| Object : | M13, Globular Cluster |
| Coordinates/Direction : | RA: 16h41m, DEC: +36o27' |
| Object size : | 20' |
| More to know : |
Wikipedia:
https://en.wikipedia.org/ wiki/ Messier 13 |
| Date : | 2021-03-18 |
| Time (UT) : | 21:45 to 23:59 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, Guide telescope 200 mm f/3.5, camera QHY5 |
| Lens/telescope : | Pentax 645 ED medium format, 300mm f/4 |
| Corrector/Barlow : | - |
| Field (FOV) : | 6.8x4.5 degree, before cropping |
| Filter : | none |
| camera : | Canon 6D, controlled by APT software |
| Film/CCD : | Raw |
| Exp. time : | 27x30 seconds, 58x60 seconds, ISO1600 |
| Image process tool : | AstroImageJ, Fitswork, IrfanView |
| Processing : | demosaic, synthetic flat calibrated, hot pixel removed by dithering, level |
| Weather : | clear sky |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
Things start to work now with my new used Pentax medium format lens. Motor focus excellent, auto focus some times.
Problems left to solved, there is some tilt of the sensor because of the adapter doesn't fit very well, project Pentax 645 300mm.
When this problem is solved I have a very high performance lens that have low vignetting even at full frame. |
| Date : | 2021-03-18 |
| Image process tool : | AstroImageJ, Fitswork, IrfanView |
| Processing : | demosaic, synthetic flat calibrated, hot pixel removed by dithering, level, crop |
| Comment : |
Zoom in to the core of M13, 1:1 pixel relation. |
| Date : | 2020-03-12 |
| Time (UT) : | 22:29 to 00:45 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, Guide telescope 400 mm f/6.3, camera QHY5 |
| Lens/telescope : | TS130, 910mm f/7 |
| Corrector/Barlow : | Flat field corrector 3" x1 |
| Field (FOV) : | 2.25x1.5 degree, before cropping |
| Filter : | none |
| camera : | Canon 6D, controlled by APT software |
| Film/CCD : | Raw |
| Exp. time : | 93x60 seconds, ISO1600 |
| Image process tool : | AstroImageJ, Fitswork, IrfanView |
| Processing : | demosaic, synthetic flat calibrated, hot pixel removed by dithering, level |
| Weather : | clear with drifting clouds |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
Now in Mars I have the globular cluster M13 in Eastern direction, we had a clear sky this night and I started up the telescope.
I got a total exposure of 93 minutes, the images in the middle are a bit of focus.
This time I flat calibrated the image with the new tool Flatfield.
It make a synthetic flat frame adapted mathematically to the optics vignetting.
No problem with old flat frames that are not updated to a cleaned sensor, and no problem with reflections in the telescope that destroy the flat frame.
Compare with the photos below.
Stains and dust on the sensor is a big problem, you can see here:
'cleaning sensor' how I fight it (only Swedish). |
| Date : | 2020-03-12 |
| Image process tool : | AstroImageJ, Fitswork, IrfanView |
| Processing : | demosaic, synthetic flat calibrated, hot pixel removed by dithering, level, crop |
| Comment : |
Zoom in to the core of M13, 1:1 pixel relation. |
| Date : | 2019-03-19 |
| Time (UT) : | 22:11 to 23:41 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode, Guide telescope 400 mm f/6.3, camera QHY5 |
| Lens/telescope : | TS130, 910mm f/7 |
| Corrector/Barlow : | Flat field corrector 3" x1 |
| Field (FOV) : | 2.25x1.5 degree, before cropping |
| Filter : | none |
| camera : | Canon 6D, controlled by APT software |
| Film/CCD : | Raw |
| Exp. time : | 62x60 seconds, ISO1600 |
| Image process tool : | AstroImageJ, Fitswork, IrfanView |
| Processing : | demosaic, flat calibrated, hot pixel removed by dithering, level |
| Weather : | clear, Moon |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
Globular cluster are one of the few objects that you can catch even if the light pollution is high.
This is the first image of M13 where I have the telescope setup for 910 mm focal length.
