Announcement

Collapse
No announcement yet.

Astro Photos

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Re: Astro Photos

    Originally posted by birdboy View Post
    But I thought you have a goto mount Dave

    Great star image though.

    10 min exposures is a long time without narrowband filters so what ISO were you using and what is the effective aperture of your 550mm telescope lens?

    I have found that if I stop down with zuiko lenses I can get the star burst effect and assume its because when stopped down the blades of the iris contribute.
    The scope is 550mm focal length and 100mm aperture so its focal ratio is equivalent to an f/5.5 lens. I was at ISO 800. If you use a lens at a very small aperture you do get the star burst effect., not just four spikes. With a reflector scope the spikes are caused by the support struts for the secondary mirror and are quite normal, but I don't think refractors have them.

    When your field of view is 1 to 2 degrees you really have to work at getting the right target. My mount is a Go-To but they are nowhere near spot on, especially if they are not set up on a pier in a fixed location. Every time you set up on a tripod you have to re-do polar alignment. Polar alignment has to be as accurate as possible ( to avoid elongated stars on long exposures) last night I was 25 arc-second out which is pretty good.

    I use Carte du Ciel sky chart( free) which directly links to the mount via Ascom (also free), it reads the RA and DEC info from the mount and shows where it thinks the scope is pointing on the chart and you then confirm its pointing at a given star by looking through the eyepiece., Then you sync the RA and DEC readings with the mount and the chart. You can then click on a star on the chart and tell the scope to slew to that star. You can use the fine movements controls in Ascom to move the image so the star is central and again confirm that by sync the scope and chart. Once you have confirmed the target is right you can then start guiding with PHD2 which is brilliant and it keeps the target within < 1 arc second ( on a good viewing night).

    The mistake I made last night was that I had been messing with the Carte du Ciel and switched the time to 2 hours ahead of real time so I was slewing to the wrong place. There was no really recognisable star that I could guarantee was the target I wanted so I let it go ! thats my mistake. I used plate solving from this site http://nova.astrometry.net
    on the image afterwards to see exactly where I was pointing and I should done that after the first shot to confirm. I am going to try out astro tortilla to do live plate solving when I get my head around the set up.

    All good fun and it keeps me out of mischief!
    Dave

    My Flickr

    Comment


    • Re: Astro Photos

      Thanks Dave this is very informative for me as I have often considered going to a goto mount because of the difficulty finding the targets, but I half suspected that the initial set up is crucial to the accuracy of finding targets. The sales infor seems to suggest its easy.

      Just lately I've been concentrating on the wider angles of view cira 40-25deg using 25mm f 1.4 and 40mm f2.8 lenses. Because of where I am I am getting reflections on front of the glass. With the longer reaches I was able to extend the hood cover to cut out these reflections on the 300mm and 150mm. So Its all a learning game trying things out and seeing what works or more often what doesn't work with the kit you have. And so few clear nights to try.
      John

      OM-D E-M1, 12-40 f2.8 Pro, Tamron 14-150mm f5.8, E5, E3, Zuiko 50-200mm SWD, Zuiko 12-60mm SWD, Zuiko ED 70-300mm f5.6, 50mmf2, Zuiko ED 9-18mm f5.6, Sigma 50-500mm f6.3, EC14, EC20, RM-1, VA-1

      Comment


      • Re: Astro Photos

        Originally posted by birdboy View Post
        Thanks Dave this is very informative for me as I have often considered going to a goto mount because of the difficulty finding the targets, but I half suspected that the initial set up is crucial to the accuracy of finding targets. The sales infor seems to suggest its easy.

        .............. And so few clear nights to try.
        Don't get me wrong the GoTo mounts do get you pretty close to your target using their inbuilt star databases. If you are at a low magnification the star you want is usually in view. But getting accurate polar alignment is really critical, if you start from the wrong place then the further you slew the bigger the error becomes.

        I have started using Sharpcap (free) which in its latest release 2.9 has a polar alignment tool which works really well in good viewing conditions. It plate solves in an area about 5 degrees of the pole and in a couple of minutes shows you how to move your mounts RA and Dec adjustments to get it very close. Definetely less than 50 arc seconds and even down to less than 10 if you are patient. Worth having a look at. I already had my EM5mk2 mounted on my scope so my field of view was only 1.7 degrees which doesn't give much room for targeting error.
        Dave

        My Flickr

        Comment


        • Re: Astro Photos

          Finally managed to get out last night and had a go at Orion.
          Not happy with the processing on this one but this is how far I have got today. Need to work on the noise and alignment between different sets of exposures.

          [IMG][/IMG]


          This is the last shot taken with my em5mk2, as I sold it yesterday.
          Just ordered an EM1mk2
          Dave

          My Flickr

          Comment


          • Re: Astro Photos

            Originally posted by wornish View Post

            This is the last shot taken with my em5mk2, as I sold it yesterday.
            Just ordered an EM1mk2
            I do not think you will be disappointed with the EM1 MKII for astrophotography. I think it is a marked improvement on the previous OMD models. The live view boost seems to work better and quicker and the sensor noise much reduced.

            Here are some from the very cold nights this Jan 2017.
            Rosette Nebula



            M42


            Horse head and Flame nebula
            John

            OM-D E-M1, 12-40 f2.8 Pro, Tamron 14-150mm f5.8, E5, E3, Zuiko 50-200mm SWD, Zuiko 12-60mm SWD, Zuiko ED 70-300mm f5.6, 50mmf2, Zuiko ED 9-18mm f5.6, Sigma 50-500mm f6.3, EC14, EC20, RM-1, VA-1

            Comment


            • Re: Astro Photos

              Originally posted by birdboy View Post
              I do not think you will be disappointed with the EM1 MKII for astrophotography. I think it is a marked improvement on the previous OMD models. The live view boost seems to work better and quicker and the sensor noise much reduced.


