Salvador Alicea's Blog

Necesitas Un Editor – Descubre El Más Completo y Gratis

salvador alicea — Mon, 23 Aug 2010 21:35:00 -0500

“Llevo días buscando aquella foto de la playa y no la encuentro”, “me encanta esta foto, es una pena que los colores no estén correctos”. De seguro alguna vez has dicho estas dos frases de aquí arriba. Es porque en el mundo de la fotografía puedes dispara tu obturador una y otras vez para terminar con una gran cantidad de fotos que luego tienes que organizar y editar. Pues existe una aplicación para la plataforma Windows y para la Mac que no solo encuentra y organiza todas las fotos en tu computador por ti, las muestra, las edita y hasta te permite compartirlas por correo electrónico, en línea, e impresas. Esto también lo hace para tus videos y archivos de audio. Lo mejor de todo es que es GRATIS. No me crees? pues descúbrelo… sigue leyendo…

Su nombre es Picasa de Goggle

Cuando instalas Picasa, el programa explora el disco duro de tu equipo para buscar las carpetas que contienen archivos de imagen y mostrar las fotos correspondientes. Estas carpetas, junto con los álbumes que creas, constituyen la organización de tus fotografías.

Las carpetas de Picasa representan carpetas reales del disco duro del equipo que contienen fotos. Las modificaciones que hagas en las carpetas de Picasa afectan a las carpetas correspondientes del disco duro del equipo. Por ejemplo, si suprimes una foto de una carpeta, también se suprime del disco duro.

Los álbumes, al contrario de las carpetas, solo existen en Picasa. Puedes crear un álbum que contenga combinaciones de fotos de varias carpetas. Por ejemplo, puedes crear un álbum que se llame "Fotos con la abuela" e incluir fotos con tu abuela que procedan de carpetas distintas. A diferencia de las carpetas de Picasa, los álbumes no corresponden a carpetas reales del disco duro. Si eliminas o mueves fotos de un álbum, los archivos originales permanecen en sus ubicaciones originales del disco duro.

Funciones

Reconoce los formatos mas populares de fotos, video y archivos de audio;

fotos: .jpeg, .tif, .tiff, .bmp, .gif, .psd (Photoshop), .png, .tga
Formato RAW: Adobe (.DNG) , Canon (.CRW, .CR2) , Casio (.RAW), Fuji (.RAF) ,Kodak (.DCR, .KDC), Minolta (.MRW) , Nikon (.NEF, .NRW) ,Olympus (.ORF) , Panasonic (.RAW, .RW2), Pentax (.PEF), Samsung (.DNG) , Sigma (.X3F) , Sony (.SRF,.SR2)
Videos: mpg, .mod, .mmv, .tod, .wmv, .asf, .avi, .divx, .mov, .m4v, .3gp, .3g2, .mp4, .m2t, .m2ts, .mts, .mkv
Audio: mp3 y wma

Etiqueta Automática Por Rostros:

Picasa es capaz de reconocer los rostros en tus fotos y no solo eso, sino que también una vez le dices quien es, él recuerda su nombre y etiqueta todas las fotos donde encuentra su rostro por ti. Luego crea un álbum virtual con su nombre. Quieres ver las fotos de Mary, haces clic en el álbum etiquetado Mary y ahí estas todas la s fotos donde ella aparece. Excelente No!

Añade etiquetas geográficas mediante Mapas Google:

Añade etiquetas geográficas rápidamente mediante la nueva función integrada de Google Mapas. Haz clic en el botón Lugares y arrastra las fotos hasta el sitio donde las tomaste. Aunque si lo prefieres, puedes utilizar Google Earth para etiquetar o ver las fotos.

Álbumes conjuntos con subidas desde Picasa:

Álbumes web de Picasa. Ahora puedes subir imágenes al álbum de un amigo directamente desde el programa Picasa.

Importa, sube y comparte imágenes, todo al mismo tiempo:

Cuenta con un mejorado el proceso de importación y ahora puedes destacar tus imágenes preferidas, subirlas a Álbumes web de Picasa y compartirlas con tus grupos de contactos de Google, todo al mismo tiempo

Además:

Hace impresión de imágenes
Crea CD o DVD con solo un par de clics
Crea Collages, películas y presentaciones de diapositivas
Fondo de Escritorios, salva pantallas y mucho más…

Puedes descargar el editor de fotografía digital Picasa en español aquí

La versión del editor de fotografía digital Picasa en ingles aquí

En un articulo futuro estaré explicando como importar las fotos desde tu cámara a tu computador utilizando Picasa. Si no te has subscrito a la lista de correos de Aprende Fotografía Digital puedes hacerlo en el siguiente enlace para que te enteres cuando sea publicado.

