Washington Apple Pi

A Community of Apple iPad, iPhone and Mac Users

August 2008 General Meeting:

Images, From Capture to Presentation

Meeting photos by Richard Sanderson

By Lawrence I. Charters

It seems that every adult and child on the planet has a digital camera, but precious few of them have thought about how to handle the flood of digital images they are capturing. The August General Meeting had as its theme capturing images with a digital camera, storing them, and offering tips for those who have gone beyond the basics.

The August meeting started out with an innovation. For the first time in a long while, the meeting did not start off with a Question & Answer session. At least not the usual, Mac-centric, undirected Q&A session. Instead, in a bold move, President Bob Jarecke decreed that the Q&A session would follow the main presentation, allowing attendees to ask questions with the presentation fresh in their minds. This seemed to flummox a few, but they coped by turning the meeting breaks into impromptu Q&A sessions. In terms of interaction, the August meeting was a winner.

By-Laws and other business matters

If Bob thought questions would be confined to the end of the meeting, he soon learned otherwise. He brought up three issues that each led to spirited dialogue. First, he informed the crowd of five dozen or so of a possible Pi office move. Our landlord has offered alternate office accommodations on the second floor of the building we currently occupy. While a move would involve some turmoil, and the stairs could cause problems for the Tuesday Night Clinic and Reclamation Programs, we could save a considerable amount of money. This prompted a fair amount of discussion, but no firm decision has been made.

Bob then covered a Board-approved transition to an electronic version of the Journal. Nora Korc, our Design and Production Editor, has built a prototype of the Journal optimized for viewing on screen. The layout and look is dramatically different (for one thing, it is in color) and many members may find this method of receiving and viewing the Journal an improvement. Members who prefer to have a paper copy in hand to read could, of course, download the online version and print it out themselves. Alternatively, the Board is considering offering a print version mailed to the member as an extra-cost option. This could be quite costly, but if members are willing to bear a good share of the cost, the Board will consider it. The Board is committed to an electronic version, but is not committed to any specific path.

Finally, the membership in attendance was asked to review one proposed amendment to the Pi corporate Bylaws concerning, ironically, amendment procedure. The amendment proved to be so contentious that, after several minutes of fielding questions and proposed changes, Bob suggested the subject be tabled. That turned out to be the only thing the group could agree on: with a second, the vote was unanimous to table the motion. Who said Bylaws votes were real sleeper moments at our meetings?

Image Capture

Lawrence Charters then did a quick overview on image capture. Generally speaking, there are three different kinds of digital cameras in wide use: mobile phone cameras, pocket cameras, and digital single lens reflex (SLR) cameras with interchangeable lenses. The quality of an image runs along a similar spectrum, from inexpensive mobile phone cameras producing generally poor images to pricy digital SLRs having the potential, at least, to produce outstanding photos.

Lawrence Charters

Lawrence Charters demonstrates how to copy photos from memory cards using a multi-format card reader. A photo of the audience he just took appears on the screen. (Photo by Richard Sanderson, taken with a Nikon D-300 digital camera.)

Quality, alas, is not due to price alone. Part of the problem with mobile cameras and some pocket cameras is the lack of a viewfinder. When you take a photo with these cameras, you must hold the phone or camera at arm’s length, in order to see the LCD screen. Holding a camera away from the body dramatically increases vibration, and vibration leads to fuzzy photos. Cameras with a viewfinder -- Lawrence explicitly commended the Canon PowerShot digital ELPH cameras -- allow you to hold the camera close to the body, framing the scene by looking through the viewfinder, with your elbows and eyes forming a nice, stable triangle.

At this point Lawrence casually mentioned that probably the best pocket camera out there at the moment was the Canon PowerShot G9, which is larger than the digital ELPH cameras but has the side benefits of taking very high resolution photos, having a viewfinder with a diopter adjustment (for those with less than perfect vision), and offering the option of saving photos in RAW format. (Photographers prize RAW format because it allows the maximum flexibility in correcting image color and lighting). Paige Counts happened to have a Canon PowerShot G9 with her, and was immediately besieged with questions on how she liked it, how much it cost, where could you buy one...