              Wow !
              Very nice. Cant wait now.
              Your M42 is a bit more red compared to mine.
              But the noise is much better.
              Do you shoot in RAW and if so what software are you using to read them?
              Lightroom and PS dont support it yet.
              Dave

              My Flickr

              Comment


              • Re: Astro Photos

                Originally posted by wornish View Post
                Wow !
                Very nice. Cant wait now.
                Your M42 is a bit more red compared to mine.
                But the noise is much better.
                Do you shoot in RAW and if so what software are you using to read them?
                Lightroom and PS dont support it yet.
                Thanks Dave. Star tools colour seems to be a generous with saturation and this copy had it reduced. Always shoot RAW and LR 6.8 does read MKII RAW files. I am still stacking in DSS which reads them. Save as fits file and process in Star Tools.
                John

                OM-D E-M1, 12-40 f2.8 Pro, Tamron 14-150mm f5.8, E5, E3, Zuiko 50-200mm SWD, Zuiko 12-60mm SWD, Zuiko ED 70-300mm f5.6, 50mmf2, Zuiko ED 9-18mm f5.6, Sigma 50-500mm f6.3, EC14, EC20, RM-1, VA-1

                Comment


                • Re: Astro Photos

                  Completely re stacked all the different exposure groups as one in DSS

                  Got less noise and more detail, much happier with this version.

                  [IMG][/IMG]


                  Amazing difference to first version posted above.
                  Last edited by wornish; 22nd January 2017, 06:19 PM. Reason: Re processed from scratch
                  Dave

                  My Flickr

                  Comment


                  • Re: Astro Photos

                    Very beautiful and inspiring astro photos.
                    Instagram: gvnf

                    Comment


                    • Re: Astro Photos

                      Wow now that is something special Dave. Has this image changed since you first posted the 2nd image 2 days ago I do not remember it looking this detailed? So how many hours exposure does this equate to?
                      John

                      OM-D E-M1, 12-40 f2.8 Pro, Tamron 14-150mm f5.8, E5, E3, Zuiko 50-200mm SWD, Zuiko 12-60mm SWD, Zuiko ED 70-300mm f5.6, 50mmf2, Zuiko ED 9-18mm f5.6, Sigma 50-500mm f6.3, EC14, EC20, RM-1, VA-1

                      Comment


                      • Re: Astro Photos

                        Originally posted by birdboy View Post
                        Wow now that is something special Dave. Has this image changed since you first posted the 2nd image 2 days ago I do not remember it looking this detailed? So how many hours exposure does this equate to?
                        Well spotted, yes the original second image had detail but just didn't look right. I had stacked three groups separately 20 x 20sec, 20x60sec and 15x120 sec lights in DSS and then layered them them in PS to try and get more out of the bright core. But the alignment was out no matter how I tried to tweak it.

                        So I decided to re-stack them all together in one run of DSS this really fixed the alignment issue, but I did lose a little of the core detail. I found the noise level was lower as well. So I replaced the second image with this version rather than doing another post. Its amazing the difference between the first and final versions considering the only difference is post processing in PI.

                        I also discovered that using a high pass filter blended as overlay makes a big improvement in the detail on the final image. The total exposure time was still less than an hour.

                        Got my EM1-mk2 yesterday so can't wait to give it a go.
                        Dave

                        My Flickr

                        Comment


                        • Re: Astro Photos

                          Thanks for the update Dave I thought I was going mad.

                          One thing you will need to consider with your EM1 MKII is that you will not be able to stack the EM1 MKII frames with your previous OMD's frames in DSS as the frame sizes are different and it throws up an error. If you bin/resample each image then DSS will handle that. When I was trying PixInsight the star alignment performed on different size frames. I found stacking in PI better than DSS but could not bring myself to pay the high price of PI when I am happy using Star Tools.
                          John

                          OM-D E-M1, 12-40 f2.8 Pro, Tamron 14-150mm f5.8, E5, E3, Zuiko 50-200mm SWD, Zuiko 12-60mm SWD, Zuiko ED 70-300mm f5.6, 50mmf2, Zuiko ED 9-18mm f5.6, Sigma 50-500mm f6.3, EC14, EC20, RM-1, VA-1

                          Comment


                          • Re: Astro Photos

                            The clouds have cleared !

                            Just got a new lens and wanted to give it a try.

                            [IMG][/IMG]

                            I am very pleased with what it can do.
                            300mm with MC14 Teleconverter.
                            Dave

                            My Flickr

                            Comment


                            • Re: Astro Photos

                              Excellent detail. How many images for that one?
                              Stuff from Cuba
                              More stuff from Cuba
                              It all started here

                              Comment


                              • Re: Astro Photos

                                Great image Dave. Lovely crater detail.
                                John

                                OM-D E-M1, 12-40 f2.8 Pro, Tamron 14-150mm f5.8, E5, E3, Zuiko 50-200mm SWD, Zuiko 12-60mm SWD, Zuiko ED 70-300mm f5.6, 50mmf2, Zuiko ED 9-18mm f5.6, Sigma 50-500mm f6.3, EC14, EC20, RM-1, VA-1

                                Comment

                                Working...
                                X