off the retina, reflecting back red.

Sharpen is all good, but you should say that sharpening can only do so much, and won't make a blurry photo in focus.

Feathering, change "naturally" to "gradually"

Maybe mention adjustment layers in the layers definition? Or make it a separate entry?

Depth of Field: that whole "bigger the aperture" thing always confuses me, at first. That's because the number's bigger, but the aperture is actually smaller. Anyone else get confused by that?

Shay Stephens · January 16, 2006

How about this...

DavidTO wrote:

Depth of Field: that whole "bigger the aperture" thing always confuses me, at first. That's because the number's bigger, but the aperture is actually smaller. Anyone else get confused by that?

Depth of Field
The amount of your image that is in focus. All lenses are capable of putting everything in focus. But you can make some lenses put only a small part of your overall image in focus. This is called a narrow depth of field. You need a lens that has a long focal length and a wide aperture to get the narrowest depth of field.
Here’s the technical language for it: “The amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in your photograph. Depth of field depends on the size of the aperture, the distance of the camera from the subject, and the focal length of the lens. A small aperture like f/16 will have a wider depth of field than a large aperture such as f/2.8 which has a very narrow depth of field.

DavidTO · January 16, 2006

Shay Stephens wrote:

Depth of Field
The amount of your image that is in focus. All lenses are capable of putting everything in focus. But you can make some lenses put only a small part of your overall image in focus. This is called a narrow depth of field. You need a lens that has a long focal length and a wide aperture to get the narrowest depth of field.
Here’s the technical language for it: “The amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in your photograph. Depth of field depends on the size of the aperture, the distance of the camera from the subject, and the focal length of the lens. A small aperture like f/16 will have a wider depth of field than a large aperture such as f/2.8 which has a very narrow depth of field.

Works for me!

wxwax · January 16, 2006

Cool stuff, thanks guys.

David, I avoided "stitch" as that adds one more definition to the list. But I guess it needs to be there anyway.

Shay, would be it be more accurate to say "deeper depth of field" rather than "wider depth of field"? And "shallow" rather than "narrow"?

Shay Stephens · January 16, 2006

Probably tomato toemahtoh ;-)

Whatever floats the boat hehehe

wxwax wrote:

Cool stuff, thanks guys.

David, I avoided "stitch" as that adds one more definition to the list. But I guess it needs to be there anyway.

Shay, would be it be more accurate to say "deeper depth of field" rather than "wider depth of field"? And "shallow" rather than "narrow"?

DavidTO · January 16, 2006

wxwax wrote:

Cool stuff, thanks guys.

David, I avoided "stitch" as that adds one more definition to the list. But I guess it needs to be there anyway.

How about "join"? Side by side doesn't mean to me that they've become one image, they could still be separate.

pathfinder · January 16, 2006

Shay Stephens wrote:

Depth of Field
The amount of your image that is in focus. All lenses are capable of putting everything in focus. But you can make some lenses put only a small part of your overall image in focus. This is called a narrow depth of field. You need a lens that has a long focal length and a wide aperture to get the narrowest depth of field.
Here’s the technical language for it: “The amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in your photograph. Depth of field depends on the size of the aperture, the distance of the camera from the subject, and the focal length of the lens. A small aperture like f/16 will have a wider depth of field than a large aperture such as f/2.8 which has a very narrow depth of field.

I don't want to ruffle feathers here, but, the relationship between focal length and DOF gets really confusing.

Shay is correct that shooters tend to think of long lenses as having shallow DOF and wide lenses as having much more DOF. I use them myself with this intention frequently.

BUT - Technically, the focal length of a lens has NOTHING TO DO with Depth of Field IF the subjects are the same size in the image plane. That means a wide angle lens must be much closer to a subject than a telephoto lens for the image sizes to be the same size at the image plane - IF the image sizes are different, then we're comparing apples to oranges.

The easiest reference I found for my assertion that focal length does not affect DOF is here in wikipedia - http://en.wikipedia.org/wiki/Depth_of_field#Depth_of_field_formula

But I can also quote it from the Time-Life series on Photography, and Gilles Martin's tome about Macrophotography.

Depth of Field is strictly a function of aperature and distance from the image plane for a given film format.

Long focal length lenses TEND to be used for things far away, short focal length wide angle lenses TEND to be used for things much closer with a much wider perspective than the narrow view of a long lens. This is why we think of wide angle lenses as having more DOF than telephotos.

