Digital Cameras and Genealogy - Storing Digital Photos

Introduction
The advent of high quality digital cameras at affordable consumer prices has provided some great opportunities as well as a number of potential problems. The goal of this article is twofold, to make sure that your descendants a hundred years from now can enjoy the pictures you take today, and to make sure that people today can enjoy photographs of their ancestors, taken a hundred years ago.

There are several concerns about moving into the digital world. If proper steps are not taken, a single computer failure can wipe out your treasured digital family photos. Printouts made on many of today’s ink jet printers (even those labelled as being "photo printers") have a shelf life of less than a few decades so don’t expect ink jet printouts to be a means to preserve your photos (see "a word about printers"). Does your camera have the capacity to take high quality photos, and if so, are you using this capacity to its fullest? These are some of the issues that will be discussed.

I've broken out the topics into eight articles:
1) Storing Digital Photos (this page)

2) Making digital copies of old family photos
2a) My own workflow in making digital copies of old family photos

3) Labelling Digital Photos - how to add internal captioning data to a photo using the IPTC/XMP standard.

4) Captioning Photos using Breezebrowser - how to easily put the IPTC/XMP caption data (see 3) as text captioning on digital photos using the program Breezebrowser.

5) Choosing a digital camera

6) A Few Digital Genealogy Project Ideas

7) The Myth of DPI

8) Geotagging Digital Photos - how to add geographic location right into a digital photo or scan. Although not part of this section, you may also be interested in reading my website titled: All About Digital Photos which discusses digital photos in detail.

Storing Digital Photos
Switching from a conventional film camera to a digital camera can be a recipe for disaster unless the concepts of digital imaging are understood. All that is needed to make sure that your digital photos will last through the ages is to understand a few simple concepts and to follow some basic guidelines. Please note that while this website discusses the use of digital cameras, a scanner can also be used, there are pros and cons to each. I've discussed this a bit on my Digital Copying page. Storage methods (listed below) are the same for either digital camera images or scanner images.

Advantages of a Digital Camera
One of the real advantages of a digital camera is it's portability. You can visit relatives, have them pull out their old photo albums and take photos of them on the spot. Since many (most) relatives are normally unwilling to part with these old albums, this is a great way to make copies of the photos without unduly imposing on them.

Digital cameras also give you full photographic freedom. You can take as many pictures as you want (the cost of taking pictures is essentially free), see the results immediately and create any kind of photographic product with them (including regular photo prints). The bottom line is that digital cameras are just plain fun.

Disadvantages of a Digital Camera
The good quality ones are still fairly expensive and they can be tricky to use (many contain so many bells and whistles that there may be a long learning curve). They also require a computer to do the image editing and storage and this in turn requires at least a minimal level of computer knowledge.

The Concepts
What digital formats and current computer technologies are going to survive the next 20, the next 50 or even the next 100 years? Frankly, we don’t know. The principle to follow when taking digital photographs for genealogical purposes is stay mainstream, using common, widely used formats.

Storage Medium: It is best NOT to store your photos on some type of proprietary format such as a tape or ZIP drive. In fact all types of magnetic media should be avoided. The only current technology long term storage that is suitable for photographs is the CD-ROM or DVD-ROM. It is common, it is cheap, it has a relatively high storage capacity and a good shelf life (at least 30 to 50 years with a good quality CD - see CDROM Storage Update below). The ultimate storage medium will be a universal standard, high capacity, solid state storage with unlimited shelf life. When that wonderful storage medium arrives it should be easy to transfer your CD/DVD ROM collection to this new media.

Image Type: The photographs themselves usually be stored in the original format they were photographed in, usually a low compression JPEG. The other common format is TIF. Proprietary formats (i.e. Photoshop PSD, Paint Shop Pro PSP, etc.) should be avoided (you want to make sure that any program in the future can view these files - so store them in a long-term standard format). The pros and cons of various formats will be discussed later.

Photo Information: While many digital cameras store some photo information in an EXIF header within the photo itself and some can even incorporate sound files into the image, it is best to digitally label using the IPTC/XMP archival standard or even create a separate document file with information about the photos (who is in them, places, dates, etc.). Those of us who have gone through old photo albums showing all sorts of interesting people with no names, places or dates will appreciate this step.

The idea is that when someone finds your dusty old CDROMs some 50 years from now, they will still be able to view the images and identify who is in the photos.