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Como Añadir Matt a tus Fotografías – Photoshop® Tutorial

salvador alicea — Mon, 16 Aug 2010 00:58:00 -0500

Introducción

Bienvenido a otro tutorial de fotografía digital. Esta vez compartiré contigo el método o la técnica que utilizo para añadirle un marco digital a una imagen. Este marco no es cualquier marco, es uno que simula ser lo que se conoce en la industria fotográfica como un “matt board” ( ver imagen a la derecha).

Al igual que tú, en ocasiones comparto imágenes con amigos y familiares y hasta envío algunas de mis fotos a competencias fotográficas. Esta técnica que te mostraré hoy te permitirá añadir un “matt electrónico” a tu imagen. Trae como beneficio que resalta la presentación visual de tu foto, y le provee a la imagen un enmarcado que te permite guiar al ojo de espectador de forma más directa al sujeto principal de tu imagen.

El tutorial te enseña a como crear una imagen con dos matts, pero puedes utilizar la técnica para crear cuantas capas de matts prefieras.

Veamos como se hace…

1. Selecciona y abre el archivo de tu foto

Selecciona y abre el archivo de la foto que vas a editar. Vamos a duplicar la imagen ( Menú – IMAGE > DUPLICATE ) para evitar hacer cambios en la foto original. Una vez hayas creado el duplicado, cierra el archivo de la foto original.

Una vez de nuevo en la imagen a editar, vamos a renombrar el layer (capa) “background” a “imagen”. Siempre es buena practica nombrar nuestras capas de forma que sea fácil identificarlas luego.

2. Creamos una capa nueva de fondo y modificamos el tamaño del Canvas.

Será necesario crear una capa (layer) de fondo para facilitarnos el poder ver claramente lo que hacemos al editar. También necesitaremos proveer el espacio necesario alrededor de la imagen para el enmarcado.

Para esto con la capa (Layer) llamada imagen activa, oprimimos el botón de nueva capa mientras oprimimos la tecla de CRTL ( CTRL + ), esto creará una nueva capa debajo de la activa. Llenaremos la totalidad de esta capa con color blanco ( Menú – EDIT > FILL > WHITE). Llamemos a esta capa “background”.

Utilizando la herramienta de “crop” ampliamos el cuadro de la imagen para crear el espacio para los matts. Esto lo hacemos colocando la herramienta de corte en una de las esquinas de la imagen y oprimimos - arrastramos el cursor hasta la esquina opuesta. Ya el marcador de corte colocado en el borde de la imagen, oprimimos – arrastramos una de sus esquinas (donde tienes un cuadrado) mientras oprimimos las teclas ALT + SHIFT hacia afuera de la imagen para proveer el espacio para el marco. Oprimir estas teclas al mismo tiempo que el arrastre hace que el recuadro modifique su tamaño manteniendo su proporción largo-ancho.

3. Creación Del Primer “Matt Board”

Primero utilizando la herramienta de selección de colores (eye dropper) escogeremos un color de la imagen para el matt exterior.

Ahora utilizando la tecla CRTL oprimimos sobre el icono del layer llamado imagen para seleccionar el contenido de la misma. Ahora vamos al Menú – SELECT >MODIFY >CONTRACT y contraemos la selección 1 pixel para cubrir el borde de la imagen. Hacemos un nueva capa (layer) , e invertimos la selección (SELECT > INVERSE) de forma tal que esté seleccionado todo el recuadro menos la imagen y llenamos el nuevo layer con el color Frontal EDIT > FILL > FOREGROUND COLOR y cambiamos su nombre por “Matt exterior”

4. Creación del Espesor del Matt Para Darle Efecto Tridimensional

Ahora teniendo aun la selección del marco activa , invertimos SELECT > INVERSE para volver a tener solo el cuadro de la imagen seleccionado y contraemos la selección por una cantidad de pixeles que será determinada por la resolución de la foto que estas utilizando, esto determinará el espesor visible del borde del matt exterior, en nuestro caso usaremos 10 pixeles. Hacemos un nueva capa (layer) debajo de la recién creada oprimiendo la tecla de CRTL y el icono de nueva capa ( CTRL + ), vamos al menú SELECT > INVERSE para invertir nuestra selección de forma tal que este seleccionado todo el recuadro y llenamos la nueva capa con el color blanco EDIT > FILL > WHITE y cambiamos su nombre por “Borde Matt exterior”

5. Creando Otras Capas De “Matt Boards”

Si desea colocar otros matts a su imagen repita los pasos 3 al 4. En nuestro caso añadimos dos matts por lo que repetimos los pasos 3 al 4 una vez mas.

