Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_solar_25_winners.thumb.jpg.fe4e711c64054f3c9486c752d0bcd6f2.jpg

Search the Community

Showing results for tags 'optics'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Welcome
    • Welcome
  • Beginners
    • Getting Started General Help and Advice
    • Getting Started Equipment Help and Advice
    • Getting Started With Observing
    • Getting Started With Imaging
  • Community
    • Official SGL Announcements and Events
    • SGL Challenges and Competitions
    • SGL Star Parties
    • Star Parties & Astro Events
    • Celestial Events Heads Up
    • The Astro Lounge
  • Retailers
    • Sponsor Announcements and Offers
    • FLO Clearance Offers
    • Supplier Reviews
  • Astro Classifieds
    • For Sale / Swap
    • Wanted
  • Equipment
  • Observing
  • EEVA (Electronically Enhanced Visual Astronomy)
  • Imaging
  • Science
  • WADAS's WADAS Discussion Forum
  • Beaufort Club's Topics
  • Swindon Stargazers Club's Topics
  • East Midlands Stargazers''s Topics
  • Central Scotland Astro's Topics
  • SGL Cumbrian Skies's Topics
  • Herts, Beds and Bucks Group's Topics
  • SGL East Anglian Group's Topics
  • South Leicester Observers's Topics
  • South Wales Group's Topics
  • SGL Surrey Observers's Topics
  • South Yorkshire Stargazers's Topics
  • Yorkshire Astronomers's Topics
  • Devon and Cornwall's Topics
  • West Midlands's Topics
  • Essex Cloud Dodgers's Topics
  • Essex Cloud Dodgers's New equipment
  • NLO and Planetarium's Topics
  • Astronomical Society of Edinburgh's Discussion
  • Dorset Stargazers's Topics
  • Hairy Stars Club (Comets)'s Tutorials and Guides
  • Hairy Stars Club (Comets)'s General Discussion
  • Hairy Stars Club (Comets)'s Observing Campaigns
  • Hairy Stars Club (Comets)'s Analysis results
  • Hairy Stars Club (Comets)'s Useful Links
  • Pixinsight Users Club's Pixinsight Discussion Forum

Calendars

  • Astro TV
  • Celestial Events
  • SGL Calendar
  • Astro Society Events
  • Star Parties
  • WADAS's Events
  • Beaufort Club's Events
  • Astronomical Society of Edinburgh's Events
  • Dorset Stargazers's Events

Blogs

There are no results to display.

There are no results to display.


Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


AIM


MSN


Website URL


ICQ


Yahoo


Jabber


Skype


Interests


Location

Found 36 results

  1. Hi, I spend a day here to analyze my master flats and what vignetting I have on my lenses and telescopes. It's very simple done but still interesting to set figures on it. It's done on a full frame camera and I use the values from the center and the corner of the sensor. The corner is 22 mm of from the center on a full frame sensor. I never liked to have strong vignetting in my optics, and in the future I want to go for bigger size than full frame. I have put together a page over the vignetting I got: http://www.astrofriend.eu/astronomy/projects/project-different-lenses-vignetting/01-different-lenses-vignetting.html Maybe interesting for some of you to have a look at. My telescope shall handle a medium format sensor of the size 48 x 36 mm with the setup I have now. My medium format optics already do it. Just missing the medium format camera. /Lars
  2. Update 16th June: I could not wait to tell people that I was just notified that my image of Omega Centauri will be published as a future NASA's Astronomy Picture of the Day ( APOD ) - my first ever I will update the thread when they publish. ................................. A deep look at Omega Centauri ( NGC 5139 ) This image is an attempt to look deeply into the the Omega Centauri globular cluster by using HDR techniques to record as many faint stars as I can whilst retaining colour and detail in the bright stars, including at the core ... ............. Reprocessed to bring out more faint stars and to produce a smother transition between brightness levels. New version ( 12 June 2017 ): Omega Centauri ( NGC 5129 ) ( please click / tap on image to see lager and sharper ) .......... Old version: Omega Centauri ( NGC 5129 ) ( please click / tap on image to see full size and sharper ) Image details: from www.nova.astrometry.net: Size: 58.6 x 39 arcmins, Centre: 13h 26 min 50.4 sec, -47deg 28' 39.1''. Orientation: up is -89.9 East of North ( ie. E^ N> ). Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1410mm f4.7. Mount: Skywatcher AZ Eq6 GT. Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 . Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels). No filter Long Exposure noise reduction off Location:. Blue Mountains, Australia. Moderate light pollution ( pale green zone on darksitefinder.com map ). Capture: 9 sets of sub-images with exposure duration for each set doubling ( 1s to 240s ) all at ISO800. Processing:. Calibration: master bias, master flat and no darks. Integration in 9 sets. HDR combination. Pixinsight May 2017
  3. Hey guysIm really struggling with an issue. Recently purchased an Orion ST80. At 20x to 44x using stock 20mm/9mm eyepieces stars look pretty good. But if I test it at 175x using 2.3mm eyepiece and point to bright star I get the pattern like in the images below.Will unscrewing the ring and tapping on the side of the tube resettle the lenses? Or is this an alignment/collimation issue that isnt fixed easily? Defocused, the center circle isn't too off the centre..but focused in, it looks like a cone. Really annoying. If I send this back, no guarantees that the next one will be any better. Or is this typical for type of scopeThanks in advance!
  4. Carina Nebula with the bright unstable star Eta Carinae in the centre of the image. edit ( 27 March ): Tweak to shadow levels to bring out more detail and also a slight reduction in the brightness of the highlights. A much larger version ( 4562 x 3072 6062 x 4082) is available on my Flickr page. previous version: Carinae Nebula ( NGC 3372 ) ( please click / tap on image to see larger and sharper ) From Wikipedia ... "Eta Carinae is a highly luminous hypergiant star. Estimates of its mass range from 100 to 150 times the mass of the Sun, and its luminosity is about four million times that of the Sun." This HDR image is constructed from 12 sets of exposures ranging from 1/8 sec ( to capture the bright centre of Eta Carinae ) through to 240 seconds. Total exposure time around 13 hours 17-19 March 2018 Image details: Objects in image: Hypergiant, Eta Carinae ( HD 93308 ) in the centre of the Homunculus Nebula Carina Nebula ( NGC 3372 ) Keyhole Nebula Open Star Clusters: - Trumpler 14, 15, 16 - Collinder 232 Field of view ..... 59' 18.2" x 39' 56.0" Image centre ...... RA: 10 45 01.762 Dec: -59 40 52.87 Orientation: North is up Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 17, 18 & 19 March 2018 ): 12 sets of sub-images with exposure duration for each set doubling ( 1/8s to 240s ) all at ISO250. ( 181 x 240sec + 10 to 20 each for the other durations ) Processing: Calibration: master bias, master flat and master dark Integration in 12 sets HDR combination Pixinsight March 2018