Try it - Shoot a series of images with a 24, 50, 100 and 200mm lenses with a constant subject size on the image plane and check the DOF - you will find my statement is correct - Focal length does not affect DOF.

Flame suit on

One other thing - bokeh means 'fuzzy' according to Mike Johnston who was one of the first to use the term BOKEH in English language publications ( http://www.luminous-landscape.com/columns/sm-04-04-04.shtml ) , or 'blur' according to wikipedia again - http://en.wikipedia.org/wiki/Bokeh. Maybe a Japaneese speaker can chime in here for a better term.

I'm so glad you are doing this rather than me waxy

wxwax · January 16, 2006

In 10 words or less?

Any definition we give here has to be truly simplified. I think we're explaining the concept, not the details. Bokeh could be as simple as "selective blur in an image."

ginger_55 · January 16, 2006

Was the word "mask" included, didn't notice, but it seems to be used many ways and I have no idea what is being talked about most of the time?

I have many more things I don't know, but only think of them when they come up. "Mask" came up recently, as a response and suggestion to me.

I just can't grasp that word.

Plus many other words that have to do with layers.

Plus "blending"..........???

ginger, all I can think of now. I am very jargon impaired.

wxwax · January 16, 2006

Yeah, Ginger, mask is in there. I know, it's a long list, and not yet alphabetized.

Layers is in there too. Not sure about blending. How d'you mean?

Art Scott · January 16, 2006

it is a great list..but for my 2 centsa worth..I would prefer to have a list of abbreviations included..as I can find a dictionary to give me a def..however trying to decipher what some of you are talking about when YOU use abbreviations truly baffles me at times.....

Thanks just my $.02 worth

Frog Lady · January 16, 2006

more words

wxwax wrote:

OK, that's the list so far.

Any suggestions?

how about definitions for vignetting, chromatic aberation (?)

thx for doing this

wxwax · January 16, 2006

Frog Lady wrote:

how about definitions for vignetting, chromatic aberation (?)

thx for doing this

Ah, good ones, thanks.

wxwax · January 16, 2006

Art Scott wrote:

it is a great list..but for my 2 centsa worth..I would prefer to have a list of abbreviations included..as I can find a dictionary to give me a def..however trying to decipher what some of you are talking about when YOU use abbreviations truly baffles me at times.....

Thanks just my $.02 worth

Hmmm, I could include abbreviations, but that wouldn't help you find the meaning of one. That would have to be a different list.

Shay Stephens · January 16, 2006

How about including the abbreviation in the definition

Depth of field (DOF)
Chromatic aberration (CA)
etc...

wxwax wrote:

Hmmm, I could include abbreviations, but that wouldn't help you find the meaning of one. That would have to be a different list.

David_S85 · January 16, 2006

Couple more
Purple Fringing

Vignetting

DavidTO · January 16, 2006

David_S85 wrote:

Purple Fringing

See Chromatic Aberration.

jwear · January 16, 2006

wxwax --great idea and well done

how about adding abbreviations ve pp ca ect sorry i did not read all the threads but a list of def ,s would be great also

gtc · January 16, 2006

a good idea-a glossary of terms which new users can consult before asking the same questions over and over again.

some others that may be considered and defined:

noise

aps-c sensor size and crop factor

cmos vs ccd

dark field subtraction for long exposure noise reduction

chimping- oo oo ooh, give me a banana

Keep up the good work!

Greg

DavidTO · January 16, 2006

jwear wrote:

wxwax --great idea and well done

Yeah, Sid, great idea!

wxwax · January 17, 2006

DavidTO wrote:

Yeah, Sid, great idea!

:buttkiss

wxwax · January 17, 2006

gtc wrote:

that may be considered and defined:
dark field subtraction for long exposure noise reduction

Keep up the good work!

Greg

Ummm, that's not a term!

windoze · January 17, 2006

wxwax wrote:

Some bright spark had the idea of making a glossary of digital photography terms. And of giving me the project.

The idea is to explain in layman's terms what our weird words mean. Layman's terms? I'm the man for the job. But the problem with being a layman is that I don't know much.

So I need your help. Check out the list I have so far. What mistakes have I made? What needs to be added?