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6. Añadiendo Estilo a las Capas De Matt Para darle Profundidad

Para crear el efecto luz sombra en el borde del matt utilizamos la función de estilos de los layer (capas) y añadimos “embose” y sombra

Ya hemos completado la edición de nuestra imagen, abajo puede ver la diferencia entre el antes y el después, como puedes ver , realmente la técnica te ayuda a mejorar la presentación visual de tu imagen.

Me gustaría conocer tus comentarios sobre el tutorial y que compartas con nosotros tu experiencia o alguna otra técnica para enmarcar tus fotos. Puedes dejar tus comentarios aquí abajo.

Mantente en contacto pues publicaré en un futuro este tutorial en video.

Photoshop® – Consejo Para Principiantes: Control de Pantalla

salvador alicea — Tue, 10 Aug 2010 23:58:00 -0500

Es seguro que en alguna ocasión has estado trabajando en Photoshop la edición de alguna de tus fotos y has necesitado navegar en la pantalla y no has encontrado una fo

Bird Eye View Demo

rma fácil y eficiente de hacerlo.

Pues hoy voy a compartir contigo alguno de los trucos que utilizo para agilizar mi trabajo de edición. Me concentraré en el control de la navegación de la pantalla en Photoshop.

También podrás encontrar otros ”shotcuts” para photoshop® en mi otro articulo titulado Photoshop® keyboard Shortcuts – How to Help You!

Navegar ágilmente en el documento - Haz lo siguiente:

Para ver la imagen en su tamaño actual (100%) presionas CTRL-1 ( Mac -CMD-1). Para llenar el área total de la pantalla, de forma tal que puedas ver toda la imagen, presiona CRTL-0 ( Mac –CMD-0).

Para hacer “zoom -in” o “ zoom-out” presiona CTRL-+ y CTRL- - respectivamente.

Vista Ojo de Pájaro

También existe lo que se conoce como “ bird eye view” . Esta característica fue introducida en la versión CS4 y las siguientes.

Presionando la letra H y con la herramienta de mano has click sobre el documento, este hará un “zoom-out” y presentara un recuadro el cual usted podrá arrastrar al nuevo lugar donde al soltar el botón del mouse hará un “ zoom-in” .

Has la prueba ahora mismo, te encantara! Yo lo adoro!

Recuerda que si tienes algún comentario o pregunta, no dudes en incluir tu comentario y con gusto te ayudaremos.

También te recuerdo subscribirte a nuestra lista para que recibas un correo electrónico cuando publiquemos un nuevo articulo. Lo puedes hacer en el panel derecho titulado “ Newsletter” o si prefieres suscribirte a nuestra fuente de contenido RSS

Hasta nuestro próximo articulo

Vacaciones Punta Cana Republica Dominicana - Consejos

salvador alicea — Tue, 03 Aug 2010 15:46:00 -0500

Ya estoy de regreso después de unas merecidas vacaciones. Durante esta semana estaré planificando la agenda de lo próximo a publicar en el blog.

Hoy quiero compartir con ustedes algunos detalles y consejos de lo que fueron mis vacaciones en Punta Cana, Republica Dominicana. Fueron 7 días de puro descanso, excelente comida, playa, ejercicios, piscina, lectura, baile y algo de alcohol.

Excelentes vacaciones familiares junto a mis padres, mi querida esposa, mis dos hijos , mi hermana, sobrinos, cuñados y amigos, en total 12 personas.

El Traslado

Viajamos en aviones de la empresa Express Jet con capacidad para 50 pasajeros desde el Aeropuerto Luis Muñoz Marín de Carolina directo a Punta Cana y de regreso. El viaje fue excelente y rápido.

El Hotel

Nos hospedamos en el hotel Ocean Blue & Sand de H10, Punta Cana, hotel con todo incluido, cuenta con 8 restaurantes de los cuales 6 entran en el paquete, dos grandes piscinas con barras y deportes acuáticos. Las habitaciones cuentan con lo básico, y en mi opinión cumplen con su propósito para el precio del paquete. El servicio de los meceros es variable, nuestro amigo Amaury y Edgar excedieron nuestras expectativas, otros no. Así que cuando llegues al restauran procura encontrarlos.

