iMovie '08 How-To

WikiHow has a great tutorial up on how to get started with iMovie '08. It's a very basic tutorial that will get you up and running, creating a new project to use as a slideshow or video project.

High Dynamic Range, Part 2

This is a quick follow-up to my first post on High Dynamic Range. I don't feel that I used the best subject matter there- I really just took a few pictures to try it out.

I ended up having better luck at sundown- both in shooting a sunset (a great source of contrast and color) and in just shooting random landscape in that low-light setting. I found I could get some really moody results.

Surrealstic	More Saturated

Changing the way your HDR image is processed can have some dramatic effects on the results. Try to create different moods that fit your subject matter.

I have also learned a bit more about how HDR images are stored and processed in Photoshop. Here I will get into some technical details- but only because the knowledge has changed the way I save and process HDR images in Photoshop (for the better, I think!)

Everything on a computer is stored as bits- ones and zeros. You've probably heard this before, but consider for a moment what this means for storing image data. Putting aside the complexities of compression, a digital image is stored as a series of pixels. Each pixel is a single color, representing the smallest granularity represented by the image.

This is still fairly common knowledge- but, putting the two together, we reach an interesting point- how many bits do we need to store one pixel?

The answer is a little complicated, and gets into the topic of color depth, something that is very relevant when talking about HDR.

Each pixel is made up of several channels. In most cases, there will be three channels- red, green and blue. Other storage methods include 4-channel CMYK, or having an additional alpha channel to define transparency. (This is often called RGBA, for red, green blue plus alpha).

So, now the question becomes- how many bits do we need to store one channel of a pixel? The most common answer is "8". When you choose a raw color value in Photoshop or HTML, you specify a number between 0 and 255 for each channel. This is because each channel is represented as an 8-bit value (and 2 to the power of 8 is 256, giving us that many possible values to work with).

An 8 bit-per-channel image is often simply called a 24-bit or 32-bit image (depending on if there is room for CMYK or RGBA). This can be confusing, so keep in mind the difference between 8-bit color and 8 bits per channel.

In HDR, the idea is to allow for a wider range between the lightest areas and darkest areas of the image. If we end up squashing those color values down into a tiny range, we can lose some of that extra clarity and contrast.

For this reason, HDR images are often stored with more bits per channel. In the "Merge to HDR Pro" dialog, you can choose the numbers of bits per pixel you want to use.

Since learning about this option, I now render all of my HDR images in 32bpc first, saving the PSD file before rendering into a lower color depth. This lets me save a version of the HDR image that is as close to "original" as I know how to get at this point.

When you save your 32-bits-per-channel HDR image, you may notice a serious lack of options! There are not many image formats that support 32 bits per channel.

In order to save your 32bpc HDR image in another format (for instance, JPEG), you must first convert it to 16 or 8 bits per channel.

This will bring up the HDR Toning dialog, with all of the same presets and options as the 16-bit selection in the original "Merge to HDR Pro" dialog.

From here, you can select how you want to render the 32-bit channels, playing with the various effects as before.

The main difference is that now you have the original 32-bit version, and can easily revert to it and try different styles when rendering to 16-bit.

High Dynamic Range

Cameras are generally only capable of capturing a relatively limited range of "luminances" (gradations of brightness). This can often leave photographs feeling "flat" when compared to the original subject because the human eye is capable of perceiving more variance in the light and dark areas.

High Dynamic Range (HDR) is an imaging technique that aims to counteract this effect. It can be used on still subjects to infuse a greater sense of color and depth into your photos.

HDR is generally accomplished by taking multiple photographs of a single subject at different exposure levels. This works best if you use a tripod, and a camera with a good manual mode. Ideally, your camera supports exposure bracketing- a camera mode that automatically takes a few pictures at different exposure levels.

Underexposed	Original	Overexposed

For instance, my wife's Canon has an exposure bracketing mode that takes 3 shots at one time. It allows you to specify a range, and then it takes a photo at the current exposure setting, and one at the high and low ends of the selected range.

To make my HDR images, I took several "brackets", to get a wider sample set. This is only really possible if your subject isn't moving at all.

If your camera does not have exposure bracketing, you can still work with a completely still subject. Set the camera to manual mode, and then take several photos, each with a different shutter speed, while keeping the other settings the same.

The end result will be a set of photos, all essentially the same except for the shutter speed used to capture each one.

