I’ve been nerding out looking at memory cards over the last week or so. Although in principal I don’t need ‘fast memory’ cards the latest gadgets always catch my eye. So it was with these Lexar cards that are 1066x, sounds faster than my 300x cards but 1066 times what. It turns out this is in reference to the speed of the original CD-ROM of 150 KB/sec. So cards that are rated 300x have sustained write speeds of 45Mb/s and cards that are rated 1006 will have write speeds of ~160Mb/s. To me this seems important in two places – if you’re shooting fast action such as sports or chasing your kids around and when you’re downloading the cards where faster cards will download faster.
It seems that even with the faster cards for the long exposures that I take at the fringes of the day the write time is roughly equivalent to the length of the exposure. So a 20 second exposure will mean a 20 second write. While I know I ought to be more relaxed about it that can seem like an awfully long time between shots.
The other thing that I’m trying to balance in addition to write time is how large should the card be. I like to have enough memory cards on hand so that when I go off shooting for a couple of days I don’t have to reformat any of the cards. This gives me a third back up in addition to storage on my hard drives. I have typically settled on 16GB cards as a good size, I get a good number of images per card – often a morning or an afternoons shoot per card – without it being too many that if I were to lose the card or if it were to crash I wouldn’t have lost the entire trip.