Think of this as your charitable contribution to the cause. Not tax deductible. I don't think.

i dont know if your glossary is gpoing to include this / these terms but I can tell you that they confuse "newbies":

stops / stopping down / the whole spot metering vs. evaluative metering thing / etc..

wxwax · January 17, 2006

windoze wrote:

i dont know if your glossary is gpoing to include this / these terms but I can tell you that they confuse "newbies":

stops / stopping down / the whole spot metering vs. evaluative metering thing / etc..

Interesting. I can see "stopping down" and "stops." The whole metering thing? That might be more of a 'read the manual thing.'

ginger_55 · January 17, 2006

wxwax wrote:

Yeah, Ginger, mask is in there. I know, it's a long list, and not yet alphabetized.

Layers is in there too. Not sure about blending. How d'you mean?

HAHA, Sid, that is one of the problems. YOu smart people give instructions like next you "blend" those.............................?????
After that I am lost, try to pick it up on the other side, but I often can't.

That thing about crop factor. Someone explained that to me, still don't understand the term like "100%" Crop. It only bothers me intellectually, I don't actually understand the importance of knowing the percentage, except as a tech or something.

Or, now on this masking thing, there are instructions like, (never in a book, from you smart people), like do it in layers so you can "mask" off.........then .................

And I am trying to figure out a different way. As you said "in what way did I mean blend", so many things depend on context, I think, can't be sure as I don't understand them.

I think I just, for instance, figured out what do an "adjustment layer" was. I mean I think I now know that you probably just click on the adjustment thing on the layers (Palette??? that is another term, which is the layer's palette, seems to me there are two, one on top of the screen and one w the layers), so now I think you click on the one w the layers and a new layer probably pops up, but I haven't tested that theory yet.

And how long have I been doing this???

Yeah, took me a year to figure out chimping. And on that one I kept asking. I only learned as there was a photo titled, "and there is Andy chimping".

Problem is once you know this stuff, it is difficult to "speak/write/explain" etc w/o using the jargon. It seems self evident and essential, but when you don't know it, well, it IS a new language.

I don't even want to talk to my husband, or any other beginner about most of this stuff. One thing I am not is patient, nor am I a teacher. Would never do a tute (got that one down, smile.?).

Thanks so much, Sid. And when, if ever, you get this done, polished, etc, I bet it would sell...................shop it around. ("Shop it" is a word, isn't it?)

ginger

wxwax · January 20, 2006

OK, kids, here's the list. I've incorporated your suggestions. Anyone want to add anything?

A

Adjustment Layer
A magical way to edit your photograph without changing the original image. In a darkroom, when you make a change, you can only do it to the original photo you’re printing. But with some photo editing software, you can make an almost unlimited number of copies of your image. They’re all stacked on top of each other, in “layers”. And each layer has a single change made to it, like contrast or saturation. Each is called an Adjustment Layer. When viewed from above, the image you see combines all the changes from each layer. Even better, you can “turn off” a single layer, and see what it looks like to remove one of your changes. And you can “mask” portions of each layer. It’s a wondrous thing.

Anti-aliasing
Removing the tiny jagged edges in the curved lines of your digital images. Your digital photo is made of millions of tiny pixels. They’re square. Squares don’t make good curves. Corners stick out. Anti-aliasing smoothes out these corners so curves look even, not jagged. Cindy Crawford thanks you.

B

Backlit/Backlighting
When the strongest light in your image comes from behind your subject. Usually that means your subject is a silhouette and you can’t see much detail on them because they’re darker than the surrounding light. You can defeat backlighting by using fill-flash.

Bokeh
Blur. When the subject of your piccie is sharp and in focus, and everything else is out of focus, the out-of-focus stuff is called bokeh. It happens when you set your lens to have a narrow “depth-of-field”. It’s a great way to draw attention to your subject. Bokeh is a Japanese word that means fool. As in “to fool”. I hope.

Brightness
The amount of light your image is putting out, or reflecting. The overall lightness of your piccie. A well-exposed photo has good brightness, without being overexposed. Also, think of the color in your image as being broken down into three components – brightness, saturation and hue.

Burning and Dodging
Lingo from the old darkroom days. Dodge means to make a portion of your shot brighter. Burn means to make a portion of your image darker. Can be applied to Shadows, Midtones and Highlights.

C

Camera Shake
Ever tried to keep your hands steady after an all-night bender? Camera shake is what happens when you hold your camera with those trembling hands. It’s a major cause of blurry photographs, especially in low light conditions.

