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Viewing and using EXIF data

Almost all digital cameras save JPEG files with EXIF (Exchangeable Image File) data. Camera settings and scene information are recorded by the camera into the image file. Examples of stored information are shutter speed, date and time a photo was taken, focal length, exposure compensation, metering pattern and if a flash was used.

Other formats that included EXIF data inclue RAW and TIFF files.

 


Use the data as a learning tool

Many camera owners study EXIF to compare successful photos to those that are not. Data provides insight about how camera settings affect photo characteristics such as exposure, depth-of-field and subject movement.

Viewing EXIF data

EXIF data can be read by several applications. The software that came with your digital camera lets you view the data. Other viewing applications include EXIF web browser plug-ins, photo editing and organizing programs and some printer drivers. The printer drivers use the EXIF data to automatically enhance images and can result in a better looking prints.

Preserving EXIF data

You can keep EXIF information in edited versions of original image files if they are Saved correctly. Most or all of the data embedded in the original will be in the edited file. Check the Help files of your photo editing software for specifics about preserving EXIF information during the editing process.

Viewing EXIF data at photo hosting sites

The information can be viewed online at photo hosting sites. It is often visible under, or to one, side of a photo on display. Or there will be a link or icon near the image that needs to be clicked to reveal the EXIF data.

Different photo hosting sites may use terms other than EXIF. For example, Flickr uses the word properties instead of EXIF; Picasa web albums have an area called Photo information; click on the More Information link to see additional photo EXIF data.


Using a browser EXIF viewer is great if you enjoying viewing photos posted online and want to gain insights about how a photo was taken. See a great action shot? Check the EXIF to see what focal length, shutter-speed and ISO settings were used.

There are EXIF viewers compatible with most browsers that must be installed as a plug-in. Some of the viewers only provide basic data but it can still be very useful.

Once the viewer is installed in your browser, right-click a jpeg image. As shown in the illustration to the left, click the EXIF Data link in the drop down menu. A window will open revealing available data.

For many, reading EXIF data is a worthwhile way to help improve their photo-taking skills.

by Gail Bjork

All DSLR systems offer a dizzying selection of lenses for their cameras.
These range from fisheyes that give a 180° field of view, to telephoto lenses up to 800mm or more.
You’ve got zooms, primes, macro, super telephoto, and of course, tilt-shift lenses as well.

In my time as a photographer I’ve often had friends, students,
or casual acquaintances ask me “What lens should I get?”
There is no one right answer to this question, and it can lead to more confusion unless I ask a few questions myself.

First off, and easiest to figure out is, “What do you want to shoot?”
It could be sports, wildlife, birds, landscapes, architecture, portraits, or any number of other subjects.
Next is to find out what their budget is. The cost of the lens depends on several things.
Less expensive lenses will generally have variable apertures, meaning as you zoom,
the maximum aperture gets smaller. More expensive lenses have a fixed aperture.
The good news is that all major camera and lens manufacturers offer a variety of focal lengths to satisfy most budgets.

After those two questions are answered it becomes more difficult.
I try to lead them to their choice, rather than just tell them “Get this lens.”
So let’s take a look at different types of lenses and how they can be used.

Sand_Harbor.jpg

We’ll start with the wide angles. In my early days as a photographer,
I NEVER used wide angle lenses.
I started my career as a sports photographer and rarely used anything shorter than a 70-200, often going for 400mm f2.8 or 600mm f/4 lenses.
As I began shooting landscapes as more of a hobby, I began to discover the magic of wide angles.
Wide angles give a wide expansive view, and when used correctly, can wrap you in the scene.
My favorite lenses for landscape work tend to be in the ranges from 14mm f/2.8, 16-35 f/2.8, and 24mm f/1.4.

Wide angles should be used when prominent foreground objects are present.
The primary mistake made by new photographers is to use wide angles incorrectly- by not being close enough,
having no interest in the foreground, or by trying to include too much in the scene.
Wide angles are also handy in tight areas, like small rooms, cars, caves, etc.
They can give volume to the small area. Wide angles have the potential to drastically change your photography.

