The other day I watched with pride when a group of learners presented a collage of images taken during a history excursion to a local museum.
The process of taking the pictures, downloading them on to a computer, reassembling them into a presentation format, then connecting the computer to a data projector and finally presenting the ”show” in a lively and enthusiastic manner to the school was to be commended.
This episode made me realise that digital photography has truly come of age. Cheap, high quality images are now easily produced using even the most basic digital camera or average cellphone. The days of photography being a niche hobby affordable only to the rich or the most committed are gone. Consequently digital images should become a stock resource in your lesson planning.
Teaching and learning applications for the use of digital images are numerous. You can take your own pictures to illustrate your worksheets, spice up your class notes, overhead projector slides or lesson support materials. You can task learners to collect evidence to demonstrate learning by asking them to document some aspect of your lesson out in the community using cellphone cameras. Learners could also use their own pictures in the construction of PowerPoint presentations, WebQuests or simple websites.
The museum assembly presentation did, however, throw up one particular problem that’s worth considering before you embark on a digital photography crusade; the issue around size and image compression.
When the first version of the presentation was ready the group tried it out on a trial run. Sadly the transition from one slide to the next was so slow that the presentation was next to useless.
That’s when the student group relented to my intervention. There were only 20 images but the size of the presentation was in excess of 100MB. The little old laptop that they were using just did not have the processing power, nor memory, to quickly work from slide to slide. The resolution of the 5MB pictures was just too large for it to handle.
Just what does this mean? A common problem for new users is that while they are aware that the larger the number of megapixels a camera boasts, the better the quality of the images it takes.
What they don’t realise is that this also means a larger file size is necessary to store all the data. For example a camera that takes pictures at eight megapixels could be generating image files in between 4MB and 6MB. When these pictures are displayed on a computer monitor they are enormous and the edges of the picture disappear off the screen. This is because monitors normally display pictures at between 96 and 150 pixels per inch.
In an application such as PowerPoint or Word, a simple remedy is to drag the image smaller so that it fits inside the application. By resizing the image on the screen you have not, however, actually changed the size of the file.
The solution is simple, compress the pictures in your document. Resize the pictures so that they look right on the screen and then tell the application to lose all additional information to reduce file size.
To access this facility call up the ”picture” toolbox and select the ”compress pictures” option.
In Office 2003 you need to right click an empty space inside the application’s main menu bar.
Select ”pictures” from the dropdown toolbox menu.
I work with Office 2007 and to access this toolbox I simply click on the picture itself.
Size also counts when you are out selecting digital images from the internet. The search results from a Google image search show you just how ”large” both the images and the files are.
Andrew Moore is a former teacher. He has a MEd in computer-assisted education. He works for Neil Butcher and Associates, an education technology consulting company that offers services in database design and materials development