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.



Advanced Members
  • Content Count

  • Joined

  • Last visited

Community Reputation

263 Excellent


About kens

  • Rank
    Proto Star

Profile Information

  • Gender
  • Interests
    Deep sky, fly fishing, cycling
  • Location
    Melbourne, Australia
  1. The calibration failed - possibly because the calibration parameters were incorrect. Find the guide log and attach it - you may need to zip it first. The guide log can be found by using the Help Menu > Open Log Folder option.
  2. kens

    PoleMaster equivalent software

    You could try Static Polar Align in PHD2. It uses a similar algorithm to PoleMaster. I use it with my RC8 and ASI1600 imaging cam which has a similar sensor size to the Atik 383L. Should be able to connect in PHD2 through theASCOM driver. Tutorials here: https://openphdguiding.org/polar-alignment-tool-video-tutorials/
  3. kens

    KStars INDI System Requirements

    Should be ok to post in that thread unless you have more general questions about Indi.
  4. kens

    KStars INDI System Requirements

    The Avalon driver is under development. You would need to build the driver from source. You can find a link to the source code on the Indi forum at https://indilib.org/forum/mounts/2411-avalon-mzero-stargo-with-lx200-protocol.html You also need to edit the drivers.xml file I use it all the time now with no issues and any problems I can help out.
  5. kens

    PHD2 and Star Adventurer

    The trails are in declination so they are actually caused by non-guiding This illustrates why you need very good PA when not guiding in declination. Its a bit hard to tell from a JPEG but it looks like you've got about 3 pixels of drift per subframe.The pixel scale is 8.6 as/pixel so that's around 25 arcsec of drift. You didn't mention the length of the subs but assuming 5 minutes that means your PA error was in the order of 30 arcmin which is quite large. Now that you've got PHD2 running I'd suggest using its drift alignment tool to improve your PA. That will help you get more detail since they wont be smeared. I'm not familiar with using a DSLR with HA filter but I imagine you'd want to take a set of subs with no filter to make up a synthetic lum channel and another set with the Ha filter for the nebulosity. For the no-filter case, doubling the integration time will improve SNR by the square root of 2 (1.4x). With the Ha filter you'll get light on only 1/4 of your pixels. Plus at 7nm even the red pixels will be getting just a small fraction of the sky background - in the order of 1/14th. That will affect how long you need to expose each sub.
  6. kens

    PHD2 and Star Adventurer

    PHD2 has an option on the Guiding tab of the brain to Auto-restore Calibration. If this is ticked then PHD2 will use the existing calibration when you start guiding. Otherwise it will start calibrating when you first start guiding. (This option can be overridden by holding down the shift key when you click the guiding button to force a recalibration). When PHD2 uses the existing calibration, it divides the RA correction duration by the cosine of the declination - or what it thinks is the declination. Or more correctly it multiplies by the cosine of the calibration declination then divides by the cosine of the current declination. So its important that it knows both the declination used at calibration and the current declination or it will issue RA corrections of the wrong duration. With a ST4 guided mount you use the "Ask for coordinates" driver at both calibration and when you guide on your target to achieve this.
  7. kens

    PHD2 and Star Adventurer

    Correct. The main thin is to enter the correct declination when you calculate the calibration step size. There is also an option PHD2 to set the Aux Mount to "Ask for coordinates". When you use this option, each time you start guiding, PHD2 will pop up a window asking you to enter the declination. If you calibrated with this option on, you can reuse the calibration like with an ASCOM controlled mount.
  8. kens

    PHD2 and Star Adventurer

    At Dec 67 I'd still use guiding. Since you are ST4 guiding: in the calculator you need to manually enter the declination (default is 0). You wont be able to set it higher than 60 so use that to calculate the Calibration step size. Then manually increase the step size by 25-30% to make up the difference for dec 67.
  9. kens

    PHD2 and Star Adventurer

    When you are connecting click the settings button as shown and you'll get the options for 8bit and 16bit NGC7822 is at dec 67 which is not very extreme although PHD2 recommends against it. At that declination the RA pulses need to be 2.5x longer than at the equator for a given movement. In the step size calculator make sure all the values are correct and enter the maximum 60 degrees declination. Then manually add 25-30% to the calculated value. When you are very close to the pole (say > 85 degrees) you can turn off RA guiding You'll also want your guide star to be close to your target as the relative motion difference between the two will be greater if they are at different declinations. You also want to be sure not to chase the seeing as your mount will be making large movements in RA to correct for small star movements on the sensor.
  10. kens

    PHD2 and Star Adventurer

    If you are not guiding in Dec then you do need very good PA. As a guide the amount of drift you get will be equivalent to the PA error over a period of 6 hours. If you want less than 1 arcsecond of drift on a 5 minute exposure your PA needs to be in the order of 1 arcminute. You can use PHD2s drift alignment tool to adjust your PA. Getting a good focus on the guidescope will help a lot. Is there a focus ring near the objective lens you can use? Also, since you have the ASI120 you may be able to use a threaded connection. Then you can use spacers to adjust the focus. To choose a guide star you can either let PHD2 choose one (Tools > Auto select star) or if you do it manually, display the star profile and ensure that it does not have a flat top. You can adjust the camera gain if there are no suitable stars. Also, when you connect the camera, select 16 bit mode. It tends to give better profiles for guiding. Since you are not guiding in Dec the guide star does not need to be very close to where you are imaging. Obviously not pointing 90 degrees away or anything like that but within a few degrees wont make much difference.
  11. Try this: http://www.qsimaging.com/ccd_noise_your_camera.html
  12. kens

    PHD2 and Star Adventurer

    Looks like the Star Adventurer will only accept guide commands whilst in celestial tracking mode so you can't test it in daylight. PHD2 will start calibrating automatically when you start guiding. For RA only guiding you need to turn off Dec guiding as shown below. Also, you can find the PHD2 manual at https://openphdguiding.org/manual/?section=Introduction.htm Personally I would not recommend using PHD1 as it has not been supported for many years now
  13. kens

    PHD2 and Star Adventurer

    If you use ST4 you need to set the mount to On Camera. The further away the easier it will be to focus. To test during the day aim at anything you can get into focus on the camera. Turn on the cross hairs or grid (View > Bullseye or View > Fine Grid). Set the manual guiding Guide Pulse Duration to its maximum (5000). Tools > Manual Guide to get the popup dialogue. Click the various buttons and you should see the image move a small amount. The grid/bullseye makes it easier to detect the movement.
  14. PHD2 has a feature that lets you guide on a star but adjust its lock position to match the movement of the comet https://openphdguiding.org/man-dev/Tools.htm#Comet_Tracking
  15. kens

    Drift Align Problem

    Polar alignment error causes drift in declination. If you are getting movement East-West in right ascension then it is most likely periodic error in your mount. Autoguiding is the best solution to that.

Important Information

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