I just upgraded from a Canon XS to a Canon 50D. I had to purchase a CF memory card and went with the Sandisk 8GB Ultra II which transfers at 15mgps. Do you think that this memory card is sufficient for the 50D’s 6fps? As always, I appreciate all of your help and expertise.
*your mileage may vary* For card speeds in camera, I use Rob G's site: ; He's tested most of the current cards on the market, in both JPG and RAW modes. http://www.robgalbraith.com/bins/camera ... =6007-9672 He was only able to get 6.6mb/s out of the Ultra II 8 GB with JPG only. ; Not sure how big each JPG file is with the 50D, but you can do the math to figure out how fast the card will empty the buffer, which will tell you how long you can shoot without stopping. Your buffer limit is based on a specific card (usually 1 or 2GB) in the camera, and then how many shots it can take before it won't let you because the card has to catch up. ; With a faster card, your buffer will clear faster and allow you to have an apparently larger "buffer". ; ; I think in JPG only mode with the fastest cards you probably have a 99 shot buffer, and that's because they only programmed the cameras with 2 digits in the buffer....
Thank you Roger, that is a great link. When it comes to the technical aspects I'm about as sharp as a tennis ball so bear with me. So if the memory card is only capable of transfering at 6.6mbps and a file size is 5mb, how many shots can I get get off until the buffer is full? I don't have the memory card yet as I bought it online.
It's hard to say; the specs say 90 shots, but that is for an UDMA card: ; The old Extreme IV for example. Let's assume that the card was 20 MB/s: 90 shots would take 15 seconds. ; So it would have a total transfer of 450MB over those 15 seconds. ; Subtracting the card write, it appears the buffer is about 150MB. Using a little bit of excel, it looks like you'd be able to get just over 6 seconds of continuous shooting at 6fps before your buffer filled, and then you would be restricted to about 1 shot per second until the card writes, which could take another 21 seconds to finish completely according to my rough calculations. ; Now the more time you wait you'll be able to have larger bursts while still waiting for the original pics to write to the card.
Excellent, thank you Roger. I guess the Ultra II will be sufficient for now since I'm doing portraiture and not action sports. You are a wealth of knowledge my friend!
