I am a frequent visitor to the dpreview Olympus SLR Forum. It was there that I first came across some E-10 depth of field calculations done by Ken McGuinness. Since it's the only work of this type I've found for the E-10, I requested his permission to reproduce his work here.

Ken lives in Glasgow, Scotland, and enjoys his privicy. So at least for the time being, I can't give you his Email address. I can tell you that he has a degree in electronic engineering and 20 years design experiance in the field of military lasers. In fact, he specialised in the design of optical sensors and high energy lasers. Ken reports that "These days, since peace broke out, I build and install computers and networks." He has been involved in photography for 25 years using mainly contax gear. Recently however, he has gone completely digital and owns an Olympus E10 and a Canon G1. My thanks to Ken for sharing his work with us.

Basic Assumptions / Givens:

The size of the imager is 2/3” diagonal this gives a CCD dimension of

13.53mm         x         10.17mm

The resolution of the CCD is

2240    x         1680 pixels

This gives a pixel size of 6 x 10^-6 mm

In the data for the E10 and the white paper it is implied that the E10 lens can resolve onto a single pixel and indeed in the review of the E10 on this site they quote a figure for the circle of confusion of 4 x 10^-6 mm. This would seem to be valid and is therefore the figure I have used. On other sites where people have dealt with this subject the have used figures related to film lenses and as we know the E10 lens was designed for this particular application with the CCD dimensions in mind.

In terms of calculated size the pixel separation is 6 microns however this does not take into account the gap between each pixel.

An exerpt from a datasheet shows the following Information an a Panasonic CCD Chip

(1) High-performance pixel technology A pixel size of 4.0 µm × 4.0 µm has been achieved for large type-2/3 chips. Using ion implantation and low temperature process technology, the photodiode and vertical CCD structure have been optimized to prevent pixel performance degradation, such as reduction and variation in pixel sensitivity and dynamic range, as a result of the extremely high level of integration. This is why I used a figure of 4 microns however if someone wants to use 3.9 microns, ok. It makes no difference to my graphs at 1 decimal place.

The rest of the equations are well known but I will list them anyway

Hyperfocal distance

“The "hyperfocal distance" is the nearest distance that you can focus a given focal length/aperture combination at and still have "infinity" in focus. Practically speaking, this is the deepest possible depth of field for that focal length/aperture combination.”

Depth of Field

“When you focus your camera's lens at a certain target distance, objects at exactly that distance from the camera are exactly in focus. Technically, everything else is out of focus. In practice, however, there is a "zone of acceptable focus" surrounding the focus plane, so that objects within that zone are considered "in focus" and those outside that zone are "out of focus". The size of this zone is called the "depth of field."”

General Rules About Depth of Field:

• Smaller apertures make for deeper in-focus fields.
• Wide angle lenses have deeper field depths at a given aperture than telephoto lenses do.

               or            

Where

1/   s = Target distance in mm

2/   A = Aperture

3/   f = focal length in mm  i.e.   9 – 36 mm

4/   c = circle of confusion – taken at   4 x 10^-6 mm

DOF Charts

	Two Meters

	Three Meters

	Three Meters with Hyperfocal curves

	Six Meters