Before this exercise I didn’t know much about black-and-white photography, I didn’t understand why some images stand out over others, I assumed the secret was contrasting colours but didn’t think about tones, how colours turn into different shades of grey. I guess I never really experimented with this.
I chose to shoot a still life photo as advised in the course notes, I used the grey card to determine the white balance, made sure it stays the same shade during the filtering process than cropped it out as it was disturbing the composition.
It’s interesting to see that the normal black and white conversion lightened the dark colour (blue) and darkened all lighter colours (red, green, yellow). Reviewing these images I learned that each filter makes its tone very light and makes other colours darker and it appears to me that the effect depends on each colour’s brightness, for example there isn’t much difference between red filter changing red and green, and yellow changing red and green, there is only slight difference, probably the same as between red and yellow colours. However on this chart the differences are more significant, but they aren’t the exact shade though. I hope I got this right, I feel I’m on the right way to understand how this works.
Since I’m shooting with my DSLR, I always take images in colour, I tried to convert some of my photos to black and white but I didn’t get pleasing results most of the time, but when I did, the message of the image was something emotional. I was thinking, how can I decide when to convert (or shoot) in black and white, Freeman  validates my opinion when I see the picture of the lioness, there are no distracting colours, the attention is on the animal rather than the surroundings. He also mentions texture and form, how this format enhances lines and shapes giving a different overall feel to the image, absolutely amazed by Ansel Adams’ work , incredible amount detail and contrast.
Looking for more practical advice, I came across an article  on this subject showing what filters do to different images and also found this brilliant chart which really helped me understand how this work.
I really like how the red filter enhanced the sky on a beautiful landscape, how orange filter gives smooth skin tone, how green filter separates objects from nature’s green, the way blue filter gives smooth, calming feeling by reducing contrast as it darkens most colours. On that account I will definitely experiment more with black and white photography.
 Michael Freeman – The photographer’s eye, Page 126.