Time to show my ignorance.
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tdcist
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RAW, is literally what it saws.. the raw data seen by the cameras sensor... no processing, no compression... Jpeg is just a compressed file format, and also the camera processes colour tone WB etc. before it saves the picture... At least thats my understanding of it ...
Yup, that's about it really.
Shooting only a jpeg loses data that might have been useful in post processing - there is literally no reason to shoot in it exclusively other than limited memory space. (In which case, buy more memory cards...so basically no reason at all).
HoppyUK
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raw is the equivilant of a Film Negative, jpeg would be more like a print, raw holds more detail in the file.
Technically, Raw is the equivalent of the film latent image
It is the unprocessed data recorded by the sensor, ie it is undeveloped, 'uncooked'. You can't actually see a Raw file. It is just a pile of data and must be turned into a processed image file, usually a JPEG, so you can see it, print it, upload it etc. The LCD image you see is a tiny processed JPEG which is permanently tagged to the Raw file, whether you select JPEG or not.
If you could see the Raw, it would look pretty rubbish so the JPEG processing applies improvements which are pre-set in Picture Styles, white balance, noise reduction etc. In that sense, the image is processed in same same way as you would do in the computer, except that the modifications are pre-set beforehand and are obviously not as extensive as you can do with a full post processing programme. They cover all the fundamentals though and can make a big difference if you adjust them carefully.
JPEG processing also compresses the file, because uncompressed files are huge and impractical. You can adjust the level of compression and although even the highest quality JPEG throws away very large amount of data, if it's properly done you can never tell the difference.
The only problem with going straight to JPEG output is that if you don't like the result, or have made a mistake etc, the changes you can make are limited. If you still have the Raw, you can go right back to the original file and start again, and again and again, until it's just right. The Raw always remains original, untouched base data.
tdcist
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you'll need either a RAW converter or... (if using say Adobe CS - CS5) the right CameraRAW software... (available for download...) As each RAW File differs from camera to Camera... not just Brand to Brand, So a canon 5DmkII uses a different format to the Canon 550D..
Hang on i'll find u a link to a good review on RAW...
Hang on i'll find u a link to a good review on RAW...
HoppyUK
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Thanks for your help and patients fellas.
If you use Canon, you got a free copy of Canon's DPP Raw processing software on CD with the camera.
It's very good, and has some unique custom features for correcting lens aberrations. You can upgrade to the latest version with a free download
I'd recommend looking at Lightroom. The new version, 3, has just come out and it really is a lovely piece of software. It's a combination of lots of the clever bits of photoshop (including great RAW options) and a way of organising your photos.
Plus it's "only" about £230 - not exactly cheap, but that is £370 cheaper than Photoshop which it has a lot of the features of.
OP
Didicoy
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Wookie
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jpegs do lose data because of compression, but if you are using the highest quality setting (minimal compression) you won't see a lot of loss, unless you open it and resave it multiple times (it loses a bit more every time)
the biggest practical difference between RAW and jpeg is that the RAW holds more data, each pixel of image has a greater brightness range available to it, including some above and below the brightness range that can be displayed.
When a camea saves a jpeg it uses processing settings, canon call them "styles", which determine how the RAW image is processed into the jpeg, it's a one way trip, it cannot go back as data is modified or removed.
With images saved as RAW you have all of the original data off the sensor and can override the camera style settings while editing on your computer and apply a different set of processing settings.
the biggest practical difference between RAW and jpeg is that the RAW holds more data, each pixel of image has a greater brightness range available to it, including some above and below the brightness range that can be displayed.
When a camea saves a jpeg it uses processing settings, canon call them "styles", which determine how the RAW image is processed into the jpeg, it's a one way trip, it cannot go back as data is modified or removed.
With images saved as RAW you have all of the original data off the sensor and can override the camera style settings while editing on your computer and apply a different set of processing settings.
Really, you don't need to understand why. RAW is just better - when you find an example of why it is better, you'll be glad you shot that way!
It's just when a lens has something non-perfect that would be worth fixing before printing out images. Eg. The corners of a photo appearing warped due to using the edge of the lens.
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CGeezer
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If you download faststone viewer You can view your raw files and even convert them to jpeg's also resize etc. A great free program.