faster card worth it?

[keithsnyder]

I have a 5D and a CF card that is about a 40x speed. I know the speed at which

the camera will write is limited by the camera, and that a faster card might

not be worth it. What is the fastest speed I could use before the camera

doesn't write to the card faster enough to matter. And will a card faster than

the camera can take advantage of copy to my hard drive faster with a card

reader than hooking up the camera to the USB port?

[james_frater]

I have a sandisk 2gig card, an Ultra II 2gig card, and an Extreme III 2gig card.

 

Now I can tell you on my 7D that from the first to last card, the little red light on the camera vanishes faster and faster with each jump in cards that write faster.

 

And writing from camera to computer is just the same.

 

Your 5D will take advantage of the faster cards. But only if you are rolling off continuous shots at large resolution.

 

For a 5D, stick with a Sandisk Ultra II, Extreme III type speed cards. You can garantee they will work faster, than some of these lesser known cards that may not be compatible. And if bought off ebay, most likely to be fake and not very fast and reliable at all.

[james_frater]

Oh, I almost always use a card reader, I find it does work faster than the camera cable. I do not think this apsect matters too much. There is usually not a big difference I have found, but with reader coming out ahead.

[keithsnyder]

Thanks for the input. I'll be careful on where I get them.

[matt hedgecoe]

Keith,

 

There are a number of factors to bear in mind when deciding if you need a faster memory card and these have more to do with your shooting style.

 

You say, "I know the speed at which the camera will write is limited by the camera, and that a faster card might not be worth it". This is not strictly true.

 

'Normal' memory (the type you would find in your computer) is known as volatile memory, i.e. you loose the data when you remove the power supply. Flash cards use different technology and are non-volatile. While the advantages of this are obvious, the downside is that it takes longer to write to non-volatile memory than it does volatile memory.

 

When you take a picture with your camera, the image is not written directly to your flash card, but is written to a buffer memory. The buffer (as you probably guessed) is volatile memory and is configured to allow very fast write times. The image is then transferred from the buffer to your flash card at a much slower rate. It is this transfer rate is limited by the maximum write speed of your card.

 

Because the buffer can hold more than one image, its importance becomes clear when you are shooting at a high frame rate.

 

The following figures are based on a Dynax 7D:

 

Max. continuous capture (RAW+JPEG)=9 frames.

 

Max. continuous capture (JPEG, Large, Fine)=15 frames.

 

At a max. frame rate of 3fps, this would give you 3-4 seconds continuous shooting capability. (If you were to drop to the lowest image quality settings you would get a max continuous capture of 43 frames, equating to about 14 seconds at max. rate shooting.)

 

These frame rates will NOT be affected by the speed of the flash card you use. What WILL be affected is the time delay before you can next shoot a full burst of frames at max. frame rate because the data stored in the buffer has to be transferred to your card. This time delay can be quite considerable! 10 RAW images captured at 3fps being transferred to a 1 GB SanDisk Extreme III will need approx. 12 seconds before the next full rate burst can be taken (Based on 7D tests at dpreview.com).

 

So what's the bottom line here?

 

Well, if you're an action photographer who regulary uses the continuous advance mode then a high-speed card makes sense as it will minimise the waiting time between bursts. If on the other hand you're a landscape photographer who spends five minutes fiddling between shots then it is not going to make any difference to you in the field, and you could get away with using a far slower card. (Obviously when it comes to downloading your images to your computer a faster card will make a difference.)

 

For general, everyday photography a 40x card strikes a good balance bewteen speed and price (however the prices of the faster cards have dropped significantly recently). If you're after an additional card, try a faster one but I wouldn't go and buy one just for the sake of having one unless your particular shooting style warrants it.

 

Matt

[joseph_anthony]

What is the buffer size of the Maxxum 7D?

 

I also use San disk Extreme II 1GB cards

How are the Lexar and Kingston cards?