I have recently written an article that explains hyperfocal distance, and how to calculate what your hyperfocal distance would be for your situation. As well as a more useful use for this kind of information: I show you how to calculate what your focus distance and aperture should be in order to cover the entire object you're photographing with your depth of field. Ok.., right, sorry. Let me do some copying and pasting then, so that you can access the information the link would have led you to. I've skipped the hyperfocal distance story because you can find that info anywhere on the net, but I've included the part that I really struggled to find on the net, so I think this info would be the most interesting So sorry. ----------------------------------------------------------------------------------------- Finding the Right Focus Distance and Aperture to Render the Whole Object Sharp Getting to know and understand how and why you’d use the Hyperfocal distance to maximize the use of your DoF will naturally make you wonder about where else you could use this kind of technique. For example, if you were being paid by a magazine or any kind of client, to photograph something in a studio, and part of the client’s requirements is that the entire object be sharp. How would you go about making sure that the object in the picture is completely sharp, would you wing it? Or would you be a professional and make sure the job is done properly the first time? Below is a diagram explaining the situation in the studio, and its your aim to get the entire table sharp. In other words, you’re trying to fit the entire Depth of Field over the entire table. There is a way to calculate what the minimum Aperture and focus distance should be, to make your DoF just the right size for the object you’re photographing to be rendered sharp. This is the diagram explaining the hyperfocal situation in which the aim is to get the whole table acceptably sharp The closest point to the camera that needs to be sharp is called the “near DoF limit’, and is designated with this symbol 'Dn' The farthest point to the camera that needs to be sharp is called the ‘far DoF limit’, and is designated with this symbol 'Df' The focus distance setting of the lens (subject distance) is designated with this symbol 's' The Aperture that we need to use in order to get the whole object sharp will be designated with this symbol 'N' In this situation I am using a 35mm format digital camera, which has a sensor dimension of 36mm X 24mm. This format has a circle of confusion size that is 0.03mm, and circle of confusion is designated with this symbol 'c' So you’re standing in the studio with this table in front of you, and you know that the closest point to the camera that needs to be sharp is 1.5metres away, and you know that the farthest point that needs to be sharp is 3.5 metres from the camera. You could ascertain this information by either measuring the distances yourself, or by focusing on each point and reading the distance off of your lens. The first thing you need to work out is what your focus setting should be, and you are able to calculate this with the information you already have. Use the following formula and solve for “s” This is the formula to calculate the focus distance (subject distance), with the near and far DoF limits. s = subject distance All measurements were converted to millimetres, but in this format you could also just leave the measurements in metres. Now you know that with the camera at the distance from the closest and farthest part of the table, the lens focusing distance should be set to 2.1m. At this point you can guess where 2.1m is and just manually focus the lens to that point, or you could take out a measuring tape, your choice. Now to calculate what the aperture is that we need to use, we need to work out the following formula and solve for N. This is the formula to calculate the Aperture needed N = the Aperture we need All measurements were converted to millimetres because the focal length (f) and circle of confusion (c) are always expressed in millimetres. And there you have it. With the aid of mathematics we have calculated that the focusing distance should be 2.1m, and what the Aperture should be using is f/16. Now you can go forth with confidence and fulfil the brief explained above, if you ever get one like that. On the other hand there are much easier methods to work out the information that we have just worked out. There are Depth of Field and Hyperfocal distance calculators online, and available to download to your cell phone or tablet device. These are much easier and time saving, but at least now you understand what these devices are doing.