Tuesday, October 21, 2008

Processing RAW Files in Adobe Lightroom

I saw this article in a post that i read on Flickr and thought that you might like to read it.

The following tutorial on Processing RAW Files using Adobe Lightroom was submitted by John Short from www.canonphoto.co.uk and www.johnshort.co.uk

Why do we read so often then it is best to shoot your image in raw and not as jpegs?

The first image in this tutorial is a jpeg of a Gannet where I have deliberately blown the highlights. One of the problems with a jpeg image is once exposed it is processed in your camera and the raw data is lost. If you have blown the highlights the information is simply not there for you to recover in your favourite processing application.

Gannet Jpg-1

The following images are the basic steps in processing a raw file and I hope will demonstrate to you the benefits of shooting in raw mode. If you want to try to emulate my final image using the jpeg file and your favourite image editing software be my guest. It will be interesting to see what can be achieved in comparison with working with the raw file.

Adobe Lightroom is not just a processing application for raw files, it is also a library for storing, retrieving and searching for images. I have 20,000 raw files on my computer and Lightroom has catalogued them all in the library for instant display. Images can be filed by title,date metadata and so on. This aspect of Lightroom is really for a different tutorial and if there is interest I will put one together but for today let us concentrate on processing your raw files.

First we must open our raw file in the develop module of Lightroom. This screen capture shows the basic image in Lightroom with the develop module circled in red. The picture of the Gannet is ‘as taken’ and saved as a jpeg for you to see the blown highlights.( if you feel like taking on the challenge feel free to try and process the basic jpeg version of the image.

1St Screen

The first change I always make to an image is to try and correct exposure problems by reducing or increasing the exposure slider. The exposure values are roughly equivalent to f stops and you can either type directly into the box or move the slider with your mouse. In this instance I have reduced the exposure by 1.27, just over 1 f stop.

Reduce Exposure

Now we can adjust the recovery slider.This tool will only effect the highlights and will recover additional detail that may not be visible in the original image.

2 Recovery

leave the fill in tool for now and go instead to the Blacks, this darkens the darkest parts of the image without affecting the highlights. It is the opposite of the recovery tool used earlier. Moving the slider only a slight amount will give the appearance of more depth. In this instance I have increased the blacks by 5

3 Blacks

The fill tool brings details back into the shadow areas without affecting the highlights. This is a great tool for pulling detail back into the shadow areas and in this example I’ve increased the fill tool by 11.

Fill

In the top left corner of Lightroom select 1:1 this will enlarge the image in your viewing screen to full size. the clarity slider increases local contrast making the image appear sharper. This tool needs use with care, it is all too easy to overdo the effect.

5 Clarity

The vibrancy control will enable you to increase the depth of colour without the risk of over saturation , I find it a subtle enhancer for colour depth.

6 Vibrance

All that remains now is to export the image as a tiff to your favourite processing application for the final touches.

Final

In this example I have only shown the basic processing tools available in Lightroom. The objective is to whet your appetite and to illustrate the benefits of working In raw. If you think you can achieve the quality from a jpeg then do try with the gannet.jpg image. You will soon see that the lost highlights are lost forever.

Here’s the first and last image side by side (click to enlarge):

Gannet Jpg-2

At a later date perhaps it will be worth while looking at some of the more advanced tools such as noise reduction and curves!

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