Emma.jpg

Standard lenses tend to range from about 35mm up to around 85mm.
Lenses in the standard zoom range will cover moderate wide angles- typically 24mm to 35mm,
to moderate telephoto lengths- around 70mm and up to about 105mm.
Standard zoom lenses are great “walk around” lenses.
They are versatile, allowing both for wide angle work such as a landscape, or zooming in to the telephoto
end of the lens to take a great portrait.

Standard zooms are generally included in many SLR kits that come with lenses. 18-55mm, 18-135mm, 24-105mm, 24-70mm, and others are popular standard zooms. However, there are also standard prime lenses. Prime lenses are lenses that are just one focal length. Back in the good ol’ days of film, the most popular standard lens was a 50mm. When I was a student, everyone in the class started with a 50mm lens. Whether you choose a zoom or a prime is up to you. Most people tend to feel that zooms offer more bang for the buck these days, while a prime forces you to think more about composition and point of view, simply because it can’t zoom.

Heather.jpg

More often than not, when I speak to neophyte photographers looking to purchase their next lens,
they are looking for something on the telephoto end. The most popular seems to be various flavors of 70-300mm or 70-200mm. These lenses are excellent when used properly. However, too often, telephoto zooms allow the photographer to become lazy.

“If your pictures aren’t good enough, you’re not close enough,” said famed war photographer Robert Capa.
Telephoto zooms allow one to stand back a little when the subject isn’t quite as approachable,
or when your subject might be feeling overwhelmed by the presence of the camera.
This makes telephoto zooms extremely useful for portraiture,
but keep in mind Capa’s words, as it is easy to get lazy and let the lens do the work for you.

Shenandoah_sunset.jpg

Telephoto lenses compress distance, making everything appear closer,
as opposed to wide angles which distort perspective and make things look further away.
This can be useful for landscapes when you want the sun or moon to appear large in comparison to other objects in the image.
In this shot of Shenandoah Valley at sunset, the telephoto lens compresses the distance,
making the layers of mountains and mist look almost flat.

Of course, telephoto lenses are also excellent for sports, nature, and wildlife, where it can be difficult to get close.
Sports, however, presents its own set of challenges.
To be able to stop action without blurring, you need to use a fast shutter speed.
Typically, faster telephoto lenses are required. Faster telephoto lenses have larger maximum apertures.

A “fast” lens is usually one that has an aperture of f/4, f/2.8 or larger.
If sports is one of your primary subjects, a telephoto zoom such as a 70-200 f/2.8 is an excellent choice.
If you really want to shoot like the pros, you’ll want a 300mm f/4, or 300mm f/2.8 or 400mm f/2.8. These lenses are great for getting you closer to the action, but you need to be sure your shutter speed is fast enough.
Too slow a shutter speed will result in motion blur. Typically, AT LEAST 1/500 to 1/1000 shutter speed is the minimum. Using these longer lenses can be challenging to track movement, so it becomes much easier if the subject is coming directly at you, rather than trying to track movement parallel to the camera.

Beyond the usual types of lenses, there are a variety of specialty lenses available.
Like shooting tiny things? Try a macro lens. Architecture?
A tilt-shift or perspective correction lens might be your choice.
There is a lens for every purpose, it’s just a matter of putting it to good use.
As always, remember that a lens is just another tool on the camera; it’s up to the photographer to make it work.

Rick Berk is based in New York and has been involved in photography for 20 years, shooting portraits, landscapes, and professional sports. His images can be viewed and purchased at www.rickberk.com.

Introduction to Aperture in Digital Photography

ApertureOver the last couple of weeks I’ve been
writing a series of posts on elements that digital photographers need
to learn about in order to

get out of Auto mode and learn how to manually set the exposure of
their shots.

I’ve largely focussed upon three elements of the ‘exposuretriangle‘ – ISO,
ShutterSpeed and Aperture.

I’ve previously written about the first two and today would like to
turn our attention to Aperture.

Before I start with the explanations let me say this.