Lugares a Visitar:

Altos de Chavón

Altos de Chavón, es una maravilla arquitectónica, una réplica del siglo 16 de un pueblo mediterráneo ubicado en lo alto sobre el río Chavón. La aldea fue diseñado por el arquitecto dominicano José Antonio Caro, y creado por el diseñador y director de fotografía maestro italiano Roberto Coppa. Artesanos dominicanos hicieron a mano los caminos de piedra, herrajes decorativos, muebles y encantadores edificios , reviviendo la artesanía casi olvidada de trabajo con metales y piedras labradas. Bajo la dirección de Copa, cada piedra fue cortada a mano, cada marco de la puerta de madera estaba hecho a mano y cada detalle de hierro forjado forjado a mano.

La construcción de la aldea comenzó en 1976 y la aldea fue inaugurado en 1982 con el concierto de Frank Sinatra en el anfiteatro.

La iglesia de San Estanislao

En el corazón de la aldea Altos de Chavón está la Iglesia de

San Estanislao.

Consagrada en 1979, el Papa Juan Pablo II ha enviado las cenizas del santo patrón de Polonia, San Estanislao y una estatua tallada a mano de Cracovia para conmemorar la inauguración de la iglesia.
La iglesia es el lugar de las misas católicas semanales y es un sitio valorado por las muchas bodas - cuyas novias y novios de todas partes del mundo han venido a casarse aquí.

Basílica de Higuey

Obra construida en el periodo constitucional 1974 - 1978. Es el monumento religioso mas importante de Republica Dominicana y centro de atención de los demás pueblos de América. Es el lugar mas venerado y donde los dominicanos la identifican como el hogar de la patrona del pueblo Dominicano la Virgen de la Altagracia.

La Basílica actual fue inaugurada el 21 de enero de 1971. Los arquitectos que realizaron la construcción fueron los franceses A. Dunover de Segonazc y Pierre Dupré. Este monumento religioso lleva el nombre de la Virgen de la Altagracia, patrona del pueblo dominicano. En él se exhibe un cuadro de la virgen de 33.5 centímetros de ancho por 45 centímetros de alto. La pintura es de la escuela española y se cree que data de finales del siglo XV o principios del siglo XVI.

Comentarios

Si has visitado el este de la Republica Dominicana y deseas compartir algunos consejos o tu experiencia, no dudes en incluir tu comentario abajo.

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En Qué Idioma Prefieres el Blog? Preferred Language Blog?

salvador alicea — Sat, 31 Jul 2010 15:56:00 -0500

Como parte de mi esfuerzo por hacer de mi blog uno útil para todos estoy considerando cambiar su idioma al español. De esta forma se me haría mucho más fácil comunicarle con ustedes. Sin embargo quiero conocer cuál es tu preferencia antes de tomar una decisión, es por eso que incluyo aquí una encuesta. Por favor déjame saber tu preferencia.

As part of my effort to make my blog useful for everybody I am considering to change its language to my native language "español". By doing this it will be easier for me to communicate with you. However I want to know your preference before make a decision that is why I am including this poll. Please let me know your preference.

Photography Tips - Understanding Shutter Speed

salvador alicea — Sun, 25 Jul 2010 22:51:00 -0500

Using shutter speed for creative composition and Capture Motion

This is the fourth post in this “How to craft better photos” Series. I will be talking about how controlling the shutter speed you create the effect of motion in your images. Follow this link to read the third article titled Photography Tips - Understanding Depth of field!.

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How I see Photography?

Few years ago an alumni of one of my digital photography course asked me “What photography means for you? My immediate answer was “Photography to me, Is the ability to freeze a moment in time that was painted with light”.

That answer was not technically right but it is what photography means to me.

As humans, we see the life in front of us as continuous sequences of actions, like a movie. The still photography allows us to stop the time from moving forward , giving us the opportunity to capture (or freeze) a fraction of time for ever, with its details, colors, lights and shadows.

However, the still photography allows us to communicate motion!

Capturing the Sense of Motion

The camera’s shutter is the mechanism that controls how long the light coming through the lens gets to hit the media; film or sensor.

The shutter works as your eyelid. It is normally closed, when you press the shutter, it open for a fraction of second to allow the light to get the media. Controlling the shutter speed means controlling the time the eyelid is opened.

The longer it stays open, the more light enters. If it’s open for too long, the photo will be overexposed. Not open for long enough and your photo will be too dark. Combining the shutter speed with aperture determine how much light go to the sensor.
See Understanding Exposure Will Help to Improve Your Photos!

