Photography- Raw files / Smart objects

What is a raw file 

 RAW is a file format that captures all image data recorded by the sensor when you take a photo. When shooting in a format like JPEG image information is compressed and lost. Because no information is compressed with RAW you’re able to produce higher quality images, as well as correct problem images that would be unrecoverable if shot in theJPEG format.

What are the advantages of raw - 

• records all data from the sensor 

• has a higher bit depth 

• can undo damage and change white balance easily when editing 

• can use none destructive editing 

• produces better prints 

• can adjust the colour space 

What is bit depth 
this is the amount of tonal levels available to each colour captures.    Jpeg images produce 8 bits of colour or 256 tonal levels which looks like this 

because the colours do not follow evenly between each other and look more like steps when editing 8 bit images there is not many colours to edit  so images can start to look posterised because of colour bandaging. 

here is an example of what posterization looks like - 

How ever RAW files capture in 12 (some times 14 ) bits meaning they have a tonal range of 4096 which looks more like this 

What is a colour space 
There a several ways colours can be mixed together to create new colours, if you have a larger colour space it will allow more colours to be mixed together and be seen. 

as we view are files on a monitor an we use a red green blue colour space as this is what makes up the light on the screens.

here is an example of different sized colour spaces 

as you can see prophoto RGB has a larger variety of colour then sRGB  so when setting up your camera you are best to choose ProPhoto RGB  to get the most colours. You also need to change these setting when printing as well. 

The difference between jpeg and raw in editing in photoshop  

so when you open a JPEG in photo shop  take this one of my lunch as an example 

It opens as a normal layer, This allows you to use adjustment layer to edit the image 

 as the jpeg didnt save all the information from the sensor  and you are working in 8 bit its really hard to adjust the colours correctly to get a really good image. 

How ever when you open up a Raw file it takes to to a new screen like this 

Which because it has a higher bit and remembered the information means you can edit more easily, you can even go back and change the white balance if you shoot in the correct one.

You can also change the colour space bit depth and get it to open in photoshop as a smart object.

opening it as a smart object not only means that you can go back into the raw settings and make changes to them if needed  but it also  but it protects the image so if you scale it down then back up it will not become all pixelated. 

Here is a comparison on the edited version of raw / j peg of this image. 

Raw

Jpeg 

  

When saving a raw file you should save it as a tiff or psd  as this saves all the information and edits you have made so it you want to open it back up you can see everything you have done. 

See TASK 1  for more about this lesson and editing in raw