0- General view 5D2 + 24-105 mm

Stray Light components

In the practice of Design of Image Producing Systems, it is usual to sort the different causes of Stray Light affecting all Systems into seven categories:

  1. Ghost Images
  2. Singly-Scattered light
  3. Multi-Scattered Light
  4. Edge Diffraction
  5. Straight Shots
  6. Self-Emission of Infrared Systems
  7. Combinations of the above items

In practice, for standard photography with refractive optics (i.e. with "Lenses"), only Items #1 to #4 apply but #7 is indeed a hard fact-of-life in photography too.

 

This pair of images intended to show how the different aspects of Stray Light, a.k.a. Flare, a.k.a. Veiling Glare look like and effects on a photograph.

Explanation shall be given in five different slides each concerning the origin of the (4 +1) physical contributions to the whole phenomenon.

 

This image was shot with a Canon EOS 5D II camera with a EF 24-105 mm f4 L zoom lens @ 24 mm ; f/5.6 with the EW-83H lens hood installed on it.

The camera was put vertically (i.e. in portrait mode) with the shutter release button at the bottom: the underside was thus on the left of this image.

In the Live View mode and looking at the LCD on the back of the camera, I pivoted the camera around a vertical axis so as to get the maximum "parasitic" signal on the side of the frame (where the sun chimes to enter the image).

A large French window on the right side is almost wholly out of the field but a big chunk of it is still within the lens "circular coverage". The sun is shining and it is out of the field while still being within the circular coverage of the lens.

13 photographs: bracketing was done by Promote Control Remote and the time of exposure varied from 1/4000 up to 1 sec. for +/- 6EV

The raw files were converted with the help of Adobe Camera Raw leaving all correction parameters settings at zero (No contrast correction at all). EnfuseGui was used for the "Enfusion" of the individual images.

Automatic contrast correction by Photoshop was finally applied in order to "remove" most of the veiling and to more clearly distinguish details of other flare effects. The haze of the glare veiling due to a complex mix of all the flare effects was not removed and is however left visible on the last image (on the far right of this row of images).

This image was shot with a Canon EOS 5D II camera with a EF 24-105 mm f4 L zoom lens @ 24 mm ; f/5.6 with the EW-83H lens hood installed on it.

The camera was put vertically (i.e. in portrait mode) with the shutter release button at the top: the underside was thus on the right of this image

In the Live View mode and looking at the LCD on the back of the camera, the camera is pivoted around a vertical axis until getting the maximum "parasitic" signal on the side of the frame (where the sun chimes to enter the image).

A large French window on the right side is wholly out of the field but a part of it is within the lens circular coverage. The sun is shining and it is out of the field while still being within the circular coverage of the lens.

13 photographs: bracketing was done by Promote Control Remote and the time of exposure varied from 1/4000 up to 1 sec. for +/- 6EV

The raw files were converted with the help of Adobe Camera Raw leaving all correction parameters settings at zero. EnfuseGui was used for the "Enfusion" of the individual images.

Automatic contrast correction by Photoshop was finally applied in order to "remove" most of the veiling and to more clearly distinguish details of other flare effects. The haze of the glare veiling due to a complex mix of all the flare effects was not removed and is however left visible on the last image (on the far right of this row of images).