CCD/CMOS
Types of digital camera sensors. CCD is a Charge Coupled Device. CMOS is Complementary Metal-Oxide Semiconductor. Aren’t you glad you asked?

Center Weighted
Just what it sounds like – an exposure setting for your camera that gives priority to the light levels in the center of your frame. They get priority as the camera decides the best exposure for your shot. If the important stuff in your shot isn’t in the center, you shouldn’t be using enter weighted metering.

Chimp
If you’re so in love with your photography that you spend a lot of time reviewing your images in the camera’s monitor, grab a banana, because you’re “chimping.”

Chromatic Aberration/Purple Fringing
Some digital camera sensors have a hard time handling sharp contrasts of light – say, a dark branch against a bright sky. When they do, you can see a purple border where the light meets the dark - along the edges of the branches, for example. That’s called chromatic aberration, or purple fringing. You can also get cyan/green fringing and red fringing.

CMOS/CCD
Types of digital camera sensors. CCD is a Charge Coupled Device. CMOS is Complementary Metal-Oxide Semiconductor. Aren’t you glad you asked?

Cold/Warm
An image is considered warm if it tends towards being red. And cold if it tends towards being blue. It all has to do with color temperature and white balance.

Color Cast
When the colors in your image don’t look like they should, when they have a tint. If your grass seems too red, for example, then you have a warm or red color cast. Usually this happens when your camera has the wrong white balance.

Color Profile
Computers are dumb. They need to be told how to handle color. The instructions are called a “color profile.” Because life is complicated, there is more than one kind of color profile in the world. Each has its own uses. It’s a good thing to know what color profile your camera and your software are using, when you post-process your images.

Color Temperature
This is how the color spectrum in light is measured. It’s the actual temperature of different colors in light, as measured in degrees Kelvin. Red and blue are at opposite ends of the spectrum. Red is considered warm and blue is considered cold. The higher the color temperature, the more light is being put out.

Compact Flash
A memory card used to store digital images in your camera.

Composition
It’s what you decide to include inside the frame of your picture. Composition is the order in which those things are arranged, their relationship to each other. The human eye finds some visual relationships more pleasing and interesting than others. Check out the “golden ratio” – it’s fascinating stuff.

Contrast
Having distinct bright and dark portions in your image. As opposed to a more uniform, or grey, lightness. The brighter the brights and the darker the darks, the more contrast you have. Contrast is generally considered a good thing, makes your shot “pop.”

Crop
Literally, cut off a part of your image. Imagine taking a pair of scissors and snipping off parts of a photo print. Usually done to help the composition or to remove distracting elements.

Crop Factor
Most digital camera sensors are smaller than 35mm film. Because they’re smaller they capture less of the image that’s coming through the lens. This reduction is known as a “crop factor.” This is because it looks just like the image has been cropped. This cropping is sometimes mistakenly called a “magnification factor” as well. It’s a mistake to use this term, because the image is not magnified, only cropped. This cropping makes lenses appear to have longer focal lengths.

D

Desaturation/Saturation
The intensity of the colors in your image. More intense color = more saturation. If you desaturate your image, you are removing the color from it. A black and white image is completely desaturated.

Depth of Field
The amount of your image that is in focus. All lenses are capable of putting everything in focus. But you can make some lenses put only a small part of your overall image in focus. This is called a narrow depth of field. You need a lens that has a long focal length and a wide aperture to get the narrowest depth of field.
Here’s the technical language for it: “The amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in your photograph. Depth of field depends on the size of the aperture, the distance of the camera from the subject, and the focal length of the lens. The bigger the aperture, the greater the depth of field.”

Dynamic Range
Your camera’s ability to handle a wide range of light, from bright to dark, in the same image. Digital cameras have a narrow dynamic range, far more narrow than film used to make prints. That is to say, they have a hard time handling extremes of darkness and brightness in the same picture. For example, bright sunlight with a deep, dark shadow.

E

Evaluative Metering
Canon’s name for a meter that uses the zone system to give you a correct exposure. Also known as a Matrix meter in Nikon cameras. The meter breaks your frame down into multiple segments and measures the light in each one. It tries to figure out what you’re shooting, then give you an exposure in which your whites are white, your blacks are black and your greys are grey. Hopefully.

