How to Use Image Format and Size for Canon Rebel T3I

show more Image format and size provides you with in-depth training on Photography. Taught by Ben Long as part of the Shooting with the Canon Rebel T3i (600D and Kiss X5) show less
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Image format and size

By default, your camera shoots in JPEG format. Established by the Joint Photographic Experts Group, JPEG is a compressed image format. That is, it takes the original image data that your camera captures and it crunches it down so that it takes up far less storage. JPEG compression is a lossy compression scheme. That is, there is a loss of quality when JPEG compression is applied to an image. The more compression you apply, the more your image is visibly degraded. Most cameras give you a few different JPEG conversion choices.

Some compress more than others and therefore degrade your image more than others. Your camera also captures a certain number of pixels. When shooting JPEG images, most cameras give you the choice of shooting at lower pixel counts in addition to the full-pixel extravaganza. So you might be able to save an image that's only half-size. This is another way of saving space on your storage card. Finally, some cameras also give you the option to shoot in RAW mode, a non-compressed format that offers a lot of editing advantages over JPEG.

To change file formats, I hit menu button to go in to my menuing system. Very first menu, very first item is Quality, Image Quality, because the format I choose has a large bearing on the quality of my final image. You can see that I am set to Large JPEG and I think this little icon is going to make a little more sense to you when you see what our options are. L refers to the size of the image and right now, I am at an 18 Megapixel image with 5184x3456 pixels. I can fit approximately 431 of those onto the space on my card.

There's this curve here that's very smooth. That indicates that I'm at the best level of JPEG compression. If I go over here, I still have an L so I'm getting the same pixel dimensions, but now that curve has gotten kind of chunky. That indicates that I'm not at such a good level of JPEG compression. But look at my image count. Even though my pixel dimensions have stayed the same, my image count has gone from 431 to 863. So I'm getting dramatically more images with the lower quality compression. I've also got two sets of Ms. This is Medium size, 8 Megapixels, basically 3000x2000 approximately, and I have got two level of JPEG settings there.

And at that setting I'm up to a count of 1700 images. Then I have two S1s. This is a 4.5 Megapixel image and I have got two JPEG settings there. Then I have S2 which is a 2.5 Megapixel image. I don't have JPEG choices here. I can just go there and get a tremendous number of images. Then I have got S3 which is a third of a Megapixel. This is 720x480, so this is kind of a standard video size. Then I have these two options out here, RAW + High-Quality JPEG.

So when I am in this mode, I'm going to shoot a RAW image plus my best-quality JPEG. I only get 96 of those on the card. It's going to write both files out separately, and that's going to take a while. So when I am shooting RAW + JPEG, my buffer is going to fill up faster. It's going to take longer for it to clear out. I'm possibly not going to be able to burst as quickly or as often. Or, I've got just a straight RAW file. This is the same RAW file that would be written here, but there's no accompanying JPEG. So those are my different settings. I'm going to go back here to Best-Quality JPEG for now and hit OK and my quality is set.

If you're shooting JPEGs, my recommendation is to always shoot at full pixel count with the very best quality that your camera can manage. Storage is real cheap these days, so there is little reason to try to save space on a card. If you're finding you're running out of space during a typical shoot, then invest in some more media cards. But if you're in the field and storage is running low and buying another card isn't an option and you absolutely need to cram more images onto your card, then you should change your JPEG settings, or your image size, ideally not both.

If your images are destined for print, then be sure that you don't lower the pixel count below what you need to get the print size that you want. Maybe go down to half size and one stop down in JPEG quality. If your images are destined for online viewing, then you can cut the pixel count dramatically and probably not need to increase JPEG compression and that will preserve more quality. Mostly though, I would recommend shooting RAW. You get tremendous postproduction and image quality advantages if you leave JPEG behind and become a RAW shooter.

Image format and size
Video duration: 4m 21s 3h 16m Beginner


Image format and size provides you with in-depth training on Photography. Taught by Ben Long as part of the Shooting with the Canon Rebel T3i (600D and Kiss X5)

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