tag:blogger.com,1999:blog-41405440646446874762024-03-14T03:58:33.891-05:00How Do I Use My Digital SLR?<center><p><b><i>For those new to Digital SLR cameras and the creative/technical world of photography.</i></b></p></center>
<center><p><b>© 2007-2015 Keith Harrod | Image Works, All Rights Reserved</b></p></center>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comBlogger17125tag:blogger.com,1999:blog-4140544064644687476.post-2572924065395865452011-08-20T14:45:00.000-05:002012-07-19T14:37:14.008-05:00What is a pixel, and how does it work?From Wikipedia.org;<br />
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"In digital imaging a <strong>pixel</strong>, or <strong>pel</strong>, (<strong>picture element</strong>) is a single point in a raster image, or the smallest addressable screen element in a display device; <u><em><strong>it is the smallest unit of picture that can be represented or controlled</strong></em></u>."<br />
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Most pixels are square, which means they can't be called dots. Some camera image sensors have had both square and rectangular pixels. The Nikon D1x image sensor has both square and rectangular pixels as an example.<br />
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The D3's and D300's I use have 12.1 and 12.3 mega pixel (MP) image sensors, respectively. In round numbers that's 12 million picture elements on each image sensor.<br />
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There are 2 kinds of image sensor: Charge Coupled Devices (CCD's), which were invented in 1969, the year I graduated from high school (Class of '69 Forever!!! Yep, I'm an old guy), and Complementary Metal–Oxide–Semiconductor, or CMOS - active pixel sensors.<br />
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Both types of sensor do essentially the same thing, capturing light and converting it into electrical voltages (signal). CMOS image sensors use less power, and because CMOS uses less power, CMOS generates less heat. Heat is one source of image noise, so less heat, less image noise.<br />
Part of the reason long digital exposures have more noise is because the image sensor gets hotter the longer power is applied to it.<br />
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Make a note here: The image sensor in a digital camera (CCD pixels or CMOS pixels), isn't a digital device, it's an analog device. Make another note here: Neither type of image sensor can record color. <br />
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OK, so we now have the basics of what a pixel is.<br />
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About now you ask, "OK! But how does the voltage (pixel) get changed into a piece of a picture, and how come we can make color photographs if a camera image sensor can't record color?<br />
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I'm glad you asked.<br />
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First lets handle where the color comes from. The color is mathematically interpolated. For our purposes only part 2 of the Dictionary.com definition of interpolate is needed: <br />
<strong><span style="font-size: medium;"><span style="color: black;"><span style="font-family: 'Arial Unicode MS';">in·ter·po·late</span></span></span></strong><span style="color: #333333;">2.</span><em><span style="color: #333333;">Mathematics</span> </em>. to insert, <u><strong>estimate</strong></u>, or find an <span style="color: #333333;">intermediate</span> <span style="color: #333333;">term</span> <span style="color: #333333;">in</span> <span style="color: #333333;">(a</span> <span style="color: #333333;">sequence).</span> <br />
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Yep, the color is estimated, but the estimate is pretty accurate because of a filter array that is placed in front of the image sensor, called a Bayer Array:<br />
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<img alt="" border="0" src="http://i307.photobucket.com/albums/nn290/CougarWilbur/TPF/BayerArray.png" /> note that each array segment has 3 colors - red, green, and blue (RGB) and the array is passive. It just sits there in front of the pixels and it uses no power.<br />
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Digital images are made using the RGB color model. A single Bayer Array has 2 green squares, because human eyes are most sensitive to green light. The red square covers a single pixel, each green square coves a single pixel, and each blue square covers a single pixel. A 12 MP image sensor has 3,000,000 more of those 4 pixel Bayer arrays (4 times 3,000,000 = 12 MP).<br />
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The light falling on any 4 pixels arrayed right together like that, is almost certainly <u>all the same color and the same intensity</u> because those pixels are really, really small. <br />
