Digital Cameras And Photo Storage
Digital Cameras And Photo Storage
Mark Comon (Vice President, Paul's Photo, Torrance, CA) gives expert video advice on: What are the differences between photo formats? and more...
How does my digital camera store the pictures I take?
Your digital camera stores the pictures you take on the memory card. So remember, the light comes through the lens, through the computer in the camera, and off to the memory card. The camera creates a folder in the memory card. So, when you take the memory card out of the camera, put it into your computer into the card reader, the first thing you'll see is the DCIM folder, and you'll click on that. Then, you'll click on the next folder which will be where the actual pictures are. You click on that, and then all the pictures will open up for you and you'll get to see them.
How does my digital camera compress my photos?
In your digital camera, when you take a picture, the file can be quite large and cumbersome. So, the digital cameras compress the file. What that means is that mathematically they eliminate some data, which it rebuilds again in the computer. That's image compression. The most popular way to do compression is with a JPEG file. It's a mathematical algorithm that preserves a great deal of the quality of your picture and makes a very popular file format for normal photographers to use.
What are the differences between photo formats?
In your digital camera you have the choice of three file formats that you're going to use. JPEG which is what I recommend for most people for most photographers. RAR which is what serious photographer and the computer friendly people. And finally TIF which use to be a big popular format but kind of fallen by the wayside today. Let's talk about whyyou would use one or the other. The advantage of a JPEG file is the image comes right out of the camera onto the memory card. You can put it in any computer anywhere and look at it. It's really cool, because JPEG's are universal between MAC and Windows. I can send a JPEG to China, Japan I don't care and everybody can look at it as a picture. If I shot a RAR picture, the RAR picture is specific to my camera. So if I have a Nikon D2, or a Canon 3D or whatever camera the RAR pictures I make are specific to that camera and I must use a piece of to convert that RAR data into a picture. So if I shoot with RAR, I can't send you my file unless I work at it in the computer first. That's the definition of RAR. Why is RAR better? Because in the computer I have the opportunity to correct the image, to make some changes to the image without any lose in picture quality. One of the difficult things today is to make the picture look on my screen like it does on your screen, when I send it to you, and I know for a fact that TIF is very difficult that way so that's why TIF is kind of going by the wayside. RAR and JPEG are the top file formats today.
How many pictures can a digital camera's memory card hold?
It depends on a couple of things. Number one; how many mega pixels is the camera? Number two; how big is the memory card? And number three; what file format do you use? And if you use the best jpeg, which I'll call JPEG Fine, the image size on the memory card is roughly half the mega pixels of your camera. So if I'm in JPEG Fine, which is always where I recommend that you shoot, with an 8 mega pixel camera, that means the pictures are going to be approximately 4 mega bytes on the card. If I shoot with a raw file format, the pictures are roughly two times the mega pixels of the camera. So if I have an 8 mega pixel camera, raw files are sixteen mega bytes. If I shoot with a TIFF, the files are roughly three times the mega pixels, so a TIFF file would be 24 mega bytes on the card. So let's say we have a 1 giga byte card, with our 8 mega pixel camera, so 1 giga byte means 1,000 mega bytes, so with a Fine JPEG, those pictures are 4 mega bytes a piece. On our 1 giga byte card we stored 25. If we use a raw file those pictures are 16 mega bytes a piece. We're going to get about 125 pictures on a 1 giga byte card. If we're shooting TIFFs, they're 24 mega bytes a piece, we're going to get roughly 400 pictures on a 1 giga byte card. That's how you figure out how many pictures you get on your memory card.