An interesting and under used filters in the Cokin range is the Incolor 061. It’s part of the spot color range, and unlike many of the other colour spot filters this one is very practical and can be used in different ways for different effects. The spot filters with colour can sometime look quite poor if not used well, whereas this one can be adjusted to give a soft focus style effect or a lovely white vignette. This makes it perfect for wedding photography or portraits.
The filter is available in Cokin’s A and P series and has a small hole in the centre. When placed in front of the camera lens the hole either appears small or large, hard edged or soft edged, depending on the lens focal length and aperture used.
To get a large soft edge you should take photos using a longer focal length (around 50-80mm is fine with this filter) and use a wider aperture. If you want a more pronounced circle, use a wider lens and a smaller aperture.
You can buy the filter here: Cokin A series 061 Spot In color Filter