RAW vs Jpeg wite balance correction in Lightroom

[PhilipHowe]

We haven't had a debate on here for a while about RAW vs Jpeg, so thought I'd have a go!

I've been watching a lot of Lightroom videos lately, as it's my new best friend. This shows the difference when you need to correct your white balance. There is a section from 17.10 on rescuing photos and how applying the same corrections to a jpeg and a raw file differ, however, have a look atthe white balance correction from 21.38 of this video.

Remember, Lightroom works directly on a RAW file, it is not converted in any way.

http://www.yesimadesigner.com/photoshop ... /#more-642

[Janice Freeman]

I have recently started shooting in RAW and from a beginners point of view it is a godsend. I try to get it right in camera but don't always succeed (believe it or not ). Currently using ACR and elements. What I have noticed is that once I have done my conversion and saved to JPEG, it also saves another file with a .xmp extension as well as retaining the original RAW file. What is this and do I need to keep it? How different is Lightroom to ACR and does it have any distinct advantages?

[PhilipHowe]

Janice, I think this is the metadata from the raw file conversion. I think you can delete it, but bridge uses it for cataloguing your metadata. If you move a file in bridge, it will also move the .xmp file with it.

That's a good point Janice, beginners tend to use jpeg and convert to RAW when they understand it a bit more, but, as you say, shooting in RAW could help a beginner with exposure and rescue more than anything else. I didn't think of it like that.

[Paul Jones]

We haven't had a debate on here for a while about RAW vs Jpeg, so thought I'd have a go!

Interesting video.

No debate here... I've been shooting RAW for so long now that I couldn't contemplate shooting in any other format. That's not to decry anyone who shoots JPEG though. Everyone has their own preferred workflow.

Regarding White Balance, I always carry a Digital Grey Kard in my bag and use it at the start of every shoot and every time I move location or change lighting. Very handy...

Link - http://www.amazon.co.uk/Digital-Premium ... B000HDFH6W

[Paul Jones]

What I have noticed is that once I have done my conversion and saved to JPEG, it also saves another file with a .xmp extension as well as retaining the original RAW file. What is this and do I need to keep it?

I think that when you make any changes to a RAW file, for example change the white balance, exposure, etc, it saves this information in the XMP file alongside the RAW file.

If I'm making white balance adjustments to a batch of RAW files I usually backup the XMP files aswell as the RAW files just so the data is saved.

I don't think there's any danger in deleting the XMP file if you don't need it - though it does mean that you will be reverting back to the original RAW file before any changes were made.

Link - http://www.google.co.uk/search?sourceid ... ll0&aqi=g5

[mike-e]

Good question Janice. Try to answer it without beig too technical if I may
.
To begin with ALL digital files are number sequences using a binary code ( using combinations of 1or 0
-a bit like off or on -)
These numbers are strung together to make code, and each individual string set has a value
Each value has an extra prefixed code first to identify what it is and where it belongs.

In digital photography each string of code has its prefix and a colour and luminance ( brightness ) value, and in a single image they run into several million sets of string ( ie numerical codes)

When you shoot in Jpeg, the cameras processor locks these code strings permenantly so things like the white balance are fixed.
In shooting raw, the 'prefix codes are left unlocked as to enable adjustment later in processing software like photoshop, elements,or lightroom..

When you make any adjustment the Raw files they add to the code as opposed to change it. To add to it they need to make something like a handbag to keep notes of what these changes are ( called a sidecar) this is what the xmp files are, and need to be kept if you wish to keep any changes to you raw file you have changed in processing.

This 'sidecar' or handbag simply holds the numbers to tell the file when it is reopened to change to the adjustments you made . This way the original raw file is left intact and not altered, and is why so many favour it over other formats.
- The changes are kept outside the file in the sidecar xmp file containing the commands you set when you processed it, and will only effect those changes when you open it again. (phew!!!)

Unlike Jpegs, or tifffs or PSD or any other file ( as far as I know ) When you make changes in your processing of these files they physically overwrite the number strings of code with whatever command you give it permenantly when you resave the file. Note thats why its useful to have as big a history cache as possible, so you can go back in the history pallette to undo some of the changes before you save it . Or to work in layers, which really are almost duplicate files stacked ontop of each other.

