Principles of Exposure: Capturing Action and Controlling Motion Blur

Exposure: Shutter Speed, Aperture, ISO:

Exposure is the measure of light falling on the media, be it film or CCD. It's controlled by three factors namely shutter speed, aperture and sensitivity of the sensor (ISO). Let me try to explain each of these in a greater detail.

Shutter Speed is the amount of time the shutter screen remains open, in other words, it is the duration for which the light hits the media. Shutter speed is the feature of the camera and not the lens. Faster the shutter speed, lesser the duration for which light hits the sensor, so lesser amount of light is captured.

The shutter speeds range from 1/4000th of a second (1/8000 on a pro camera) to 30seconds, with a special "B" (bulb) mode wherein the shutter could be kept open as long as the photographer wishes (of course, constrained by battery).

The shutter speed controls another most important aspect - freezing the subject in time. Simply stated, you shoot a speeding car with slow shutter speed, you tend to see the trails of the car resulting from motion blur. On the other hand you shoot the same car with higher shutter speeds, the car will appear as though it is stationary. In case you're wondering what magic, the photographer has done to capture those long trails of headlights, the answer is simple: he would have just kept the shutter open long enough to capture the trails.

When you're shooting with slower shutter speeds (under 1/100th of a second) holding the camera, it is highly likely that you end up with a blurred photograph. Why? It's obvious that when you're shooting at lower speeds, even the slightest camera shake will contribute to the blurring of the photograph. Solution for this problem is to mount the camera on a tripod or try to find a platform nearby to place the camera and shoot.

The answer for the question "What shutter shutter speed to use for a particular shot?" is "It entirely depends on the kind of shot and it can't be generalized". If you're shooting birds, wildlife, sports, street shots etc. which require the moment to be captured tack sharp use high shutter speeds. Night shots, trail capture, abstract photographs, light painting, milky waterfall photographs etc. require slow shutter speeds.

Aperture is the feature of the lens and has nothing to do with the camera, except that the aperture values are set/controlled by the camera. As the name itself suggests, aperture is an "opening" at the rear end of lens through which the light enters the camera. Earlier days, the lens barrel had an aperture ring to set the required aperture values, but these days the aperture could be controlled by the knobs on the camera or changing a setting on the digital menu of a DSLR.

The maximum and minimum value of aperture depends, as mentioned earlier, on the lens and not on the camera. You may find a lens with aperture as big as f1 or f1.4 or as small as f45 or f64. Aperture is measured in terms of f-stops and hence the f. It's notated f/1.8 or f/5.6 as well. As you can see the size of the aperture is inverse to the value of f-stop, higher the f-stop smaller the aperture, smaller the f-stops bigger the aperture. So at f1.8 the light received by the medium will be more than f5.6; least light will be received at the smallest aperture say F22 of F45 or whatever your lens supports.

Like shutter speed, aperture also controls one other aspect, apart from the amount of light, it's called Depth of Field (DOF). You maybe confused by amateur photographers who are fond of terms like DOF, Bokeh, Hyperfocal distance etc. Just remember this rule of thumb & don't get lost in the jargon: Bigger the aperture, smaller (shallower DOF) the region of focus; smaller the aperture larger (deeper DOF) the region of focus. You may, therefore, want to open up the aperture for a portrait shot wherein you want a focused and sharp face and blurred background and close down the aperture for a landscape shot wherein you want the entire landscape to be focused. Also in macro shots, the amount of DOF is very critical since the available DOF is very less. DOF is used sometimes to give artistic effects to the photographs.

Photo credit: Seth Wilson 2013

Portraits would come out well with bigger apertures (smaller f-stops) for it makes the subject really sharp against a background of soft background, Also night shots usually require bigger apertures which would allow lot of light to enter.

Landscapes need smaller apertures (bigger f-stops) for most times it wouldn't have a specific focus point. Smaller apertures help on a very bright day to cut-off excess light entering (of course this could be controlled by shutter speed too).