Unless your camera is super fancy and has built-in HDR functionality, that is. Some cameras can take the next step and combine those photos for you on board. My Casio, for instance, has a limited ability to combine multiple shots into a single image.

High-Speed Lighting Mode	Automatic Landscape Mode	Low-Light Mode

The Casio EX-FH100 has a few different modes that will combine images taken at high-speed using different exposure settings. One of them is meant for scenes with variable brightness- such as someone sitting in front of a well-lit window. Another mode is meant for low-light settings (without using a flash).

While neither camera mode really creates a true HDR image, I thought it was still worth mentioning. In my opinion, the camera's automatic "landscape" mode made for a prettier picture in this case, but you can be the judge. Under some circumstances, these modes work really well.

Using HDR creation software gives you complete control over how your photos are combined. Some quick Google searching will reveal a couple of good sites that list free HDR creation software. Gizmo's Freeware boasts the best collection of free HDR software, but I found this page on the Panotools wiki to be more informative. Your mileage may vary depending on the software you choose, so try a few of them out and pick whichever seems to work best for you.

The only tool I have personally used for HDR is Adobe Photoshop, so until I get the chance to try out other software this tutorial will only go over Photoshop.

Creating an HDR Image in Photoshop

Photoshop has a built-in automation feature for creating an HDR photo that is surprisingly easy to use.

Begin by opening up all of your images in Photoshop. The easiest way to do this is to select them all in Finder and drag them to the Photoshop icon.

Your images will open up. By default, in CS5, they will open in tabs- your behavior may vary depending on settings and version, but the overall process should be about the same.

To start the HDR automation tool, select "Merge to HDR (Pro") from the "Automate" menu, under "File".

Photoshop will ask you which files you want to use- select "Add Open Files" to bring in all of the files you've loaded.

You should see your images load into the HDR dialog. Select "OK" to proceed.

After some thinking, Photoshop will bring up this screen. You will see all of your photos, sorted by shutter speed, and a preview of the HDR result.

You can play around with the various presets and options until you get a look you like. The different presets can produce some drastically different results. Unfortunately, you can't save multiple files from here. You must repeat this entire process to create images using the different presets.

Surrealistic	More Saturation	Default Settings

When you're happy with the preview, hit "Ok" and wait a while. Photoshop will perform a series of automated tasks, combining, aligning and cropping your images to produce the final result. You can continue to modify the image in Photoshop, or simply save it as is.

Try to find some nice, still subject matter with good contrast- and snap away! Take as many photos as you can, this will give you the most flexibility once you get back to your computer. Good luck, and have fun!

If you are interested in learning a little more about HDR, I posted a follow-up shortly after writing this post. Continue reading to learn more about the technical aspects of HDR, and how to save your image before rendering it.

Featured Artist: blu

I don't know too much about this artist, "blu", except what I've seen on their page on Vimeo. The two videos posted there in the last year have captured my imagination- the use of stop-motion graffiti to create an animated story is so unique and amazing.

It's worth a watch even if you don't stay til the end, just to see this unique art form.

Fourth of July Light Art

In celebration of America's independence day, we like to light things on fire and blow stuff up.

What an excellent opportunity to talk about a phenomenon called "light art"- one of my favorite things to do with a camera. Light art is a fairly vague term that essentially means using a long exposure time and some sort of light source to "paint" on film, or in this case a CCD.

Fireworks, including (and especially!) the humble sparkler, are some of the easiest and best ways to make quick, but very fun and creative, light art.

If you've got a camera with a decent manual mode (I used my Casio), and you're at least somewhat familiar with the exposure settings and their related concepts, you're ready to create some nice-looking light art. (A tripod is also a really helpful tool).

With your camera in manual mode, what you'll basically want to do is:

	Set ISO as low as possible. Set aperture as wide as possible. Set a very slow shutter speed (which equals a long exposure time).

The idea is for the shutter speed to be slow enough for you to do something interesting with light while the shutter is open.

The exposure length you'll want to use depends on what you're going to be doing, but generally you'll want it as long as possible, assuming the camera will be steady.

Keep in mind that with longer exposure times, you'll start to see the surroundings, at least a little. For instance, this 30-second exposure caused the Hood Canal, and particularly some of the lit houses across it, to show up.

If this is a look you want- consider using a flash, which will illuminate the area and make it a "background" of sorts over which you will paint with light.

Just be careful not to use too long of an exposure time, particularly when combined with a flash- you may end up with a somewhat washed out end result- and you may even start to see "ghost" images of yourself!

