Maximum Memory Card Size for a K-7

We don't need to be over anxious about our SD cards, just treat them properly. They do have a finite life, but it's a very long life.

We tend to change them every few years as our requirement for larger capacities grows. At the moment we are moving from 4GB to 8GB cards as we replace. Older cards get moved to use in the compact cameras.

That is hearsay.

I fill the card with images; take is from the camera; insert either direct into PC or via an adapter; copy all images across; check a random sample from the various directories; delete the contents of the directories; and card is ready for reuse.

I don't believe I have formatted any of my SD/SDHC cards in the camera - all done on the PC and I have three top level files contact.txt, contact.rtf & contact.doc all of which contain my contact details in case I loose or misplace a card. Each card also has a directory located in the DCIM directory: X00_0000 where X is the card number; that way when I am using several cards on one day I do not get identical directory names.

It's not all hearsay Gamka, it's actually in the manufacturer's instructions. Pentax have advice about the use of SD cards in the manual, right at the front.

We always format a card in the camera it's being used in and do this every time we re-use the card. The cards are used in rotation, so they all get the same use. We have never, ever had a corrupted card.

I'll agree that you can treat them more casually and usually get away with it, but it's not best practice and sometimes it does cause problems.

I have had it confirmed by Pentax in an email that it is NOT necessary to format the cards in the camera.

The only time I have have seen problems with a card was trying to read a card that had been formatted in a camera and that happened several times. This is what prompted the call to Pentax.

What does an in-camera reformat do? All it does is erase the file tables - the data is actually still there. If the table is not present it creates that and any directory.

I hear what you say Gamka, but I shall continue to follow the instructions. Others will do as they wish.

Incidentally, formatting does set up again the file structure for that camera. As it doesn't actually erase anything this makes it possible to use file recovery software to reclaim "lost" images. If the software doesn't work or only partially works, then formatting can actually give us a second shot at getting those images back.

An exception seems to be some cameras that overwrite the files with a zero, which I understand causes a problem with recovery. Pentax cameras don't cause this problem as far as I know.

As I work a bit with these things in my day job I ought to perhaps comment

Firstly there is absolutely no need to worry about how many times you read data from a memory card. View it, read it, copy to other computers as many times as you like. That said it is good organisational practice to get the images off the card and on to permanent storage as soon as possible and if you do that you won't be doing many reads anyway.

There is however a limit on how many times you can write to a card, often called a 'wear limit'. It is however a very large limit and cards are getting more sophisticated in how they manage wear so in practice we are never going to get anywhere near the limit and your card won't wear out. That said I really like to minimise the opportunity for things to go wrong and recommend trying to always leave a bit of spare space on the card, this makes life easier for the card's wear management algorythms.

In theory there is no difference whether you write to the card from your camera or the computer, it is simply a file system and it should make no difference which device writes to it. To repeat myself however I really, really like to minimise the opportunity for things to go wrong so I prefer to only write to the card from one device just in case one of the devices (more likely the camera than the computer) hasn't really written its file system routines properly. That means I use the camera to initially format the card, write images, and delete images. I prefer to keep the card 'clean' so after a shoot I transfer all the images to permanent storage and then 'delete all' in camera.

I try to avoid on-card reorganisation through selectively deleting images but if I exceptionally do this I do it on computer for convenience (breaking my only write to the card from one device preference). However if I mess around like this I prefer to subsequently reformat the card in camera rather than just delete all the images. The reformat guarantees a nice clean file system - but you don't want to do it to often as it increases wear.

So in summary most of the myths are just myths. Cards are sufficiently robust and reliable and have sufficient wear limits that you can ignore everything I say and just get on and use them without worrying. *BUT* all the reliability figures are averages and a (very small) percentage of cards are going to fail very much quicker than expected, I hope (but don't know) that my card isn't one of the bad ones and really, really don't want it to fail with my images on it - so I give it the easiest life I can but don't waste my time worrying about it.