ISO is the measure of sensitivity of the media (film) and digitally is a camera dependent feature. ISO values are typically in the range of 100 to 3200 (on a pro camera it can have an extended range from 50-102400)

When the ISO is set to 100 the sensor is the least sensitive, it can sense less light. When it's set to 1600 or 3200, the sensor can sense a much more light. Which means for a given condition if ISO 100 gives a standard exposure with F8.0 & 1/250th of a second, ISO 1600 may give a standard exposure at F8.0 & 1/1000th of a second. ISO comes very handy while shooting hand-held under low light conditions, it gives an advantage of slightly faster shutter speeds which helps in avoiding motion blur.

An obvious question may arise to a novice, "Why should I shoot at low ISO when higher ISO gives an advantage of faster shutter speed?" Though ISO seems to be such a cool feature, it carries with it something very undesirable - NOISE. Higher the ISO, higher the noise.

Brighter the ambience smaller the ISO (unless you want grainy effect), darker the ambience higher the ISO.

To Make It Easy Just Remember The Rule of Equivalent Exposure: Each Change In ISO Is Equal To One Full F-Stop

Imagine you've pointed your camera at a scene and it's recommending the following settings:

1. A shutter speed of 1/100s 
2. An aperture of f/5.6 
3. A sensitivity setting of ISO 400 

We could make the photo appear twice as bright by doing any of the following:

1. Doubling the shutter speed to 1/50s 
2. Doubling the area of the aperture by increasing it one full f-stop, to f/4 
3. Doubling the sensitivity setting to ISO 800 

Any of these could be described as increasing the exposure by 1 stop.

Likewise, to make the scene appear half as bright, we can reduce the exposure by 1 stop by taking one of the opposite steps: 

1. Halving the shutter speed to 1/200s 
2. Halving the aperture area by reducing it one full f-stop, to f/8 
3. Halving the sensitivity to ISO 200. 

Note that we use the word "stop" even when we're not adjusting the f-stop (aperture) setting. It's just become a general term to mean a factor of 2.

That's about it. For even more information, read this page here at Cambridge In Colour.

Key Assignment 5: Capturing Action

Students, your new assignment is a challenge for you to demonstrate an understanding of the basics of exposure through capturing action and controlling motion blur. Create images that meet the criteria listed below

Assignment Deliverables:

This pelican was shot with a fast shutter speed to capture it in motion, even the water droplets splashing up are frozen in time. Photo credit Will Tierney 2015

1- Object Frozen in Time: Create 2-3 images of a moving object that is frozen in mid-action, this image must show no motion blur. For each image write a short description of the process used in taking the photo, what settings were used to create the visual effect and describe the affect the image may have on the viewer.

A fire spinner creates a silhouette of herself through motion blur. Photo credit Seth Wilson 2005

2- Object in Motion: Create 2-3 images that show an object in motion. The moving object must show motion blur. For each image write a short description of the process used in taking the photo, what settings were used to create the visual effect and describe the affect the image may have on the viewer.

3- Tracking Motion: Create 2-3 images that shows an object in motion with the background behind the object showing motion blur. For each image write a short description of the process used in taking the photo, what settings were used to create the visual effect and describe the affect the image may have on the viewer.

4- Zoom Blur: Create 1 image that shows zoom blur by cranking the zoom and taking a photo at the same time, try it a few times and post your best. For each image write a short description of the process used in taking the photo, what settings were used to create the visual effect and describe the affect the image may have on the viewer.

Post all images with accompanying written content to your blog when complete.

Due by Wednesday...

- Mr.W

Typography Scavenger Hunt: Create a Typeblock Poster

Alphabet Scavenger Hunt

This is your first assignment that involves taking pictures. Now that you can open files in photoshop, manipulate their color, use layers and understand some of the tools we can move forward.

Your new assignment is a Photography Scavenger Hunt. The subject matter is typography and the challenge is to create a photographic typeblock poster of the alphabet.