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But not all red light is exactly red. It more often is some subtle shade of red. In the RGB color model different shades of color can be made by adding differing amounts of the three colors in the model.<br />
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Pure red is R=255, G=0, Blue=0. Pure green is R=0, G=255, B=0. Pure blue is R=0, G=0, B=255.<br />
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Yellow is a mix - R=255, G=255, B=0. Cyan is a mix - R=255, G=0, B=255. Any shades of red, yellow, green, blue, or cyan in between will have some of all 3 RGB colors. <br />
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White is a mix of all 3 at maximum value R=255, G=255, B=255.<br />
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So though the image sensor can't record colors, by having the Bayer Array in front of the pixels the voltage each pixel generates is in part determined by the color of light falling on the pixel, so the colors in the image can be mathematically <strong><u>interpolated</u></strong>.<br />
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The voltages are still analog information though, and the mathematical interpolation can only be performed on digital data. But the voltages the pixels generate are really small, and they need to be amplified. <em><strong><u>How much the voltages get amplified is determined by the camera's ISO setting</u></strong></em>.<br />
once amplified the voltages are then input to an Analog To Digital (A/D) converter.<br />
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If the camera has been set up to record only Raw image data files, the output of the A/D converter is written to the memory card and the image data is not yet a photo you can see, it's all just 1's and 0's or Raw data. The Raw image data file has to be converted into a photo <strong>outside the camera</strong> using any of many Raw converters.<br />
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If JPEG, TIFF, or Raw + JPEG has been selected for output the JPEG and TIFF files have to be made in the camera. <br />
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In the camera, a demosaicing algorithm (a set <span style="color: #333333;">of</span> <span style="color: #333333;">rules</span> <span style="color: #333333;">for</span> <span style="color: #333333;">solving</span> <span style="color: #333333;">a</span> <span style="color: #333333;">problem</span> <span style="color: #333333;">in</span> <span style="color: #333333;">a</span> <span style="color: #333333;">finite</span> <span style="color: #333333;">number</span> <span style="color: #333333;">of</span> <span style="color: #333333;">steps)</span> is applied to the digital data that interpolates the digitized voltages the image sensor/Bayer Array captured, and further processes the image data to complete the JPEG or TIFF file conversion process before the image files are written to the memory card.<br />
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Since JPEG is a lossy, compressed, final, ready-to-print, file type, those files require less memory card space. Unfortunately, because so much image data is discarded making a JPEG file they can't be edited very much, if at all.Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-26396181882721006162011-03-17T17:13:00.001-05:002011-03-18T10:11:09.072-05:00Most Popular LensesHere are some of the most popular lenses around:<br>
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<iframe align="left" frameborder="0" marginheight="0" marginwidth="0" scrolling="no" src="http://rcm.amazon.com/e/cm?t=hdiumds-20&o=1&p=8&l=bpl&asins=B00007E7JU&fc1=000000&IS2=1&lt1=_blank&m=amazon&lc1=0000FF&bc1=000000&bg1=FFFFFF&f=ifr" style="align: left; height: 245px; padding-right: 10px; padding-top: 5px; width: 131px;"></iframe><br>
This is one of Canon's least expensive lenses, which is why it is so popular. It's wide open, fast, f/1.8 aperture is handy for utilizing the selective focus technique because of the very shallow depth-of-field (DOF) the lens can produce. The wide aperture is also useful when you don't have a lot of light available. Sharpest focus is obtained by using intermediate apertures, f/4 to about f/11.<br>
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Care must be taken with shallow DOF though because the DOF can get very thin, and you have to remember that the plane of focus is always parallel to the plane of the image sensor. If you want both of someone's eyes in focus in a portrait,<br>
<a href="http://kharrodphotography.blogspot.com/2011/03/most-popular-lenses.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-65336491225846799852011-03-09T14:20:00.003-06:002011-03-10T18:10:15.869-06:00How Do I Use My Digital SLR's Auto Focus? Part-2Most digital SLR's will offer some auto focus mode options, like single focus, continuous focus, and that trusty old stand-by - manual focus.<br>
