Camera Repair Tools You May Not Have Heard Of

by Kevin on

Instead of our usual topics of repairs themselves and things that go bump in the night that want to hurt your camera, let’s change it up this week and look at the tools used in digital camera repair. Many of the tools used are fairly common, easy to acquire, and mostly what you would expect. So forget those, they’re boring; the interesting stuff is the equipment you probably have never even heard of before.

The simplest piece of equipment is what is called a Calibrated Light Source. Basically it is a box that produces specific lumen values at a specific color temperature. After a camera has been repaired it is important that it is producing correct exposures and this box lets us do that. Images are taken at specific values (lens and focal length standard varies by camera type, manufacturer and model), the camera is hooked up to software, the software is fed the images and the adjustments are made electronically. A couple other uses for a Calibrated Light Source are for finding dust and for finding bad pixels. When checking for dust it is as easy as taking a picture and inspecting it; for the best results it is done with an aperture value of 16 (or higher) and focused at infinity. You can also do this at home by using the same settings (F16 or higher, focus at infinity), taking a picture of a clear sky during the day and inspecting the images.

Resolution Chart Full

You may remember the Slope Chart from a previous article on this blog all about calibrating lenses. Another chart we use is called a Resolution Chart (pictured above). This is the starting point when we get the common complaint of “soft images”. Just a quick primer on lenses, the center portion of every lens renders the sharpest image; which in turn means that the sharpest portion of images produced by cameras is the center of them. There are many different resolution charts made but their main purpose is always the same, to determine the sharpness of the lens and/or determine if the lens or sensor is out of alignment. The camera with attached lens begins with the front of the lens touching the center of the chart where the unit is then leveled. It is then backed away to a distance where all four outer corners can be seen by the sensor. So when a photo is taken there are a number of things we look for. It may go without saying but it is worth mentioning that the images are taken with the lens aperture wide open. If the entire image is soft then it is front-focused or back-focused and off to the slope chart it goes. If some, but not all, of the corners are soft then something is out of alignment (lens element, the sensor, the mount). The quality of a lens is easily visible with this test and is distinguished by how sharp the corners are (detail below). In other words, consumer level lenses will not show as much detail in the corners as pro lens.

corner of resolution chart

Hope all that made sense; if you have any questions or would like further detail please leave your questions in the comments section below.

{ 2 comments… read them below or add one }

roniel magno August 25, 2011 at

is there any association or a group’s of digital camera technician’s, there is a lot of association of cellphone technician’s they share every knowledge that they know, is there any group’s just like that???

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camerarepair August 26, 2011 at

There is indeed. The web site with contact information can be found at:

http://spt.info/

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