Colour Study: Red vs Green

This image is taken by Pentax Fa 77mm f1.8 limited

Some friends of mine have asked me about the applications of colours. Use of colours in photography is very important. Usuaully the colour profile of an image series creates a signature style of a photographer.

Sometimes the colour choice helps to protrays a desirable context to influence a viewer's mental state.

The most interesting and utilised choice of colour combination is Red vs Green, These two colours are equally weighted towards each other in terms of impact. A visual balance of these two colours is in 1 : 1 ratio. Therefore, a variation of proportion from these two colours will help a photographer to determine where the intended focus of any image shall be. Increasing the proportion of the red colour in an image will diminish the importance of the red itself, helping the viewer to look for the colour green subconsciously. Vice versa. This is a crucial knowledge to bear in mind during composition of any image.

The colour "Red" is the most ancient colour ever used in human history. In fact, the intensity of the red resets the brightness of a photograph to a medium dark overall. Most of the time, Red is avoided simply because the colour can be too dark, brooding and distracting if the subject of interest is not in red...
Very often, Red can only be a "host" colour in the image rather than a "guest" colour. Colour red has several effects on people. For example, normal red neck ties signifies ambience while burgundy red signifies classical or tradition. Intense Ferrari Red often denotes a flamboyant, progressive kind of message. Whenever an attention is needed, red colour helps to direct a confused and tired viewer to the desirable area of an image in order to perceive a certain message by the photographer.

No matter how bright red the colour is, colour red is considered to posess "darkening" effect. To compliment red, green is a must. However, green is considered even darker than red in general unless a choice of light olive green is considered. In general, light green is "no match" for any kind of red. Under such circumstances, the light green will be ignored by our higher centre of colour differentiation since light green is too "weak".
When Red is used, it shortens the viewer to the image distance in perception. Therefore, Colour red is not helpful in grandeous type of landscape images. Usually a dot or two of red is more than enough in most landscape if the scene is supposed to be vast and of huge scale. For moody, sentimental, sad, melanholy type of images, red or orange hue will be an ideal choice.
The choice of Green will hit hard in the visual cone cells of the human retina against the colour Red. Hence the impact is usually great enough to "elicit" certain type of emotion depending on one's upbringing experiences. This colour arrangment lasts visually even when the eyes are turned away from this particular colour combo.

Red and Green does cast great impact on viewing experience of many. But a port folio of images using only red vs green is not wise. This type of colour choice usually fatiques human vision. Hence tiring and exhausting for viewers. Therefore, this colour combination needs to be carefully planned out in a photography exhibition.
Lastly, the image I posted here obviously has the red leaf in the centre surrounded by the background bokeh, mixing red and green with variation of colour intensity. The colour choice is really these two colour where the intensity helps to create the sentiment. The rest is up to the viewer to interpret the red leaf...

Hope this article of colour red versus green will help many of my friends :)

What is MTF? Not WTF

This image is taken by Canon 50mm f1.2 L in Country Victoria. East Gippsland

MTF

What is the first thing you look for in a photograph? Is it the colour quality, brightness or the sharpness that you focus on?

Everyone loves a good sharp image. If the image does well in that perspective, only then people love to admire the colour combination and other features.

The sharpness of a photographic imaging system or any component of this system such as lens, sensor etc is characterized by a parameter called MTF [Modulation Transfer Function].

Learned opticians love to call it the spatial frequency response but we would like to keep it simple and easy to understand.There are thousands of formulae and many complicated MATLAB functions that help us to understand the complete phenomenon but we’ll generalize the understanding part.

The MTF factor needs to be compared when you buy a new digital camera.

As a layman, how do you know whether MTF50 or MTF50P is better as a comparison parameter?

All latest cameras have the ability to sharpen the image to some extent. Sharpening an image surely increases its contrast at the boundaries by reducing the rise distance. In such cases, the edges overshoot thus enhancing the perception of sharpness. But a large overshoot can create ugly halos near the boundary section which become obvious at high magnifications.

Such a mistake can destroy the sharpness and quality of the image completely.Every digital camera will have MTF50 and MTF50P specifications. While MTF50 corresponds to the frequency band where MTF becomes 50% of its low frequency, MTF50P implies to 50% of its peak values. These 2 indicators greatly determine the perceived sharpness.

Along with increase in sharpness, noise also increases.Suppose a digital camera sharpens an image which increases 50% MTF frequency. If the camera does over-sharpening, we may have an image with good MTF50 but very poor image quality; whereas a low sharpening will show the low potential of a camera. Either ways, MTF50 comparisons fail to help in picking the right camera.Moving on to the MTF50P factor, we see that MTF50P is same as MTF for a moderate level of sharpening. The MTF50P falls if we go for over sharpening.

Hence this is better as compared to the MTF50.The MTF factors come into picture only when a high degree of sharpened image needs to be evaluated. Otherwise, Standardized sharpening and Raw MTF50 without standardized sharpening are better comparison attributes for images.

MTF50P is one of the best features to compare while going for over sharpening of images.As discussed earlier, small overshoots across the edges give a good overall sharp image. Suppose you are going for a customized camera, then you need to keep the lens features in mind.While comparing the lens performance for the same camera, uncorrected MTF50 is one of the best parameters to compare. Sometimes people tend to confuse the term of ‘sharpening’ with "Unsharp masking’.

You must be remembering the old films and the way the slides for the film were prepared. The process of ‘unsharp masking’ reduced the overall contrast of the image which is needed for a better print version and increased the contrast near the edges rather than at a distance from the edges.Thus unsharp masking Is a bit tedious and cumbersome too.

In a nutshell, we have discussed as to how MTF factor can be used to compare the features and picture quality of cameras and how does the sharpening process depend so much on MTF.