Up until recently, I have heard many discussions online about “Which film is best?” New films aren't released too often, but the introduction of Velvia 100 seemed to bring up a lot of these topics up again. As film shooters know, all films record light differently, so results from Provia may be suitable for one scene, and Velvia is preferable for another. It's also pretty well known that Velvia is great for recording eye-popping reds and deep blues.

Digital cameras and media are a “very different animal.” While each digital camera and its sensor records light differently, the media that this information is recorded onto (some kind of memory card) is generally the same. So for film shooters converting to digital, while some card manufacturers like to call their product “Digital Film™” that's not really appropriate. The “film” in a digital camera is actually the CCD or CMOS sensor, so you won't hear photographers saying “My Lexar card renders really great blue water,” or similar comments – at least if they know what they're talking about…:-)

From a practical point of view, what this means for us is that all digital media is capable of recording our photos in exactly the same way. Therefore, the important factors to consider when buying memory cards are: speed, compatibility, battery consumption, and reliability. I'll address compatibility first; unfortunately, not every memory card will work in every camera. Some cameras have dual media slots so that they can use SD cards - a smaller format that is popular with compact cameras - as well as compact flash. However, for this article, let's focus on compact flash cards, as these are the most popular for underwater photographers.

Before buying a card, do a search on the net to find a list of compatible cards, the factors that will influence this are the card capacity (cards over ~2 gigabytes require a FAT32 file system in order to utilize all of the space) and the card controller. A good example is the Fuji S2, as it just seems to have trouble with the internal circuits in some cards. For DSLR shooters, a good place to start your research is Rob Galbraith's website – www.robgalbraith.com. Rob is a professional photographer and imaging consultant and he has put together quite a database of information about compact flash cards; here's a link to the information:

Rob Galbraith CF Card Database

Select your camera from the pull-down menu to find a list of compatible (or incompatible) cards. You'll notice that Rob has also tested the cards for read and write speed for each of the cameras in the pull down list. To me, the most important quality for a memory card is the write speed – how fast does the camera write a shot or shots to the card before we can take more. Based on the write speed data that Rob produced, I've put together some tables which we can use when making flash card purchasing decisions. You'll also find the given retail price for each card, as listed on the B&H website. I've gone to one of the big online shops to obtain these numbers for uniformity of comparison as I wanted to find all of the top contenders at one store. Keep in mind that these may not be the best prices that you can get – as it pays to shop around. The one card highlighted in red (1GB Microdrive) was not available at B&H, but is still readily available through other sources. Another card that was hard to find was the Ritek/Ridata 512 and I had to go outside B&H to obtain a price for this item as well.

I'll present the following tables with a short commentary for each. I wasn't able to easily locate this information for the popular compact cameras, but if the readers know of a ready source, please let me know and I'll incorporate it in later revisions.

Nikon D100

The most cost effective card for use in all of the cameras tested is the Hitachi 4gb Microdrive, at a mere 12 cents per megabyte. This is half the cost of the highest priced solid-state cards. With the D100, the 4GB Microdrive is about ¾ the speed of the fastest flash cards. Note that a few of the less expensive cards beat out the Sandisk Extreme 2GB card in Rob's tests. The fastest card for the money is the Sandisk Extreme 512, which when used with the D100 will store about 50 uncompressed RAW files.

Nikon D70

When it comes to write speed, the D70 is an absolute screamer. With the fastest flash cards, it will write over twice as fast as the D100! The Microdrive (1GB or 4GB) is not a very good performer in the D70. The fastest card for the money is the Sandisk Extreme 512.

Canon Digital Rebel 300D

Write speed tests for the Digital Rebel again show the Microdrive at the bottom of the list. The fastest card for the money is the Lexar 1GB 40X w/ WA.

Fuji S2pro

The Fuji S2pro's write speeds are nearly the same as the D100 so it appears that Fuji's engineers have done their homework (or vice versa). Surprisingly, the fastest card for the money is the 1GB Hitachi Microdrive - but it's not so much of a surprise when you learn that the S2pro was actually designed for use with this drive. The S2pro will fit about 72 RAW files on a 1GB Microdrive. Even the most expensive cards aren't written to much faster than the Microdrive. It's also good to note that if you are looking for a solid state card for your S2pro, then the Sandisk Ultra II 1GB card performs just as well as the Microdrive and at about the same cost.

Canon 1Ds

These results were a bit of a surprise as well. The less expensive Lexar 1GB 40X WA card beat our many of the more expensive products. However, the fastest card for the money is the Sandisk Extreme 512, which is a shame, since you can't fit many of the 1Ds raw files on this card. Again, the 4GB Microdrive stores the most files for the money.

Kodak Pro SLRn

Another surprise – the 4GB Microdrive is the fastest media card when used with the Kodak Pro SLRn. Couple that with the fact that this is also the most cost-effective storage and this card becomes a very attractive purchase.

With that last table in mind, let's take a closer look at Microdrives as this is where the other important factors become important. Since the Microdrive has moving parts, it is not as durable as solid state flash media and these moving parts also use more battery power. If your camera has a large battery pack, or you intend to change batteries as often as necessary, then the Microdrive may be an attractive option. Personally, I have not had any reliability problems using Microdrives for over 2 years but on the other hand, the Microdrive is the ONLY media card that has ever failed on any of my friends and fellow photographers. For “mission critical” shooting situations, it's prudent to go with a higher priced solid state flash card, but in many situations, it's simply not worth the money.

In this short article, I've addressed some of the common questions about digital media and I've provided some useful data about card compatibility, speed, and price. The other factors, battery consumption and reliability will vary widely depending on your shooting style and how you treat your equipment, so I'll leave judgement about these factors to the reader. A special thanks goes to Rob Galbraith for doing the testing and obtaining the data that I used in this article.