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They also offer some focus area modes that use just the one focus point you have selected or some other focus area mode that help keep things in focus in your photos.<br>
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<div style="text-align: center;"><strong><em>Auto Focus Modes</em></strong></div><br>
<strong><em>Single Servo Focus</em></strong><br>
The most commonly used focus mode is Single focus. (Nikon - AF-S, Canon - One Shot AF)<br>
Use single focus when you are making photographs of subjects that aren't moving.<br>
When the shutter is pressed halfway the camera focuses, turns on an in-focus indicator in the viewfinder, and then locks the focus until the shutter is released, or until the shutter button is returned to it's normal position.<br>
That's so <br>
<a href="http://kharrodphotography.blogspot.com/2011/03/how-do-i-use-mydigital-slrs-auto-focus.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-40820538532323685112011-01-08T14:05:00.003-06:002011-03-10T10:18:32.965-06:00How Do I use My Auto Focus? Part-1<div style="text-align: center;"><div style="text-align: left;">There is a lot to cover when explaining auto focus, so it will take 2 installments to cover it all.</div><br>
<strong><em>Auto Focus From The Beginning</em></strong></div><br>
The first auto focus SLR for general sale was released in 1978. That camera, the Polaroid SX-70 Sonar OneStep, used an active auto focusing system that sent out sound waves. Today's digital SLR's use a passive system that takes advantage of light coming in through the lens.<br>
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So, auto focus sure isn't anything new, having been around for 30+ years now.<br>
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<div style="text-align: center;"><strong><em>How Does My Digital SLR Auto Focus?</em></strong></div><div style="text-align: center;"></div><div style="text-align: left;"><br>
</div><div style="text-align: left;">It’s called SIR TTL passive phase detection - (<u><em><span style="color: #990000;">S</span></em></u>econdary <u><em><span style="color: #990000;">I</span></em></u>mage <u><em><span style="color: #990000;">R</span></em></u>egistration - <span style="color: #990000;">SIR</span>, <u><em><span style="color: #990000;">T</span></em></u>hrough <u><em><span style="color: #990000;">T</span></em></u>he<u><em> <span style="color: #990000;">L</span></em></u>ens - <span style="color: #990000;">TTL</span>).</div><div style="text-align: left;">It’s a pretty simple system actually. It’s used by most dSLR cameras today for that reason.</div><div style="text-align: left;"><br>
</div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCHoRiiGNUG0mkYLQR13BK9cxo5LM9PAmqUijNSqqmdLc_mqJni0Dw63QxAydeae-IB1Kq3mA7_mqqSg_ZbyNW3blByFXlMOZLRcDfbQOqtiJKAf2gDvrR8BI9ou-B2kN6akgkCB8TA9I/s1600/800px-E-30-Cutmodel.jpg" imageanchor="1" style="clear: left; cssfloat: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="296" n4="true" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCHoRiiGNUG0mkYLQR13BK9cxo5LM9PAmqUijNSqqmdLc_mqJni0Dw63QxAydeae-IB1Kq3mA7_mqqSg_ZbyNW3blByFXlMOZLRcDfbQOqtiJKAf2gDvrR8BI9ou-B2kN6akgkCB8TA9I/s400/800px-E-30-Cutmodel.jpg" width="400"></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Wikipedia - GNU Free Documentation License</td></tr>
</tbody></table><div style="text-align: left;"><strong><u>Here is how it works</u></strong>:</div><div style="text-align: left;">Light enters the lens and is reflected by the main mirror, but the main mirror (<span style="color: red;">1</span>.) is only 50% reflective.</div><div style="text-align: left;"><br>
</div><div style="text-align: left;">Half of the light goes up through the pentaprism/pentamirror (<span style="color: red;">4</span>.) and to the viewfinder eyepiece<span style="color: black;"> (</span><span style="color: red;">5</span>.).<br>
</div><a href="http://kharrodphotography.blogspot.com/2011/01/how-do-i-use-my-auto-focus-part-1.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-4742250587523885382011-01-06T19:35:00.007-06:002011-01-08T11:05:14.526-06:00How to Get Sharply Focused ImagesIf the subjects in your pictures aren't sharply focused they won't look very good. They'll be missing one of the qualities that makes a photo an <em><strong>image</strong></em> and not just a snapshot. <br>
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Here are some things you can do to get <em><strong>tack sharp</strong></em> images. It's a combination of technique and equipment use, rather than just one thing. <br>
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<div style="text-align: center;"><strong>It's the Photographer</strong></div><br>
You'll hear many people say it's not the equipment, it's the photographer. Well, yes and no. Photography is one of the few pursuits where equipment can make a pretty big difference and we'll look at equipment first. <br>