  5. Update: 3rd June Re-processed to remove slight magenta tint caused by the non-uniform removal of light pollution by the DBE process ( it was being fooled by the very bright image centre ). The globular star cluster Omega Centauri ( NGC 5139 ) in Centaurus ( please click / tap on image to see larger and sharper ) A full size image can be found here. original below ..... A newly captured ( May 2018 ) image of the great southern globular star cluster, Omega Centauri ( NGC 5139 ) Omega Centauri ( NGC 5139 ) in Centaurus - ( please click / tap image to see larger and sharper ) A full size ( ~ 6000 x 4000 ) image can be found here ....... This image is an attempt to look deeply into the mighty Omega Centauri star cluster and, by using HDR techniques, record as many of its faint members as possible whilst capturing and bringing out the colours of the stars, including in the core. Image details: Resolution ........ 0.586 arcsec/px ( full size image ) Rotation .......... 0.00 deg ( up is North ) Focal ............. 1375.99 mm Pixel size ........ 3.91 um Field of view ..... 58' 20.9" x 38' 55.1" Image center ...... RA: 13 26 45.065 Dec: -47 28 27.26 Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher Eq8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels)\ Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( May 2018 ) 8 sets of sub-images with exposure duration for each set doubling ( 2s to 240s ) all at ISO 250. Processing: Calibration: master bias, master flat and master dark Integration in 8 sets HDR combination Pixinsight May 2018
  6. Galaxy NGC 4945 in Centaurus Details: Galaxy NGC 4945 in Centaurus 19 May 2018 Orientation: North is up Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7\ Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.91um pixels) image Plate Solver script version 5.0 =========== Resolution ........ 0.586 arcsec/px Rotation .......... North is up Focal ............. 1375.43 mm Pixel size ........ 3.91 um Field of view ..... 43' 27.2" x 28' 54.2" Image center ...... RA: 13 04 51.790 Dec: -49 30 37.17 ========== Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 19 May 2018 ): 10 sets of sub-images with exposure duration for each set doubling ( 1/2th sec to 240 sec ) all at ISO250. ( 41 x 240sec + ~8 each forthe other durations ) Processing: Calibration: master bias, master flat and master dark Integration in 10 sets HDR combination Pixinsight May 2018
  7. Hello! So I have been an amateur astronomer since last few years and now I see that so many people have asking me about general telescope suggestions. (Guess the next step will be helping to set up small observatories...Ah dreams!) We don't have many telescope brands available. The major brands that are available here are Meade, orion, celestron and skywatcher. The confusion starts to rise when the other party is interested in little larger scopes like 8 inch sct or 12 inch reflector with eq mount or dobsonian mount. Would like to know overall experience that you guys have had with these brands like optical tubes, mount, eyepiece etc. Sort of like "this is good, this is not so good" type. For e.g. I have used celestron 6 inch sct, 12 inch (sort of) sct and 102mm short tube refractor. Although I love their optics, I haven't had good experience with their mounts. Meade : Used their 8 inch sct with fork mount (and liked it). Used their 90 mm refractor and didn't like it much. Skywatcher has given balanced performance overall. Decent mount, decent optics, decent supplied eyepiece etc. Also, on the same topic, I am quite confused with how much importance does having a good telescope dealer has. As in we do have many dealers here, but many times I have experienced things like overpriced scopes, no decent guidance etc. If I suggest just one dealer with whom I hadam good experience then it looks like biased opinion.
