SD Card Compatibility

has anybody tried a 4GB memory card in an *isds or other pentax digital camera
their are quite a few selling on ebay at silly money my questions are

1/do thay work with our kit

2/can our kit work with them

3/do thay drain the power quickley

4/ is their any point having 4GB i mean the obvious advantages are their more storage

has anybody bought these cards off the internet and if so was it happy ever after or a total horror story

your thoughts please guy and gals

It's already been answered:
https://www.pentaxuser.com/forum/viewtopic.php?t=2513&highlight=4gb

The answer's no

But if they did work they would not drain the power any more quickly
In some ways you are better off spreading your images across a few cards - just in case a card goes bad (which they can do from time to time).

Hope that helps!
Matt

I just ordered a couple of 1GB SD cards to add to the collection.
The 1GB cards take about 90-95 pictures when you are shooting raw.
So my collection for the DS is 3x 1GB and 1x 512MB. This will hopefully take me through the 3 weeks of summer holiday coming up.
But I might order an extra 1GB before I leave.
These cards get cheaper by the week. I ordered the 1GB 133x speed cards for Euro. 27,90 each.
Until now I have never had a card fail, but yes flash memory can fail but the number of write cycles gets higher and higher.
I was tempted on buying a 2GB card, but I think that about 90-95 pictures on one card is just about enough.

Ok, so I've had a little time (insomnia again!) to look at the RAW formats. Interesting results!

I took the SD-CF adapter, put a brand new Kingston 133x 1Gb card into each camera:
*ist-D = 67 RAW shots
*ist-DS = 90 RAW shots

Next I take almost the same shot on both cameras onto the one card. What's interesting is that both cameras can preview each other's image. The newer camera (the *ist-DS) can view the EXIF data for both, whereas the older (*ist-D) cannot view the EXIF data for the newer.

I then take a look at dcRAW, extract the embedded thumbnail and find the thumbnail is pretty tiny in each case - about 1.1Mb and no difference to write home about (1.10Mb vs 1.08Mb).

Finally I resort to viewing the files in a hex editor and I find the main cause of difference:
The *ist-D uses 16-bits of storage per CCD pixel
The *ist-D uses 12-bits of storage per CCD pixel

Which is really obvious when you think about it. The CCD has a bit depth of 12-bits, and the *ist-D is just wasting storage space (filling the extra four bits with zero). That calculation would make the *ist-D use 11.5Mb (12,080,128 bytes) for the CCD RAW, and the *ist-DS use 8.6Mb (9,060,096 bytes). Taking into account the 1.1Mb embedded JPG, and other tables and data those values pretty much tally.

So, actually neither camera is using compression... it's just that the *ist-D stores the extra zero bits to make it 16-bits wide.

Could it be changed in the *ist-D? Probably. Will it be changed? I doubt it, given firmware development costs (mostly in terms of time).
I suspect that the RAW convertors just read the TIFF header within the RAW file (because that's largely what these RAW files are) and decode appropriately. There's certainly nothing "hard coded" regarding image file format within dcRAW.

So I hope that explains everything!!
(And, by the way, the adapter seems to work very well in the *ist-D - a RAW file takes roughly 8.5 seconds. However there is a slight pause when you power up, almost as if the adapter is "booting up" and working out the SD card. I think I'll buy SD cards from now on )
Matt

CHEERS FOR THAT MATTMATIC A VALID POINT I THINK TWO 2GB CARDS IS THE WAY TO GO

hope you don't mind me asking but where did you find them at this price?

Steve

Matts results seem to beg the question as to why Pentax decided the D would use 16 bits per pixel. Were they expecting some chip developmenst which would use those extra bits?

Just bought a couple of Kingston 1 GB 50 x speed SD cards (because they were cheap http://www.mymemory.co.uk/memory/Kingston/1GB/SD/Card/(Secure/Digital). My DS reckons itill only get 90 shots on these comared to the more normal 93/96 for other brands.

I got them from a local PC shop which allso has a webshop: http://www.gistron.com
It is a Dutch shop, so maybe not so usefull for most people here.
At this moment (June 7th) the prices for 133x SD cards from the TakeMS brand are:

1GB: 26,90
2GB: 51,90

Someone posted that 2GB cards were the way to go. I think not. card manufacturers calculate with a MB as being 1.000.000 Bytes. So the bigger the card gets, the more you loose in storagespace to these calculation methods. two 50GB HDD's offer more storage then one 100GB HDD.
two 1GB cards will probably hold more pictures then one 2GB card.

The difference in the amount of shots between different SD cards is due to the fact that these cards allways have some 'bad sectors' which are not useable. To be able to get at least the amount of storage that is on the label they have to enlarge the flash chip so that there will allways be enough.

Not 100% true for flash memory. It is true for HDDs.
But you are right about the bad blocks. However, some manufacturers reserve some of the good blocks ready to swap out an acquired ad block, so that you'll have a consistent amount of space. The bad block management and error tolerance does vary, depending on the quality of the controller. That was definitely the case with CF, but I'll have to double-check SD.

I use the raw chips in our electronic products, and have been writing firmware to use them for many years. xD-card and MMC are raw NAND flash chips (ie no controller chip)

Matt

How do they calculate it then? I see considerable differences between capacity between different brands of SD cards, but I have never seen a single card which delivers the full printed capacity.
The 1024MB cards I have vary between 954 and 978 MB.

/Remco

Ok, I can tell you that the flash chips themselves:

* There are two layouts, small and large.
* Have 512 byte pages, or 2048 byte pages
* Each page has "out-of-band" data of 16 bytes or 64 bytes. The OOB data is used for error correction, filesystem info etc.
* Pages are written individually - you should write a whole chunk of 512 or 2048 bytes.
* A set of pages are arranged in a block. A block is 2k or 128k. Only the whole block can be erased.
* The number of pages is always a power of 2.

So, your differences can be accounted in two ways:

1. Bad blocks. Can't remember the figures, but I think a max of 5% or 10% bad blocks is the max.

2. Reserved blocks. These are "set aside" for when a good block fails. The controller can copy the data out into a reserved block and ditch the bad block. It will do this without you knowing at all - and to do that it needs these reserved out of the set.

So, maybe a manufacturer may use the HDD term for a gigabyte, but use the extra 2.4% for reserved blocks.

And, as I mentioned, different manufacturers have different qualities and capabilities of controller (the bit that glues the SD interface to the NAND flash chips). Some controllers are dumb and will corrupt your file when a bad block occurs, other controllers will copy it to a reserved block and preserve the file.

The trouble is, there's never much information on extactly what the controller chips can manage...

Hope that explains a bit
Matt

Thanks, this makes it a lot more understanding. Now we should have a list with the information about which manufacturer uses which controller. Allthough it is allmost impossible considering how much private label manufacturing there is... Even different types from the same brand can be a different manufacturer.

All the PEF files, in fact have 3 jpg files embedded in them.

Regarding SD card compatibility, does anyone know if the Datawrite 4gb 150x Datasafe SD Card is any good?

It is very reasonably priced at around £55, but is this an indication of how good it is in comparison to say, a Sandisk Extreme IV?

As the Datawrite card is a lot less pricey, does this necessarily mean it will suffer compatibility issues or is an SD card... an SD card?

I bought a 2gb Datawrite for my partners HP compact camera and it works fine, but would I need a better card for a better camera such as a K10D?