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themos

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Everything posted by themos

  1. Hello, Please download the installer and run it. Before running PhotoPolarAlign, you will need to have a Python installation that includes all the modules it needs. (I used the Anaconda distribution) You will also need to register with http://nova.astrometry.net/ and get an "API key". AstroPolarAlign can be started by double-clicking the PPA.py file that the installer puts on your file system. The first thing to do is to add the key you got from nova. Use the File -> Settings menu for that. The second thing is to try out the supplied test image files. The two big buttons to the left of the Operations panel are used to select image files. Please select the file v.jpg for the top one and the file h.jpg for the bottom one. Hit the Solve button next to the big button, first for one image, then wait until the "Solved" label goes green, then do the second one. This will need an internet connection, o course. Once both "Solved" labels are green, you can hit the Find Polar Axis button and wait for the annotated image to pop up. Your polar alignment is also displayed on the main screen. Then select the i.jpg file with the big button on the right side of the Operations panel. Click its Solve button and wait for a solution. Then click on "Show Improvement" button to see a new plot. Then, exit the program and restart it to try it with your own images (the reason is that the scale is remembered in a single session but not across sessions and it's unlikely that your image scale will match the examples). Ok, let's see how this works out! Thanks for your time, hope you will find it useful.
  2. I wish there was more standard terminology! No, you don't rotate the camera in the focuser, there may not even be a focuser. The camera stays rigid with respect to the mount. Now, if I say "rotate the mount", somebody might think that I mean change the direction of the polar axis to the left or right. That is what's making writing the instructions a headache!
  3. Shame! Do you happen to know what the Field of View is of your imaging setup? That 200mm Canon with a DSLR would perfect for this method.
  4. StuartJPP, I keep to the Polaris region for both images but the RA axis does get swung around by 90 degrees or some similar large angle.
  5. Merlin66, could you provide some examples of JPEGs and matching WCSs for me to check, please?
  6. I'm sorry Earl, there is still no documentation written for it (busy this weekend) , but you could try taking a pair of JPEGs of the Polaris region with your camera. I don't want you to waste valuable time with a clear sky getting all the python stuff setup. The two images I need must be taken with the camera fixed on the mount with the only difference being a rotation in RA axis. Also, take the 2nd one with the camera sensor oriented n the horizontal direction (like you would normally shoot a snap). Keep them in your drive and you can later try them with the software when the skies are bad.
  7. I've added you, cthorpey. I will work on the help document over the weekend, hopefully. Merlin66, does it produce .wcs files for each image solved? I might make a more self-contained version that requires you to input the pixel coordinates of Polaris and Lambda UrsaMinoris, although nobody likes to type numbers in the dark.
  8. The mount (or RA or polar) axis! After a rough polar alignment, I set the camera somewhere close to declination 90 so I can see Polaris in the field of view. Keeping the camera fixed to the mount, I slew in RA by a large angle (40 degrees say) and watch where Polaris goes. If it goes off the FOV, the RA axis is not close to Polaris. So I adjust the polar alignment, bring Polaris back into the FOV and try again (the details of this iteration need to be worked out). Once it's set so that Polaris stays in FOV after a large RA slew, we are good to fine-tune the polar alignment by PhotoPolarAlign. The first two images give us the position, in pixel coordinates, of the RA axis (the red cross). I take the first image at an RA position so that the sensor is taking a picture of the sky in "portrait mode" and the second image in "landscape mode", with the long side of the sensor horizontal. The plate solving tells me where the NCP is (allowing for precession since 2000), in pixel coordinates and what the scale is. Now that the camera is horizontal, x and y pixel offsets translate directly into instructions to move the mount RA axis up-down or right-left by so many arcminutes. After I adjust the polar alignment, I take another image and check for improvement. The RA axis pixel coordinates have not changed, only the NCP pixel coordinates move. With practice, it should take only 3-4 iterations to get it close enough (whatever close enough is for your imaging needs).
  9. No, it doesn't. I will be writing the Help file next so once that is done you can have a play.
  10. Michael, I have used it with around 5 arcsec/pixel. The images above were reduced by a factor of 4 from the originals. You probably don't want to take the images with the Canon set to the highest resolution. You would use the 1936 x 1288 pixels resolution. PPA will upload the images to nova.astrometry.net for plate-solving so you don't want very big images. If your typical 15 second exposure is recognised by nova.astrometry.net you will have no trouble with PPA.
  11. Thank you, Earl, Steve_Max127 and RusselHQ! A couple of points : polefocus requires ASCOM mount, PhotoPolarAlign won't. You can use a barn-door mount or a Dob equatorial platform. polefocus requires the measured Az/Alt polar alignment error which PhotoPolarAlign can provide. AstroTortilla can also provide that error but the last version I used produced unreliable and wildly fluctuating estimates.The EQMOD polar align tool that simulates the polarscope view has been my preferred method. However, it's tied to the EQMOD supported mounts and your alignment is only as good as your reticle calibration.I found AlignMaster to be almost useless for my location as most of the stars it wanted to slew to were behind trees. It also requires GoTo capability. I will be in touch with the beta testers soon. Clear skies! Themos
  12. Hello, if you would like to volunteer to try out a new Polar Alignment method, please let me know. The requirements are: You can see the Polaris/NCP region from where you usually set up. (South hemisphere? get in touch!) You can attach a camera to the mount and bring the JPEG image files to your computer. You can freely rotate the RA axis (this excludes AstroTrac mounts and similar, I think). You have Internet connectivity. You can run Python on your computer (e.g. Anaconda for Windows, Linux, MacOS X) You might be able to verify your Polar Alignment within 2-3 minutes. The software will be in the public domain. Regards Themos Tsikas PS: (added in edit, latest version for Windows, 1.0.4 https://drive.google.com/open?id=0Bws-dmFqKZThUjBtc2FCeENOdXc )
  13. themos

    Comet C/2014 E2 Jacques

    This is my result from just after midnight 23-24 August 2014 (00:15:55 - 03:21:10) 65 lights, 24 flats, 24 bias, 24 darks. Canon EOS 450D ISO 400, 120-second. Meade 5000 80mm triplet, SW Field-flattener, Astronomik CLS, on EQ6. PHD2 for guiding, APT for capture. Calibrated, registered and comet-stacked with IRIS, a bit of stretching and colour balancing in DSS. The comet was too fast for 120 seconds so it is smeared in the stack but the tail managed to show up regardless.
  14. themos

    Meade 5000 80mm APO

    images with the 80/480 triplet
  15. themos

    4.5" f/8 Newtonian

    Photos taken with the "toy" 4.5-inch f/8 Newtonian
  16. themos

    Canon 200mm f/2.8L

  17. From the album: Canon 200mm f/2.8L

    Three planets visible in the western sky, after sunset. Left is Jupiter, top is Mercury, Venus below. EOS 450D (modded), 1/20, f/3.5, ISO 400, Canon 200m f/2.8L lens.
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