# Thread: no of pix<< size of storage / size of pix

1. ## no of pix<< size of storage / size of pix

each pix is 0.7meg
MD is 1Gb
but can only contain 700 pix.
why?

2. Hmm, will try to smoke ya out in this, pls correct me if i'd the wrong perception

Basically, the camera assumes each pic to be within a range, not 0.7mb per se, even if the previous pics are generally in the .7mb range.

I think it estimates it on the "higher" end of the range (of size taken up), so after taking .. say ard 600 pics, u should have more than 100 more to go... since things are more 'firmed' up.. ie (you might had used 600 * 0.7mb)...

In short, it'll recalculate base on (current space left/overestimated size usage of pic).

Again, I think it is how it works -- would also like to know other ideas on this...

3. Originally posted by aong
Hmm, will try to smoke ya out in this, pls correct me if i'd the wrong perception

Basically, the camera assumes each pic to be within a range, not 0.7mb per se, even if the previous pics are generally in the .7mb range.

I think it estimates it on the "higher" end of the range (of size taken up), so after taking .. say ard 600 pics, u should have more than 100 more to go... since things are more 'firmed' up.. ie (you might had used 600 * 0.7mb)...

In short, it'll recalculate base on (current space left/overestimated size usage of pic).

Again, I think it is how it works -- would also like to know other ideas on this...
Yes, that makes sense.
So since different pictures can be compressed to a different ratio depending on the details in the pic, the camera will calculate on a 'worse' senario, rite?

But would the remaining storage space which are not being utilised being recalculated and used up eventually? Maybe not. Cos as far as i remember, after each pix i took, it always minus one number form the no. of shots left. Which means it never recalculate the remaining space. And of course when the remaining space reaches zero, then i cant take any more pix.

I am refering to minolta 7i for this case.

4. Try taking a lot more, then u shud see a 'change', i guess.

eg, before you start, it says 700 pics left, take 100 pic (of different things, so the sizes does vary), then see how many left, take 600 pics, see any more space. Actually, you can get a small 64mb one and try, no need to go thru full 1gb MD

5. ## ...hmmm look like maybe due to sector size....

Hiee....

Well...as we know, memory devices like basic diskettes...stores the data in small sectors......

So in a CF card....physically we may have let say 4MB.

If the sector size is 1 MB each (this is just a matter of visualization) and the file size always be about 1.2 Mb , then we theoretically will have only space to stroe 2 files.....as 1.2MB will ocupy 2 sectors.....wasting about 0.8MB of memory space.

This kinda problem may be solve by defragmenting the memory.
As i know there are thwo ways a CF can be formated...

mainly:

1- Class B Flash file system is also known as the low end file system (LEFS).

2-Class C Flash file system is similar to the standard DOS file system.

Each has its own handling structure....resulting in different usage of memory.

Well.....in the camera...i think its using the DOS one....
hence the "sector" method.

Well.....hope this helps to give you some idea on the physical memory and the actual useable memory....

regards,
me

6. ## Re: ...hmmm look like maybe due to sector size....

Originally posted by sulhan
Hiee....

Well...as we know, memory devices like basic diskettes...stores the data in small sectors......

So in a CF card....physically we may have let say 4MB.

If the sector size is 1 MB each (this is just a matter of visualization) and the file size always be about 1.2 Mb , then we theoretically will have only space to stroe 2 files.....as 1.2MB will ocupy 2 sectors.....wasting about 0.8MB of memory space.

This kinda problem may be solve by defragmenting the memory.
As i know there are thwo ways a CF can be formated...

mainly:

1- Class B Flash file system is also known as the low end file system (LEFS).

2-Class C Flash file system is similar to the standard DOS file system.

Each has its own handling structure....resulting in different usage of memory.

Well.....in the camera...i think its using the DOS one....
hence the "sector" method.

Well.....hope this helps to give you some idea on the physical memory and the actual useable memory....

regards,
me
ICIC... thks!

7. Hmm, not sure if its applicable.
But 1mb is actually = 1024kb for computer HDD.

8. ## hai yoh........why so rigid one!!!

Hie....

The numbers i plugged is just for visualization (example). Its just aimed at helping the person have a rough idea.....

so i know 1MB is 1024Kb...........

regards,
me

9. Sorry i still don't geddit.

Are you trying to say that files are actually stored on sectors, resulting in the amount of wasted space which aren't filled up.

Or are you trying to say that 1mb = 1024kb, hence logically 1GB does not equate to 1GB but 976.5625MB instead?

10. did a test just now.

covered the lens with the lens cap, and shuttle speed switched to fastest, took 25 pics of total black pics. As total black pics got little details, the compression is easier for the camera. After taking 25 pics, the numbers of space shown on the camera only dropped by 3.

11. ## Yes its stored in sector....

Sorry i still don't geddit.

Are you trying to say that files are actually stored on sectors, resulting in the amount of wasted space which aren't filled up.
Yes it is stored in sectors......But here is a site i found talking
about Sandisk CF using smaller sector of 512byte....(last paragraph)

Regards,
Sulhan

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•