Basic Guidelines
These guideline have been divided into two groupings, those for the general public and some more rigid guidelines for the photo purist or professional.

General Public:

1) Take photos, particularly family photos, at the highest resolution your camera allows. Make sure your photo compression is set to low (or on some cameras this will be the superfine or best option). You can always shrink a photo – you cannot expand a photo without loss of image quality.

2) Copy the photos to your computer as soon as convenient. Make a copy of these photos to a CD/DVD-RW disk (re-writeable CD or DVD) or a regular CD or DVD prior to deleting the photos from your camera’s memory. This will provide you with a temporary backup file until you can write the final images to CD-ROM.

3) If you have some computer knowledge, go and mark the photos on your computer’s hard drive as being “read-only” (go into Windows Explorer, highlight all the photos, right click your mouse and select “properties”, click the “Read Only” option at the bottom of the dialog box). This will prevent accidental erasure of your photos.

4) Digitally label your photos using the IPTC/XMP metadata standard supported by most good photo programs (it's not a good program if it doesn't support this standard). Or, use the low-tech method of creating a text file with captions for your photos using your favourite text editor or word processor to list the photo names (usually a numbered sequence) and then make notes for each one. Save this file as a raw text (ASCII text, DOS text) file in the same directory as your photos.

5) Remember - your original photos are your negatives – NEVER MAKE CHANGES TO YOUR ORIGINAL PHOTOS – always work with a copy of the photo. When you load a photo into your image manipulation program ALWAYS do a Save As to make a copy of the photo and then work with that copy. If you make a mistake, you can always go back to the original and try again.

6) When making copies – take advantage of long file names. You may wish to keep the original file name as part of the new name for cross-reference purposes, but add more details. A file name such as 103-1234.jpg can become “sue-laurie-phil-at-newboro-lake-103-1234.jpg.”

7) Once you have created a text file with the captions, copy the original photos with the caption file to two CD or DVD ROMs. Keep one CD/DVD-ROM handy for your own use, put the other one off-site (your office, a neighbour’s house, safety deposit box, etc.). If fire, flood or other disaster hits your house, your precious photos will be safe. This is very cheap insurance for your photographic memories.

Purist/Advanced user:

Same as general public except for the following:

1) Take photos in a “lossless” format – either the camera’s RAW format (exactly what the CCD sees with no image processing) or TIF format.

2) Make copies of your originals in a separate directory (folder). Never use or alter the original directory/folder until you have copied it CD/DVD ROM.

3, 4, 5, - same as general public

6) In addition to the long file name, you should always add IPTC/XMP metadata to the photo. In addition, for absolute foolproof labelling, add a caption space below the image and type in the caption text or use a program that can watermark your photo using the IPTC/XMP caption data. That way the text description is now physically part of the photo.

7) same as general public

8) Make thumbnail images of your photos. Keep these thumbnail images on your main computer. This will provide a quick visual catalogue of all your photos and allow for easy photo retrieval.

CD/DVD ROM Storage There have been a couple of studies that have shown some problems with the archival life of CD and DVD ROMs. To ensure the best archival life, follow these rules:

Use good quality, recognized brand name CDs/DVDs (do not use cheap no-name brands)
Do NOT put paper labels on the CDs/DVDs - label them with a marker specifically designed for CD/DVD labelling.
Store the CDs/DVDs in a dark place, within the temperature and humidity ranges specified by the manufacturer.

Keep in mind that like all current digital media, CDs/DVDs have a shelf life and are not the final method of archiving. When better products/techniques come along, you should move your existing archive to the new (presumably better) medium. Data was originally stored on tape. Then it was stored on floppy disks. Then it was stored on removable disks (i.e. Syquest, ZIP). Now it is CDs and DVDs. Next it will be ?.

Image Quality
There are four things to think of when you take a photo to achieve the maximum quality your camera will allow.

1) Image Format - maximum quality is achieved by taking the photo in a "lossless" format such as RAW or TIF.
2) Image Size - maximum quality is achieved by taking the photo at the largest picture size your camera is capable of.
3) Exposure - maximum quality is achieved by taking the photo at the lowest ISO (equivalent to film speed) the camera allows - usually 50 or 100 (lower is better) This can make a big difference in digital imaging.
4) Sharpness - maximum quality is achieved by making sure camera shake is kept to a minimum. This usually means using a tripod. In addition, a shutter release cable (if your camera will allow it) or remote shutter release will further enhance the steadiness of the shot (a poor man's substitute is to use the camera self-timer to take the photo). Later sharpening in an image editing program is no substitute for a sharply focused (optical), steady image.

