Git commit 44e5086501f8c6513bfd00e321b42d4c5ef0b46d by Yuri Chornoivan. Committed on 02/12/2023 at 22:23. Pushed by yurchor into branch 'master'.
Fix minor typos M +4 -4 doc/ekos-capture.docbook https://invent.kde.org/education/kstars/-/commit/44e5086501f8c6513bfd00e321b42d4c5ef0b46d diff --git a/doc/ekos-capture.docbook b/doc/ekos-capture.docbook index 5f816339a7..3f48da3f16 100644 --- a/doc/ekos-capture.docbook +++ b/doc/ekos-capture.docbook @@ -520,12 +520,12 @@ Approaches to imaging can vary greatly in the selection of exposure times, and n <para> <guilabel>Sky Quality</guilabel>: The <guimenu>Sky Quality selector</guimenu> sets the measurement of the magnitude per square arc-second of the background sky.</para> <para>The range for Sky Quality is from 22 for the darkest skies, to 16 for the brightest (most light-polluted) skies. The magnitude scale is non-linear; it is a logarithmic scale based on the 5th root of 100. So 5 steps on the scale represent a change in brightness by a factor of 100. (A Sky Quality of 17 is 100 times as bright as a Sky Quality of 22. Each full integer step on the scale is a change by a factor of approximately 2.512.). <ulink url="https://en.wikipedia.org/wiki/Light_pollution";>Wikipedia Sky Brightness</ulink> -<ulink url= "https://en.wikipedia.org/wiki/Light_pollution";>Wikipedia Light Pollution</ulink></para> +<ulink url="https://en.wikipedia.org/wiki/Light_pollution";>Wikipedia Light Pollution</ulink></para> <para> All light scattered in the background sky is considered to be light pollution regardless of its source, so the effects of moonlight should be considered as "natural" light pollution. But weather conditions can also impact Sky Quality, as humidity or cloud cover can reflect and scatter any source of light through the atmosphere</para> <para> - A <ulink url= "https://en.wikipedia.org/wiki/Sky_quality_meter";>Sky Quality Meter (SQM)</ulink> - can provide the most accurate reading of sky quality if used during an imaging session, but an estimated value from sky quality surveys may also be found on the web at sites such as <ulink url= "https://www.lightpollutionmap.info/";>www.lightpollutionmap.info</ulink> or <ulink url= "https://clearoutside.com/";>www.clearoutside.com</ulink>. But these on-line sources for estimated light pollution generally do not account for the effects of moonlight or local weather conditions. So the values from light pollution web sites should only be considered as a “best case scenario” for a cloudless night during a new moon.</para> + A <ulink url="https://en.wikipedia.org/wiki/Sky_quality_meter";>Sky Quality Meter (SQM)</ulink> + can provide the most accurate reading of sky quality if used during an imaging session, but an estimated value from sky quality surveys may also be found on the web at sites such as <ulink url="https://www.lightpollutionmap.info/";>www.lightpollutionmap.info</ulink> or <ulink url="https://clearoutside.com/";>www.clearoutside.com</ulink>. But these on-line sources for estimated light pollution generally do not account for the effects of moonlight or local weather conditions. So the values from light pollution web sites should only be considered as a “best case scenario” for a cloudless night during a new moon.</para> <para> If a light pollution map value is used for the input value of SQM, but imaging will be performed with a partial moon, then a decrease in the input of the SQM value should be applied in the calculator. Moonlight can be overwhelming; at a location where a light pollution map showed an SQM value of 19.63. An SQM reading was made on a night with a waxing crescent, shortly before half-moon, (moon age 5.4, and KStars moon magnitude = -10). The SQM reading at zenith showed the sky to be much brighter with measured value of 18.48. A reading taken on a night with a waxing gibbous, shortly before a full moon, (moon age 12.4, and KStars moon magnitude = -12). The SQM reading at zenith showed a measured SQM value of 15.95.</para> <para>The value of Sky Quality has a drastic impact on the calculated exposure because of the logarithmic scale involved. An image taken from a location with heavy light pollution (a low sky quality value), especially when filtering is not applied, may result in a very short exposure time to prevent light pollution from overwhelming the target signal. An image taken from a location with very little light pollution (a high Sky Quality value) may result in an sub-exposure time of several hours.</para> @@ -559,7 +559,7 @@ Even within the bands that filters are intended to pass, filters are not 100% ef <para>Camera sensors are one of two types: "Charge Coupled Device" (CCD) or "Complementary Metal-Oxide Semiconductor" (CMOS). For the exposure calculation the main difference between these sensor types is that CCD sensors do not have a variable gain setting that would impact the read noise; so a CCD sensor will have a single constant value for its read noise. A CMOS sensor does have a variable gain (or ISO value), and changes to that setting usually result in a change to the read noise.</para> <para>The exposure calculator relies upon the selection of a camera data file so that it can access an appropriate read noise value for use in the calculation. The camera selection drop down allows the user to select an appropriate camera data file. For a CCD camera the file will only hold a single read noise value, but for a CMOS camera the file includes a table (or a few tables) of values which relate the gain or ISO value to a read noise value. Do not be confused by "CCD" appearing in the names of many dedicated astrophotography cameras, most of these cameras are using CMOS sensors. </para> - <para>The camera data files provided in KStars contain values which are transcribed from manufacturers technical documentation. But actual read noise values for a camera may vary from the published data; so a user may which to utilize a tool that can determine the read noise values for their specific camera. Dr. Glover provides a sensor analysis tool in his MS-Windows based product SharpCap <ulink url= "https://www.sharpcap.co.uk/sharpcap/features/sensor-analysis";>SharpCap Sensor Analysis</ulink> The specific data from such a tool can be used to create a customized camera data file for use with the KStars exposure calculator.</para> + <para>The camera data files provided in KStars contain values which are transcribed from manufacturers technical documentation. But actual read noise values for a camera may vary from the published data; so a user may which to utilize a tool that can determine the read noise values for their specific camera. Dr. Glover provides a sensor analysis tool in his MS-Windows based product SharpCap <ulink url="https://www.sharpcap.co.uk/sharpcap/features/sensor-analysis";>SharpCap Sensor Analysis</ulink> The specific data from such a tool can be used to create a customized camera data file for use with the KStars exposure calculator.</para> </listitem> <listitem> <para><guilabel>Read Mode</guilabel>: Some cameras manufactured by QHY have the capability to function in multiple modes. These modes alter the read noise values, so the camera data files for these cameras include multiple read noise tables. When using one of these multi-mode cameras the Read Mode dropdown will become enabled, and allow the user to select the read mode table that would correspond to the mode in which the camera will be operated for imaging.</para>