Lightroom to ACR is a bit more tricky as they are made by the same company. Elements simply has less features than Full blown photoshop,Light room doesnt do layers but can create pictures ready to print without anything else, unlike ACR, which generally needs photoshop
Many people say that its looks easier to use lightroom, because of its controls , and its t file organising, batch processing, and printing capabilities, and if you were to say go from shooting to printing in one operation then its the one to use.

If you are used to ACR it may be easier to stay with photoshop, but you can download lightroom for a free 30 day trial to see if you like it
Hope this helps
Mike-e

[Janice Freeman]

Many thanks Gentleman for your sound and easy to understand advice. I went out on Sunday (Astley Mining Museum) for the first time in about 3 months - merely to have a play around with my camera and settings etc. Then to practice RAW conversion. I got some half decent shots and a little bit more confidence! Always a little disappointed in my results though. I need to slow down I think, and give a lot more thought to what I am taking and the composition. Never say die - enjoying the learning process and with practice (lots more!) hope to start producing better photos.

[Theo Dibbits]

Why convert to JPEG?
If you are using RAW to fix exposure problems fine but if you are trying to get the very best print file I would have thought 8 or 16 bit TIFF would be more appropriate.

Oh and whilst you are at it, how about ditching sRGB for Peophoto and convert to a proprietary print profile at the end.
Now there is a debate.

Theo

[mike-e]

Certainly from a copying point of view a tiff file is a valid archive file,but I'm not sure ,Theo, about the 16bit file for printers, or prophoto (sounds a very american outlook?)
AS for colour space Adobe RGB is certainly the industry standard, but I do Know of many people (mainly Canon users ) who prefer ProPhoto.

For saving a file for printing in 16 bit there hasn't been a revalation as far as I can remember in printing in 16 bit, and am I right in thinking you would need a 64bit operating system to run it or even a Mac?.

Even so the majority of labs still use 8 bit output for being cost effective. At which caseyou may lose half the information as it is dumped in printing.
But pound for pound if you have the capability to save and print in 16 bit, then every pixel counts.
As a matter of interest do have / or have you seen any comparison prints. Always happy to up the ante.

[Walter Brooks]

Janice Freeman wrote

I need to slow down I think, and give a lot more thought to what I am taking and the composition

Janice - good now you are thinking photography and when you get 12/15 images on a roll of film, it makes you think more and more about what you are taking!

W

[mike-e]

Janice Freeman wrote

I need to slow down I think, and give a lot more thought to what I am taking and the composition

Janice - good now you are thinking photography and when you get 12/15 images on a roll of film, it makes you think more and more about what you are taking!

W

You are absolutely right Walter, the very fact it would cost money just to purhase each set of 12/15 images curtailed wanton wastefulness, let alone the thought of process cost and then prints too.
In my college days we were often sent out with 2 sheets of 5x4 film to complete an assignment!
Nothing like scarcity to concentrate the mind.

Phil for me there is really no debate on shooting Raw or Jpeg.

If your exposure is spot on, and white balance has been customised to the lighting enviroment you are in ,
then it makes no discernible diffrence to the camera exposure. The only adjustment one should make would be that of camera controlling colour/tone/sharpness capability. either way shooting Raw or Jpeg these controls should be turned off The final look should be determined in post processing.
There are some that say that in camera processing detracts from the final quality of the file and that Jpegs are 'lossy'
Yet the reality is how you treat the camera exposure in the first instance., and making descisions before you press the shutter to decide how you want the file to look is really important.

Walters point of having to be expedient with how many frames you have at your disposal can still be valid even though digital lets you shoot hundreds at no 'cost', the ability to discern what you need to get as a correct image has lessened. ' Machine gun shooting tattics' , and 'putting it right ' in post processing has led to 'good enough syndrome' for many camera users, as opposed to excelling in their camera craft
That is another debate though!
Mike-e

[Theo Dibbits]

Here is a link that maybe of interest.

http://www.afximages.com/articles.php?a ... lorProfile

or this one

http://www.luminous-landscape.com/tutor ... -rgb.shtml

Theo