Continuing the discussion about image file formats, you may have noticed that I put the term "original" in quotes. The reason for that is simple, what is an "original"? In pre-computer, pre-copy machine days, the concept of an original was very much an issue. For example, in court proceedings, we would often get into discussions about whether or not the original document was being presented in court and whether a copy could be substituted for the original. Those categories of discussions are long gone just as handwritten and typed copies of documents are mostly gone. It assumed now that there are copies of all documents and it is extraordinarily rare to get into a discussion about producing an original document.
That said, the same thing applies to photographs. In pre-digital times, there was an original photo. Film cameras made one individual photograph with either negative film or positive film i.e. slides. The only way to reproduce the photo was either make multiple prints from a negative or use a camera to make a photographic copy of the original. My original slide copier was a device that hooked to my camera so I could take another photo of the slide. If multiple prints were made from one negative, each print was a separate original but because of variations in the development process, every print was slightly different from the last. But the real question, usually not asked, was whether or not the original was the negative or the print? This issue became the idea in the plot of many movies and TV shows. Remember the scene where the original photo is destroyed but, aha!, they still had the negative?
In genealogy, we are faced with the common situation of only having one copy of a photo or negative. That one copy is truly, for us, the original. If lost it cannot be replaced and if it is in poor condition, it will not ever be in any better condition.
What a difference there is in the digital age. When I take a picture with my digital camera, the original is a series of 1's and 0's on the storage chip. If my camera supports the RAW image file format, then all of the information in the camera, including the camera settings and lens data can be transferred to my computer. In essence I now have two originals; one on the computer and one in the camera. Even if I choose to erase the image file in the camera, I still have all of the information contained in the original photo on my computer. Just as a note, not all cameras that support a RAW image file format actually transfer all the image information to the computer when the file is downloaded.
So what about the other file formats? TIFF? JPEG? BMP? and others? Why use them at all? Well, its back to the issue that the RAW image file is analogous to a negative. The information in the RAW file has to be "developed" into an image that can be used on the Internet, displayed or printed. There are specific programs that provide that function. One of them is the Camera RAW plug-in for Photoshop. For an in depth explanation of the advantages of Camera RAW and all of its features, please see Real World Camera Raw with Adobe Photoshop CS4. The advantage of using a TIFF file or a JPEG file is that the image is already developed. My guess is, that very, very few people use photo editing programs regularly for every-day family photos. But what about photos that you want to archive? Photos with real family history value? Is it realistic to use an image file format that loses information from the "original"?
In my next installment, I will discuss the current standards for archive quality images and where to find the standards.