SD Card Capacity

RonHendriks1966 · 01-05-2011, 03:11 AM

Originally posted by Smeggypants

1,950 RAWs on a 32 gig card?

On my K20D I get 670 RAWs on a 16GB card. this works out at about 23MB a pic, which is about right.

1,950 RAWs on a 32 gig card works out at 16Gb per RAW.
What RAW format are you shooting at?

I always shoot RAW in DNG format. The RAW files of the K-7 are smaller then the ones from the K20D. Also there is a huge variation in file sizes of RAW. For K-7 it goes from 11 Mb to 19 Mb and with the K-5 i've seen from 14 Mb to 32 Mb for a single DNG RAW file.

The second thing to take notice of is the difference in capacitie for different brands SDHC cards. Not every 16 Gb card is the same as the next one brand when you compare them.

cats_five · 01-05-2011, 07:34 AM

Originally posted by RonHendriks1966

<snip>
The second thing to take notice of is the difference in capacitie for different brands SDHC cards. Not every 16 Gb card is the same as the next one brand when you compare them.

Could you explain this a bit further please?

RonHendriks1966 · 01-05-2011, 09:18 AM

Originally posted by cats_five

Could you explain this a bit further please?

SD cards are more like apples. You don't always get a full kilogram when you buy one.

There is always a little room for the card wich you can't use. My 32 Gb card is more likely to be 31 GB in bits and bytes.

**jbinpg** · 01-05-2011, 11:36 AM

As well, some manufacturers include recovery software on the SD card which takes up room.

cats_five · 01-05-2011, 12:57 PM

OK, let's clarify. Firstly there is the confusion caused by how many bytes are in a gigabyte. SD Cards are usually sized at 1 000 000 000 bytes per gigabyte, but Windows divides bytes by 1073741824 to arrive at gigabytes so straight away you have apparently lost some space in the card.

Then, the card has to get formatted and whatever format is used (FAT32, NTFS, anything else) that takes up some space for the File Allocation Table.

Lastly as jbinpg says, sometimes makers include software on the cards which again takes up some space.

However, I find it very hard to believe that different maker's 8GB (or whatever size) cards are different sizes unless they are using different definitions of a GB.

simico · 01-06-2011, 03:06 AM

Originally posted by cats_five

Firstly there is the confusion caused by how many bytes are in a gigabyte.

It's plain simple: almost all of the manufacturers (not just of SD card, but all storage manufacturers) follow the ISO standard where 1 KB = 1000 B, 1 MB = 1000 KB, etc; while software developers follow the "IT standard" where 1 KB = 2^10 B = 1024 B, 1 MB = 1024 KB, etc.

blockamon · 01-06-2011, 09:17 PM

I don't have the camera to check right now, but I think I get just shy of 220 DNG on my 8GB cards.

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01-05-2011, 03:11 AM	#16
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Originally posted by Smeggypants 1,950 RAWs on a 32 gig card? On my K20D I get 670 RAWs on a 16GB card. this works out at about 23MB a pic, which is about right. 1,950 RAWs on a 32 gig card works out at 16Gb per RAW. What RAW format are you shooting at? I always shoot RAW in DNG format. The RAW files of the K-7 are smaller then the ones from the K20D. Also there is a huge variation in file sizes of RAW. For K-7 it goes from 11 Mb to 19 Mb and with the K-5 i've seen from 14 Mb to 32 Mb for a single DNG RAW file. The second thing to take notice of is the difference in capacitie for different brands SDHC cards. Not every 16 Gb card is the same as the next one brand when you compare them.

01-05-2011, 07:34 AM	#17
cats_five Veteran Member Join Date: Nov 2010 Location: Fife, Scotland Posts: 835	Originally posted by RonHendriks1966 <snip> The second thing to take notice of is the difference in capacitie for different brands SDHC cards. Not every 16 Gb card is the same as the next one brand when you compare them. Could you explain this a bit further please?

01-05-2011, 09:18 AM	#18
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Originally posted by cats_five Could you explain this a bit further please? SD cards are more like apples. You don't always get a full kilogram when you buy one. There is always a little room for the card wich you can't use. My 32 Gb card is more likely to be 31 GB in bits and bytes.

01-05-2011, 11:36 AM	#19
jbinpg Site Supporter Join Date: Mar 2008 Location: Prince George, BC Photos: Gallery \| Albums Posts: 3,546	As well, some manufacturers include recovery software on the SD card which takes up room.

01-05-2011, 12:57 PM	#20
cats_five Veteran Member Join Date: Nov 2010 Location: Fife, Scotland Posts: 835	OK, let's clarify. Firstly there is the confusion caused by how many bytes are in a gigabyte. SD Cards are usually sized at 1 000 000 000 bytes per gigabyte, but Windows divides bytes by 1073741824 to arrive at gigabytes so straight away you have apparently lost some space in the card. Then, the card has to get formatted and whatever format is used (FAT32, NTFS, anything else) that takes up some space for the File Allocation Table. Lastly as jbinpg says, sometimes makers include software on the cards which again takes up some space. However, I find it very hard to believe that different maker's 8GB (or whatever size) cards are different sizes unless they are using different definitions of a GB.

01-06-2011, 03:06 AM	#21
simico Veteran Member Join Date: Jan 2009 Location: Budapest Posts: 821	Originally posted by cats_five Firstly there is the confusion caused by how many bytes are in a gigabyte. It's plain simple: almost all of the manufacturers (not just of SD card, but all storage manufacturers) follow the ISO standard where 1 KB = 1000 B, 1 MB = 1000 KB, etc; while software developers follow the "IT standard" where 1 KB = 2^10 B = 1024 B, 1 MB = 1024 KB, etc.

01-06-2011, 09:17 PM	#22
blockamon Forum Member Join Date: Nov 2010 Location: Lynchburg, VA Posts: 57	I don't have the camera to check right now, but I think I get just shy of 220 DNG on my 8GB cards.