If you can master aperture you put into your grasp real creative
control over your camera.

In my opinion – aperture is where a lot of the magic happens in
photography and as we’ll see below,

changes in it can mean the difference between one dimensional and multi
dimensional shots.

What is Aperture?

Put most simply – Aperture is ‘the size of the
opening in the lens when a picture is taken.’

When you hit the shutter release button of your camera a hole opens
up that allows your cameras image sensor to catch a glimpse of the
scene you’re wanting to capture.

The aperture that you set impacts the size of that hole. The larger the
hole the more light that gets in – the smaller the hole the less light.

Aperture is measured in ‘f-stops’. You’ll often see them referred to
here at Digital Photography School as f/number – for example f/2.8,
f/4, f/5.6,f/8,f/22 etc.

Moving from one f-stop to the next doubles or halves the size of the
amount of opening in your lens (and the amount of light getting
through).

Keep in mind that a change in shutter speed from one stop to the next
doubles or halves the amount of light that gets in also –

this means if you increase one and decrease the other you let the same
amount of light in – very handy to keep in mind).

One thing that causes a lot of new photographers confusion is that
large apertures

(where lots of light gets through) are given f/stop smaller numbers and
smaller apertures (where less light gets through) have larger f-stop
numbers.

So f/2.8 is in fact a much larger aperture than f/22. It seems the
wrong way around when you first hear it but you’ll get the hang of it.

Depth of Field and Aperture

There are a number of results of changing the aperture of your shots
that you’ll want to keep in mind as you consider your setting

but the most noticeable one will be the depth of field that your shot
will have.

Depth of Field (DOF) is that amount of your shot that will be in
focus.

Large depth of fieldmeans that most of your image will be in
focus whether it’s close to your camera or far away

(like the picture to the left where both the foreground and background
are largely in focus – taken with an aperture of f/22).

Small (or shallow) depth of field means that only part of the image
will be in focus and the rest will be fuzzy

(like in the flower at the top of this post (click to enlarge).

You’ll see in it that the tip of the yellow stems are in focus but even
though they are only 1cm or so behind them that the petals are out of
focus.

This is a very shallow depth of field and was taken with an aperture of
f/4.5).

Aperture has a big impact upon depth of field.

Large aperture (remember it’s a smaller number) will decrease depth of
field while small aperture (larger numbers)

will give you larger depth of field.

It can be a little confusing at first but the way I remember it is
that small numbers mean small DOF and large numbers mean large DOF.

Let me illustrate this with two pictures I took earlier this week in
my garden of two flowers.

The first picture below (click them to enlarge) on the left was
taken with an aperture of f/22 and the second one was taken with an
aperture of f/2.8.

The difference is quite obvious. The f/22 picture has both the flower
and the bud in focus and you’re able to make out the shape of the fence
and leaves in the background.

The f/2.8 shot (2nd one) has the left flower in focus (or parts of
it)

but the depth of field is very shallow and the background is thrown out
of focus and the bud to the right of

the flower is also less in focus due to it being slightly further away
from the camera when the shot was taken.

F-22F-2.8

The best way to get your head around aperture is to get your camera
out and do some experimenting. Go outside and find a spot where you’ve
got items close to you as well as far away and take a series of shots
with different aperture settings from the smallest setting to the
largest. You’ll quickly see the impact that it can have and the
usefulness of being able to control aperture.

Some styles of photography require large depths of field (and small
Apertures)

For example in most landscape photography you’ll see small aperture
settings (large numbers) selected by photographers. This ensures that
from the foreground to the horizon is relatively in focus.

On the other hand in portrait photography it can be very handy to
have your subject perfectly in focus but to have a nice blurry
background in order to ensure that your subject is the main focal point
and that other elements in the shot are not distracting. In this case
you’d choose a large aperture (small number) to ensure a shallow depth
of field.

Macro photographers tend to be big users of large apertures to
ensure that the element of their subject that they are focusing in on
totally captures the attention of the viewer of their images while the
rest of the image is completely thrown out of focus.