Exposure
How much light has been allowed into the camera to make your image. Underexposed means you let in too little light and everything’s too dark. Overexposed means you let in too much light and everything’s too bright. Digital cameras don’t have as much dynamic range as film and so are more sensitive to over- and under-exposure.

F

Feathering
Making a sharp edge seem softer in your image. Usually used when making a selection in post-production. You often soften its edge so your selection blends-in more gradually with the background.

Fill Flash
Using a flash in daylight to fill-in the shadows, or when your subject is backlit. It lights the shadows and reduces contrast.

Filter
A way to add effects to your photograph. With SLR cameras you can put a filter in front of the lens to get an effect. The people who make photo editing software have taken the same concept and gone wild with it. You can make your photo blurry, make it sharp, distort it, all sorts of whacky things.

Fisheye Lens
A super wide angle lens that gives almost a 180-degree view. It also has an almost limitless depth of field.

Focal Length
Oh boy, this is the one the math folks love and the rest of us dread. Focal length is the distance between the film or digital sensor and the optical center of the lens when the lens is focused on infinity. The focal length of the lens on most adjustable cameras is marked in millimeters on the lens mount. Got that? Yeah, me too.
In 35mm-format cameras, lenses with a focal length of approx. 50mm are called normal or standard lenses. Lenses with a focal length less than approx. 35mm are called wide angle lenses, and lenses with a focal length more than approx. 85mm are called telephoto lenses. Lenses which allow the user to continuously vary the focal length without changing focus are called zoom lenses. These numbers are skewed with most digital cameras, which have sensors smaller than 35mm film and have what is called a Crop Factor.

Full Frame Sensor
A full frame sensor is approximately the same size as 35mm film. There is no “crop factor” in the image. All lenses are true to their focal lengths. This makes folks with wide angle lenses very happy, as they get a true wide angle image.

G

Golden Ratio
This is literally a mathematical formula that describes shapes that the human eye finds pleasing. For example, the shape of Cindy Crawford’s face matches the golden ratio. Lucky her. You can use the golden ratio to organize the elements of your photograph into a pleasing assemblage. Literally, the golden ratio is 1.61803, or the ratio of a diagonal of a pentagon to its side. Huh?

Gamut
The number of colors your eye can make out is your eye’s color gamut. Gamut = range. Your eye is the top dog when it comes to color gamut. Your camera, your computer monitor, your software, your printer – they all have their own color gamut, or range. And all of them are more limited than your eye’s. All hail the human eye.

Gaussian Blur
Makes your image blurrier, or out-of-focus, usually for dramatic effect. Imagine holding a piece of gauze in front of your eyes. It makes what you’re looking at a little blurry. If it doesn’t, go see your eye doctor. You can get the same effect with computer software in post-production. Most programs have a filter called Gaussian blur, that allow you to control the amount of blur. By the way, Gaussian has nothing to do with gauze – it’s actually a math thing. And therefore incomprehensible.

H

Highlights
The brightest, lightest 30% of your image. The relationship between your shadows, midtones and highlights constitutes the contrast of your photo.

Histogram
A handy graph that shows you how the light in your image is distributed, from light to dark. It will also show you if you’ve exceeded your image’s dynamic range. Digital SLR’s can show you a histogram for each photo, so you can adjust your exposure while you’re shooting. Good photo editing software does too, so you can better control your photo’s brightness and contrast.

Hot
Jargon for over-exposed. A portion of your piccie is “hot” if it’s so bright it’s white and you can’t see any detail in it. This is the worst sin you can commit – you cannot recover detail from a hot, or overexposed, portion of your image. This is where “RAW” and “histograms” come to your rescue.

I

Image Stabilization
The ability of a lens or camera to compensate for your shaking hands and give you a sharp picture. It can only do so much. But it’s extremely helpful with lenses that have a long focal length and therefore readily show any camera shake.

Incident Light Meter
The light meters in your camera try to measure how much light is over there, on your subject. But there’s another kind of meter. This one measure the amount of light over here, right where the meter itself is. It typically has a small white dome and is called an Incident Meter. You walk over to the place you want to photograph, hold up the meter and measure the light. Put on a beret and they’ll think you’re a movie director.

ISO
A measurement of film sensitivity. Now it’s a measure of your digital sensor’s sensitivity to light. Digital cameras have a range of ISO settings. Higher ISO settings increase the sensor’s sensitivity so you can shoot in low light. But high ISO’s can also introduce noise into your shot.

