Colours into tones in black-and-white

The exercise required shooting a still life arrangement comprised of pure contrasting colours with even lighting and shadow fill (not sure I got the lighting and shadow right...), and then converting the images into monochrome and applying various filters and filter strengths.  Here is the original arrangement:

I then carried out a straight forward conversion into black and white without applying any filters:

Red filter

I processed two images with a red filter using 50% brightness and 75% and 100% filter strength:

Red 75%

As expected, the red pepper is lighter with the red filter applied - it looks as if it would be an orange or yellow pepper and the green chillies and the lemon are darker.

Red 100%

With the filter 100% applied the pepper is even lighter still and then lemon is darker.

Yellow filter

Yellow 75%

The yellow filter had the effect of lightening the lemon, the green chillies and the red pepper, but these are quite subtle changes.  The red pepper is however darker than it is with the red filter applied.

Yellow 100%

With the yellow filter 100% applied, the effect is more noticeable with the card becoming darker, the green chillies much darker, the lemon and the red pepper lighter.  Now you really would image that the red pepper had been a yellow one!

Green filter

Green 75%

The green filter at 75% has an overall lightening effect on the image, and seemed to have more impact on the red pepper than anything else.

Green 100%

The effect of the green filter at 100% seems to be as above a general lightening.  The course work implies that the red pepper should get darker, but its not - it's definitely lighter!  

Cyan_Blue 100%

I then played with the colour slider watching the tones change as it moved through the different filter colours (this is in Nikon Capture) and noticed that the red pepper became dark with the slider set right at the point where cyan meets royal blue.

Blue filter (cyan)

Cyan 75%

I used the light blue (cyan) filter next; I found this image not too dissimilar to the neutral original - perhaps slightly darker.  The lemon is darker.

Cyan 100%

At 100% the cyan had the effect of darkening the lemon and pepper but lightening the green chillies very slightly.

This was a really interesting exercise and showed me something I hadn't thought about before.  Which filter and strength you would use would depend on the subject and context, however I really liked the effect of the yellow filter at 100% - it gives a really strong tonal contrast.  I also liked the strength of colour in the original against the grey card.  That is why I chose the colour scheme that I did for my blog - because colours look incredible against grey!