Tutorial draft 1
What is raw anyway?
Raw is easiest to understand if you compare it to the negative from a film camera. You know it has the image the camera recorded but it is not much use for showing to people.
A chip inside the camera can turn that raw data into a jpeg that you can view easily. Having done that it throws away the 'negative'. The chip will use any settings (picture style) you set the camera to when deciding how much sharpness and contrast etc. to apply.
Alternatively you can have the camera save that raw 'film negative' file and leave it for you to choose what adjustments to make later on your computer. Just like you would make prints from a film negative and not alter the negative itself, a raw file is special in that it cannot be overwritten with an edited version. The raw editing program keeps a list of the changes you want then applies them when you tell it to make a jpeg or other format version of the picture. It also uses the list to give you a preview of what your picture can look like but the actual raw file is never changed.
There is no standard version of a raw file from a camera. So a raw file from a Nikon camera for example cannot be processed using Canon software. New cameras from the same maker may well have different raw files to previous models and you may have to update your software to the latest version if you get a new camera of the same brand.
There is a lot of stuff inside a raw file. The raw data from the sensor, the exif (camera settings list) data, the picture style settings that the camera would have used if it made a jpeg and a small version of that jpeg image.
There are editing programs made by Adobe and others that are not tied to any camera maker and they understand the raw files from many brands and models of camera. They do all suffer the same problems of having to keep up with new camera models and changes to the file format. You may find you need to look for updates if you have a recent model camera. Some old version software is no longer supported with updates which will force you to buy a new version.
Why shoot raw?
You don't have to shoot raw. Often when you process a raw file you end up with an image not much different to the Jpeg produced in the camera. If you got the exposure right, the white balance was right or near enough then the jpeg from the camera may be all you need. The jpeg can be also be edited and can be ready to share or use quickly. If like sports photographers with deadlines you need images quickly or you are still learning how to use the camera and don't need the complication of raw processing then do continue to shoot jpeg.
If you want the best level of detail, more dynamic range (retained detail in bright areas and shadows), the ability to correct wrong exposures and to easily change white balance then shooting raw is the way to go. The downside of shooting raw is that you will have to spend some time at your computer to convert (or 'develop') them.
How much time raw processing takes is down to you and how much you like tweaking. Because the raw file contains the cameras picture style settings, if you use the camera makers own raw conversion software you will have the option to see your picture just as the camera would have done it. This can be a very quick way to convert your raws to jpegs or other format. Unlike letting the camera do it for you (where you can't change settings after the shot), you can with the raw processing software. So you can just accept pictures that look right and only adjust those with problems.
Generally only the camera makers own software will take any notice of picture style settings. If you open the raw file in Adobe Lightroom for example it will make its own preview from the raw data. The preview will not have any sharpening or other adjustments so initially it may look a little dull and soft compared to camera jpegs.
You can still save time with Lightroom (and probably other conversion programs that I have not tried).... 'Auto tone' can do initial adjustments that you then tweak a bit yourself..... if you have say 10 pictures of one location you can convert the first one then copy all the adjustments to the other 9 as they will be similar and need similar changes made. So in brief, raw conversion will always involve some work but you can minimise it significantly
Jpeg is a lossy format. That means some information is thrown away when a jpeg is created. Because a jpeg can only have 256 shades of each of the 3 RGB tones making up a pixel colour, some similar but different colours that were in the raw are all made the same in a jpeg so colour 'depth' is lost. This all helps compression and makes the file size smaller. Using a high quality setting all that is not usually a problem. However when things are less than ideal it can mean detail is lost for ever in a jpeg.
Your cameras sensor can record a range of brightness in the scene. At the bright end more detail is recorded than in dark shadow areas. So a well or slightly over exposed picture will have more data in it than an under exposed one (read up on 'expose to the right'). The jpeg creating chip in the camera has to decide how bright is too bright and what to throw away as 'clipped'. This level is lower than what is really clipped in the raw data.
These photo examples show what that means in an over exposed image...
I don't normally shoot raw and jpeg together but do remember trying it whilst on holiday in Yosemite...
Not checking the settings and having forgotten that I had the camera on manual the result was this not very good, over exposed shot.
