Depth Of Field Table

I have taken a few common focal length options and formed a table with their corresponding "acceptable" DOF at certain subject distances. This should reiterate the fact that some common focal length options are not necessarily better when it comes to wide open Numeric references.

Low light capabilities may seem inviting when purchasing a new lens, although taking into account your subject isolation at given wide open apertures may render those apertures useless for your chosen situation. Low light High ISO capable camera's are becoming more and more common with unbelievably good noice control.

Although some lenses have higher optical grade qualities for their larger aperture lenses, meaning better overall image quality, if Bokeh and subject isolation are the main objectives, smaller aperture lenses also create this. If that particular lens is of high grade, then the resulting images will be just as good in my opinion.

As with all "acceptable" sharpness information, this is dependant on the person viewing the image & image size. The centre of the DOF will be the sharpest, falling off towards the sensor and behind the subject.

All Measurements are in meters - the resulting number is the Acceptably sharp depth of field for each focal length at various subject distances.

Using this tool you can visualise how subject isolation would work in certain situations with certain lenses.

For instance, the 35mm lens with your subject @ 5m aperture F1.2 you have roughly 22mm Depth in your 3 dimensional plane, @ F/2.8 you have 51mm DOF.