Image Formats
JPG/JPEG – This is the most popular file format. JPEG which stands for Joint Photographic Experts Group is a standard developed in the 1980s to handle colour digital images. It works best with photographic images (as opposed images of text) because it relies on the blending of colour. It is a “lossy” format, it compresses the image by throwing out “redundant” image pixels. As the image is compressed, artifacting appears in form of blurriness around edges of objects in the photo (see photos below).

Most cameras will show something like a normal, medium, and high image compression (or low, fine and superfine). This is not to be confused with image size, they are two different things (cameras generally show image size as small, medium and large). In image manipulation programs, JPEG compression is usually expressed as a percentage, 100% is no compression, 0% is maximum compression. Usually visible distortion starts to appear at 50%. Some programs such as Adobe Photoshop use a sliding scale from 0 to 12 (really 0% to 100%). Once compressed an image cannot be uncompressed. This is why the original photo should be taken with as little compression as possible.

A significant problem with using a JPEG file as your editing original is that each time you do a "save as" with a JPEG, it further degrades, even if the JPEG compression is to the highest quality. Because JPEG images lose quality each time they are opened, edited and saved, the image should be "saved as" into a lossless format such as TIF, PNG or BMP, all editing done in that format (which might require multiple saves) and then the final image can be saved back as JPEG. Note that you can copy a JPEG file using your computer's copy function, multiple times with no loss of quality (like all digital files) - it is just the re-saving of a JPEG from any image program after editing (or even cropping) that will add to the degradation of the image.

Pros: small image size, very good photographic reproduction, best format for emailing or posting to the web, compatible with virtually every image editor and viewer. Supports IPTC data (with certain software - see Labelling Photos).
Cons: "lossy" format, it compresses by removing information which can never be recovered, photo degradation on a save after editing (even at highest quality setting).

Note: A newer version of JPEG, called JPEG2000 is starting to be implemented. It compresses through "wavelet" technology rather than block technology and at 0 compression it is a "lossless" format. It compresses 25-35% better than a standard JPEG with higher image quality. It will likely be some years before we see full scale implementation of this standard. A 0 compressed JPEG2000 (.jp2 file) is about half the size of an uncompressed TIF.

TIF/TIFF – This is a lossless image format, that is, no pixels are removed from the image. TIFF stands for Tag Image File Format. This generally results in very large image sizes. TIF has the option of being compressed, using a lossless compression technique known as LZW, which will shrink the image with no loss of data. Some programs will also allow compression within a TIF by ZIP (lossless) or JPEG (lossy). Even compressed, TIF files are generally quite large. TIF is a favourite of graphic designers since it was an early standard on the mac and can hold CMYK colour information.

Pros: "lossless" format - all image information is retained. Supports IPTC/XMP data (with certain software - see Labelling Photos).
Cons: Huge file size even when compressed, has multiple "standards" so not all programs can read all TIF files. Not web browser compatible.

BMP – BitMaP file (also sometimes known as DIB - Device Independent Bitmap) – a lossless file format produced by Microsoft. It is optimized for fast screen display. It can hold up to 24 bit colour information. Although it can be compressed, this feature is rarely implemented.

Pros: "lossless" format, can be read by any imaging program.
Cons: Much larger image size than JPEG. Not web browser compatible.

PNG – Portable Network Graphics (pronounced “ping”) – this is a newer format, it has most of the advantages of TIF, GIF and JPEG with few of the downsides in that it is a lossless format that can hold full colour information (up to 48 bit). It does equally well with both photographic and text images. It is an excellent format in which to hold photo originals. It's gaining popularity with graphics designers since it can hold high levels of transparency information.

Pros: "lossless" format, smaller image size than TIF, good as an editing original. Supports transparency data.
Cons: Much larger image size than JPEG. Newer standard so not all programs can read PNG. New standard also means that not all programs properly implement PNG (so there can be problems creating PNG files). Only most recent web browsers can read PNG files. Does not yet support IPTC/XMP metadata.

GIF – Graphics Interchange Format (pronounced “jif”) – used for text images. Since it compresses by reducing the colour pallet to 256 colours it should never be used for photographs.