The in camera created jpeg picture just resized -
Using Lightroom (which can edit jpegs as well as raw files) to recover as much detail as I can from the original full size jpeg I get this-
Again using Lightroom but this time working from the raw file i get -
Now none of those are particularly attractive pictures but you can see the raw file has allowed a much better result.
Getting your computer ready for raw
If you have not already installed software for your raw files there is a good chance your computer will not know what to do with them. Instead of listing like picture files in explorer they may just be unknown file type icons and you cannot show them as thumbnails. To overcome this problem the camera makers have a 'Codec' that you can download from their web site. Installing the codec tells the computer what sort of file it is and lets it display a thumbnail view showing the jpeg saved inside the raw file. So it is worth installing the codec to make browsing easier.
Raw files can be quite large. Whilst you may not use them for everyday picture viewing, just like negatives from film days you don't want to throw them away either. That means storing them. Either on your computer if you have plenty of space on the hard drive or on some sort of backup disk.
You can change a lot of things during raw conversion so one day you may want to revisit an old raw file and make a new edit.
You don't need a high powered super fast computer to edit raw files... but it can help. As you make changes the preview of the picture will update to reflect those changes. A slow computer may take a second to show the changes you made which makes seeing small differences a little tedious. Most recent computers will be up to the job.
The easiest software to start out with is likely to be the one that came with your camera. It will work with your files 'out of the box'. There are many paid for and free raw conversion programs. There is a fairly comprehensive
list here. As each new camera comes out so the publishers of the raw conversion programs have to update their software to be able to understand another new raw format. So if your newly installed 3rd party (not from the camera maker) program does not recognise your raw files it may need updating. Further reading on that
here.
Different raw conversion programs can produce slightly different results and some may suit your way of working more than others. It is worth looking at other programs once raw becomes a regular part of your 'workflow'.
What to do with a raw file
This really needs its own tutorial as there is so much you could do! Below are the commonest things you would check or tweak. How you actually do it will vary according to the software you use.
How is the colour balance? If it is OK then skip this bit. If the white balance was set wrong then an indoor night shot could be too orange for example or it may just be a little out. There should be a white point dropper tool that lets you pick something on the picture that is white or neutral grey. Make sure you pick something white and not looking white because of clipping (too bright for the camera). You can just adjust the colour temperature until it looks right if you don't like the dropper tool results or have no white or neutral in the picture.
Does the exposure look right? Adjust the exposure slider so the overall look of the picture is the right brightness. There should be a way of showing 'clipping' (things that are so bright they are burnt out or so dark they are solid black) so turn it on. Some clipped areas is OK but if too much you may have to adjust the settings for highlight recovery and/or fill light (or equivalent controls in your software) and possible adjust the exposure again if the clipping is still too great. If your image does not have any solid blacks or clipped bright areas you may wish to adjust the black point level and exposure to get some - if it looks right.
Brightness and contrast adjustments can also improve the image but do it after the exposure adjustments.
You may want to change the saturation a little to brighten colours or make them more subltle.
Low light high iso images may need some noise reduction adjustments.
Raw has no sharpening applied so it may look a little soft. How much sharpening you need to apply is a bit of a black art
It is a mixture of art and science. There may be pre-sets in your program for 'portrait' or 'landscape' sharpening and those are a good starting point. Main thing is to zoom in to 100% and have a look to see if your sharpening still looks as good as it does in the smaller preview.
Don't worry about getting the settings right or wrong - you are making a picture look how
you want it. You may even decide a 'wrong' exposure or white balance for example looks great.
Now you can just stop there and start up your raw editor to view the files changed to how you like them. If you want to share them easily or get them printed then you will need to 'export' them to a normal picture file - usually jpeg. You should be able to select all your edited pictures in your raw editor and export (save) them to a folder on your hard drive as jpegs. Those new jpg files can then be uploaded to a printing company etc. just like you used to with jpegs from the camera - but the quality is how you decided not a chip in the camera.
If you are into editing pictures with Photoshop or other applications like Photomatix for 'hdr' images then starting from raw will give you the bit depth and detail levels they may need and the option of saving in lossless formats like tiff. Personally, I shoot raw, convert to best jpeg in Lightroom and consider the job done
. Raw gives you the option to do as much or as little with your images as you choose.
