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kens

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About kens

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  • Birthday 08/05/61

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    Melbourne, Australia
  1. Right click the link and Save link as... worked for me
  2. Guiding lets you take longer images without star trails caused by Periodic Error (PE) or Polar Alignment (PA) error. Periodic error causes an oscillating movement in RA whilst Polar Alignment error causes a drift in Dec. Guiding uses a second camera to monitor the position of a guide star and sends small corrections to the mount to adjust for any movement caused by PE or PA. You need a second camera because the guide camera checks the guide star position every few seconds whereas your imaging camera might only take one expsoure every few minutes. The guide camera and scope can be relatively inexpensive. Guiding is pretty much essential for DSO imaging. For lunar and planet the exposures are so short it isn't really needed.
  3. Some cameras are equipped with a ST-4 port that can be connected to the mount. You connect the camera to your computer with a USB cable as usual and connect the camera to the mount with a ST4 cable. In PHD2 you select a mount type of On Camera. PHD2 sends guiding commands to the camera via the USB cable and the camera in turn sends them to the mount via the ST4 cable. The advantage of this is that you don't need a driver for your maount. With ASCOM guiding you install the driver for the mount on your computer and connect the mount to your computer with a suitable USB cable. You connect the camera to your computer with a separate USB cable but you cdon't connect the camera to your mount. In PHD2 you select a mount type that corresponds to your mount e.g. HEQ5/6. PHD2 sends guiding commands directly to the mount. The main advantage of this approach is that PHD2 can communicate with the mount so it knows where it is pointing. This lets you reuse your calibration in different parts of the sky. For guiding you need a separate camera from your imaging camera.
  4. The attempted calibration should be recorded in the guide log
  5. If you could attach the guide log it will help to get to the bottom of your problem more quickly. It is normally saved in Documents\PHD2
  6. And if you have the meteor lens - remove it before putting the camera into the guidescope.
  7. When you focussed the camera did you do that in PHD2? Not that it is necessary but it would indicate that PHD2 is working as it should. Once you have the exposure, gain and focus correct you can use the Screen Gamma (brightness) slider next to the expsoure time drop down to get the brightness correct. Your camera driver may also have a brightness control. Another thing you can do is to use the Tools>Auto-select Star on the menu when you are pointed at the night sky. If PHD2 can detect stars in the picture it will select one and display a green box around it. That will tell you that PHD2 is working and you just need to sort out the brightness on the screen.
  8. They have the same size sensor and same pixel size. In fac, looks like the same sensor on the color models so the FOV is identical. On closer look, I would (and did) go with the ZWO as it has a 12bit ADC vs 8bit on the Touptek
  9. Both those camera should do the job. Just be aware that if you ever want to run off an ARM device like a Raspberry Pi that there is no ARM driver for the Touptek but you can connect the ASI camera with INDI. Mono is not essential for guiding. But if you are having trouble with finding guide stars mono can be better as the Bayer filter reduces the amount of light hitting the sensor. With an ST80 as guidescope that should not be a problem.
  10. I think that would be due to PHD2 autostretching the image. Once the hot pixels are gone it stretches the image more so other noise becomes more evident.
  11. Leave the min pulse width and DEC backlash at their default values in EQMOD. Use the Guiding Assistant tool in PHD2 to work out out your PHD2 settings. With the belt mod the 121 second spikes should be much reduced - at least thats what Im hoping for with mine. You should also have less Dec backlash. With the normal gears, adjusting the mesh between the idler gear and stepper should help although I've never got it right. Apparently the trick is to use a piece of aluminium foil to get the spacing right. However, its almost impossible to adjust the mesh between the idler and the spur gear on the worm shaft as it is hidden away out of sight save for a tiny peephole in the casing.
  12. You would need to change it in EQMOD. I thought PHD2 would feed the value from EQMOD into the calculator but I could be mistaken. Whatever value you choose in EQMOD should also be entered into the calculator. I'm also in the middle of belt-modding my EQ6. It should reduce the signature EQ6 122 second periodic error. This is quite prominent on your RA graph.
  13. Overall you are getting pretty good performance from your mount. The exception is the big spikes in Dec. In fact they are not spikes but a big movement that PHD2 is able to pull back so it appears as a spike. The movement is only in declination so cable drag is less likely but should not be discounted. I'd start by looking at your balance. Another possibility is the gear mesh. Could be a bit slack giving you a large amount of backlash. Is a reason why you are guiding at 0.1x sidereal? Most people would use 0.5x or 0.9x.
  14. It would be easier and more sueful to attach the guide log instead of loads of screen shots. One thing I can just amke out by squinting is that your guide rate wuld suggest that it is set to 0.1x rather than 0.2x. It is odd that PHD2 isn't picking up the correct guide rate and declination in the calculator. The guide rate error explains why you are taking 24 steps instead of 12. The declination error of 0 degrees versus the -22 deg reported in the calibration is not that significant. Unfotunately I can't see what declination is reported whilst guiding on those screen shots. The spike is most likely some sort of flexure. Hard to say more without more information.
  15. Your guidescope looks fine. The FOV is only due to the small sensor on the ASI120 but as long as you cn find guide stars that is not a problem. I'm personally not keen on the adjustable rings and finderscope attachment as the can be a source of flexure but they will do for now. Just make sure everything is nice and tight. The orthogonality error is likey due to polar alignment error causing drift in declination. The sign of this is that your RA leg does not retrace its West bound steps when returning East After you've done a first polar alignment, redo your calibration. When doing your calibration, use the calculator in the Brain, making sure you enter the correct values. The default is for 12 steps. Your calibration took 24 steps which is on the high side. This is not an issue in itself but may indicate some of the input values were incorrect. As a general rule, you shoudl attach your guide log when you need help with PHD2. It contains a wealth of information for troubleshooting. You can also view it yourself using PHDLogViewer or PEMproLogViewer to analyse your guiding. You might also consider rotating your guide camera so that it aligns more closely with the RA and Dec axes. This can be useful for troubleshooting later as it makes it easier to tell if things like star trails on your images are in RA or Dec direction.