When some semblance of order had been restored, Lawrence went on to the next issue in image capture. Taking the picture is only part of the process; the next part involves preserving the images. For this, Lawrence highly recommended using a multi-format digital card reader. With a card reader, you remove the Compact Flash or SD memory card or whatever kind of card your camera supports, put it in the card reader, plug the card reader into a USB or FireWire port on your Mac, and “mount” it as if it were a disk drive. You then drag the images off to a folder on your Mac. Lawrence suggested giving the folder a name and date, such as:


for photos taken on August 23, 2008. Giving the date in year-month-day format is critical if you have a lot of photos, as it allows the folders to be properly sorted in chronological order.

Lawrence discouraged people from using a cable to pull photos directly off the camera. This uses up camera battery power and, depending on what application you use, risks accidentally deleting photos before they have been copied to your Mac. Once the photos are on your Mac, in a properly labeled folder, you can then import them into an image sorting program such as iPhoto, Aperture, Adobe Photoshop Lightroom, or Microsoft Expression Media (formerly iView Media Pro), where you can tag the photos with captions and keywords, and sort them by subject or whatever other criteria you might wish. These programs also allow for photo editing and correction, and can be used to create proof sheets, printed photo books, and entire Web sites.

Lawrence also recommended archiving photos to CD-ROM. In his case, he places his original images (unedited, fresh from the memory card) in a folder until there are roughly 620 megabytes of material, and then burns them to a CD. Why a CD and not a DVD? Unlike DVDs, there is an international standard for CD-ROMs, and name-brand CDs such as Sony and TDK have a life expectancy of ten years or more.

There was a coffee break following Lawrence’s presentation, but questions and comments didn’t stop. Fortunately, an angel appeared in the form of Kitty Richardson and provided him with a donut and something to drink. He was, and is, most grateful.

Fiat Lux

Ed Miller followed with a presentation on working with difficult lighting situations. Next to blurry images, the most common problem with photos is lighting. On a bright day with overcast clouds, lighting tends to be fairly uniform and almost any digital camera can take a good photo. But on a dark day, at dawn or dusk, or indoors, lighting is far more difficult. A very bright, cloudless day can also present problems, as some objects will be well lighted while others will be in dark shadows.

Ed Miller

Ed Miller talks about some photos he took under unusual lighting conditions, the second most common problem with digital photos. (Photo by Richard Sanderson, taken with a Nikon D-300 digital camera.)

As Ed noted, the human eye tends to be very forgiving, constantly adjusting to changing lighting conditions and constantly adjusting the point of focus. We give next to no thought to how readily our eyes adjust to an indoor scene lighted only by candles on a birthday cake, and are surprised when our photos of the event look bad.

To illustrate his points, Ed showed a series of photos he has taken on trips around the world, from the Pyramids in Egypt to monuments in downtown Washington, DC. In each case, Ed explained the problems posed by lighting, from artificial lighting at night to strong shadows cast at mid-day to the challenge of capturing motion in dim light.

One common challenge: taking a photo when the light source is behind the subject. Photographing someone in a doorway, for example, often results in an overexposed doorway with an unidentifiable silhouette. Is that Grandma? Uncle Jack? The next-door neighbor?

There are two common techniques to cope with such problems: bracketing and exposure locking. In bracketing, you simply take a series of overexposed pictures, adjusting the overexposure to bring out the person instead of the silhouette. Exposure locking, on the other hand, requires getting close to the person, locking the exposure (usually by pressing down halfway on the shutter), and then moving back into position to take the photo. Ed also mentioned using a light meter (a hand-held device that gives a reading on the amount of light available on the subject) if you have a camera that can be manually adjusted. As with most photography, success requires practice and experimentation.


Once you have a digital camera, film is essentially “free,” as flash memory (the memory contained in the removable cards in cameras) has plummeted in price over the years. This means you should be taking lots of pictures, since lots of pictures will turn you into a better photographer.

And what can you do with lots of pictures, aside from print photos for friends and relatives, make photo books and calendars, and create Web photo galleries? Why, you can make photo mosaics!