Also, the camera's shutter speed determines how the action in a photo is recorded.

A fast shutter speed can freeze action, even stopping a hummingbird's wings. A slow shutter speed can let action blur or even make a moving subject seem to disappear. First, let's look at how a high shutter speed can stop action.

Stop the Action

When you want to take a photo that stops the action of your main subject, you must consider the speed of action. The speed of action will help you to determine the proper shutter speed to freeze the action. The shutter speed should be relatively faster than the action to stop.

For example, stopping the movement of a walker or runner might be possible using 1/250 shutter speed. To stop a baseball player doing a swing, you may need 1/10000 sec of shutter speed.

Sense of Motion

Sometimes, it’s better to not freeze the action and let the sense of motion be part of the image. This is achieved by setting the shutter to a relatively lower speed than the action itself. The object in motion will appear blurring adding a feel of motion to the image composition.

The key to create and capture the motion sense of an image is the shutter speed.

Do you take photos to reflect the sense of motion?

What was your better motion effect picture?

You may share them with us in the comment area. You may subscribe to Our RSS too!”

Read the Full Series

This post is part of a series on “How to craft better photos” . It will be all the more powerful if you taken in context of the full series which looks at 5 points of how to improve your photography and do it in a creative way. Start reading this series here.

Photography Tips - Understanding Depth of field

salvador alicea — Tue, 20 Jul 2010 23:09:00 -0500

Using apertures for creative composition and relative sharpness

This is the third post in this “How to craft better photos” Series. I will be talking about the depth of field (DOF) and how to use aperture to control it. Understanding DOF will allow you to create better images, with better composition. Follow this link to read the second article titled Exposure Histogram, It's Your Friend!.

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Why I need to know about DOF (Depth of Field)?

Understanding depth of field and having the knowledge to control it is the first step to convert your ordinary photograph into an amazing one.
The aperture setting strongly affects depth of field and is key for the creative control of your image composition.

Choose to let the background and foreground go blur and you've effectively isolated your subject and called specific attention to it. Choose to have the foreground and background sharp, and the subject becomes an element in the overall scene. See sample below.

The key to using depth-of-field to isolate or blend your subject is lens aperture.

No matter what kind of photography you enjoy to do – landscape, commercial, portrait, food, architectural, wedding photography, people, wild life - the depth of field is one of the most important concept that a good photographer should understand and known how to manage.

What is depth of field?

In optics, particularly as it relates to film and photography, the depth of field (DOF) is the portion of a scene that appears acceptably sharp in the image. Although a lens can precisely focus at only one distance, the decrease in sharpness is gradual on each side of the focused distance, so that within the DOF, the un-sharpness is imperceptible under normal viewing conditions.

This zone of sharpness is called the depth-of-field, and it extends in front of and behind the point that you actually focused on. The size of the zone is determined by three key factors -

the aperture of the lens,
the focal length of the lens used,
and the distance you are from the subject

Varying these three elements allows you almost complete control over the depth-of-field in a picture. I will be talking about the first key factor: aperture of the lens. In the first post of this series; Understanding Exposure Will Help to Improve Your Photos! I explained the basics of exposure. One of the key elements of exposure is aperture. Today I will explain you how the DOF is affected by the change in the lens aperture.

Exposure – Depth of Field Relationship

From the first post we learn that the "amount" of light allows to strike the film/sensor plus the duration (time) for the light to strike the film/sensor forms an exposure;

Shutter Speed + Aperture + ISO = Proper Exposure

The general rule of thumb for selecting the right aperture for a desired depth of field is: for a same given object distance and focal lens, the bigger lens opening (aperture) used (like f/2.8, f/2, f/1.4 etc.) will have a narrower band of depth of field - meaning critical focusing will be required in this kind of situation because when you use a large aperture (in particularly when focuses at a near to the subject), the zone of sharpness (DOF) can be very limiting.

While on the other hand, if extended depth of field is required, you can just choose a smaller lens opening like f/8, f/11, f/16, f/22 to make the plane of sharpness is extended, so everything will be in sharper focus.

Smaller aperture = More DOF		Bigger Aperture = Less DOF

f/5.6 at 1/60 sec	f/11 at 1/250 sec	f/22 at 1/1000 sec

Therefore, The smaller the aperture, the deeper the depth of field (the other two factors remaining the same). For example, if the lens focal length and the shooting distance stay the same, the depth of field is much deeper at f/11 than at f/5.6.