The project specs are below:

• Subject Matter: Typography
• Deliverable: Poster, PSD Format, 11"X17"
• Challenge: Use whatever camera is available (phones and smart devices allowed) and take pictures of signage, print, posters, artwork that uses typography. Attempt to capture the entire alphabet. If you can't find a certain letter you may create an interpretation of it.

Format: For your current project the final document size should be a poster that is 11X17 inches with a resolution of 150 pixels per inch. Set your New Document settings like I have shown below:

Process: Collect your photos, download them to a folder. Create a large document in photoshop at 11X17 inches, 150 Dpi, bring in your photos and arrange, crop and work them into an eye pleasing typeblock poster of the alphabet.

Saving: Make sure you save your document in the PSD format. Remember to convert to JPG before uploading, you can do this by Photoshop's File / Save As function and changing the image format to JPG.

Template: Use my simple template if you desire...

Student Samples:

It's Bloggerin' Time!

Students, your new assignment is to create an online repository for your photography work as a portfolio or showcase. You will turn in assignments by posting your  work along with any written material. You can choose to use blogger or wordpress, weebly, bechance or any other online platform that lets you post images, text and looks professional. The choice is yours, blogger is simpler and more straightforward but wordpress will give a more flexible and professional option... but it can be a bit more challenging. The choice is yours, choose wisely.... and make sure your platform isn't blocked by the school network. if you choose to use blogger you can follow the guide below:

Blog Setup Assignment:

1. Create an account and set up a blog either at blogger.com or wordpress.com
2. Go back through your work and post your recent assignments, photo manipulation, tutorial results, collage and your typeblock poster
3. Email your site link to your instructor for inclusion in the blog link list
4. Chillax and get ready for the next project!

Now, you may be asking yourself:
"Do I have to use Blogger?"Which is a strange question to ask yourself, but the short answer is no. Many platforms such as Wordpress, Weebly, Wix or even Flickr or Imgr can be used. The quality, flexibility and ease of use are the determining factors. Wordpress is the professional standard, everything else will work and look "ok" but not "amazing". Think of the life of your blog, will you continue to use it in the future and show it to potential employers? That use Wordpress, if not then it is your choice for platforms. As long as you can post images, text and share the URL with the class it will work.

How to set up a Blogger Blog:

Despite all of the hype with "blogs" in recent years, a blog really isn't anything much more complicated than a means for publishing work on the web in an easy to read and easy to update format. Some blogs are very personal, resemembling a diary, while others seem more akin to newspaper or magazine journalism. For our class this term, you will keep a blog where I'll ask you to post several short writing responses this term. Most of these exercises will be just a few pages long and they should help you working on the longer writing projects this semester.One easy way to do this is with Blogger, a free and easy to use service. Here are the instructions for how to set up a blog with Blogger.

Step 1: Go to http://www.blogger.com and sign up for a blog

Again, it's an easy to use service, but let me give you a few pieces of advice on how to accomplish this:

• At the start page for blogger, click on the orange arrow that says "create your blog now."
• Blogger now is part of Google, so if you have a Google account (which allows for things like gmail) you should use that to set up your new blogger account. If you don't have a Google account, now is a pretty good chance to set one up. Otherwise, it is just a matter of following the instructions on this page.
• Be sure to check the "terms of service" box; of course, you might actually want to read through it a bit first, though the rules are pretty standard for these sorts of services.
• Save your username and password some place. In fact, I would encourage you to write it down some place. Don't lose this!
• When you're done, click on the orange "continue" button, which will take you to another page. If you did something wrong or you supplied a username or password that doesn't work, Blogger will stop you from proceeding until you fix the error.
• The "Blog Title" will be what appears in the title portion of your blog. I recommend you keep it something simple like "My English 328 Blog" or whatever you want.
• For the address of your blog, I'd encourage you to use your username. So, in my case, the blogger blog address would be http://krause328.blogspot.com Unless you know what you're doing with ftp functions, you should use blogspot.com to host your blog.
• The "word verification" section is a security set-up the blogger folks have; simply type in the word you see in the funky font into the provided box. Click "continue" when you're done.
• You can choose any template you want for your blog, and you can also change the template later if you would like. Click continue when you're done.
• After waiting a few moments, you should get a screen that says your blog has been created. Good for you! Click on the "start posting" arrow and get to work!