This photo is a good example of not setting a long enough exposure time- a friend was trying to spell out my daughter's name ("Aurora"), but I didn't give her long enough to finish it.

Try out different perspectives- if you've got friends who can help, see if you can get far away from the subject. Combine this with long enough exposure for some of the environment to show up, and you can get different and interesting shots.

You can achieve some dynamic effects by moving the camera intentionally during the shot. In this picture, I moved the camera up to follow the path of the rocket. This movement caused an elongation of the end explosion, changing the overall image.

The most important thing (besides, of course, to be safe) is to simply be creative and have fun with it. Try out different light sources, after you've gotten started tonight with fireworks (for us Americans, anyway). Get inspired- there are lots of excellent examples of light art out there- some of it taken to a high art form, others going to the next level and creating an animated short film using light art. Good luck!

The Playstation 3 as a Video Editor

It's not often that we suddenly receive new tools for free, but with the recent release of PS3 firmware 3.40, many of us Playstation 3 owners got just that.

While Sony was touting the Playstation Plus network features, I was more interested in the new video editor and uploader. With this tool, you can combine and trim video clips, add titles, and even slow down or speed up time.

I was delighted to see this new menu item in my XMB after upgrade to 3.40.

The editor has a very simple, easy to use interface.

In the first step (not shown), you select video clips from your PS3's hard drive, and add them to a timeline.

The second step is the main video editor, shown here. This editor has the following options (clockwise from the top-right):

• Playback Speed: Lets you speed up or slow down (by 2x in either direction) specific segments of your video.
• Music: Lets you add one of a handful of preselected (and somewhat cheesy) soundtracks.
• Text: Add titles and other text to your video in various fonts and formats.
• A-B Erase: Trim sections of your video.

Right off the bat, two of the four of these are failures in my mind. "Music" could have been a huge feature, but for reasons that I can only imagine come down to licensing fears (Sony is also a music company, after all), you are not able to select a soundtrack from any of your personal audio tracks available on the hard drive of your PS3. We won't stop to question how it's any less legally ambiguous to be publishing any video from your hard drive, while somehow music is exempt.

The second useless option is "Text"- at least, if you plan on uploading to YouTube. Please, use YouTube's text overlay features instead- they are nearly as flexible, and (most importantly) they allow the user to turn them off. There's no reason to burn this stuff into your video- unless the PS3 offered some really cool text effects, which it does not.

Moving on to what's great- "A-B Erase" is easy to use, and functions just as it should. "Playback Speed" was the big surprise, to me. It works as well as you can expect, though the speed selection being limited to 50% and 200% is a bit disappointing.

Here is a quick test video I made that exercised all of these features. It took me only a few minutes to throw together. I use MediaLink, which was $20 paid software. It works flawlessly as a solution for playing iTunes music and video over the PS3- and, fortunately, also works for showing photos and video from iPhoto as well.

With MediaLink, I was able to browse my iPhoto library on my PS3, choose a clip, copy it to the PS3's hard drive, and then launch the video editor and import it right in. It was amazingly easy.

I'm not sure what Sony's intention is with this tool, exactly. To my knowledge, there are only a handful of games that support video capture- and I think you just upload to YouTube straight from the game, generally. If they were to announce global video capture ability built-in to the PS3, that would really be something- and would put this tool in context.

But, for now, it's something of a curiosity- which can be a pretty fun toy for us video enthusiasts to play with.

An Introduction to Exposure

If you have a camera that allows you to manually adjust exposure settings (and even if you don't), it pays to really understand things like aperture and ISO, and how they will affect the end result of your photograph.

The photo blog at tutsplus has a really excellent beginner's introduction to exposure. There, they go over in depth the "triangle of exposure" - an excellent model for visualizing the relationship between ISO, aperture and shutter speed. The article describes each component in detail, and then goes on to describe how they will affect things like depth of field and low-light shooting.

The author recommends a DSLR, but any camera with a manual mode will do. Both my Casio point-and-shoot and my wife's Canon have a very useable manual mode, and neither is a DSLR. The big advantages you'll get using a DSLR are much wider aperture and ISO ranges, which give you greater flexibility in composing your shot. Clearly, having better gear is always a win- but don't pass on this article just because you don't have a tremendously expensive camera.

In short, this is great information for all shutterbugs, pros and beginners alike- check it out!