Compare with the photos below. |
| Date : | 2016-09-03 |
| Time (UT) : | 19:54 to 20:55 |
| Mount : | Star Adventurer |
| Guide : | - |
| Lens/telescope : | Sigma APO 150mm f/2.8 (set to f/4.0) |
| Corrector/Barlow : | - |
| Field (FOV) : | 13.6x9.1 degree, before cropping |
| Filter : | none |
| camera : | Canon 6D, controlled by intervallo meter |
| Film/CCD : | Raw |
| Exp. time : | 29x120 seconds, iso400 |
| Image process tool : | AstroImageJ, Fitswork |
| Processing : | demosaic, flat, hot pixel removed by dithering, level |
| Weather : | clear |
| Site : | Sweden, Mariestad. Bortle class 4 |
| Comment : |
Wide angle version, at this photo M13 looks like a bright star.
This photo was taken under the Mariestad Starparty, Under the Stars. We got a very dark night almost free from clouds.
It gave me a chance to do more test with different setting.
This time I lowered the iso setting to 400 to achieve more dynamic.
The image is processed in the AstroImageJ software which I have developed macros to.
It need that I have taken the images with dithering, now I didn't had that possibility with this mount,
but polar align was not perfect so I got some kind of dithering, enough to get rid of the hot pixels.
The Sigma 150mm APO 2.8 give me very sharp stars compare to other lenses I have.
And it will be better when I have practice the polar align process better. |
| Date : | 2016-03-01 |
| Time (UT) : | 00:44 to 02:02 |
| Mount : | EQ6 controlled by EQMOD |
| Guide : | PHD2 in dithering mode and QHY5 camera off-axis |
| Lens/telescope : | TS130, 910mm f/7 (682mm, f/5.3) |
| Corrector/Barlow : | Riccardi flat field corrector 2.5" x0.75 |
| Field (FOV) : | 3x2 degree, before cropping |
| Filter : | none |
| camera : | Canon 6D, controlled by APT software |
| Film/CCD : | Raw |
| Exp. time : | 33x120 seconds, iso800 |
| Image process tool : | Fitswork, Irfanview |
| Processing : | crop, level, no cal dark&bias, only dithering, crop |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
A new shot on M13, no calibration, only dithering to get rid of hotpixels. |
| Date : | 2016-02-24 |
| Time (UT) : | 00:12 to 01:34 |
| Mount : | EQ6 controlled by EQMOD |
| Lens/telescope : | TS130, 910mm f/7 (682mm, f/5.3) |
| Corrector/Barlow : | Riccardi flat field corrector 2.5" x0.75 |
| Field (FOV) : | 3x2 degree, before cropping |
| Filter : | none |
| camera : | Canon 6D |
| Film/CCD : | Raw |
| Exp. time : | 60x60 seconds, iso800 |
| Image process tool : | Fitswork, Irfanview |
| Processing : | resize, level, no cal dark&bias, only dithering |
| Weather : | clear, full moon |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
First shot with my Canon 6D on M13. |
| Comment : |
A zoom in to the core of M13, pixel 1:1 relation.
In the future I will use the dithering technique as an alternative to dark&bias calibration.
It doesn't work perfect today, but I will test out the settings to get it to work better.
The sharpness wasn't perfect this time and the full moon also disturb, |
| Date : | 2015-03-16 |
| Time (UT) : | 00:09 to 01:37 |
| Mount : | EQ6 controlled by EQMOD |
| Lens/telescope : | TS130, 910mm f7 (682mm, f5.3) |
| Corrector/Barlow : | Riccardi flat field corrector 2.5" x0.75 |
| Field (FOV) : | 3x2 degree, before cropping |
| Filter : | none |
| camera : | Canon 5D |
| Film/CCD : | Raw |
| Exp. time : | 43x60 seconds, iso800 |
| Image process tool : | Fitswork, Irfanview |
| Processing : | resize, level, cal dark&bias |
| Weather : | clear |
| Site : | Sweden, Stockholm, Hagsätra. Bortle class 9 |
| Comment : |
An easy shot even under my light polluted area. |
English
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