# How raw is RAW?



## SteveCallaghan413 (Sep 24, 2015)

I'm pretty new to LR and a recent convert to using RAW files. I'm a little perplexed that when I make changes to the file in the develop module and then export to either print or share, the subsequent JPEG is a much smaller file size than the original RAW image captured in camera.
Given that the RAW file is exported to a JPEG (a lossy file format), why not just shoot Jpeg's and benefit from the camera's inbuilt processor? I know there is greater latitude shooting RAW with regard to enhancing the image but exporting to a jpeg seems to my mind, counterproductive. 
Also, the RAW image viewed in LR is just a preview or rendering of the captured image. Therefore, where is the benefit of having a 15mb RAW file as opposed to a 2mb jpeg when viewing a much smaller preview in LR? A newbie question I know but I like to know where the nuts and bolts go!


----------



## davidedric (Sep 24, 2015)

A quick answer.  The key point is the one you mention - greater flexibility.  Let's suppose you want to change white balance.  It's trivial if you have a RAW file because it has no inherent wb.  Then, when you export the jpeg you have the corrected wb.

I am sure Jim or someone is already typing a more comprehensive answer 

Dave


----------



## Tony Jay (Sep 24, 2015)

Hi Steve, welcome to Lightroom Forums.

The differences, and similarities, of the various file types are often a bit hazy for beginners.

Raw files generally have these characteristics:

They are generally 12-, 14-, or 16-bit files. What this means is the that the tonal levels present in the file are 2[SUP]12[/SUP], 2[SUP]14[/SUP], or 2[SUP]16[/SUP].
JPEG's are 8-bit files and therefore only have 2[SUP]8[/SUP] tonal levels. It is much easier to edit a raw file because the number of tonal levels allows much smoother gradation of tone (and colour for that matter).

A raw file has a colour gamut but has no colorspace applied to it. A JPEG on the other hand will have either sRGB or AdobeRGB colorspace applied in camera to the file. Generally it is best to edit on the largest colorspace possible. The working colorspace for raw files in Lightroom is ProPhotoRGB which is far larger than even AdobeRGB. Once an edited image needs to be rendered for some purpose such as printing or electronic display or whatever that is the time to apply a rather more limited colour gamut in the form of either an ICC printer/paper profile or another colorspace such as sRGB or AdobeRGB.  

A raw file has no white balance applied. The raw file records the white balance setting the camera used but does not actually apply it to the pixel data.
This makes it a cinch to alter the white balance as necessary.

We expand this answer into a book but this should do for a potted summary!

Tony Jay


----------



## SteveCallaghan413 (Sep 24, 2015)

Thanks Dave and Tony, I guess I'm focusing too much on the size of the exported jpeg. Colour space is another subject altogether. I have a pleasant learning curve ahead.


----------



## Jim Wilde (Sep 24, 2015)

There are plenty of articles online which talk about the differences between Raw and Jpeg. This one for example:

http://www.slrlounge.com/school/raw-vs-jpeg-jpg-the-ultimate-visual-guide/


----------



## SteveCallaghan413 (Sep 24, 2015)

Thanks Jim this is a very helpful link.


----------



## Conrad Chavez (Sep 24, 2015)

Steve Callaghan said:


> I'm a little perplexed that when I make changes to the file in the develop module and then export to either print or share, the subsequent JPEG is a much smaller file size than the original RAW image captured in camera.


File size isn't a good way to compare file quality. A raw file can be uncompressed, compressed with a lossless method (no image quality lost), or compressed with a lossy method (some image quality lost). With some cameras you can change the raw compression setting so that your comparison to the exported JPEG file size would give you different results.



Steve Callaghan said:


> where is the benefit of having a 15mb RAW file as opposed to a 2mb jpeg when viewing a much smaller preview in LR?


That is a good question. Some cameras now have such high quality built-in raw-to-JPEG converters that some photographers choose to shoot in JPEG because it's good enough for their needs. For example, if you know those images are only going to be used at web display sizes that might be OK.

One reason I shoot raw: Over the years Adobe and others have upgraded their raw processing software to provide conversions with lower noise and better sharpness and color. If I had shot JPEG on my 10-year-old digital cameras, what I shot back then was as good as it's ever going to be. But because I shot on those old cameras in raw format, I can now produce higher quality raw-to-JPEG conversions of those old images in today's software than will ever be possible using the in-built converters in those cameras.

JPEG is like getting developed film back from the lab. Raw is like being able to leave the film undeveloped so you can redevelop it later when you have better techniques or chemistry.


----------



## Ian.B (Sep 25, 2015)

Good question Steve
sometimes I feel Steve it's best to just accept that something is better because the experts say so :blush:. I personally don't understand much of the digital (or LR) techo stuff; I just accept that is better  .


----------



## SteveCallaghan413 (Sep 25, 2015)

Thanks Conrad for your comments. I like your raw / jpeg analogy in your last paragraph.


----------



## SteveCallaghan413 (Sep 25, 2015)

Ian.B said:


> Good question Steve
> sometimes I feel Steve it's best to just accept that something is better because the experts say so :blush:. I personally don't understand much of the digital (or LR) techo stuff; I just accept that is better  .


Very sage advice Ian! We are so fortunate that we don't need to know everything . . . We can simply enjoy the fruits of the efforts of the experts! Thanks for your comments.


----------



## tspear (Sep 25, 2015)

Conrad Chavez said:


> JPEG is like getting developed film back from the lab. Raw is like being able to leave the film undeveloped so you can redevelop it later when you have better techniques or chemistry.



Conrad, 

That is a great summary statement. I am going to have to remember it!
Then find a new one for anyone under the age of 40....

Tim


----------



## Johan Elzenga (Sep 25, 2015)

Eggs and omelettes. Your raw files are like raw eggs. Your jpeg is like an omelet. If you like the omelet that your camera creates, then there is no problem. You can even add a little salt and pepper if you want it a bit more spicy. But you can't remove any salt or pepper if it's too much for you. If you make your own omelets, you never have that problem.


----------



## tspear (Sep 25, 2015)

Hmm, this could be fun. How many more analogies can people come up with?
Cookie dough, cake batter and cake?...

Tim


----------



## Rob_Cullen (Sep 26, 2015)

And jpgs are like "Readers Digest Condensed Books"- they tell the story but don't have the exciting detail.


----------

