Optical Observing Techniques for Faint Extended Surface Brightness

Surface Brightness Measurements of Extended Galactic Nebulae

We discuss the importance of digitised sky-limited Schmidt Band R-band, and H images of extended translucent (A B ' 1 ? 5 mag) and dark (A B > 5 mag) clouds. In translucent clouds (e.g. high-latitude cirrus) photons can penetrate through the whole cloud and control the physical and chemical processes. Comparison of the B images with far-infrared/submillimetre CO, C I], and C II] emission provid...

Deep Field limiting magnitude : faint galaxy number counts from surface - brightness fluctuations

The faint end of the differential galaxy number counts, n(m), in the Hub-ble Deep Field (HDF) North has been determined for the F450W, F606W, and F814W filters by means of surface-brightness fluctuation (SBF) measurements. This technique allows us to explore n(m) beyond the limiting magnitude of the HDF, providing new, stronger constraints on the faint end of n(m). This has allowed us to test t...

Experimental Techniques for Observing Dislocations

Experimental problems in the application of the BergBarrett Method to the observation of dislocations in metal single c r ystals a re dis c u ssed . The problem of background nois~ caused by fluorescense from the s pecimen and inelastic scattering is considered. A c r i t e rion for selecLing an appropria t e f ilte r to discriminate against the background CALT 4 7 322 noise is presented. The p...

Robust Brightness Description for Computing Optical Flow

Most optical flow algorithms are based on the assumption of brightness constancy of individual pixels while moving on the image plane. Although being attractive analytically, this assumption is often violated under non-ideal visual conditions resulting in poor flow estimates. This paper presents an approach to support the validity of the assumption under such conditions. The method describes th...

Low Surface Brightness Galaxies