I hope that you found this introduction to Aperture in
Digital Photography
helpful.

Source :  Digital Photography school -
by Darren Rowse

Introduction to Shutter Speed in Digital Photography

Previously I’ve introduced the concept of the ExposureTriangle as a way of thinking about getting out of Auto Mode and
exploring the idea of manually adjusting the exposure of your shots.

The three main areas that you can adjust are ISO, Aperture and Shutter
speed.

I’ve previously
looked at making adjustments to ISO and now want to turn our
attention to shutter speed.

What is Shutter Speed?

As I’ve written elsewhere, defined most basically – shutter
speed is ‘the amount of time that the shutter is open’
.

In film photography it was the length of time that the film was
exposed to the scene you’re photographing and similarly in digital
photography shutter speed is the length of time that your image sensor
‘sees’ the scene you’re attempting to capture.

Let me attempt to break down the topic of “Shutter Speed” into some
bite sized pieces that should help digital camera owners trying to get
their head around shutter speed:

  • Shutter speed is measured in seconds – or in
    most cases fractions of seconds. The bigger the denominator the faster
    the speed (ie 1/1000 is much faster than 1/30).
  • In most cases you’ll probably be using shutter speeds of
    1/60th of a second or faster
    . This is because anything slower
    than this is very difficult to use without getting camera shake. Camera
    shake is when your camera is moving while the shutter is open and
    results in blur in your photos.
  • If you’re using a slow shutter speed (anything slower
    than 1/60) you will need to either use a tripod
    or some some
    type of image stabilization (more and more cameras are coming with this
    built in).
  • Shutter speeds available to you on your camera will
    usually double (approximately) with each setting.
    As a result
    you’ll usually have the options for the following shutter speeds –
    1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8 etc. This ‘doubling’ is
    handy to keep in mind as aperture settings also double the amount of
    light that is let in – as a result increasing shutter speed by one stop
    and decreasing aperture by one stop should give you similar exposure
    levels (but we’ll talk more about this in a future post).
  • Some cameras also give you the option for very slow
    shutter speeds
    that are not fractions of seconds but are
    measured in seconds (for example 1 second, 10 seconds, 30 seconds etc).
    These are used in very low light situations, when you’re going after
    special effects and/or when you’re trying to capture a lot of movement
    in a shot). Some cameras also give you the option to shoot in ‘B’ (or
    ‘Bulb’) mode. Bulb mode lets you keep the shutter open for as long as
    you hold it down.
  • When considering what shutter speed to use in an image
    you should always ask yourself whether anything in your scene is moving

    and how you’d like to capture that movement. If there is movement in
    your scene you have the choice of either freezing the movement (so it
    looks still) or letting the moving object intentionally blur (giving it
    a sense of movement).
  • To freeze movement in an image (like in the
    surfing shot above) you’ll want to choose a faster shutter speed and to
    let the movement blur you’ll want to choose a slower shutter speed. The
    actual speeds you should choose will vary depending upon the speed of
    the subject in your shot and how much you want it to be blurred.
  • Motion is not always bad – I spoke to one
    digital camera owner last week who told me that he always used fast
    shutter speeds and couldn’t understand why anyone would want motion in
    their images. There are times when motion is good. For example when
    you’re taking a photo of a waterfall and want to show how fast the
    water is flowing, or when you’re taking a shot of a racing car and want
    to give it a feeling of speed, or when you’re taking a shot of a star
    scape and want to show how the stars move over a longer period of time
    etc. In all of these instances choosing a longer shutter speed will be
    the way to go. However in all of these cases you need to use a tripod
    or you’ll run the risk of ruining the shots by adding camera movement
    (a different type of blur than motion blur).
  • Focal Length and Shutter Speed - another thing
    to consider when choosing shutter speed is the focal length of the lens
    you’re using. Longer focal lengths will accentuate the amount of camera
    shake you have and so you’ll need to choose a faster shutter speed
    (unless you have image stabilization in your lens or camera). The
    ‘rule’ of thumb to use with focal length in non image stabilized
    situations) is to choose a shutter speed with a denominator that is
    larger than the focal length of the lens. For example if you have a
    lens that is 50mm 1/60th is probably ok but if you have a 200mm lens
    you’ll probably want to shoot at around 1/250.