To change your comment settings:

• Log into your blog
• Click on the "design" tab
• Go to "settings" and then "posts and comments" and change your settings to the example above
• Save your settings before finishing

Please change your blog settings to block comments and set all comments to be moderated always.

Your comment settings should look like the one shown here...

Step 2: Get posting!

• The posting screen for blogger is pretty straight-forward. Give your entries a title, type in the appropriate window, and use the editing tools for your blog entry as you want. We'll talk about more advanced options for your posting later, but if you know any basic html, you can incorporate most of that code into your blog posts.
• To post or "publish" your post, click the button at the bottom of the screen "Publish Post." If you start writing something but you don't want to post it until later, click where it says "Save as Draft."
• When you publish your post, blogger will process the information and then, if everything worked (and it usually does), it will give you the option to "view blog." Take a look at it; you should notice a couple of things:
  • The address for your blog-- something like http://stevendkrause.blogspot.com-- is the address for your blog. Send this URI (web address) to me! I will link to your blog from the class web site.
  • Readers should be able to post a comment to your post by clicking on the "comments" link.

Step 3: Do some adjustments to your account

There are a number of different things you might want to do to make your blog a bit more useful. But here are a couple of things you really should do no matter what.

Blocking blog spam. I know, hard to believe, but yes, the world of spamming extends to blogs too. Fortunately, Blogger has a pretty decent security feature that will eliminate almost all spam posts from your blog. Here's what to do:

• If you aren't already logged in, log in to your Blogger account. You did remember your username and password, right?
• From the "Dashboard" screen, click on the name of your blog.
• Click on the tab "Settings."
• Click on the link near the top of that page under the tabs labeled "Comments."
• Set "Who Can Comment?" to "Only Registered Users." It isn't essential that you do this, but I'd recommend it.
• A bit further down, set "Show word verification for comments?" to "Yes." This is a security feature that requires the comment poster to type a specific word that shows up as slightly distorted text in a window.
• Select "Save Settings" at the bottom of the page.

Time zone. It'd be nice if the time was right on your blog, right? Here's how to do that:

• If you aren't already logged in, log in to your Blogger account. You did remember your username and password, right?
• From the "Dashboard" screen, click on the name of your blog.
• Click on the tab "Settings."
• Click on the link near the top of that page under the tabs labeled "Formatting."
• Under "Time Zone," select the right time zone (and if you're reading this as part of one of my classes, that'd be "Detroit." Duh.)
• Select "Save Settings" at the bottom of the page.

Doing things to customize your blogger blog. There's lots of stuff you can do customize your blog. At a minimum, I'd recommend including some links to your classmates' blogs or other blogs you like to read, but there are a lot of other things you can do, too-- include pictures, lists of stuff you like, etc., etc.

• If you aren't already logged in, log in to your Blogger account. You did remember your username and password, right?
• From the "Dashboard" screen, click on the name of your blog.
• Click on the tab "Template."
• Make sure the "Page Elements" tab under this is selected, and click on "Add a Page Element." From here, simply follow the instructions. Be sure to save you page element additions and double-check that it worked.

Step 4: Repeat

This is all you need to do to set up your blogger interface (though, as you can see further down on this page, there are some other things you will probably want to try to do sooner than later). Easy, right?

