RAW CONVERSION- EXERCISE

Exercise

• Demonstrate the processing advantages of a raw image.
• compare and contrast the same image taken and processed
• as a jpeg by your camera.
• Show the same image under three different lighting conditions
• natural light, artificial light, high dynamic light

compare the following

• dynamic range
• white balance and colour
• local adjustments ( often by raw conversion)

IMAGE 1- NATURAL LIGHT

bright light sunlight overhead

image taken in shade

iso 200

f10 1/30 sec

WB preset to avail light

original jpeg

original raw file

The first variance that is very noticeable is the colour 

tone between the two images. 

The image was taken in shaded light so the camera

would have read this as blue light so the jpeg

 has been balanced by the camera setting 

by adding red so the image is very green/blue.

The raw image was also taken under blue available light. 

The variance is the raw image is very red/green. 

The kelvin value is 7050 which means the

image will be captured as yellow/red tones.

There has been no added blue to reduce 

balance the overall hue.

the linear red reading in the raw image is 121 against 105 of 

the j peg.

The jpeg image seems that have better contrast than the

raw image which seems lack light and dark tones.

I also think the yellow tones in the raw images are

too high and therefore the colour looks incorrect

to the actual leaf. 

PROCESSED IMAGES

processed jpeg

processed raw image

processing notes

I added light to both images by adding white in photo

shop via level changing.

I also added contrast to give definition of light an dark

to show the variation between the shadow and highlights.

I choose to colour balance both image as jpegs so I

converted the raw image with white balance set as 

shot.

In both images I added blue, but with the raw image

 I changed the cyan levels to reduce/yellow tones

findings

Overall I prefer the camera's conversion levels via

the jpeg image. I think the biggest variation that is 

better is the initial contrast levels. The image has 

very dark shadows in the rigids and these have

been captured better in the jpeg image than that

of the raw image. The green hue is better also

in the jpeg. I think this because there is more

blue tone that that of the raw image. 

It may have been better to convert the

image as "daylight" which meant the 

kelvin reading would be close to 5500

which reads and blue/green.

below is the example of the raw image 

converted to daylight white balance.

this is closer to the jpeg original image.

IMAGE 2- ARTIFICIAL LIGHT 

tungsten light back right

front white reflector

f 13.1.6 sec

wb tungsten setting

original j peg

original raw image

The image is underexposed but the original files

show instantly the variation between the captured

colour tones.

Tungsten light is very red so the camera will add

blue to balance the colour back to " white".

The jpeg colour contrast again is better than the raw

image. 

processed j peg

processed raw image

Processing notes

Both images were lighting by adding white via

levels.

Additional light was added to the shadow areas by

using the dodge tool with photoshop.

I did not change the colour balance in the jpeg 

image. In this image it was harder to control the

colour tones in photoshop as adding blue 

made the central yellow centre too blue.

As the image had already been processed

by the camera there was little changes I could

do to change the colour tones. Also contrast

was also quite high so I did not change any

contrast levels.

I had much more control over the raw image

and could instantly adjust colours in photoshop.

I used colour balance in photoshop to add yellow

to balance to the blue tones captured by the

camera. I could also increase the contrast levels

which gives the image has a bit more depth than

the jpeg image. 

findings

I prefer the raw image in this instant mostly

due to the fact I had more control of the 

final image. The strong tungsten light

meant the camera converted the jpeg

as using a 80a filter by adding blue.

This gave me little scope to change

that level in photoshop. I could also

control more the contrast levels with

the raw image. It allowed me to

produce the final image to the

colour tones and contrast levels

I prefered.

IMAGE 3- NATURAL LIGHT

natural light from right side

silver reflector left side

f25 8 sec

wb auto

original j peg

original raw

The variation of the image colour is the 

colour variation. The j peg image

has been warmed by the camera as the

available light was shaded and therefore

seen by the camera as very blue. The

camera has then added warmth to the

image.

The raw image is as seen by the camera

and as the white balance was not adjusted

to compensate for the available light, the 

camera has read the scene as blue.

Even though the jpeg image looks more

rich and warm than the raw image at this

time. I feel the colour is too yellow and 

not representative of the actual flowers

processed j peg

processed raw image

processing notes

both images were processed identically

but colour balance was altered on

each image

I changed levels by adding more black

to darken the back drop, but added

light using the dodge brush were needed.

I found it difficult to alter colour balance

on the j peg image as added blue made

the image look too artificial. I added some

red and green to offset the yellow tone.

On the raw image I added green and some

red to warm the image and counter balance

the overall blue tone.

I prefer the raw image as I could control the

levels and colour tones better than the j peg

image. I think the camera compensation 

for the light  has given me less scope to 

make colour changes in photoshop. I

do prefer the colour contrast and warmth

level of the jpeg. In retrospect I have added

some more saturation the the final raw image

and think this is the better final raw image

Conclusion

I have learnt through this exercise is that it is

raw images are not necessarily better than jepg

images. What raw gives you is better control

over the tone, contrast and quality of the final

image. What is important that the raw image

is captured correctly. This includes making

sure that the white balance is set correctly.

It is also important to understand what 

colour cast is being set by the camera and

also the final colour outcome you want

in the final image. This makes it so

much easier to balance tone and colour

in the final image.