J

Jpeg/jpg
A format for storing your images. Jpegs are compressed versions of your image – in other words, some information is removed in order to make a smaller file. Jpeg stands for Joint Photographic Experts Group. It’s the most common format for a digital photograph. Jpeg is “lossy’ which means that when you open up the file it has lost some of the original information.

K

Kelvin
A scale for measuring light temperature.

L

Layers
A magical way to edit your photograph without changing the original image. In a darkroom, when you make a change, you can only do it to the original photo you’re printing. But with some photo editing software, you can make an almost unlimited number of copies of your image. They’re all stacked on top of each other, in “layers”. And each layer has a single change made to it, like contrast or saturation. Each is called an Adjustment Layer. When viewed from above, the image you see combines all the changes from each layer. Even better, you can “turn off” a single layer, and see what it looks like to remove one of your changes. And you can “mask” portions of each layer. It’s a wondrous thing.

M

Masking
Literally, putting a mask over a part of your image. It’s a technique used in post-production. When you want to change only a part of your image, you “mask” the parts you want to protect. That way your changes are only applied to the parts you don’t mask.

Matrix Metering
Nikon’s name for a meter that uses the zone system to give you a correct exposure. Also known as Evaluative Metering in Canon cameras. The meter breaks your frame down into multiple segments and measures the light in each one. It tries to figure out what you’re shooting, then give you an exposure in which your whites are white, your blacks are black and your greys are grey. Hopefully.

Midtones
The tones that fall between shadows and highlights in your image. No kidding, huh? Roughly, the lightness that makes up the middle 30% - 70% of your image. The relationship between your shadows, midtones and highlights constitutes the contrast of your photo.

N

Noise
Little bits of black, or distortion, or speckling in your shot. Pretty much anything that messes with the crystal clarity of your work of art. In film, it’s the grain of the film showing up. In digital cameras, it most often appears when you push the camera to shoot in low light. It can also appear in long exposures.

wxwax · January 20, 2006

O

Opacity
The degree to which a substance allows light through. The greater the opacity of a substance, the more light it stops. When you’re editing your photo in Layers, you can control the Opacity of each layer. In other words, you can control how much of your edit you allow to be seen.

Overexposure
When you put too much light on your sensor, the image is too bright and detail is lost. This is known as overexposing your shot.

P

Panorama
Several shots arranged to give a larger perspective than is possible with a single image. Usually the photographer pans their camera along the horizon, taking images that overlap one another. The shots are arranged side-by-side, or Stitched, in the post-production process.

Photoshop/Photoshop Elements
Photo editing/graphics software, made by Adobe. Photoshop is currently the premiere graphics and photo editing software. Photoshop Elements is a simplified (and much less expensive!) version.

Post-production or Post
Work you do to your image after it leaves the camera. With film, it’s what happens in the darkroom. With digital images, you use software in your computer. Photoshop is the current king of the post-production hill. Also known as post-processing.

Purple Fringing/Chromatic Aberration
Some digital camera sensors have a hard time handling sharp contrasts of light – say, a dark branch against a bright sky. When they do, you can see a purple border where the light meets the dark - along the edges of the branches, for example. That’s called chromatic aberration, or purple fringing. You can also get cyan/green fringing and red fringing.

Q

R

RAW
A way of saving your photo so that the camera does as little processing to the image as possible, before storing it. This gives you a lot of flexibility in post-production to change your photo’s exposure, saturation, sharpness, contrast and more. Normally, your digital camera’s processor will control all of this to make your picture look good. Expensive digital SLR’s give you the option to tell your camera not to.

Red Eye
What happens when a flash is at the same angle as, and close to, your camera lens when you take someone’s picture. Their eyes seem red in the image. Can be fixed in post production. Or by using a flash that’s not as close to the lens.

Reflective Meter
A device that measures light. A reflective meter measures light that is reflected back from the subject. There are three kinds of reflective metering: Spot, Evaluative and Center Weighted.

Resolution
The number of tiny little pixels that make up your digital photo. The more pixels you have in a given space, the more detail you have. Detail is considered a good thing. A lot of people use the words resolution and detail interchangeably.

Rule of Thirds
A guide for photo composition. The rule of thirds says you should divide your frame into thirds, horizontally and vertically. And you should make sure you put the important stuff in your shot, on one of those thirds. See the Golden Ratio.

