B max is the maximum antenna separation, B min is the minimum antenna separation, θ HPBW is the synthesized beam width (FWHM), and θ LAS is the largest angular scale structure visible to the array.
These estimates of the synthesized beamwidth are for a uniformly weighted, untapered map produced from a full 12 hour synthesis observation of a source which passes near the zenith. Synthesized Beamwidth θ HPBW(arcsec) 1,2,3 Table 3.1.1: Configuration Properties Configuration This table shows the maximum and minimum antenna separations, the approximate synthesized beam size (full width at half-power the resolution element) for the central frequency for each band, and the largest angular scale of detectable emission.
Table 3.1.1 displays the VLA's resolution and the scale at which severe attenuation of large-scale structure occurs. It can only be obtained by observing in a more compact VLA array configuration or with data from an instrument that is sensitive to the missing angular scales, such as a large single dish or a compact array of smaller antennas. No subsequent processing can fully recover the missing information from these large scales. For emission structures larger than the detectable range, the VLA is simply blind to the emission this is a limitation unique to interferometers. For emission structures smaller than the diffraction limit (θ ∼ λ/B max), the VLA acts like a single-dish instrument-the resulting image is smoothed to the resolution of the array. Like all synthesis arrays, the VLA is sensitive only to structures on a range of angular scales between the diffraction limit (the smallest angular scale detectable) and a "Largest Angular Scale" (which depends on the fringe spacing formed by the shortest baselines in the configuration). The VLA's resolution is generally diffraction-limited, and thus is set by the array configuration and the observing frequency. eXtra-Large Proposals Expressions of Interest.In case of smallest image details and large magnifications please use macro-lenses which are specially designed for these applications.įurther details on optical calculations can be found in chapter Optical basics. Especially in case of very small working distances of several centimetres, the calculated values are no longer realistic. The calculated working distances refer to the optic centre of the lens housing. By means of additional spacers, however, the lens distance can be reduced ("see calculation of close-up rings").
In case of F-mount lenses and other lenses for larger image circle diameters, the minimum lens distances are often considerably larger.
Hinweis: Zur einfachen Berechnung bitte einen Wert in der Dropdownbox selektieren! Eingabe eigener Werte durch Auswahl von "User def." in DropDown-Liste!Ĭalculating the working distance using object size and opening angleĪttention: Calculated working distances below 150 to 300 millimetres cannot be focused using normal C-mount lenses. Send your calculation with your own email program (MailTo-link).Īrbeitsabstand: mit Pixelgröße Sensor, Brennweite und Bauteilgröße rechnen We respect your privacy: We do not store any inputs, results or recipients. Length/ size of inspected object in mm (field of view FOV): Note: Even when using the drop-down lists own values can be entered. Using object size& opening angle Calculating the working distance using focal length, object and sensor size