SD---SDHC?
Posted 14/03/2010 - 08:56
Link
It was me who mistakenly said SD ends at 4GB. It ends at 2GB. 4GB and above and it should be SDHC.
Tim
AF - Pentax K5, Sigma 10-20/4-5.6, Tamron 17-50/2.8, Sigma 30/1.4, Sigma 70-200/2.8, Tamron 70-300/4-5.6
MF - Vivitar CF 28/2.8, Tamron AD2 90/2.5, MTO 1000/11
Stuff - Metz 58 AF1, Cactus v4, Nikon SB24, Raynox 150, Sigma 1.4x TC, Sigma 2x TC, Kenko 2x macro TC, Redsnapper 283 tripod, iMac 27”, Macbook Pro 17”, iPad, iPhone 3G
Flickr • Fluidr • PPG • Street • Portfolio site
Feel free to edit any of my posted photos! If I post a photo for critique, I want brutal honesty. If you don't like it, please say so and tell me why!
AF - Pentax K5, Sigma 10-20/4-5.6, Tamron 17-50/2.8, Sigma 30/1.4, Sigma 70-200/2.8, Tamron 70-300/4-5.6
MF - Vivitar CF 28/2.8, Tamron AD2 90/2.5, MTO 1000/11
Stuff - Metz 58 AF1, Cactus v4, Nikon SB24, Raynox 150, Sigma 1.4x TC, Sigma 2x TC, Kenko 2x macro TC, Redsnapper 283 tripod, iMac 27”, Macbook Pro 17”, iPad, iPhone 3G
Flickr • Fluidr • PPG • Street • Portfolio site
Feel free to edit any of my posted photos! If I post a photo for critique, I want brutal honesty. If you don't like it, please say so and tell me why!
Posted 14/03/2010 - 09:31
Link
SD to (officially at least) 2GB, SDHC above that, though there are some 4GB cards that are SD only. Not many, mind...
Bret
Bret
Posted 14/03/2010 - 14:04
Link
Many people advertise SD cards over 2GB But in reality they are all SHDC in fact. Usually not mentioned until in the small print). As Brett says you can find the odd SD to 4GB but few and far.....
Paul
Paul
K5's (2)both gripped, K10d gripped, Pentax 28-90 f3.5, Sigma 18-250mm, Sigma 150-500mm. Sigma 105mm f/2.8 EX DG Macro, Sigma 10-20 f.4-5.6.EX DC, Hoya 135 f2.8, Take on 28mm f2.8 Pentax AF360 flash, 2 fill in slaves. 30 metre remote release, Rt angle viewfinder, Giotto NOT 3261B Tripod with Manfrotto 808Rd4 ball head, Manfroto 4861RC2 monopoly, shoulder stock, various filters etc, Panasonic SET HBS HD Video cam, Tamrac Explorer 8x backpack and a sore back.....
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Photography is an index for measuring futility and pride.......
Paul
:wink
http://s743.photobucket.com/home/pg20_photos/index
https://www.flickr.com/photos/pg20
-------------------------------------------------------
Photography is an index for measuring futility and pride.......
Paul
:wink
http://s743.photobucket.com/home/pg20_photos/index
https://www.flickr.com/photos/pg20
Posted 14/03/2010 - 15:08
Link
I must have 2 of the odd ones then. I got them some time ago, (when I got my K10) from "MyMemory" Jersey or Guernsey. It doesn't state what speed they are, 2/4/or6 but they work well enough. I have since graduated to 8GB and then to 16GB in my K7 but still use the 4GB cards to transfer various things.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.
Posted 14/03/2010 - 15:24
Link
Basically it comes down to the number of bits on the memory cards. While a 32-bit number, in theory, can address 4GB worth of data ... it'd have to be an signed 32-bit number which is 2^32-1 (2 to the power of 32 minus 1) addressable bytes. So in reality, that's 1 byte short of 4GB - which can cause problems. I suppose it would be possible, but also unlikely that manufacturers would go this route. This is the same reason that why on newer computers if you have a 32-bit version of Windows that only 3GB of memory is useable.
I hope that makes sense, though it'll probably sound more like incoherent engineering babble
I hope that makes sense, though it'll probably sound more like incoherent engineering babble
K-5; Siggy 10-20 f4, 30mm f1.4, 18-50mm f2.8, 70-200mm f2.8; Tammy 400mm f4, 500mm f8
Posted 14/03/2010 - 16:15
Link
Whelmed I believe all cards sizes have a -1 byte so it shouldn't be a problem.
btw I wonder why they didn't make the 645D SDXC ready
btw I wonder why they didn't make the 645D SDXC ready
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 14/03/2010 - 18:10
Link
that's what I figured. Then I read the wikipedia page and saw a *lot* of this is definitions from teh SD authority.