There are some aspects of photography that if you want to get pro results, you have to use the same equipment the pros use. You can always rent instead of buying if your need is short term, or your photography equipment budget is tight.<br>
<a href="http://kharrodphotography.blogspot.com/2011/01/how-to-get-sharply-focused-images.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-77807066245018963022010-12-26T16:16:00.007-06:002011-01-06T19:51:59.439-06:00LENS INFO<div style="text-align: center;"><strong>Lens Lingo </strong></div><br>
One of the things new photographers grapple with is lens lingo.<br>
What do all those numbers and abbreviations mean?<br>
We’ll start with the kind of lens, or lenses, that likely came with your dSLR.<br>
<span style="background-color: yellow; color: #cc0000;"><strong>Note</strong></span>: Each camera maker has their own lens mount design. Nikon lenses (F-mount) cannot be directly mounted on Pentax cameras (K- mount). However, someone may make an adapter that allows such a mash up.<br>
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<div style="text-align: center;"><b>Two Lens Types</b></div><br>
There are 2 lens types:<br>
<a href="http://kharrodphotography.blogspot.com/2010/12/lens-info.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-86094233090893603882010-07-04T16:21:00.014-05:002011-01-03T15:20:22.087-06:00Digital SLR Camera SettingsMore people than ever before are using digital SLR cameras.<br>
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When film was the primary medium people used to make photos, you didn't get to see your photos until they were printed. If you didn't do your own darkroom processing, you relied on the photo lab to develop the negatives and make the prints for you.<br>
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<div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;">Now, dSLR photographers can see a small version of their photo right on the camera, but if they want those photos to display nicely on a computer monitor, somewhere online, on some other digital device or have it printed, there are choices about camera settings that need to be made. Those choices can have a big impact on how sweet your photos look and how much editing you can do to them and still have them look nice.</div><br>
Each camera has many settings, and most are covered in each camera's users manual, but 2 of the more important, somewhat esoteric settings, are worth taking a closer look at. <br>
<a href="http://kharrodphotography.blogspot.com/2010/07/digital-slr-camera-settings.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-60403989936271019282010-07-02T13:14:00.011-05:002011-01-03T15:15:03.714-06:00Recommended Reading - TechnicalThe technical aspects of photography seem daunting to a lot of new photographers. From a technical viewpoint the basics are really rather simple and can be conveyed without much muss or fuss.<br>
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One of the best at doing that is Bryan Peterson. Bryan is a successful professional photographer that also has a gift for explaining technical aspects of photography in easy to understand ways. I recommend three of Bryan's inexpensive, yet information packed books:<br>
<a href="http://kharrodphotography.blogspot.com/2010/07/recommended-reading-technical.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-88890851475196823732010-06-24T18:18:00.005-05:002011-01-03T15:16:54.772-06:00Recommended Reading - CompositionI have a couple of book shelves filled with various books I have read on the many different aspects of photography.<br>
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A lot of new photographers aren't aware of many of those books so I decided it would be helpful to let people know about them.<br>
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My book collection covers several different aspects of photography:<br>
<a href="http://kharrodphotography.blogspot.com/2010/06/recommended-reading.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-52704265784656173352009-08-01T14:25:00.007-05:002011-01-03T15:21:00.977-06:00The In-Camera Light MeterSince we rely so heavily on the in-camera light meter it's very helpful to have a good understanding of how it works and how you can configure it so it provides you the most reliable information.<br>
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<div style="text-align: center;"><b><u>Reflected Light and Algorithms, oh my</u>!</b></div><br>
Your in-camera meter measures how much light is <u>reflecting</u> off the scene it is metering. If everything reflected the same amount of light we would be home free. Obviously, a nice polished piece of chrome on a motorcycle will reflect more light than the skin of a pretty girl sitting on the bike. <br>
