LOST MEGABYTES

[massamia]

I have two 512 mb memory cards which used to hold 178 large jpegs each. After formatting the cards, I now have 488 mb which only hold 159 images approx. Has anyone come across this before, and how do I restore the missing megabytes? Any suggestions appreciated.

Mike.

[RobbTC]

I have two 512 mb memory cards which used to hold 178 large jpegs each. After formatting the cards, I now have 488 mb which only hold 159 images approx. Has anyone come across this before, and how do I restore the missing megabytes? Any suggestions appreciated.

Mike.

512 mb is usually never really 512. 488 mb sounds about right. My 256 card is only 244 (so double would be 488).

The way manufacturers state memory sizes vary widely. Does 1k = 1000 or 1024? Depends. 80 GB hard drive, only 75, 200 GB hard drive, only 186GB.

About you getting less images than before, perhaps you've changed them from large, normal, to large, fine. Try large, normal again to see if you get the other number.

Robb

[Clark]

Formatting always takes up a certain amount of space.

[gasrocks]

Sizes are "nominal." How big is a 2X4? It isn't 2" X 4" (anymore.) And 6 mil plastic is 4.5 mil thick, etc.....

[RobbTC]

I noticed an interesting thing tonight...

If you change the ISO to a higher speed, you get less photos on the CF (on 20D).

Quite a difference too...
4 GB Card:
ISO 100 = 445 pix
ISO 200 = 441
ISO 400 = 429
ISO 800 = 415
ISO 1600 = 396
ISO 3200 = 367

[Jesper]

I noticed an interesting thing tonight...

If you change the ISO to a higher speed, you get less photos on the CF (on 20D).First of all, the number of photos left that you see on the camera is only an estimate, because files aren't always exactly the same size.

Second, the higher you set the ISO setting, the more noise you will see in your images. The JPEG compression algorithm works best on photos with large, smooth surfaces. The more noise there is in your image, the more difficult it is to compress it - if you try, you'll notice that photos shot at higher ISO settings will tend to be larger JPEG files than those on lower ISO settings. So because the files are larger, less photos will fit on your memory card.

[Longwatcher]

I had a weird occurance a couple of days ago which may be related also.
normally my CF cards show 93 images available when clear, but a couple days ago one of them showed 86 images just after formatting, but after taking a picture it changed to 92 images. So apparently the camera thought for a bit the images would take up more space for some reason. I was not playing with the ISO or file sizes at the time, so that was not the problem. Kind of bizarre, but no serious effecs.

[felix21685]

yeah what is up with a 2x4...that is so dumb..

[lost]

I think 2x4's are now 1-3/4x 3-1/2 or close to that. Well that was 6 years ago when I got out of carpentry.

[massamia]

Well done Robb TC. After reading your reply, I remembered that I had changed the ASA to 800.
I reset this back to 400, and I ended ip with my original 179 approximate images showing.

SORTED.
Massamia

[Jon]

2x4 (and other lumber dimensions) are based on "rough-cut" dimensions. They rip the logs down to those dimensions, but the saw marks are very pronounced. The finishing process takes them down to the final dimension. But if you want to get 2x4 rough-cut, you'll get true 2x4s.