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en:ost:ccds:astrofotografie [2016/10/25 23:50] – [Darkframes + Flatfields] rhainich | en:ost:ccds:astrofotografie [2021/06/21 13:16] (current) – [Photography with a DSRL] rhainich | ||
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====== Astro photography ====== | ====== Astro photography ====== | ||
- | The OST can, of course, be used for astro photography. Since two of our [[en: | + | The OST can, of course, be used for astro photography. Since three of our [[en: |
The images can be found in our [[en: | The images can be found in our [[en: | ||
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| | ||
* useful webpages: | * useful webpages: | ||
- | * [[ttp://www.calsky.com/|CalSky]] | + | * [[https://telescopius.com | Telescopius]] |
* [[http:// | * [[http:// | ||
* further websites can be found [[en: | * further websites can be found [[en: | ||
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==== Filter choice ==== | ==== Filter choice ==== | ||
- | There are several different | + | There are several different [[en: |
==== Exposure times ==== | ==== Exposure times ==== | ||
* extend here -- maybe a small galery | * extend here -- maybe a small galery | ||
- | * [[http:// | + | * [[http:// |
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*Flatfields | *Flatfields | ||
- select the same filter as used for the " | - select the same filter as used for the " | ||
- | - attach (carefully!) the flatfield foil (from the lab room , 1.113) and switch it on (power supply in the locker in the dome) | + | - attach (carefully!) the flatfield foil (from the lab room , 2.009) and switch it on (power supply in the locker in the dome) |
- please note, the flatfield foil must evenly illuminate the whole aperture of the telescope | - please note, the flatfield foil must evenly illuminate the whole aperture of the telescope | ||
- | - take a number of exposures with short exposure times (around 3 seconds), prevent the CCD from overflowing | + | - take a number of exposures with short exposure times (around 3 seconds), prevent the camera chip from overflowing |
| | ||
==== Data reduction / Stacking ==== | ==== Data reduction / Stacking ==== | ||
- | | + | \\ |
+ | **Data reduction by means of //[[http:// | ||
- drop bad raw frames (note the total exposure time) | - drop bad raw frames (note the total exposure time) | ||
- | - create | + | - create |
- | - create | + | - create |
- | - create | + | - create |
- | - subtract the Masterdark | + | - subtract the master dark from the raw images |
- | - add up the images (for each filter) | + | - divide that images by the corresponding master flats |
- | - devide that image by the Masterflatdark | + | - add up the images (in each filter) |
- if needed, compensate for different exposure times | - if needed, compensate for different exposure times | ||
- | - mark common objects in the images | + | - mark two common objects in the images |
- | - combine the RGB-image (with offsets) | + | - combine the exposures to a RGB-image (with offsets) |
- | - if the offsets are not good enough, mark the regions | + | - if the offsets are not good enough, mark a characteristic region (e.g. a star) in the RGB-image |
- | - define | + | - define |
- cut the image | - cut the image | ||
==== Postprocessing ==== | ==== Postprocessing ==== | ||
- | * in the finishing | + | In the postprocessing |
- | -via fitswork: | + | |
- | -via PS/Gimp ... see there ;-) | + | |
- | ===== Photography with the DSRL ===== | + | ===== Photography with a DSRL ===== |
- | * if the correct adapter (T-Ring) is available, one can also make use of the Canon EOS at the telescope | + | We also have a Canon EOS 700D, which is a digital (single) reflex camera (DSLR). This camera allows |
- | * such exposures can be interesting | + | |
- | * interesting | + | Interesting |
- | * planeten | + | * planets |
- | * the moon | + | * the Moon |
* comets | * comets | ||
- | * cranes, trees, buidlings etc. (daytime) | ||
- | ===== Photography with the Webcam | + | We also have an article on [[en: |
+ | |||
+ | <WRAP center round info 60%> | ||
+ | **Our new camera, the QHY600M, is a CMOS camera and therefore also allows much shorter exposure times than the old CCD cameras and on the other hand does not have the disadvantages of a DSLR camera, such as a high dark current. More about this when we have more experience... :-).** | ||
+ | </ | ||
+ | |||
+ | ==== Lucky imaging how-to ==== | ||
+ | This part will hopefully be filled soon... | ||
+ | ===== Photography with a video camera | ||
* we own one of these, too ;-) | * we own one of these, too ;-) | ||
- | * see lucky imaging howto | + | |
- | | + | \\ |
+ | **To be continued...** |