Exercise 11: RAW

This exercise focuses on understanding the processing advantages of making pictures in the RAW format. There are clear guidelines, which one should follow during the execution of the exercise.

  1. Set the camera to save the images in RAW + JPG
  2. Shoot three images with following lighting situations:
    • Daylight
    • Artificial light
    • High dynamic range
  3. Set the most appropriate white balance for each lighting condition.
  4. Process each image (JPG and RAW)
  5. Finally, compare the versions of each scene on the following criteria.
    • Dynamic range
    • White balance and colour
    • Local adjustment of any kind

JPGE is a familiar format. I guess most of us have been using it in various ways for many years now. Sharing JPGE through uploading/downloading, transferring via smartphones etc. has become a routine. My first interaction with the RAW format happened in early 2oo8. When I bought my first DSLR (D60), the sales person advised me to save the images in RAW format for better picture quality. Well he was correct, but he had not explained in details exactly how and why that would happen. Through self-studies and experiments, I kept learning how to achieve sharper and realistic pictures. This exercise is a good opportunity to document the learning and gather more theoretical and practical knowledge of the same topic.

RAW file is a digital version of a “negative”. It is unprocessed data straight from the camera’s sensor. In simple words how a coffee bean needs processing before it is consumed as coffee. Just like that RAW file needs to be processed, before it can be universally viewed. RAW is an exclusive format that is locked to the camera manufacturer and sensor, hence is not supported by all software products. There are two very interesting articles on this topic.

Bob Atkins has given an excellent explanation on what exactly is the RAW file, http://photo.net/learn/raw/ (read it on – 15th January 2012).

Ken Rockwell has a different point of view, which surely makes you think twice about your strategy of storing the images (archives) in RAW format. http://www.kenrockwell.com/tech/raw.htm (read it on – 15th January 2012)

As per the exercise requirement, I have shoot three images with varying light conditions. I have chosen a perfume bottle as my subject. With this kind of subject, I had an option of using the soft box. This way I can have more control over the situation and the lighting.

Note: All the readings and the comments below are according to the RAW image on my screen. To post it on the blog, I finally had to convert it to JPG, hence on the screen you might not notice considerable difference.

1. Daylight

The image below was shot with two different formats RAW and JPG. I have processed them individually to get the best results. At the first look there is not too much of difference in the image quality. I would say the camera had processed the image pretty nicely. In a side-by-side comparison at this scale one cannot notice too much difference either.

Ex-11_daylight_1

Both the images have decent play of the dynamic range. There are bright areas (shiny metal) that represent brighter end of the histogram, and deep shadow areas are also present to challenge the sensor. This gets obvious only when zoomed in. Check the image below. Notice the logo in the RAW images has more visible details.

Ex-11_daylight_2

When transferred the images to Lightroom 3, I did not adjust the “WB” for the RAW image, where as I noticed a yellow tint in the JPG format and had to do some adjustment. The details of the other local adjustments in LR3 are as below.

RAW JPG
aaaaaaaa Exposure: +0.20Clarity: +16Very slight curves adjustment.

“Dodging” and “burning”

Noise reduction 30

aaaaaaaa As camera had already done some processing.I had to make comparatively less changes.Exposure: -0.15

Clarity: +25

Slight curves adjustment to bring the contrast low.

2. Artificial light:
To have more control over the light, I decided to use the soft box. Ideally I should have used flash instead of the table lamps, however in absence of external flash this set up has come handy.

sketch

To me the JPG image looked very highly processed when imported into Lightroom 3. The sensor had tried balancing the image so much, that it was actually way too dark compared to RAW file. White balance and the colours were handled equally well by both the formats and I did not have to make any changes there. See the comparison screen shots below.

RAW JPG
aaaaaaaa Exposure: +0.25Fill Light: 14Blacks: 2

Clarity: +12

Curves: (Lights: +9, Darks: -12)

Slight “Dodging” and “Burning”

aaaaaaaaa Exposure: +0.95Fill Light: 19Blacks: 2

Clarity: +33

Curves: (Lights: -49, Darks: +14)

Slight “Dodging” and “Burning”

EX-11_Artificial-light-2

To bring both the images to almost similar looking stage there were quite a few adjustments, I had to make. In comparison the RAW file took less time to process. As usual at this level of zooming there is no noticeable difference.

RAW JPG
aaaaaaaa Exposure: +0.25Fill Light: 14Blacks: 2

Clarity: +12

Curves: (Lights: +9, Darks: -12)

Slight “Dodging” and “Burning”

aaaaaaaaa Exposure: +0.95Fill Light: 19Blacks: 2

Clarity: +33

Curves: (Lights: -49, Darks: +14)

Slight “Dodging” and “Burning”

EX-11_Artificial-light-1

Here the image quality difference is quite noticeable. There is far too much of data loss in JPG format.

3. High Dynamic Range:

For this lighting condition, I decided to continue with the soft-box set up. I changed the background to white to provide the stark contrast. This ensured that the camera as well as the scene’s dynamic range is challenged. Other observations were quite similar to the earlier two light conditions; hence I will straight go to the images comparison screen shots.

Ex-11_HDR_1

RAW JPG
aaaaaaaa White Balance: As ShotExposure: +0.05Fill Light: 14Blacks: 10

Clarity: +12

Vibrance: 0

Curves: (Lights: 0, Darks: -16)

Noise reduction 10

aaaaaaaaa White Balance: -11Exposure: +0.45Fill Light: 5Blacks: 5

Clarity: +19

Vibrance: +6

Curves: (Lights: +8, Darks: -17)

Noise reduction 19

Ex-11_HDR_2

There are some small differences in this image too. They are minor that, I can easily choose to ignore them. However it would be interesting to see, how well does JPG format handles other HDR lighting conditions.

Conclusion:

After 2008, I have always been using RAW files to record the images. This exercise has reinforced my decision. At times the difference between the RAW and JPG file quality is so insignificant that I can easily ignore it, however in many situations it is not. Hence shooting RAW and converting it to JPG would be my choice. Though for this I must ensure a robust workflow, otherwise it can complicate post-production. In a situation where I do not have access to converting software (or have time crunch) I will select RAW + JPG option on the camera. So that later I still have access to better the quality RAW file.

The point I need to pay more attention is on the issue of archiving the files. The point raised by Ken Rockwell is surely alarming. I would discuss it with my tutor for his opinion.

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