  8. Also known as the Theta Carinae Cluster, The Southen Pleiades is a very bright open cluster in the Carina constellation. It was discovered by Abbe Lacaille during his visit to South Africa in 1752. Containing around 60 stars, IC 2602 shines with an overall magnitude of 1.9 and its brightest member is Theta Carinae with a visual magnitude of 2.7. This cluster of young blue stars is relatively close to us at "only" 479 light years. 5 May 2018 The Southern Pleiades ( IC 2602 ) in Carina ( please click / tap on image to see larger and sharper ) ......... Image details: Orientation: North is up Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.91um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 5 May 2018 ): 14 sets of sub-images with exposure duration for each set doubling ( 1/30th sec to 240 sec ) all at ISO250. ( 22 x 240sec + at least 10 each forthe other durations ) Processing: Calibration: master bias, master flat and master dark Integration in 14 sets HDR combination Pixinsight May 2018
  9. The Jewel Box ( NGC 4755 ) is an open cluster of mostly hot young blue-white stars that appears to the unaided eye as a bright 4th magnitude star close to the Southern Cross. Only visible from southern latitudes, the Jewel Box was first recorded by Nicolas Louis de Lacaille during his visit to South Africa in 1751 and was later described by Sir John Herschel as "a casket of variously coloured precious stones" - hence the name "Jewel Box". The Jewel Box open star cluster ( ngc 4755 ) in Curx ( please click / tap on image to see larger and sharper ) Please see here for image details.
  10. The Jewel Box ( NGC 4755 ) is an open cluster of mostly hot young blue-white stars that appears to the unaided eye as a bright 4th magnitude star close to the Southern Cross. Only visible from southern latitudes, the Jewel Box was first recorded by Nicolas Louis de Lacaille during his visit to South Africa in 1751 and was later described by Sir John Herschel as "a casket of variously coloured precious stones" - hence the name "Jewel Box". The Jewel Box Open Cluster ( ngc 4755 ) in the Crux constellation. ( please click / tap to see larger and sharper ) ........... Image details: Orientation: North is up Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.91um pixels) image Plate Solver script version 5.0 =========== Resolution ........ 0.586 arcsec/px Rotation .......... 0.000 deg Focal ............. 1375.43 mm Pixel size ........ 3.91 um Field of view ..... 58' 49.3" x 39' 17.8" Image center ...... RA: 12 53 40.040 Dec: -60 21 02.81 ========== Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 5 May 2018 ): 11 sets of sub-images with exposure duration for each set doubling ( 1/8th sec to 120 sec ) all at ISO250. ( 10 x 120sec + at least 10 each forthe other durations ) Processing: Calibration: master bias, master flat and master dark Integration in 11sets HDR combination
  11. “The Blue Bunny Nebula” .......... Edit: 27 Jan 2018 - updated again to try to draw more faint nebulosity out of the background; ( NGC 2359 - Thor’s Helmet ) ( please click / tap on image to see larger and without compression artefacts ( and double click on that image if you what to see it as I posted it ! ) ) ......... Edit: 24 Jan 2018 - stars a little brighter and tighter with no change to the rest of the image ( NGC 2359 - Thor’s Helmet ) ( please click / tap on image to see larger and without compression artefacts ( and double click on that image if you what to see it as I posted it ! ) ) ................. original: Thor's Helmet ( NGC 2359 ) in the constellation Canis Major Thor’s Helmet ( Duck Nebula, NGC 2359 ) ( please click / tap on image to see larger ) This HDR image shows the bright nebula Thor’s Helmet in a sea of colourful stars against a background of red from dust and HA emissions. The stars in this image range from the brightest ( bottom right, HD 56501 ) at magnitude +7.7 to around +20 or more. HDR capture and processing allows all of the stars to be portrayed in colour without any burnt-out highlights. The colours of the stars and nebula are as close as I can get them to their "true colours" by using a "daylight colour balance" and allowing for the extinction of blue-green due to atmospheric absorption/scattering ( mean altitude during capture ~ 60deg ). The blue star in the centre of the bubble of expanding stellar material is HD 56925 ( WR7 ) - a massive, unstable and short-lived Wolf-Rayet star that one day will detonate in a supernova. Image details: NGC 2359 Thor’s Helmet / Duck Nebula: Magnitude +11.5, RA (2000.0) 7h 15m 37s, Dec -13deg 12' 8", approx. 1800 light years away HD 56925 / Wolf-Rayet 7 ( WR7 ) ( blue 11.5 mag star at centre of “bubble” ) Haffner 6 ( open ster cluster centre left of image ) Plate Solution: Resolution ........ 1.318 arcsec/px Rotation .......... 0.00 deg ( North is up ) Focal ............. 1398.41 mm Field of view ..... 57' 40.8" x 38' 29.0" Image center ...... RA: 07 18 36.509 Dec: -13 11 53.38 Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1410mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( 18 & 19 Jan 2018 ) 9 sets of sub-images with exposure duration for each set doubling ( 1s to 240s ) all at ISO 250. 116 x 240s + 5 each @ 1s to 120s Processing ( Pixinsight - 20 Jan 18 ) Calibration: master bias, master dark and master flat Integration in 9 sets HDR combination arcSinH stretch