Shutter Speed – Bringing it Together

Remember that thinking about Shutter Speed in isolation from the
other two elements of the Exposure Triangle (aperture and ISO) is not
really a good idea. As you change shutter speed you’ll need to change
one or both of the other elements to compensate for it.

For example if you speed up your shutter speed one stop (for example
from 1/125th to 1/250th) you’re effectively letting half as much light
into your camera. To compensate for this you’ll probably need to
increase your aperture one stop (for example from f16 to f11). The
other alternative would be to choose a faster ISO rating (you might
want to move from ISO 100 to ISO 400 for example).

I’ll write more on bringing it together once I’ve written a post in
the coming week on the last element of the Exposure Triangle – Aperture.

Update: Want more control of your Digital Camera?
Check out our eBook Photo Nuts
and Bolts: Know Your Camera and Take Better Photos
.

Source :  Digital Photography school -
by Darren Rowse

ISO Settings in Digital Photography

What is ISO?

In traditional (film) photography

ISO (or ASA) was the indication of how sensitive a film was to light.
It was measured in numbers
(you’ve probably seen them on films – 100,200, 400, 800 etc).
The lower the number the lower the sensitivity of the film and the
finer the grain in the shots you’re taking.

In Digital Photography

ISO measures the sensitivity of the image sensor.
The same principles apply as in film photography – the lower the number
the less sensitive your camera is to light and the finer the grain.
Higher ISO settings are generally used in darker situations to get
faster shutter speeds (for example an indoor sports event when you want
to freeze the action in lower light) –
however the cost is noisier shots.
I’ll illustrate this below with two elargements of shots that I just
took – the one on the left is taken at 100 ISO and the one of the right
at 3200 ISO (click to enlarge to see the full effect).

Iso-1

(you can see larger sized images of both shots here
for the 100 ISO

and here for the 3200 ISO)

100 ISO is generally accepted as ‘normal’ and will give you lovely
crisp shots (little noise/grain).

Most people tend to keep their digital cameras in ‘Auto Mode’ where the
camera selects the appropriate ISO setting depending upon the
conditions you’re shooting in (it will try to keep it as low as
possible) but most cameras also give you the opportunity to select your
own ISO also.

When you do override your camera and choose a specific ISO you’ll
notice that it impacts the aperture and shutter speed needed for a well
exposed shot. For example – if you bumped your ISO up from 100 to 400
you’ll notice that you can shoot at higher shutter speeds and/or
smaller apertures.

When choosing the ISO setting I generally ask myself the following four
questions:

  1. Light – Is the subject well lit?
  2. Grain – Do I want a grainy shot or one without
    noise?
  3. Tripod – Am I using a tripod?
  4. Moving Subject – Is my subject moving or
    stationary?

If there is plenty of light, I want little grain, I’m using a tripod
and my subject is stationary I will generally use a pretty low ISO
rating.

However if it’s dark, I purposely want grain, I don’t have a tripod
and/or my subject is moving I might consider increasing the ISO as it
will enable me to shoot with a faster shutter speed and still expose
the shot well.
Of course the trade off of this increase in ISO will be noisier shots.
Situations where you might need to push ISO to higher settings include:

  • Indoor Sports Events – where your subject is
    moving fast yet you may have limited light available.
  • Concerts – also low in light and often
    ‘no-flash’ zones
  • Art Galleries, Churches etc- many galleries have
    rules against using a flash and of course being indoors are not well
    lit.
  • Birthday Parties – blowing out the candles in a
    dark room can give you a nice moody shot which would be ruined by a
    bright flash. Increasing the ISO can help capture the scene.

ISO is an important aspect of digital photography
to have an understanding of if you want to gain more control of your
digital camera. Experiment with different settings and how they impact
your images today.

Source :  Digital Photography school -
by Darren Rowse

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