Bret
Bret
my pics: link
my kit: K3, K5, K-01, DA 18-55, D-FA50 macro, Siggy 30/1.4, 100-300/f4, 70-200/2.8, Samsung 12-24/f4, Tamron 17-50, and lots of other bits.
my kit: K3, K5, K-01, DA 18-55, D-FA50 macro, Siggy 30/1.4, 100-300/f4, 70-200/2.8, Samsung 12-24/f4, Tamron 17-50, and lots of other bits.
Posted 14/03/2010 - 23:30
Link
Anvh wrote:
Whelmed I believe all cards sizes have a -1 byte so it shouldn't be a problem.
btw I wonder why they didn't make the 645D SDXC ready
It may be ...Whelmed I believe all cards sizes have a -1 byte so it shouldn't be a problem.
btw I wonder why they didn't make the 645D SDXC ready
I believe that SDHC devices which support SDXC cards provided they meet certain criteria and the exact implementation of the spec.
.
K20D, *istD, MZ-S, Super-A, ME Super, MX
DA* 16-50, DA* 50-135, DA* 300,
DA 50-200, FA 24-90, FA 20-35,
M 400-600, A 50 f1.4, A 28 f2.8, A 70-210, M 35-80, M 50 f1.7
A x2S teleconverter and a few others ...
K20D, *istD, MZ-S, Super-A, ME Super, MX
DA* 16-50, DA* 50-135, DA* 300,
DA 50-200, FA 24-90, FA 20-35,
M 400-600, A 50 f1.4, A 28 f2.8, A 70-210, M 35-80, M 50 f1.7
A x2S teleconverter and a few others ...
Posted 15/03/2010 - 16:15
Link
I thought ask a simple question I'll get a simple answer!!!!
No such luck. I'm as confused as ever. Not to worry though I've got 2 of them and they work so that's OK. CHEERS Vic.
No such luck. I'm as confused as ever. Not to worry though I've got 2 of them and they work so that's OK. CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.
Posted 15/03/2010 - 16:32
Link
This from Wiki and it answer your question I believe
Standard-SD cards (non-SDHC) with greater than 1 GB capacity
The SD Card Association's current specifications define how a standard SD (non-SDHC) card with more than 1 GB and up to 2 GB capacity should be designed. These cards should be readable in any SD 1.01 devices that take the block length data into account. Any 1 GB or lesser card should always work (so the key question is how one's reader handles block length).
According to the specification, the maximum capacity of a standard SD card is defined by (BLOCKNR x BLOCK_LEN), where BLOCKNR may be (4096 x 512) and BLOCK_LEN may be up to 2048. This allows a capacity of 2 GB. The main problem is that some of the card readers support only a block (aka. sector) size of 512 bytes, so greater than 1 GB non-SDHC cards may cause compatibility difficulties for users of such devices.
SD and SDHC compatibility issues
The SDHC specification was completed in June 2006, but by that time, non-standard high-capacity (>1GB) SD cards (based on the older 1.x specification) were already on the market. The two types of storage cards were not interchangeable, creating some confusion among customers. SD and SDHC cards and devices have these compatibility issues :
- Devices that do not specifically support SDHC do not recognize SDHC memory cards. Some devices can support SDHC through a firmware upgrade.
- SDHC devices are backward compatible with SD memory cards.
- Some manufacturers have produced 4 GB SD cards that conform to neither the SD2.0/SDHC spec nor existing SD devices
Standard-SD cards (non-SDHC) with greater than 1 GB capacity
The SD Card Association's current specifications define how a standard SD (non-SDHC) card with more than 1 GB and up to 2 GB capacity should be designed. These cards should be readable in any SD 1.01 devices that take the block length data into account. Any 1 GB or lesser card should always work (so the key question is how one's reader handles block length).
According to the specification, the maximum capacity of a standard SD card is defined by (BLOCKNR x BLOCK_LEN), where BLOCKNR may be (4096 x 512) and BLOCK_LEN may be up to 2048. This allows a capacity of 2 GB. The main problem is that some of the card readers support only a block (aka. sector) size of 512 bytes, so greater than 1 GB non-SDHC cards may cause compatibility difficulties for users of such devices.
SD and SDHC compatibility issues
The SDHC specification was completed in June 2006, but by that time, non-standard high-capacity (>1GB) SD cards (based on the older 1.x specification) were already on the market. The two types of storage cards were not interchangeable, creating some confusion among customers. SD and SDHC cards and devices have these compatibility issues :
- Devices that do not specifically support SDHC do not recognize SDHC memory cards. Some devices can support SDHC through a firmware upgrade.
- SDHC devices are backward compatible with SD memory cards.
- Some manufacturers have produced 4 GB SD cards that conform to neither the SD2.0/SDHC spec nor existing SD devices
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
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