Memory card

gundy74 · Jul 12, 2006

i noticed that most D-SLR's use CompactFlash cards instead of SD or MMC cards. Why is that. other than the fact that CF cards can hold up to 4 GB, is there any real advantage?

964 · Jul 12, 2006

I don't think there is any answer that is going to make sense really...why do some cars use diesel and some petrol? My camera uses both simultaneously so I usually have a 2GB CF and a 2GB SD installed at all times. There is no advantage to either, as I can get 4GB SD cards if I choose, but I limit myself to 2GB cards as I don't want to lose 4GB of iamges should anything go wrong. If it is an important shoot then I set the camera to write the RAW image to both cards so I have a backup.

Digital Matt · Jul 12, 2006

Most DLSRs use CF cards I think because, when the DSLR boom started, compact flash had the largest storage, and the fastest read/write times. That's not really true any more, as other types have caught up, but the DLSR industry doesn't want to suddenly change horses in midstream.

rmh159 · Jul 12, 2006

Is there any significant difference in the read/write speeds between memory types? I had heard that reasoning before too but I had thought the difference in speeds would be negligible (though now that I think of it maybe for a high megapixel camera on raw it might be nice).

Digital Matt · Jul 12, 2006

rmh159 said:
Is there any significant difference in the read/write speeds between memory types? I had heard that reasoning before too but I had thought the difference in speeds would be negligible (though now that I think of it maybe for a high megapixel camera on raw it might be nice).

You can probably find some info on google about various read/write times. I think it's really important, and comes into play when you are talking about shooting high res 8.2mp jpg at 8.5 fps for 40 frames. You want to write that as fast as possible to the card with as little hiccups as possible.

964 · Jul 12, 2006

Yep, there is quite a big difference on write speeds, but also between cameras (i.e. the speed at which the camera is *capable* of writing at). I do have 8.2MP 8.5fps capability and I use it occasionally, and a fast card will make quite a bit of difference as 22x RAW images can take anything between 40 secs and 1.5 mins to write. However, for normal use - i.e. a shot every few seconds at most - the speed of the card will not make any difference as most cameras will have a buffer for at least half a dozen RAW images so it is irrelevant. Having said that, I use Adata cards myself, as I have been through the 'buy the most expensive brand name who must be better' phase, and I have not experienced any difference between the cheaper (adat) and the snob cards (Lexar). If you are not shooting with burst mode regularly I wouldn't waste money on expensive hi speed cards as even the slow cards can write a 8.2MP RAW image within 5 seconds.

Big Mike · Jul 13, 2006

The camera's buffer should be the determining factor for speed of shooting, not necessarily the speed of the card. As mentioned, even slower cards won't slow up your shooting unless you are blasting away.

Although, I recently noticed that slower cards are slower to call up the image to the screen (on my 20D at least). I was chimping my shots to check the histogram and I noticed a definite time increase when I put in a slower card. I guess I could set the instant preview to last longer than 2 seconds...:roll:

Jeff Canes · Jul 13, 2006

my 1D MIIn has both CF & SD and I never notice any different, likely any is unperceivable

EBphotography · Jul 13, 2006

I have had the same experiences as Mike. More determining factor is the camera! When I bought my camera it advertised a fast speed between pictures! Be sure to check the camera too, not just the card.

Hope this helps. Eric.

Simon · Jul 14, 2006

I'm no expert on this but I did read an article in a magazine.

They state that the advantage of a CF card is that they are bigger and less fiddly, in addition to that they are virtually indistructable. Other than that there appears to be no diffirence in speed, or no added advantages. :er: