We describe a new technique, high fidelity Imaging Retinal Densitometry (IRD), which probes the functional integrity of the outer retinal complex. We demonstrate the ability of the technique to map visual pigment optical density and synthesis rates in eyes with and without macular disease. A multispectral retinal imaging device obtained precise measurements of retinal reflectance over space and time. Data obtained from healthy controls and 5 patients with intermediate AMD, before and after photopigment bleaching, were used to quantify visual pigment metrics. Heat maps were plotted to summarise the topography of rod and cone pigment kinetics and descriptive statistics conducted to highlight differences between those with and without AMD. Rod and cone visual pigment synthesis rates in those with AMD ( v = 0.043 SD 0.019 min −1 and v = 0.119 SD 0.046 min −1 , respectively) were approximately half those observed in healthy controls ( v = 0.079 SD 0.024 min −1 for rods and v = 0.206 SD 0.069 min −1 for cones). By mapping visual pigment kinetics across the central retina, high fidelity IRD provides a unique insight into outer retinal complex function. This new technique will improve the phenotypic characterisation, diagnosis and treatment monitoring of various ocular pathologies, including AMD.

Additive manufacturing (AM; 3D printing) is a fabrication process that builds an object layer-upon-layer and promotes the use of structures that would not be possible via subtractive machining. Prototype AM metal mirrors are increasingly being studied in order to exploit the advantage of the broad AM design-space to develop intricate lightweight structures that are more optimised for function than traditional open-back mirror lightweighting. This paper describes a UK Space Agency funded project to design and manufacture a series of lightweighted AM mirrors to fit within a 3U CubeSat chassis. Six AM mirrors of identical design will be presented: two in aluminium (AlSi10Mg), two in nickel phosphorous (NiP) coated AlSi10Mg, and two in titanium (Ti64). For each material mirror pair, one is hand-polished and the other is diamond turned. Metrology data, surface form error and surface roughness, will be presented to compare and contrast the different materials and post-processing methods. To assess the presence of porosity, a frequent concern for AM materials, X-ray computed tomography measurements will be presented to highlight the location and density of pores within the mirror substrates; methods to mitigate the distribution of pores near the optical surface will be described. As a metric for success the AlSi10Mg + NiP and AlSi10Mg mirrors should be suitable for visible and infrared applications respectively.

UIST is a facility class near-infrared instrument recently commissioned at the UK Infrared Telescope (UKIRT). UIST provides a comprehensive imaging and spectroscopic facility with spatial resolution limited only by the delivered tip-tilt corrected seeing. In addition to long slit spectroscopic modes, UIST includes the first deployable cryogenic integral field unit in a common user instrument. We will present results obtained during the commissioning period in late 2002. These include measurements of the image quality and the sensitivities of the different observing modes of the instrument. We also discuss the use of an instrument-specific telescope pointing-model developed for UIST to allow the instrument to meet the stringent flexure requirements arising from the choice of 0.06arcsec/pixel and 0.12arcsec/pixel plate scales. We pay particular attention to the performance of the image slicing integral field unit (IFU). We will present astronomical results from the first year of UIST operations, during which time UIST carried out diverse programmes, from mineralogical studies of Mars to measuring the mass of the black hole at the centre of the most distant quasar.