To post to your blogger blog from now on, here's all you need to do:

• Once again, go to http://www.blogger.com
• Log in with your username and your password (you remembered your username and password, right?) DO NOT click on the "create your blog now" because that will just get you back to step 1.
• After you log in, you should get to your blogger "dashboard," which has a link to your blog. Click the link to manage the blog or click on "New Post" to make a new post to the blog.

Trouble-shooting

"Hey, what should I do if it didn't work?!" Well, blogger really is pretty easy to use, and while it does sometimes have bugs that are of course not your fault, usually if your blog doesn't work, it is is because of something that you did (or didn't) do.

So the first thing you should do is re-trace the steps above: are you sure you did everything I outline here? Really? Are you positive?

If you're confident that you did everything right, here are a couple of other thoughts:

"I tried to enter in my blog address into a web broswer but it didn't work"

Then try this:

• Log in to blogger, using your username and password that you used to sign up for blogger in the first place.
• Get to your blogger "dashboard."
• Click on the link to your blog.
• Click on the tab at the top that says "view blog"
• The web address (or URI) that appears in the window is the address to your blog. It will be something like http://something.blogspot.com Copy this information and paste it into an email message to me.

"I wrote my posts but nothing has shown up yet"

If this is the case, then you probably didn't "Publish" your entry yet but you did a "save as draft." Go back to it and push the "publish" button. This should bring up a window with a time-clock where Blogger indicates it is publishing your entry.

CTE Digital Photography: The Photoshop Journey to Mastery Begins With A Single Pixel

Hello Students,
Having an in-depth understanding of Adobe Photoshop and its processes is incredibly important in many areas of digital media arts, especially with photography. Photoshop was designed with the photographic process in mind and uses terminology and techniques common to the darkroom/exposure process. This is not the only software the photographers use, but it is a great starting point to begin study. In this exercise we will develop familiarity with the image editing process and the power of photoshop for image manipulation.

Post Processing Project:
Your new assignment is to enhance a portrait with the methods detailed below. Use a good portrait and a good landscape image and work through the following tutorials. Read through the color enhancement assignment and find a way to enhance the colors in your image to make it rich and vibrant.

• Work through the tutorial carefully and follow each step. Your results should show similar improvement. Experiment for best results!
• Save your final images to your desktop in a folder called "Photoshop Intro"

Beginner Photoshop Exercise 1:

• Take a few minutes and browse the photos at http://www.freephotos.se or shorpy.com.
• Find a photo that you like and want to work with, save it to your computer, create a new folder called "PSD Excercise 1" for this project.
• Open the file in Photoshop.
• Apply an artistic filter of yowur choice or alter the saturation, contrast, color etc. 
• Show me what you can do! Do you know any tricks with Photoshop? Try combining 2 images together, modifying or enhancing the color... experiment and create something unique with your original photo.
• Repeat this with a second image and save it in your project folder.
• When complete, move on to the tutorials below...

Beginner Photoshop Exercise 2: Color Enhancement Post Process

• Choose your favorite colorful images from previous photo shoots and create a copy of it, open the copy up in Photoshop (it's always a good idea to edit copies and keep backups of your original images)
• Read the entire tutorial below and try each step out on your photo, adjust settings as needed to boost and enhance the image for best results, this will be different for each image
• Create an image border

For many beginning photographers, any version of the image editor, Photoshop, can look quite daunting to use. With all the menu options, palettes, tools, filters, layer styles and various changes you can make to an image, it’s difficult to know where to start. This article provides some ways to get started.

Here’s a photo I took at the San Jose Rose Garden. Notice it’s lacking control and saturation of color. It’s a little flat and lacks depth. We can adjust it with Photoshop.

To get started, simply open a colorful photo that could use a little enhancement, or an image that needs a lot of improvement...

1. Duplicate The Background Layer

The first thing you want to get used to doing is making a copy of the background layer of your image. The Layers palette should open by default, but it is also found by clicking on Windows>Layers in the menu bar of Photoshop.

Select the Background Layer and click on the little triangle at the top right of the palette. When the palette options open, click Duplicate Layer, or you can use the shortcut keystroke, Command+J.