  12. The Fighting Dragons of Ara ( NGC 6188 ) ( please click / tap on image to see larger ) The Fighting Dragons of Ara ( NGC 6188 ) Bright Nebula NGC 6188 and open cluster NGC 6193 are embedded 4,300 light years away in the Sagittarius arm of our Milky Way galaxy and can be seen with the naked eye south of Scorpius in the constellation of Ara. With powerful stellar winds and energetic ultra-violet radiation, massive stars sculpt the interstellar gas and dust of the nebula into wonderful shapes and cause the interstellar gas to brightly fluoresce. Closer to the hot young stars of the cluster, bright blue “sunlight” reflects off the clouds of gas and dust to produce the blue reflection nebulae seenin the image. Magnitude +5.19, RA 16h 41m 42s, Dec -48deg 48' 46". Approx. 3800 light years away. Image details: This is an HDR image constructed from exposures ranging from 2 seconds to 240 seconds in length. The aim was to capture the faint stars and details in the nebula whilst at the same time maintaining colour in the bright stars without clipping the highlights. Plate Solution: Resolution ........ 1.336 arcsec/px Rotation .......... 90.002 deg ( North is to the right ) Focal ............. 1475.57 mm Pixel size ........ 9.56 um Field of view ..... 58' 28.5" x 39' 0.8" Image center ...... RA: 16 40 09.903 Dec: -48 41 27.00 Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1410mm f4.7. Mount: Skywatcher AZ Eq6 GT. Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 . Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels). Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ). Capture ( 24 June 2017 ). 8 sets of sub-images with exposure duration for each set doubling ( 2s to 240s ) all at ISO800. 34 x 240s + 10 each @ 2s to 120s. Processing ( Pixinsight - 19 Aug 2017, 13 Jan 2018 ). Calibration: master bias, master flat and no darks. Integration in 8 sets. HDR combination. ......... This is a reprocessed version using the data I captured earlier in the year...
  13. Greetings from cloudy and cold NJ! I recently had a lens replaced on a 102mm refractor, 1000mm FL, f/9.8, due to undercorrection of something more than 1/3 λ. The Ronchi lines seen in the double pass autocollimation test with an oil flat were significantly curved. The test is, of course, quite sensitive and allows one to see spherical aberration very easily. The new replacement lens is far better in that respect and a definite improvement over the original. It also shows a measure of undercorrection and I'm wondering if anyone familiar with the test and reading the images would hazard a guess as to the approximate wavefront quality of the lens. Nothing precise, just an estimate would be very much appreciated. Here are the specifics: Lens: 102mm, 1000mm FL, f/9.8 achromat. Ronchi grating: 150 lines per inch or 5.9 lines per mm. Oil flat, Double Pass Autocollimation. The distortions in the shape of the images are due to imprecise alignment and the variations in the line thickness from uneven illumination and slight oil movement. Of course, the 3 image diffraction overlap of the test gives a false impression of the poor edge quality. As I say, anyone who may have a knowledge and experience with the test and an idea as to what these results might translate to would offer an opinion as the the wavefront quality, or a range of same, I would greatly appreciate the information, for nothing else than curiosity about the new lens and a feel for the test. I'm quite happy to have received a much improved lens and I am sure it will be very satisfactory for use. Thanks very, very much! Joe.
  14. A pioneering technology capable of atomic-level precision is now being developed to detect what so far has remained imperceptible: gravitational waves or ripples in space-time caused by cataclysmic events including even the Big Bang itself. http://www.nanowerk....ewsid=27045.php