Homework

Homework for this lesson is fairly simple. Set your camera to manual mode. Keeping always the same distance from your subject and same lens. Take a photo. Then, change the aperture to a bigger stop and adjust the shutter speed for a proper exposure and take a second photo. Now change the aperture to a bigger stop and shoot again.

How the depth of field change?

You should end with similar samples as above..

I will love to see comments about your experiences… You may share them with us in the comment area. You may subscribe to Our RSS too!”

Read the Full Series

Exposure Histogram, It's Your Friend!

salvador alicea — Fri, 16 Jul 2010 19:36:00 -0500

This is the second post in this “How to craft better photos” Series. I will be talking about the basic concepts of photography exposure histogram. Follow this link to read the first article titled Understanding Exposure Will Help to Improve Your Photo.

If you need to return just subscribe to our RSS

Taking proper exposed images matter!

Using the histogram in you camera’s image viewing LCD will help you to take a much higher number of well exposed images. I will cover this feature with enough detail to give you a working knowledge of how to use the histogram to make better pictures. I do not pretend to cover everything on histogram but I will present enough knowledge to improve your proper exposure technique immediately.

Human Eye and the Camera Sensor

The human eye can cope with an enormous brightness range. For example on a bright day we can see in to the deep shadows cast by a tree at the same time we can see details in the lightest part of a white cloud directly over the tree and lit by the sun.

The camera’s sensor can only capture a more limited brightness range in a single exposure. If you want to record the subtle detail in the lightest part of the cloud then detail will be lost in the shadow areas of the image. Similarly if you set exposure to reveal full detail of subjects in shade then you will end up with "washed out" highlight detail where light tones become featureless white.

To make easier the understanding of this, I will use the term “f-stops” to represent the quantity of light that can be capture. The human eye retina has an static contrast ratio of around 100:1 that is about 8 1/2 f-stops. Today’s digital cameras are capable of “see” about 5 or so usable f-stops of light. Unfortunately, many of the higher contract subjects we shoot can contain up to 12 f-stops of light values, this is more than it is possible to capture with a digital sensor today. That is why it is important to understand how your digital camera records light, so that you can better control the quality of the captured image.

What is the histogram

Histogram is a topic that we could spend a lot of time talking about but I will give you an answer that will help you to understand it better, the simple one.

The histogram is a graphical representation of the exposure of an image. Exposure refers to the amount of light that strikes the camera’s sensor to form the photography image. Therefore, the histogram is a representation of how much light and tones the image has.

The image at the left is a typical histogram. I will explain the meaning of its part. Click here to have a better view of it while a explain.

The graph has two axes: across the bottom (the x axis) go all the distinct values your data can have, and up the side (the y axis) you plot how many times each value occurs. In a digital camera, values in 8-bit mode range from 0 through 255 for x axis. (0 = Pure Black, and 255 = Pure White).
The subject brightness range we can capture in any given image and still retain detail is about five f-stops as I said before. We can therefore divide a scale of image brightness into fifths and consider each one to be about a stop. These divisions can be referred to as very dark, dark, medium, bright, or very bright. This becomes the x axis of our histogram.

On the left hand end is black (zero) and on the right is white (255), with every other possible brightness spread in between. Eighteen percent medium gray would be dead center.

If we count how many pixels within our image have each distinct brightness value and plot this on the y axis, we get our histogram. The top of the histogram (top of mountain peak, y axis values) represents the number of pixels of color in that x range, a value you cannot control, so it is for your information only. We are mostly concerned with the left and right side values of the histogram, since we do have much control over those. (Dark vs. Light)

How interpret a the histogram

A “correct” exposure can be regarded as one where the most important areas of the image looks “right” with its details. Therefore, there is not a perfect exposure histogram.
A dark, low-key image will have a histogram that clusters mainly around the left end. The histogram of a bright, high-key image will tend towards the right. The one form an image with a more "average" character will likely be spread more evenly across the spectrum ( as a mountain).

	Underexposed Image Histogram This histogram is clipped off on the left (dark) side which means that the image is generally too dark . In fact , the light range in this histogram shows that exceeds the capability of the camera’s sensor which means that shadows details are lost.
	“Correct” Exposed Image Histogram This histogram contains almost a full range of light that the camera’s digital sensor can record. The light range is represented by a graph like a mountain peak. This is a “correct”exposure, since the histogram is not clipped off to the left or the right. If you can make your image histogram look like this, you will have good images.
	Overexposed Image Histogram This histogram like the one at the left is clipped off on the right side of the histogram (white area) which means that the image is generally too white . In fact , the light range in this histogram shows that exceeds the capability of the camera’s sensor which means that highlight details are missed.