By duplicating the background layer, you can make all types of adjustments to duplicate layers without permanently changing the original layer. If you make some adjustments you don’t like, you can drag the duplicate layers (with all the adjustments and effects you made to them) to the trash at the bottom right of the layer palette and restart the process.

2. Automatic Image Adjustments

When you start learning how to use Photoshop to improve your photos, you might want to try out some of the automatic adjustments that can be made, even if you don’t understand the tools themselves.

The basic image enhancement and adjustment tools in Photoshop are found under Image>Adjustments in the menu bar. In the Adjustment palette, there are various tools like Levels…, Auto Contrast, Curves, Brightness/Contrast.

To introduce you to these adjustment tools in this introductory photoshop tutorial, I’m going to suggest that you use the automatic and preset features of these tools. As you begin to understand them more, you will make use of manual adjustments. Try sliding the adjustments around, by exploring and experimenting you will become more fluent in expressing your artistic vision in your images.

So with your background layer duplicated and selected, click on Image>Adjustments>Auto Levels in the menu bar. When you release the mouse of the menu item, the automatic Levels adjustment should enhance or at least affect the shadow (dark), midtones, and highlights (bright) areas of your image. Often, a photo can be improved in Photoshop with just the automatic adjustments applied.

3. More About Layers

Now let’s revisit how layers work. Go back to the Layers palette and click on the little eye next the Duplicate layer that you just applied the Auto Layers adjustment to. When you toggle that little eye off, it means that you’re turning off the adjustment or effect that you made in that layer. Since the adjusted layer is on top of the background layer like a clear transparency, you can toggle the eye off and on to see how the adjustments are applied to the background layer (also remember: you can drag the duplicate layer to the trash to get rid of the adjustment(s) all together).

4. Automatic Curves

Okay, let’s return to a few other automatic adjustments and enhancements you can make to your photo. Go back to Image>Adjustments and then click on Curves. The Curves box will open. This box may look seriously scary with its grid, points, lines, and ear droppers. But don’t worry about that. We’re simply going to use some automatic adjustments to see how Curves can impact your photo.

Click on the button next to the word Preset. In the drop-down box, select Medium Contrast (RGB). If you don’t see much of a change in the contrast of your photo, go back to the Preset button and try Strong Contrast. You should be able to see the effect of the Preset on your photo before you click OK. Curves works similar to Levels but with more intensity in contrast.

Much more could be said about Curves and Levels, but this is just an introduction. You can play around with the points in the Curves box and see how they affect your photo. Remember, the changes you make are non-destructive to your photo, so you can experiment as much as you like. The illustration below explains a little about how the three main points in the grid function. If you make a mess of things, simply click Cancel and start over, or click OK when you’re satisfied with how the photo is looking.

5. Make Colors Pop

Okay, now lets move on to learn about other enhancements that can be made. One of the tools I use on nearly all the images I bring into Photoshop is one called Soft Light. Here’s how it works.

Go back to the Layers Palette, drag all the layers, except the background layer to the trash. Click on the Background layer and create another duplicate of it. Now click on the Normal button at the top of the Layers Palette. In the drop-down box, select Soft Light. When selecting this adjustment, it should make the colors of your image pop, or at least intensify the contrast of your images. The contrast of most digital images always need to be improved. This technique does that job extremely well without too much loss to detail.

If the Softlight application is too strong, select the Opacity button at the top of the Layers Palette and decrease the opacity of the layer/effect.

6. Image Border

Another tool that beginning Photoshop users might want to know is how to add a border around an image. Again there are a few ways to do this. One way is to select the top layer in the Layers palette. Next click on Image>Canvas Size. In the dialogue box that opens up, change the Width and Height to both to .2. Choose a color for your border. Make sure the center of the Anchor box is selected. Click OK and you should see a border around the image.

That's it! Save your image to your work folder for credit...

- Mr.W