DoF & Sharpness Calculator

This Depth of Field calculator is for both the experienced and the novice photographer.

For the experienced it is a quick and easy way to check depth of field for both macro and non-macro shots and hyperfocal distance for landscape shots. For the novice it is a practical means of coming to terms with the camera - discovering the effect that aperture settings, lens size (focal length), sensor size and lighting conditions have on an image.

The Depth of Field calculator will display how much of an image will be in acceptable focus, depending on sensor size, focal length, the use of a teleconvertor and the distance of the subject from the lens.
For macro photography the depth of field can be very shallow and this calculator measures that in relation to the size of the image on the sensor rather than the distance of the subject (this image-size scale is etched on the barrel of macro lenses). Because of the magnification of a macro lens less light reaches the sensor; the consequence of this is displayed as the ‘effective’ aperture, in addition to the actual aperture that you have set. For example, at f/11 and the lens focused to take a life-size image on the sensor the effective aperture will be f/22. A teleconvertor has a similar effect.

For macro photography, in particular, small apertures for greater depth of field can be counter-productive and lead to less sharpness over-all. This is because of diffraction – the spreading of light as it strikes the edges of an aperture. This calculator will alert you to the onset of the noticeable effects of diffraction with a colour-coded ‘resolution factor’. Lighting conditions can also affect diffraction and so you can change a setting to take that into account.
You do have to enter the ‘crop factor’ of your camera’s sensor. If you do not know this we provide a list from which you can select a camera maker and the select your camera from that maker’s list. At present the cameras listed are mainly DSLR’s but the range will be extended on demand.

You may check a working version on my website before you buy.