  15. The Cat's Paw Nebula ( NGC 6334 ) in Scorpius updated ( slight tweak to colour balance, a little brighter and tad more contrast ) ( please click / tap on image to see larger and sharper - a full size image can be seen here ) ...... original: ( please click / tap on image to see larger and sharper - a full size image can be seen here ) ……………………... Also known as the Bear Claw Nebula, NGC 6334 is an emission nebula near the scorpion's tail in the Scorpius constellation. Image details: Image centre ...... RA: 17 20 08.185 Dec: -35 52 30.91 Field of view ..... 57' 37.8" x 38' 51.8" Rotation .......... 0.00 deg ( North is up ) Resolution ........ 0.586 arcsec/px Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1470mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ) Capture ( July 2018 ) 6 sets of sub-images with exposure duration for each set doubling ( 4s to 240s ) all at ISO 250. 168 x 4 min frames plus ~10 frames each for the shorter exposures Processing: Calibration: bias, dark and flat Integration in 8 sets HDR combination Pixinsight July 2018
  16. I ran into this abomination in a local random junk classified ad, seller does not say much other than its a telescope, i have no intentions of buying a scope that looks like it fell form the ugly tree and hit every branch on its way down lol. can anybody identify this scope which certainly only its mother can love?
  17. Spiral Galaxy NGC 6744 in Pavo NGC 6744 is a Milky Way like barred spiral galaxy in the constellation Pavo. Visible only from lower latitudes, the light we see now left this galaxy around 25 million years ago. NGC 6744 in Pavo ( please click / tap on image to see larger and sharper ) Capture Details: North is up. Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1400mm f4.7. Mount: Skywatcher EQ8. Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 . Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels). Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ). Capture ( 16, 17, 19 Sept. 2017 ). 9 sets of sub-images with exposure duration for each set doubling ( 1s to 240s ) all at ISO800. 85 x 240s + 5 each @ 1s to 120s. Processing ( Pixinsight - 5-17 Nov 2017 ). Calibration: master bias, master flat and no darks. Integration in 9 sets. HDR combination PhotometricColorCalibration Arcsinh stretch ( function written by Mark Shelley ) Image Plate Solver - NGC 6744 - Sept 17, 2017 =================================== Resolution ........ 0.586 arcsec/px ( full size image ) Rotation ............ 0.001 deg. Focal ................. 1372.24 mm. Pixel size ........ ..3.90 um. Field of view ..... 58' 30.3" x 38' 59.0". Image center ...... RA: 19 09 46.591 Dec: -63 51 13.44 ==================================
  18. ( Edit 20 Aug: adjusted to increase brightness ) ... The Fighting Dragons of Ara ( NGC 6188 ) ( please click/tap on image to see larger and sharper ) ...................... Original: The Fighting Dragons of Ara ( NGC 6188 ) ( please click/tap on image to see larger and sharper ) Bright Nebula NGC 6188 and open cluster NGC 6193 are embedded 4,300 light years away in the Sagittarius arm of our Milky Way galaxy and can be seen with the naked eye south of Scorpius in the constellation of Ara. With powerful stellar winds and energetic ultra-violet radiation, massive stars sculpt the interstellar gas and dust of the nebula into wonderful shapes and cause the interstellar gas to brightly fluoresce. Closer to the hot young stars of the cluster, bright blue “sunlight” reflects off the clouds of gas and dust to produce the blue reflection nebulae seenin the image. Magnitude +5.19, RA 16h 41m 42s, Dec -48deg 48' 46". Approx. 3800 light years away. Image details: Plate Solution: Resolution .......0.586 arcsec/px ( original full size image ). Rotation .......... 89.764 deg. Pixel size ........ 3.90 um. Field of view ..... 58' 41.6" x 39' 9.5". Image center ...... RA: 16 40 09.856 Dec: -48 41 22.50. Image bounds:. top-left ....... RA: 16 42 10.059 Dec: -49 10 30.54. top-right ...... RA: 16 42 06.489 Dec: -48 11 57.14. bottom-left .... RA: 16 38 11.010 Dec: -49 10 39.74. bottom-right ... RA: 16 38 11.897 Dec: -48 12 05.58. Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1410mm f4.7. Mount: Skywatcher AZ Eq6 GT. Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 . Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels). Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ). Capture ( 24 June 2017 ). 12 sets of sub-images with exposure duration for each set doubling ( 1/8s to 240s ) all at ISO800. 34 x 240s + 10 each @ 1/8s to 120s. Processing ( Pixinsight - 19 Aug 2017 ). Calibration: master bias, master flat and no darks. Integration in 12 sets. HDR combination PhotometricColorCalibration.