The K-5 complies with the DCF 2.0 Specification K-5_Spec_here

From the Design Rule Manual....
1.1. Purpose
As digital still cameras(DSC) have come to enjoy wide popularity, there is a growing need for direct exchange of images between cameras and other equipment, allowing pictures taken on one camera to be viewed on another, or to be output to a printer. This DCF is aimed at the creation of a user environment in which consumers can combine products more freely and exchange media readily. To this end it specifies rules for recording, reading and handling image files and other related files used on DSC or other equipment.

1.2. Scope
DCF is applicable to products for writing image files on an interchangeable medium (removable memory) formatted with the DOS FAT file system, and to products for reading (or printing) the images recorded on removable memory by these reader products. Details
of the applicable media are given in Annex A


So the cards are usable/interchangeable with other compliant equipment.

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Well, yes (except that the original post is re the K7 not K5).

But, for our purposes here, the DCF specification is probably just redundant window dressing. There is already a proper standard for SDHC/SDXC cards and a standard in the (admittedly antiquated and please throw it away) MSDOS FAT file system, so we don't actually need anything else for interchangeability.

We digress from the original point gentlemen, back on topic please. You can always start a new thread for a new subject.

No, I'm cetainly not suggesting we don't copy files to a computer (although wasn't there a member in a thread a while back who did actually keep all his shots on cards and never copied them ?)

I was referring to my understanding of some 'best practice' guidelines that I have always been aware of and adherred to - that is that SD cards are less likely to fail or cause any data corruption to files if the amount of copy / move / write / delete operations was kept to a minimum.

My own 'best practice' then is to use a larger card to capacity prior to copying to the computer, then backing up to an external drive or DVDs before formatting the card in the camera ready for reuse. The larger the capacity card the less number of times you will be copying and formatting it.

I definately don't want to be encouraging any 'internet hearsay', but I believed this advice was fairly commonly given in digital photgraphy references and guidebooks. In any case, I am glad that repeating it here has generated the more technical responces we have had - maybe such advice is out of date, being more relevent to earlier generations of cards?

I am always delighted to be corrected by those with more technical experience, but is is not true that a card where the files were deleted on a computer and then not re-formatted in the camera was potentially more at risk of having failures when shooting?

In theory it shouldn't make it any more likely to have failures, unless the camera firmware is badly implemented (which isn't exactly a guarantee I know). You can avoid the, extremely (even vanishingly) unlikely, possibility of such problems though by using the camera itself to delete the images.

I wouldn't reformat the card each time I shoot a new set of images though - that way you really are increasing the write volume to the card.

But 'tis a storm in a tea cup. Unless you really have some sort of fake counterfeit card that's inherently faulty ( I was caught once) reliability is good enough that we can just forget all this and concentrate on the photos.

Sorry John - I did read your 'off topic' warning but just answered the question. I'll shut up about this now.

On topic: K7 is SDHC only which standard is for up to 32 GB only. Firmware update is for SDXC compatability, the theoretical max for SDXC is 2048 GB but I haven't got a card that large to test myself

Thank you everyone,

the need for a 64GB card is only for travelling over a 6 week period. We download all images every night to a NetBook Computer, copy the day's shooting to an external 500GB, USB powered HD, and keep the memory cards when full until we get home. One person carries the external HD and one carries the full memory cards and the NetBook stays in the hotel. It's a 3 level back-up system with the 3 depositories in separate locations. We just want to have the older K-7 running the same system as the new K-5. Normally I only use 16GB cards and carry 2 spares for a day's shooting, but travelling is a different matter entirely.

Also to answer someone's query about deleting images from memory cards. I have done several courses with a very respected, professional photographer here in Melbourne and he strongly recommends formatting each memory card in the camera in which it will be used, once you have transferred all your images files to the computer and backed them up, and not to just repeatedly delete the files from the computer or in the camera. He stressed that formatting "in camera" ensures more reliable writing by the camera to the card when shooting. This has some similarities to defragging a computer HD and making all the space completely blank and ready for writing in the fastest, most reliable way. I'm sure this is good advice, the photographer has vast experience from the film days 'til now and teaches at university level.

Thank you all for your advice and comments.