Recommended Camera Settings for Photogrammetry

While PhotoModeler can handle most images and camera settings from many types of cameras, you may get better results with certain settings on your camera.

In addition to the information below on settings, you may be interested in general camera information on the About Cameras page. Also, this article on achieving the highest accuracy may be useful: Getting the Highest Possible Accuracy with Photogrammetry.

Camera Settings

You may wish to review several common camera settings before taking photos for your photogrammetry project. Not all cameras will have all these settings, and in your camera, the settings might have different names.

Resolution

Most digital cameras will provide control over the resolution (that is, the number of pixels in the saved image). In most cases, picking the largest resolution (most pixels) will provide the best results.

JPEG Quality

Some digital cameras will provide control over the amount of compression used when saving images in JPEG format (or other compressible formats). Pick the High setting or similar. Pick the setting with the least compression.

RAW Images

Some digital cameras will allow images to be stored in a RAW format. This format then needs to be converted to JPEG or similar in an external program. For most work in PhotoModeler, the RAW format is not needed. In special cases of difficult exposure, a high-bits RAW format might help, but we recommend starting with JPEG, or similar, at first.

Focus

Generally, it is better to get the image in focus than to worry about the changing of the camera characteristics. That is, allow the focus to change between photographs in your project. Two cases where this might not apply: a) macro photography, and b) very high-accuracy industrial measurement. In these cases, changing focus between photos may negatively affect the solution and accuracy. These types of projects have to be planned carefully to minimize or remove focus changes between photos within a project.

Also, see the note below on Exposure and depth of field.

Exposure

As long as the images are well exposed (proper brightness and contrast) and provide the view and data needed, the exact exposure setting used is not important. The one area to address may be the depth of field and the aperture setting. If the aperture setting is wide open (lower f-number) (maybe set manually or by automated exposure controls), the depth of field may be small. This may mean objects in the distance (or closer to the camera) are out of focus. Ideally, you get as much of the image in focus as possible. If getting the image properly exposed affects the depth of field negatively (not all of the image is in focus), then additional lighting is needed (natural, artificial, or flash).

Zoom

Cameras with zoom lenses can be used with PhotoModeler but extra care is needed. It is best to set the zoom at one extreme (maybe most wide-angle) and leave it there. Perhaps even mechanically tie it down if possible. For the highest accuracy work, we recommend using a prime lens (a non-zoom lens of only one focal length).

Sharpening

Most digital cameras have a “Sharpening” feature that enhances the edges of objects that appear in the photo. This is fine for viewing images but can cause problems in PhotoModeler, notably when using the Camera Calibrator and subpixel marking or the automatic target marker. For best results, turn the sharpening to “Off” or “Soft” before taking photographs.

Optical Image Stabilization (OIS)

Some camera bodies and some lenses have a feature that stabilizes the images to help reduce motion blur. This can be done electronically or can be done by physically moving a lens element or the imaging chip. Ideally, you would use a camera with PhotoModeler that does not have this feature (esp. the mechanical kind). Even if the feature can be turned off (recommended), the ability to shift the image chip or a lens element means the camera is already less stable. Cameras that do not have good internal stability do not make the best cameras for photogrammetry. They can be used, but are not recommended for high-accuracy work. Also, note that many modern mobile phone cameras have OIS.

Summary of Settings

  • Resolution: Highest
  • JPEG Quality: Highest
  • RAW Images: Not needed (generally)
  • Focus: Allow focus (generally)
  • Exposure: Get the best focus (noting any depth of field issues)
  • Zoom: No zoom, or tied down
  • Sharpening: Off or ‘soft’
  • OIS:  Off or none