  19. My image of Omega Centauri ( NGC 5139 ) has been published as the NASA APOD for the 11th of July 2017 https://apod.nasa.gov/apod/ap170711.html Link to full size image on NASA site ( warning quite large - 4620 x 3720 ) Link to discussion of image on asterisk.apod.com ( credit apod.nasa.gov ) ( full size image - 4620 x 3720 ) Link to original post for this image back on the 10th of June
  20. Tarantula Nebula ( NGC 2070 ) in the Large Magellanic Cloud ( LMC ) Re-processed to tweak colour balance and bring out a little more faint detail: New version: Original: ( click/tap on image to see full size - the above compressed version looks a little soft; the full size version is sharper ) The Tarantula Nebula ( NGC 2070 ) is the largest and brightest emission nebula in the nearby irregular galaxy, the Large Magellanic Cloud ( LMC ). At a distance of 160,000 light years away from us, the Tarantula Nebula is so bright that it would cast shadows on the Earth if were as close to us as the Orion Nebula in our galaxy. First image with new telescope and autoguider/setup. Links: 500px.com/MikeODay photo.net/photos/MikeODay Details: Nebulae: NGC 2070 Tarantula Nebula NGC 2048 NGC 2060 NGC 2077. Open clusters: NGC 2042 NGC 2044 NGC 2050 NGC 2055 NGC 2091 NGC 2093 NGC 2100 Image centre RA 5h 38m 57.3s, Dec -69deg 20' 36.6" (nova.astrometry.net) Field of view (arcmin): 58.7 x 39.2 Scale (full size image) 0.585 arcsec/pixel. Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, FL1200mm, f4 ) Corrector: ASA 2" Coma Corrector Quattro 1.175x Effective Focal Length / Aperture ): 1410mm f4.7. Mount: Skywatcher AZ Eq6 GT Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Filter: none Exposures: 14 x 240 sec ISO400 12 x 120 sec ISO400 10 x 60 sec ISO400 11 x 60 sec ISO200 10 x 60 sec ISO100 10 x 30 sec ISO100 Pixinsight & Photoshop 20 December 2016
  21. Also known as the Theta Carinae Cluster, The Southen Pleiades is a very bright open cluster in the Carina constellation. It was discovered by Abbe Lacaille during his visit to South Africa in 1752. Containing around 60 stars, IC 2602 shines with an overall magnitude of 1.9 and its brightest member is Theta Carinae with a visual magnitude of 2.7. This cluster of young blue stars is relatively close to us at "only" 479 light years. 5 May 2018 The Southern Pleiades open star cluster ( IC 2602 ) in Carina ( please click / tap on image to see larger and sharper ) Image details can be found here.
  22. Hi there guys, i see a ton of knowledge in this forum (after been observing others forums too) and good tips, nobody shy of helping a newbie and that`s what i need. i am a over the road interstate trucker, meaning being for months at a time away from home (don`t matter, got wife and dog with me). Have been interested in the sky for a long time, but just recently decided that its the right time to begin watching the sky by myself and not only watching hubble`s pictures on the net. Alone the road in places like Arizona, New Mexico, Nevada and others places in the west of the USA, i have observed very nice spots with very little or none light pollution, observing the skies from there at night should be a stargazer dream. I have been considering a 8" dobsonian, but seeing that it have to go in the truck (space and weight matters, the tube it`s almost 3ft in length and the total weight is close to 50 pounds), i have choose to go down a little and go with a 6", my election is the one you see in my signature, a Orion StarBlast 6i IntelliScope Reflector Telescope. Being a novice , i assume it will make my life easier having some help finding objects in the sky. The similar model w/o intelliscope it`s $130 cheaper, what do you think about the intelliscope? Any experiences with it?, it`s worth it? It does have a tabletop mount, making it smaller than the ones on a tripod and a lot less heavier too, just 23.5 lbs. Will have to go in and out of the truck (lorry) every time i will want to watch the sky. For the reviews that i have seen in Amazon and other places, it`s looks like a good telescope, but i have noticed some complaints about the optics, what kind of optics do you recommend to go with it? it come with a 1.25 10 and a 25 mm Sirius Plossl, are they any good? It will need to have a Barlow too, which one do you guys recommend? 2X or 3x? brand? Filters, other that the moon filter, what are the useful ones to watch planets and deep space? any filter collection you know off with everything included? How can i take pictures with my phone from it? Thanks in advance for your help. Any useful tips, are welcome and really appreciated, thanks.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.