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Since the amount of light being reflected from different parts of the scene varies, in-camera meters measure the light intensity in different parts of image and uses an algorithm to determine the most suitable exposure for the final picture. We get to tell the meter which algorithm to use. Well, the camera manufacturer gives us the chance to select from several metering modes that each represent a different algorithm.<br>
<a href="http://kharrodphotography.blogspot.com/2009/05/in-camera-light-meter.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-44136520308609792742009-05-12T15:17:00.011-05:002011-01-03T15:38:43.609-06:00Using The Exposure Adjustment TriadExposure is the total amount of light allowed to reach the image sensor during the process of taking a photograph. We've seen there are 3 things that we can adjusted to control that exposure: the lens aperture, the shutter speed and the ISO sensitivity.<br>
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<div style="text-align: center;"><u><strong>The DSLR Reflective Light Meter</strong></u> </div><br>
<center style="text-align: left;">Your DSLR has a built-in reflective light meter. It tells you if your current settings will make a good exposure or an over/under exposure.</center><center style="text-align: left;"><br>
</center><a href="http://kharrodphotography.blogspot.com/2009/05/exposureall-3-legs.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-35621401689149089982009-04-26T15:42:00.012-05:002011-01-03T15:46:43.165-06:00Exposure...Part 3 - ISO<center><b><u>ISO - Sensor Sensitivity to Light </u></b></center>ISO stands for the "International Organisation for Standardization". The ISO was founded in early 1947 and is headquartered in Geneva, Switzerland and is composed of representatives from various of it's 158 members national standards organisations. <br>
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One of the standards defined by this organization is photographic film's sensitivity to light. An image sensors 'film speed', is often referred to as its "ISO number."<br>
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<div style="text-align: center;"><b><u>ISO - and Stops of Exposure</u></b></div><br>
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Just like aperture and shutter speed ISO is set up as multiples of 2. ISO 100 allows twice as much light as<br>
<a href="http://kharrodphotography.blogspot.com/2009/04/exposurepart-3iso.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-89606177704036984752009-04-05T12:29:00.018-05:002011-01-03T15:47:14.556-06:00Exposure.....Part 2 - Shutter SpeedToday's DSLR cameras use a two curtain focal plane shutter.<br>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhc0_7_fxhfs8t3CoAVvbXUzfSHlnq7FBbj3cFHEuWtrbMokkv5x9nxSpIgtjfa5rwtYjd3Ayg9-4-gPAoodlRUO6RVxRCdIferCLht0iSz2kOPkImVRNtq8bgzw_iPaBabH0t8BhIiZQw/s1600-h/250px-1_500_Sec_Focal_P_Shut.jpg"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5321264223010623218" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhc0_7_fxhfs8t3CoAVvbXUzfSHlnq7FBbj3cFHEuWtrbMokkv5x9nxSpIgtjfa5rwtYjd3Ayg9-4-gPAoodlRUO6RVxRCdIferCLht0iSz2kOPkImVRNtq8bgzw_iPaBabH0t8BhIiZQw/s320/250px-1_500_Sec_Focal_P_Shut.jpg" style="cursor: hand; float: left; height: 167px; margin: 0px 10px 10px 0px; width: 250px;"></a>At left is an image of a two curtain focal plane shutter part way through the sequence of making an exposure. The image sensor is immediately behind the curtains.<br>
This shutter was set to 1/500th of a second. Both curtains move from the top to the bottom. The front curtain is released first and in this image is near the bottom of it's range of travel below the black horizontal gap low in the image. The rear curtain follows close behind due to the the 1/500th of a second shutter speed.<br>
The gap between the two curtains travels down and is spaced to expose each part of the image sensor for the required 1/500th of a second.<br>
Once the exposure has been made both curtains get reset to the top of the frame so they are ready for the next exposure.<br>
If the shutter had been set to 1/60th of a second the front curtain would travel all the way down before the<br>
<a href="http://kharrodphotography.blogspot.com/2009/04/exposurepart-2-shutter-speed.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-52745496905438253352009-04-02T11:14:00.021-05:002011-01-03T15:47:38.827-06:00Exposure...Part 1 - ApertureWhile you're fresh we'll tackle the math stuff first. If you skip it I can guarantee you'll be lost further on. In fact you'll probably have to go over this first part several times. Believe me, you won't be the first, nor the last to do so but it's part of the essential knowledge you need to have for making creative exposure adjustments.<br>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkXaBe9pFxqX7MblA3ejNUpxN5miCBcsoHeSY3l4hhI9fwYXK1LyQNPmDDc3rqmYBkDFk5X-muqpPJO2dhhBxgw-kY53R3LRgiz34JHeDi_u9N3TA2BdKOCkWvvB3vPyqpmzyfaIBBNBw/s1600-h/340px-Apertures.jpg"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5320135089973565330" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkXaBe9pFxqX7MblA3ejNUpxN5miCBcsoHeSY3l4hhI9fwYXK1LyQNPmDDc3rqmYBkDFk5X-muqpPJO2dhhBxgw-kY53R3LRgiz34JHeDi_u9N3TA2BdKOCkWvvB3vPyqpmzyfaIBBNBw/s320/340px-Apertures.jpg" style="cursor: hand; float: left; height: 320px; margin: 0px 10px 10px 0px; width: 182px;"></a><br>