Here are three different exposures of the same image and their corresponding histograms.

The underexposed one is starting to clip on the shadow end which may or may not be an issue. It depends on what we want. Deep shadows and silhouettes are supposed to come out this way. Given the subject matter though, not having any pixels over medium would definitely be considered a problem.

The histogram for correctly exposed one shows a subject clustered near medium, with no completely black or white pixels (no clipped to the left or the right).

The overexposed version clearly shows clipping in the highlights. We have lost data here that can not be recovered later since we never captured it in the first place when the image was shot. Unlike on the shadow end, burned out white is rarely desirable.

Since our eye tends to know that shadows are black, and expects that, it is usually better to expose for the highlights. If you see dark shadows, that seems normal.

So, in a worse case scenario, expose the image so that the right side of the histogram graph just touches the right side of the histogram window, and the image will look more normal. This technique is commonly referred to as "exposing to the right" and can work on all types of images, providing we adjust the exposure after the fact after uploading these images to our computer.

Homework - Using the histogram While Shooting

So now you know what a histogram is – grab your digital camera’s manual and work out how to switch it on in playback mode. This will enable you to see both the picture and the histogram when reviewing shots after taking them.

Keep an eye out for histograms with dramatic spikes to the extreme ends of either side of the spectrum. This indicates that you have a lot of pixels that are either pure black or pure white. While this might be what you’re after remember that those sections of the image probably have very little detail – this is a hint that your image could be either over or under exposed.

Histograms are the best way to assess the accuracy of an exposure because they represent the exposure in a graphical form that is unaffected by viewing conditions.

Hopefully this will give you some understanding of how to read the histogram for an image. Clearly the best way to learn what a histogram can tell you though is to go out and shoot some images of your own, paying attention to the histograms after each shot. When you know how to interpret a histogram you have a much better method to check exposure.

I will love to see comments about your experiences… You may share them with us in the comment area.

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Understanding Exposure Will Help to Improve Your Photos!

salvador alicea — Wed, 14 Jul 2010 01:13:00 -0500

Understanding exposure makes you a better photographer

This is my first post in this “How to craft better photos” Series. I will be talking about the basic concepts of photography exposure.

Taking proper exposed images matter!

Today the digital cameras can handle exposure very well in automatic and semi automatic modes, but understanding exposure properly can certainly help to improve your photography.

Let's start by thinking about what's happening with light when you take a picture. The light passes through the lens and then through the shutter before it arrives at either a sensor or a frame of film. The camera's lens and shutter control how much light gets to that sensor or film frame.

Exposure is all about how much light go into the camera sensor or film.

Too much light, and your photos will be washed out, too little and they will be too dark.

Overexposed Image	Proper Exposed Image	Underexposed Image

5 Reason to have control of the exposure

If you overexposed (too much light) you will end up with blown highlights and you can never recover details in these areas of the image, never.
If you underexposed (too little light) same happens, there is not data recorded in dark areas and you can never recover them.
Poorly exposed images have low contrast
Poorly exposed images don’t have good color saturation
Light meter in cameras can be (and the often are) fooled by certain lighting conditions

Therefore, is a most to have an understanding of exposure before you press the shutter!

What Affects Exposure?

There are three things related to exposure. The relationship between aperture, shutter speed and ISO is what make an exposure. Those three are closely connected, and that connection is the basis of every photograph.
Two of those involve how much light comes into the camera; the third is the sensitiveness to light of the film or sensor of your camera.

The shutter Speed
The Aperture
The ISO (light sensitivity)

Understanding Exposure – The Shutter Speed

To understand exposure , you need to understand shutter speed. The camera’s shutter controls how long the the light coming through the lens gets to hit the media; film or sensor.

The shutter works as your eyelid. It is normally closed, when you press the shutter , it open for a fraction of second to allow the light to get the media. Controlling the shutter speed means controlling the time the eyelid is opened.

The longer it stays open, the more light enters. If it’s open for too long, the photo will be overexposed. Not open for long enough and your photo will be too dark.

Understanding Exposure – The Aperture

The other part of the exposure equation is the aperture. What the heel is that?

To understand exposure you need to know what the aperture is and does. As with shutter speed, the aperture is also a way of controlling how much light enters the camera.

The aperture is an adjustable hole in the lens. It can open to allow more light in. Or it can close to become just a tiny hole, stopping so much light from entering. It behaves as your eye iris.

So aperture and shutter speed work together to create an exposure. There is just one combination between the shutter speed and the aperture that will resulted in a proper exposed image.

