Sunday, April 3, 2011

Exercise 3.4 - Colors into Tones in Black-and-White

The task was to take a shot of that would have green, red, yellow and blue objects on it and then convert into the black&white picture applying different filters.

This is a first time the 'gray card' was mentioned as a tool for the exercise. This is a gray color card used for mid color reference. In other words, it helps your camera sensors calculate exposure in a right way, as sensors are normally calibrated to measure objects with reflection capability of 13% (mid colors). So, every time you don't have a mid color object in the frame, sensors are calculating the exposure in a wrong way.  

So, I went to the nearest photo store and bought myself a set of B.I.G gray cards 18% reflection, that has two cards 20x25cm and one card 10x12cm in the kit.

Then, I have put together the composition with all needed colors - blue, green, red, yellow. And I have placed a gray card to the center to record exposure figures from it. Looking now at this picture I realize, that gray card could be placed better, as at this angle too much light from the window was reflected and I could not rely on the automatic exposure metering. I just compared visually the 'right' gray color of the the card with the grey color I got. Using this technique, the shot still needed to be a bit underexposed according to the exposure values shown by the camera. I guess, if I have put the gray card about 90 degrees to the table, the exposure settings shown by the camera exposure equilibrium would show the same values I got in the end.

After I was satisfied with gray color I got, I have recorded the settings and removed the gray card from the composition. Using the same settings I have finally come up with a shot below. Of course, to keep composition the same, I was taking pictures from the tripod.

90mm; f/25.0; 1/8 sec; ISO 200

 As a second part of exercise I had to convert this colorful picture into black and white and apply different filters. 

1. Default Black and White

If I look at the brightness scale with default settings, it looks like this: red (40), yellow (60), green (40), cyan (60); blue (20); magentas (80).

I could have used default filters from Photoshop settings, but I decided to play bit with colors scales myself.

2. Red filter

Because the most red tones were in two berries on the picture, they have changed the most, when I have increased  red color tones to 172. As there were also red tones in lemon and I did not like the way it looked after the red tones adjustment, I have put it in balance by decreasing yellows value to 17. This has also influenced the green leaves, that also had some yellow tones ad became a bit darker. 

3. Yellow filter

When applying yellow filter, I have put yellows value to 148, which has made lemon look almost nearly. To make the leaves look not too light, I reduced greens to 28 and to add some contrast with red berries, I have put reds value to -4. 

4. Green filter

Here I have set up greens for maximum of 300. But because leaves also contain some yellow tones, it did not make them completely white. To add some contrast with a tea pot, I have reduced cyans to - 46.

5. Blue filter

As the only blue object here is a teapot, I have set up the blue filter to maximum of 297 to get white color instead. In this case, white color of the tea pot does not disturb the composition and does not make tea pot look unnatural, because there are also some cyan tones in it, which I kept untouched.   

Commenting this exercise, I can say that it was the most interesting and useful out of all exercises on colors that I have made in this part. Now I know that gray cards exist, and that they can be used in several ways. One of them I applied in this exercise. 
Experimenting with colors as tones of black-and-white photo was also very useful for better understanding of the opportunities of black-and-white photography and processing of pictures. 

No comments:

Post a Comment