Inside the lens is a mechanism called a diaphragm that adjusts the size of the lens opening (aperture), larger or smaller. Controlling that lens opening is the first step in controlling the exposure. The photograph on the left shows a 50 mm lens aperture set to f/2.8 (#1) and then adjusted to an aperture of f/16 (#2).<br>
<a href="http://kharrodphotography.blogspot.com/2009/04/exposurepart-1-aperture.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-40882652039153955232009-03-29T10:34:00.013-05:002011-01-03T15:47:52.617-06:00Exposure.....An IntroductionMost people put their camera in Auto mode and are content with the results. Some people would like to have better looking images. One of the ways to accomplish that is by selecting some or all of the exposure parameters that the camera has available.<br>
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The exposure of an image is controlled by three parameters.<br>
<ul><li>The size of the lens opening.</li>
<li>The length of time the shutter is open.</li>
<li>The sensitivity the image sensor is set to, known as ISO</li>
</ul><br>
In the first two installments we saw that light is first captured by the lens, controlled by the lens opening or aperture, then the shutter controls how long the light falls on the image sensor.<br>
<a href="http://kharrodphotography.blogspot.com/2009/03/exposurean-introduction.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-75222266331934606482009-03-26T13:03:00.024-05:002011-01-03T15:55:10.095-06:00The Basics of the LensA DSLR camera lens is not very different from a refracting telescope or even a microscope.We need the lens to gather light and focus it while transmitting the light to the image sensor.<br>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifDWV41UrM9DjXqt3E3ugJoQ6NL_qKM3_hSOzmixoaYTyTneZWdFdPUi6zFMKilZMnEJJqXzoEtdP4hIcR7HYMYnVoLRSx_V7jPWkXDY3yn1qPvDESdL3cPZbeV1MGn7tT2vNr-OHAodw/s1600-h/400px-Lens6a_svg.png"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5317581799149667810" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifDWV41UrM9DjXqt3E3ugJoQ6NL_qKM3_hSOzmixoaYTyTneZWdFdPUi6zFMKilZMnEJJqXzoEtdP4hIcR7HYMYnVoLRSx_V7jPWkXDY3yn1qPvDESdL3cPZbeV1MGn7tT2vNr-OHAodw/s320/400px-Lens6a_svg.png" style="cursor: hand; float: left; height: 193px; margin: 0px 10px 10px 0px; width: 320px;"></a>Here is an example of a simple lens: <br>
It gathers light to a focus. Sort of. There are some inherent problems with a simple lens.Lets first talk about Chromatic aberration.<br>
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Because the lens is thicker in the middle than at the edges all colors of light do not focus in the same place.<br>
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<div style="border-bottom: medium none; border-left: medium none; border-right: medium none; border-top: medium none;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCYsgofFKQ4dtgIaky_SR_ohLw8VZgd9p-PuP-KWIW1IFw5lamIO5wDb2dBosPG7loe5m497dBnkc47XDbpIGom5FICQXLhe0uUbu1UNrpAvZQpIi-MelEMTqVP28QJ6mUdlHj_K0HQj4/s1600-h/400px-Lens5_svg.png" style="clear: left; cssfloat: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5317581989453539618" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCYsgofFKQ4dtgIaky_SR_ohLw8VZgd9p-PuP-KWIW1IFw5lamIO5wDb2dBosPG7loe5m497dBnkc47XDbpIGom5FICQXLhe0uUbu1UNrpAvZQpIi-MelEMTqVP28QJ6mUdlHj_K0HQj4/s320/400px-Lens5_svg.png" style="float: left; height: 193px; margin: 0px 10px 10px 0px; width: 320px;"></a>There are 2 other undesirable properties of a simple lens: </div><a href="http://kharrodphotography.blogspot.com/2009/03/basics-of-lens.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.comtag:blogger.com,1999:blog-4140544064644687476.post-17526682721387062492009-03-25T20:01:00.011-05:002011-01-03T15:55:59.274-06:00How Digital SLR Cameras Work (basic version)First lets get SLR defined: it stands for Single Lens Reflex.<br>
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For the photographer it means when you look through the viewfinder you are actually looking through the lens you have mounted to your camera body. Who hasn't looked into the viewfinder and discovered pure black....because the lens cap was still on. The main advantage of a SLR camera is you see pretty much what the image sensor will see when you trip the shutter.<br>
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Here's how the image gets from the lens up to the viewfinder:<br>
<a href="http://kharrodphotography.blogspot.com/2009/03/how-digital-slr-cameras-work-basic.html#more">Read more »</a>Studio 101 | Image Workshttp://www.blogger.com/profile/03985933234635670389noreply@blogger.com