Therefore, if you have a slow shutter speed (to let more light in) you have to close the aperture to compensate. And visa versa – if you have a fast shutter speed (letting less light in) you have to open the aperture to allow in more light to compensate.

Understanding Exposure – The ISO

There is one more key element in the equation, ISO which refers to the light sensitivity of the sensor (or film) inside the camera. The lower the ISO, 100 for example the more light we need to get the proper exposure. The higher the number, let say 800, less light we need.

Since we need less light with a higher ISO, you might be tempted to use a high ISO all the time, Be Careful, as we go up in sensitivity, we tend to lose color saturation and gain noise, which gives images a grainy look (speckling effect on photos).

So..

So it's our job to manage exposure to get the sharp, clear photos we want. The key thing to remember is that the three elements—aperture, shutter speed and ISO—are always linked. For photographers it's a balancing act, and so we're always adjusting the shutter speed and aperture for the right exposure and the effect we want.

Of course, you can bypass all of the above simply by setting your camera for auto or program mode and letting the built-in computer do the work. Still, understanding the relationship of aperture, shutter speed and ISO will give you a greater understanding of how to take control of your photography.

Remember :

Shutter Speed + Aperture + ISO = Proper Exposure

Homework

Homework for this lesson is fairly simple. Set your camera to manual mode. Keeping always the same ISO setting. Take a photo. Then, change one of the elements, aperture for example to a higher setting, and take a photo.

How the exposure change? It is lighter or darker?

Now change the other element (shutter speed in this case) to compensate the first element changed - to a faster shutter speed. Now you get same exposure than the first taken photo. Why? Because you set the relationship between aperture and shutter speed to the same as the original photo.

I will love to see comments about your experiences… You may share them with us in the comment area. You may subscribe to our RSS too!

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How To “Craft” Better Photos – The Series

salvador alicea — Tue, 13 Jul 2010 00:22:00 -0500

This week I will start a series of posts that will walk you through a complete tutorial about how to take control of your photo exposure. If there’s one lesson that I have learnt about photography it’s that a key element to be a successful photographer is the domain of photography exposure.

An entire photographic industry has been built convincing consumers that the subject of the photo exposure is mysterious, difficult and impossible to understand, so it’s more convenient to let technology decide for you.

The fact is that the concept of photographic exposure is extremely simple. It can be mastered by anyone who can multiply or divide by two. All you need to know will be included it in this series.

I will help you to understand: What is photography exposure, how it can be used to improve your photos, how to use it in a creative way, and how to control the exposure on any lighting condition.

Below is the list of posts that will be published during the following days or weeks, stay tuned!

If you need to return,
just subscribe to our RSS or to our newsletter( see right side panel).

Understanding Exposure will help you to
improve your photos!
Get the basic terms of exposure, its key elements and its relationship.
Exposure Histogram, It's Your Friend!
Learn how to interpreted the histogram and use it to check the exposure every time you shoot.
Creative Exposure – Making the Difference! Learn about depth of field, shooter speed, how to use them to make your photography a piece of art.
- Photography Tips - Understanding Depth of field
- Photography Tips - Understanding Shutter Speed
Sunny 16 Rule – To the Rescue! Next 08/23/2010
Learn all you need to know to use your camera in manual mode.
Bracketing, How and Why? Future Post
What is bracketing and how to use it ?

I included a poll about the use of the camera histogram to control exposure, feel free to vote.

I will love to know what you need to know about exposure… You may share them with us in the comment area.

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Photography Tips - Understanding Shutter Speed

Using shutter speed for creative composition and Capture Motion

How I see Photography?

Capturing the Sense of Motion

Stop the Action

Sense of Motion

Read the Full Series

Photography Tips - Understanding Depth of field

Using apertures for creative composition and relative sharpness

Why I need to know about DOF (Depth of Field)?

What is depth of field?

Exposure – Depth of Field Relationship

Homework

Read the Full Series

Exposure Histogram, It's Your Friend!

Human Eye and the Camera Sensor

What is the histogram

How interpret a the histogram

Underexposed Image Histogram

“Correct” Exposed Image Histogram

Overexposed Image Histogram

Homework - Using the histogram While Shooting

Read the Full Series

Understanding Exposure Will Help to Improve Your Photos!

5 Reason to have control of the exposure

What Affects Exposure?

Understanding Exposure – The Shutter Speed

Understanding Exposure – The Aperture

Understanding Exposure – The ISO

So..

Homework

Read the Full Series

How To “Craft” Better Photos – The Series