I am sure that you all know that Grandad was joking about using a very large memory card in your camera,
although now days there are some really big capacity ones out there. It did set me thinking on the capacity of memory cards and that it can be a hard thing to get to grips with the concepts of how it actually works using various card capacities and photo file formats. I know we often drift a little in our threads and that makes them interesting, but I am sure that LLL won’t mind me popping this information in here as it is a bit relevant to what Grandad had written, although jokingly.
So I have tried to set it out here some info on files and capacities and hopefully some of you may find it helpful.
1. The most common file types to save on your camera are Jpeg or RAW files, occasionally the Tiff option will also exist although this is now less popular.
2. Jpeg files are universally readable on any computer without special software so can be sent to anyone, anywhere. They do remove some of the photographic information before saving the file to your memory card so as to make it smaller and then reconstruct this information again using mathematical algorithms on your PC, so some information is lost.
3. RAW files are unique to your own camera and save all of the photographic information to your memory card, so they are quite large files as nothing is removed prior to saving. A RAW file cannot be sent to other people as freely, as you need the special software to convert that cameras version of the RAW file into a picture, that is the reason that some software packages such as Photoshop may take several months to catch up after a new camera hits the market. The main advantage of shooting in the RAW file format is that you can adjust the unmodified file better as it contains far more data than a Jpeg file.
(A) A camera taking Jpeg pictures will be saving a file with a size of approximately half the Mega Pixel capacity of the camera. So for example a 10 MB camera will save a Jpeg file of around 5 MB if set to the Jpeg Fine setting in your camera. This fine setting may be called ‘Best’ or the highest of a ‘star’ rating’
(B) RAW files by comparison can be twice the Mega Pixel size of the camera, so a 10 MB capacity could be saving at 15 to 20 MB per file.
(C) A Tiff file could be up to 3 times the camera size, so 20 to 30 MB per file.
(D) A 1 Giga Byte card (or 1 GB) is One Thousand Mega Bytes (or 1000 MB)
(E) Memory cards come in lots of storage capacities with the newer SDHC type cards being available in 32 GB capacity, but your camera must be capable of reading such high capacity cards. More common sizes are 2, 4, 8 & 16 GB, personally I think you are better using two smaller cards rather than one large capacity one, as the risk of losing all your photos is reduced.
(F) So as a rough calculation, a 4 GB card would hold approximately 800 Jpeg pictures of 5 MB in size taken using a 10 MB camera. Alternatively if you saved them as a RAW file then that would drop to between 200 & 260 on the same card with the same camera.
Obviously these figures are approximate and are camera dependant, but as you can see, the file type chosen can have considerable impact on the amount of pictures stored on your card. So I suppose that LLL would need a 150 GB card to fit all of her Orchid pictures on it using Jpeg files.