Paige Counts

Paige Counts shows a photo mosaic she created using MacOSaiX. (Photo by Richard Sanderson, taken with a Nikon D-300 digital camera.)

A photo mosaic is a large photograph or other illustration composed of other photographs. Paige Counts showed several large, mounted photo mosaics she produced using MacOSaiX. This is a Mac-only program that requires little more than lots of photos, a good, strong image to act as a starting point, and a Mac OS X computer. Paige’s mosaics were composed of photos of the subjects, so a mosaic of a girl’s athletic team was composed of nothing but photos of the team in action. From a distance, the images looked like a normal photograph, but as you got closer, you could see that they were composed of hundreds, if not thousands, of individual images. As her prints were passed through the audience, you could hear gasps and startled exclamations, followed by a flood of questions.

Fortunately for the Pi, the author of MacOSaiX, Frank Midgley, is a Pi member. Frank explained how to use MacOSaiX, explained that it was still undergoing revision and improvement and, most important of all, mentioned that MacOSaiX is free. He also explained, in answer to a question, the name: it is an amalgam of "Mac OS X" and “mosaic,” and is pronounced “macosaic.”

Frank Midgley

Frank Midgley works on the programming code to his MacOSaiX application during a break in the meeting. (Photo by Lawrence I. Charters, taken with a Sony Alpha 700 digital camera.)

There are two main “tricks” to a good photo mosaic. First, you need a good, strong starting image that MacOSaiX can use as a template. In essence, MacOSaiX tries to re-create this image using other images as if they were large pixels. Second, you need lots of photos on hand. MacOSaiX has the ability to pull images from Flickr and Google. This has advantages, inasmuch as you can find an almost infinite source of images, but it does bog down your Internet connection, and if you have a slow Internet connection, the process can take forever. Additionally, you have little control over what photos end up in your mosaic. If you wanted only images of B-52 bombers, you’ll probably end up with many photos of the rock band, the B-52s.

Fortunately, MacOSaiX can also use images on your Mac, including any specific folder you select, or your iPhoto library, or even individual frames from a QuickTime movie clip. Frank showed several examples, including one mosaic composed entirely from frames of a movie that one of his children loves. One intriguing option allows you to use glyphs, which can be quite interesting if you have lots of different fonts installed on your Mac. Johannes Gutenberg would be astonished.

Needless to say, creating a photo mosaic requires quite a bit of computing power. If you have a slower Mac, things will take longer, but with patience and experimentation, almost anyone can create some truly remarkable images.

You can get MacOSaiX from Frank’s Web site,


which also includes links to lots of examples of mosaics created with the program. His “Questions” section provides a wealth of tips on how to get the most from the application.

Q&A, Lunch and SIGs

Following the presentation on MacOSaiX, there was a Question & Answer session. This focused mostly on digital photography, but occasionally ventured into the usual Mac subjects. Were it not for the arrival of pizza for lunch, the Q&A session might not have ended until the school tossed everyone out.

After lunch, the audience split up and attended Special Interest Group sessions for iLife devotees, genealogy explorers, and beginners. It was amazing that anyone had any energy left.

Original Meeting Announcement

August 23, 2008 General Meeting:

Images - From Capture to Presentation

Luther Jackson Middle School, Falls Church, VA

9:30 a.m. to 12:30 p.m., in the Auditorium

So you can take photos with your digital camera, but now what? This month’s meeting travels through the beginning, middle and end steps to producing great digital images.

Lawrence Charters will talk about taking the right shot, getting it loaded on your Mac and massaging the image to make it a work of art. Ed Miller will show his techniques on how to shoot in darker settings to produce some great images. Frank Midgley, creator of MacOSaiX, a software package that creates a mosaic from a collection of images, will demonstrate this cool application.

Our meeting will start with Pi Business and then transition into the first segment on images. We will break to have a cup of Joe and stretch and then continue with the remainder of the image presentation. We will end with a Question & Answer session focused on the meeting’s theme -- images.

After lunch, three SIG meetings will take place.


Luther Jackson Middle School from space


Questions: Contact the WAP office at (301) 984-0300.

The meeting, open to the public, starts at 9:30 a.m.