Announcement

Collapse
No announcement yet.

Communal Night-Sky Photography Thread

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

  • Re: Communal Night-Sky Photography Thread

    Originally posted by birdboy View Post
    It is always interesting to see what others are achieving with different equipment. There have been a few good clear nights recently as evidenced by the images.

    Here is my Andromedia Galaxy with an integration time of 72mins taken on the EM1MKII and 300mm f4 +MC14 at 60secs ISO400 f5.6 no filters guiding or calibration files. Stacked in DSS and processed in Startools. The mount was a iOptron CEM25EC.

    I agree that it is very interesting to see what can be done with different equipment. Yours is especially useful to me, since it shows the result from no filter on an E-M1-ii . Post-processing is clearly a very important factor and once I have a few images, I shall try various techniques.


    I hope that your fibre strand proves to have been the problem and that there are no potentially expensive sensor issues.



    Sadly, I have been plagued by thin cloud and mist over the last few days, which prevented me from carrying out polar alignment.
    Mike
    visit my Natural History Photos website:
    http://www.botanicdesign.co.uk/Natur...story/home.htm

    Comment


    • Re: Communal Night-Sky Photography Thread

      Told you I would be wrong
      Glad you found the cause.
      Dave

      My Flickr

      Comment


      • Re: Communal Night-Sky Photography Thread

        Here are a couple of crescent moon shots from the last few days. Both single shots with the 40-150 and MC20 hand held.



        http://www.flickr.com/photos/flip_photo_flickr/

        Comment


        • Re: Communal Night-Sky Photography Thread

          Originally posted by wornish View Post
          Told you I would be wrong
          Glad you found the cause.
          I now do not think you are wrong Dave.

          I cleaned the sensor which was a bit dusty but still have the problem.

          I have noticed that somehow (probably old age) I have left the image stabilization ON on the camera body. I know it should be off. I do remember turning off the lens switch IS but looking at the exif I seemed to have left the in body image stabilization on auto. It seems that my EM5 MKII images also had image stabilization on as well but does not show the same markings. I am now thinking that the sensor IS on the EM1 MKII is more sensitive and maybe it is picking up the CEM25EC mounts drive vibrations.

          It now looks cloudy for a few nights so will not be able to test this out by taking images with it switched off.

          Here are 2 images that are taken during the processing in Startools which clearly show the vertical banding. The second one shows an RGB screen shot in the colour module of startools.

          Anyone any other explanations?




          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: Communal Night-Sky Photography Thread

            Hmm, certainly is strange. I have to say I don't really see how IS could cause this effect.

            I assume this is a stacked image?

            Have you tried any other processing software to make sure it's not some Startools anomaly?

            If you are happy to share the original image I can give it a quick burst in Pixinsight to see if that gives the same result.
            Dave

            My Flickr

            Comment


            • Re: Communal Night-Sky Photography Thread

              Yes it is a stacked image using DSS 4.2.3 Beta 1 so my stacked file is from this.. This version does not do any changes to the WB as requested by Startools. I will try stacking it using an older version of DSS. I am also using Startools 1.6Beta. I have tried it on an earlier version of Startools 1.3 and the band is still visible. I have also tried stacking in an older version of DSS 4.2.1.

              I want to believe that it is the IS and not a fault with the sensor itself.

              Have sent you a pm regarding the stacked fits file.
              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: Communal Night-Sky Photography Thread

                I am even more confused now. When I said that I left the IS on it was because I looked at the exif which reports IS on Mode 1. When I look at Olympus Workspace it reports IS Off for the same orf file!
                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: Communal Night-Sky Photography Thread

                  Not good news I am afraid.

                  It's certainly still there when processed in PI just using a basic stretch and curves.

                  About 1/4 of the image is darker on the right-hand side.

                  I really don't know what could be causing this.




                  Dave

                  My Flickr

                  Comment


                  • Re: Communal Night-Sky Photography Thread

                    Thanks for checking Dave.
                    It does appear that I have had the IS off. But exif reports IS On Mode 1 for the Em1 MKII and IS On Mode 2 for the EM5 MKII. Trying to find what the difference is.
                    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: Communal Night-Sky Photography Thread

                      Can you see evidence of the bands in the raw data? You can display these data without any de-mosaicing by using IRIS software from http://www.astrosurf.com/buil/iris-software.html or by using RawTherapee and selecting 'none' under the de-mosaicing options.
                      Mike
                      visit my Natural History Photos website:
                      http://www.botanicdesign.co.uk/Natur...story/home.htm

                      Comment


                      • Re: Communal Night-Sky Photography Thread

                        Thanks Mike I have tried stretching my RAW files but so far have been unable to see the banding. Even in Startools the luminous stretches do not show it. I will give IRIS a try over the weekend though.
                        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




                        • Handheld moon photo
                          ISO 200-F5.6--1/250/sec--420mm

                          by Mark Johnson, on Flickr

                          Comment


                          • The night sky images look really great if you set the forum to Dark Mode!
                            Dave

                            My Flickr

                            Comment


                            • Have you tried stacking in Sequator to se if the error persists?
                              chris
                              shetland

                              Comment


                              • Originally posted by birdboy View Post
                                Re: Communal Night-Sky Photography Thread

                                ...............Anyone any other explanations?..............
                                I've probably been staring at this for two long and, like Schiaparelli, seeing canals where there are none, but I began to feel I could see a regular 'grid' of squares of about 320 pixels side on your 1280x956 image.


                                Click image for larger version

Name:	processing-grid.jpg
Views:	46
Size:	697.8 KB
ID:	768756

                                I recall that in the old days of small amounts of computer memory, images often used to appear in blocks on the screen, as each chunk of data was processed. It led me to speculate whether, during the stacking and other processing, the data were similarly being divided into manageable chunks, for processing and then re-assembled into the full image.

                                If there were tiny discrepancies (perhaps rounding errors in the data) then the edges of some 'blocks' could remain visible. Remember that the eye is very sensitive to tiny changes in brightness along a line and tends to build up an impression of a stronger contrast than is actually there. Look at a grey-scale step-wedge to see this effect in practice.

                                Last edited by MikeOxon; 7th December 2019, 06:11 PM. Reason: Added image now I've found out how to do it!
                                Mike
                                visit my Natural History Photos website:
                                http://www.botanicdesign.co.uk/Natur...story/home.htm

                                Comment

                                Working...
                                X