S

Saturation/Desaturation
The intensity of the colors in your image. More intense color = more saturation. If you desaturate your image, you are removing the color from it. A black and white image is completely desaturated.

SD Card
A memory card used to store digital images in your camera.

Selection
A tool in your photo editing software that lets you outline, or “select”, a specific part of your image. You can then copy that selection and put it onto another photograph as a layer. For example, you can select a bone from one photograph, and add it to another photograph that shows a happy dog. Or you can make changes only to your selection, leaving the rest of your shot unchanged.

Shadows
The darkest parts of your image. Specifically, the darkest 30% of your shot. The relationship between your shadows, midtones and highlights constitutes the contrast of your photo.

Sharp/Soft
Jargon for in-focus or out-of-focus. Sharp means in focus, all the lines and the detail are sharp. Soft means the opposite, everything looks soft, no sharp edges or detail. You can improve your piccie’s sharpness with “unsharp mask” or make it softer with “Gaussian blur.”

Sharpen
Make the edges of things in an image more distinct. When you sharpen a photo, you make the focus seem clearer, or sharper. You also see detail more clearly. This is a post-production technique. But like coffee can’t cure drunkenness, sharpening can’t cure an out of focus piccie.

Soft/Sharp
Jargon for in-focus or out-of-focus. Sharp means in focus, all the lines and the detail are sharp. Soft means the opposite, everything looks soft, no sharp edges or detail. You can improve your piccie’s sharpness with “unsharp mask” or make it softer with “Gaussian blur.”

Spot Meter
A device that measures light, an exposure meter. A spot meter measures light that is reflected back from a small portion of the subject. It is a very specific measurement.

Stitch
To arrange a series of photographs side-by-side, and/or above-and-below each other, into a single image. Typically a technique used for making panoramas.

Stop/Stop Down/f-Stop
A stop is a measurement of the amount of light that is allowed onto the camera’s sensor. The light is controlled by the size of the aperture and the length of the exposure. Stopping down means to allow in less light, either by making the aperture smaller, or by shortening the exposure time. A stop used to refer exclusively to aperture size. A one stop decrease halves the light coming in. A one stop increase doubles the light coming in.

T

TIFF
A format for storing your images. TIFF stands for Tagged Information File Format. It’s an uncompressed file format. None of your photo’s information is lost as it is stored. This makes for large files. Most image editors can handle TIFFs.

Tone/Tonal Values
This can mean a couple of things. It can mean the color cast of your image – warm tones mean there’s more red in the image, cold tones mean there’s more blue. Check out the definitions for color temperature and white balance. There’s a second meaning, too. Tone can also mean the relative amounts of lightness and darkness of your piccie – the feel of it.

U

Unsharp Mask
This is the post processing filter you use to make your digital photo sharper. It’s also a perfect example of making things more confusing than they need to be. You’d think they’d call it the “sharpen” filter. But nooooo.

V

Vignetting
Those dark areas in the corners of your shot. It happens when the light isn’t distributed evenly across your sensor. The far reaches of your frame that get less light. So you get this effect of a circle of light in the middle, with the corners and possibly the edges being darker.

W

Warm/Cold
An image is considered warm if it tends towards being red. And cold if it tends towards being blue. It all has to do with color temperature and white balance.

Warming Card
A card used to manually White Balance your camera. Normally you would use a white or middle grey colored card to get correct Color Temperatures. But if you want to make your white balance warmer, you can use Warming Cards.

White Balance.
A setting in your camera, or in your photo editing software, that makes sure white is displayed as white. When you have white set properly, all other colors in the spectrum will also be correctly displayed. If your image is too warm or too cold, chances are your white balance is wrong.

X

XD card
A memory card used to store digital photos in the camera. Very small.

Y

Z

Zoom Lens
A lens with a variable Focal Length. You know, zoom in and out.

Zone System
Dumb ol’ camera meters usually try to make everything grey. But by using the zone system, you can make accurate exposures so that snow looks white, instead of grey. The Zone System divides light values into eleven parts, from 0 (black) to 10 (white.) 5 is middle grey. Each zone is the equivalent of an f-stop. Cameras equipped with matrix or evaluative metering are using the zone system.

Bodley · March 7, 2006

WXWAX - Two things, was this put in a fixed area?

Also, adding photo's which gives a visual example of the definition, when applicable, would be a bonus.

Help me with these definitions

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