A while back I bought a SanDisk "Ultra" Compact Flash card because the single selling point was that it was supposed to be TWICE as fast as their standard product. To be honest, at that point I didn't think there were speed differences between CF cards. I assumed they were all the same speed simply because other brands didn't mention their speed.

What happened next was a surprise to me. I put my SanDisk Ultra into my camera and started taking pictures and noticed that the time between shots got longer and longer as the card started to fill up, and was clearly longer than when I had my older (smaller) card in the camera. Their Ultra card was clearly slower than my supposedly inferior older card.

That's when I started to question their claims to be twice as fast as a standard CF card. I did some research and confirmed what I had discovered; larger capacity CF cards are slower than smaller CF cards. So when you buy larger cards, you need faster memory to compensate.

That said, if speed between pictures is an issue, you have two choices: 1) Buy a bunch of smaller cards, and swap them when they fill up or 2) If you want larger cards, make sure they are as fast.

After my experience with my SanDisk card, I tried the Viking card and unlike SanDisk, they didn't make any claims of speed, but the Viking was CLEARLY FASTER! Later I found some sites where they did more scientific tests where they not only measured the time between photos, but tested them using a high speed card reader/writer. This guaranteed that the test results were not an indication of the camera's ability to manage larger cards (but that is a factor).

The bottom line: For cards this size, speed is important, and this card is FAST!


excellent price/value ratio for 4 megapixel cameras   January 18, 2003
 113 out of 120 found this review helpful

Nobody would argue that the more memory you have in your digital camera, the better. The question is what the reasonable compromise between the price of a memory card and its size is, and how to predict how much memory you actually need before you paid for it. I looked up some literature on the image compression techniques, and made some experiments with printing out pictures with different resolution and different compression ratios, and came to the following conclusions.

Most cameras offer a choice between several picture resolutions and several image compression modes. Low resolution is good for on-screen viewing, while high resolution is better suited for printouts. Additionally, one can choose between several compression modes. Higher resolution settings combined with the weakest compression result in better pictures at the expense of larger file sizes. The problem is that all digital cameras ship with very small memory cards - 8MB, 16 MB, sometimes 32 MB, and this is just not enough even for a day of shooting. I think most people would be happy to have a storage space for at least a couple of hundreds of puctures, equivalent to 8-9 rolls of film. In my experience, this is what you can expect to get from a 256 MB card if you use a 4 megapixel camera and medium compression. A few comments are in order to help you to understand better what resolution and compression mean in terms of the file size.

1. Resolution. The huge resolution numbers of ink-jet printers may be confusing, for instance, 1440 dots-per-inch (dpi) resolution may make you think that a 2000x2000 pixel image would print well only in the size of about 1.5x1.5 inches. This is absolutely wrong since resolution of the printer reflects primarily the minimum size of the ink dot which the printer can create, but not necessarily the size of a meaningful pixel of the image. In fact, printer manufacturers suggest that for the best results the resolution of the image should be 1/3 to 1/4 of the maximum printer resolution. Hence, expect that your final output will be printed with 250-300 dpi resolution. A four megapixel image will then print with a perfect quality up to the size of 8x10 inches. Smaller pictures, such as 4x6 inches, require a lot less pixels - 2 megapixels is sufficient! However, since you never know when you will need to print that one perfect picture in a larger size, I would suggest that you shoul always use the highest pixel resolution of your camera. Additionally, it gives you better flexibility in terms of cropping the image later on.

2. Compression. Unfortunately, high resolution images require lots of storage space: a 4-megapixel uncompressed image can be as large as 12 MB. JPEG compression, which is based on an algorithm specifically developed for image compressing helps to store large pictures in relatively small files. Specifically, JPEG compression algorithm divides an image into squares 8*8 pixels each, performes two-dimensional discrete cosine trasform of each of these squares, and compresses their frequency spectra by removing high-frequency components or by decreasing their accuracy through a "quantization" procedure. While this review is not appropriate for a discussion of technical details of the JPEG algorithm, it is worth saying that JPEG analyzes each small "brick" of the image individually and adapts the level of smoothing/compressing to the image to be compressed. In fact, when you choose the compression mode, you determine not the size of the compressed image, but its quality in the compressed form. Therefore, the final size of the compressed file may vary by as much as 2 to 3 times depending on each particular image. This is why you can never know for sure how many pictures will fit on your memory card, you can only have a rough estimate. The "adaptive" nature of JPEG makes it very efficient: it takes advantage of the smoothness of monotonically colored parts of the image by achieving great compression ratios in those areas without significant losses in quality, and it is also good at rendering sharp contrasts in the image. Since JPEG standard was optimized to take into account the specifics of our perception of visual information (like mp3 compression of music files takes advantage of the way how we hear music), JPEG compressed pictures are almost undistinguishable from the originals up to the compression ratios of 1:8 to 1:12. In my experience, medium compression works well almost always, with the exception of the case when you take a picture with lots of details, bright spots, contrast objects, etc., and want to print in 8x10 size. Then you should use the weakest compression ("fine"), or no compression at all.

I have a Canon Powershot S40 and used it with highest resolution and medium compression. The size of the file varied from 500 kB to 1.8 MB from picture to picture. The average size (calculated using 800+ pictures) was 840 kB. Hence, I could fit 200-300 pictures on this 256 MB card.

The last comment: note that there are three types of memory, flash, SmartMedia, and Sony memory stick. Check you camera manual which one you need, they are not interchangeable.


According to Viking's Rules...   July 26, 2003
 77 out of 83 found this review helpful

In my informal comparison of the transfer rate of 256MB compact flash cards by Viking, SimpleTech, and Kingston, the Viking card came in a distant third. The Viking card took about 40% longer to transfer identical data. My card at least, did not meet the stated specified transfer rate.

So where speed of transfer is important, the Viking card may not be the best choice. For other less critical tasks, the Viking card has proven perfectly adequate.

Viking products are competitively priced, [...]


More memory than I know what to do with.   January 26, 2002
 65 out of 80 found this review helpful

I popped this into my Canon S100 and with the default resolution, got a reading of 1478 shots available! That's an incredible amt of space and for someone heading off on an extended trip, it should be quite a boon. I have been following CF costs on a dollar-per-meg basis for some time, and while the newest & largest cards have tended to carry a premium, this one does not. It is roughly fifty cents per meg, less than 1/4 of what it cost per meg only 18 months ago!


Best Performance and Minimal Price   May 26, 2002
 47 out of 48 found this review helpful

This is an outstanding card. It is one of the best performing cards on the market and also one of the most reasonably priced. I wouldn't spend the money on Lexar or some of the other over marketed cards. This card works flawlessly in my Canon S40 and is *very* fast. I also bought the Viking PCMCIA reader for my notebook and it's awesome as well. It plugs in and works. What more can you ask for?

I did a lot of research before buying this card and if you have time, go to dpreview and check out the reviews->digital media. They have a very straightforward and comprehesive analysis of compact flash media while cutting through the marketing hype. You'll learn a lot there and save yourself some money.