Pros: Does a great job with pure text or line art. Web browser compatible.
Cons: Not suitable for photographs or any blended colour work.

RAW – some cameras have the ability to save a file out in a format that contains no image processing, the image exactly as the CCD sees it. In some cameras such as Canon this format is actually considerably smaller than a TIF. I can only speak for Canon, but a RAW picture, as do all photos taken with the camera, contains information about the white balance, colour saturation, contrast and sharpness. When a RAW file is converted, the user can choose to use the camera's best picks for these options, or these can be altered at the user's discretion.

Pros: Contains "pre-processed" information from the camera - exactly what the camera sees.
Cons: Usually large file size. Requires conversion to a standard format (TIF, PNG, JPG) before it can be used by most image editing/viewing programs.

Image Size
In the world of digital photography size does count. The bigger the image (in pixel dimensions), the better it will reproduce both on-screen and on paper. Digital cameras use the terminology Megapixels to describe how many pixels can be captured on the camera’s CCD sensor. This translates into image size as follows:

1.1 Megapixel = 1200 pixels x 960 pixels (~ 4” x 6” paper equivalent)
2.2 Megapixel = 1600 pixels x 1200 pixels (~ 5” x 7” paper equivalent)
3.3 Megapixel = 2048 pixels x 1536 pixels (~ 8” x 10” paper equivalent)
6 Megapixel = 2816 pixels x 2112 pixels (~ 10" x 14" paper equivalent)
8 Megapixel = 3504 pixels x 2336 pixels (~ 12" x 17" paper equivlanet)

What resolution does your camera need? A general rule of thumb is that printed output should be 200 to 250 pixels per inch to achieve near photographic resolution. This is not to be confused with a printer’s stated dot per inch resolution since several ink jet nozzle dots will be used to create a blended single dot on the paper. So, for instance, a Epson printer with a rated 1440 dpi resolution, using 6 inks, has a real dot resolution of 240. The easiest way to figure this out is to work back from the camera’s stated capture resolution. A 3.3 Megapixel camera will normally have its highest photo resolution as 2048 pixels wide by 1536 pixels high. If we divide these numbers by 200 pixels per inch, we get 10.24 inches by 7.68 inches. So, for all practical purposes, a 3.3 Megapixel camera can take a photographic resolution 8” x 10” picture. From a copying perspective, it also means that it can capture an 8 x 10 photo at photographic resolution. This is likely the largest size photo to be found in family albums

For information about DPI, see the section on the Myths of DPI.

Comparison of file sizes:
The following are file sizes from a 2048 x 1536 size photo

Superfine JPEG (100%/ Adobe quality 10) = 1,500 kb (1.5 Mb)
Fine JPEG (90%/ Adobe quality 7) = 600 Kb (0.6 Mb)
Regular JPEG (80%/ Adobe quality 6) = 350 Kb (0.35 Mb)
JPEG2000 (uncompressed) = 4,000 Kb (4.0 Mb)
TIF (uncompressed) = 9,200 Kb (9.2 Mb)
TIF (compressed) = 4,500 (4.5 Mb)
PNG (uncompressed) = 6,400 (6.4 Mb)
PNG (compressed) = 4,300 (4.3 Mb)
BMP (uncompressed) = 9,200 Kb (9.2 Mb)
CRW (Canon RAW format) = 2,300 Kb (2.3 Mb)


640 x 480 JPEG at "normal" setting (enlarged to 2048 x 1536)	640 x 480 JPEG at "superfine" setting (enlarged to 2048 x 1536)	2048 x 1536 JPEG at "normal" setting (at full size)	2048 x 1536 JPEG at "superfine" setting (at full size)
The two images on the left have been expanded to be the same size as the larger images. This reveals the inherent problems with both smaller images and the normal (80% or Adobe quality 6) setting. Viewing the two images on the right, on screen, will likely not reveal any real discernable difference in the image quality. However, the 1000% blow-up (see below) of one the characters (top of the "f" in "Mountford" - see bottom photo) does reveal a difference. While you won't notice this on-screen, it might be discernable later when you try to make a print of the photo.


2048 x 1536 JPEG at "normal" setting	2048 x 1536 JPEG at "superfine" setting	2048 x 1536 RAW at "superfine" setting


Taken at ISO 400	Taken at ISO 50

Just in case you were wondering - this is the full view of the photo, a black and white photo taken in 1952.

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