michael8554

The subs have "round" stars, with some tilt and coma. So no Diff Flex. I wouldn't worry about the slight Dec drift over 90 minutes, since guiding seems to be coping. The stacking error suggests a wrong mode like comet stacking, but obviously the galaxy isn't moving with respect to the stars like a comet would. Back focus for an 8" Edge HD is 133.5mm without the 0.7FR, 105mm with the FR: https://www.innovationsforesight.com/support/celestron-edgehd-back-focus-tolerance/ Michael

The MPCC spacing depends on how you have attached it, could be 57.5 +/- 1mm:

This sort of thing: https://www.365astronomy.com/tele-camera-adaptor-1.25-31.7mm-for-eyepiece-projection-by-ovl The link is low on spec, but the thread at the top may be T2. Michael

Got mine this morning Michael

Yes. To matching counts, not you're confused again 😆 Michael

The V1 does up to 6 secs exposure, the V2 up to 10, and the HQ up to 230secs. Pixels are tiny (1.12 to 1.5um) so would be best for a guide setup that requires a short FL guidescope eg 100mm FL. Does it have a driver that the guide software recognises ? Michael

Hi Stuart Oversampling doesn't matter per se in the guiding setup, it might in an imaging setup. But 0.18arcsec/pixel isn't a sensible image scale to guide with. Binning x4 would improve it, but really it means you have a camera with too-small pixels. Also as you have opted for an OAG with a 12x12 prism, you want a sensor large enough to match that. Otherwise you might as well have bought an OAG with an 8x8 prism. Michael

Hi William, https://www.firstlightoptics.com/solar-filters/baader-astrosolar-safety-film-nd-50.html IIRC it includes instructions for making custom-sized frames to suit your lenses. Michael

Not necessarily, if the DC voltage and current rating are insufficient - what are they ? Michael

Are you able to move through best focus ? Then you have a good combination of connections. So if images aren't sharp: Are stars bloated due to poor guiding, or due to too long exposures if not guiding ? Or collimation may need adjusting. Michael

Yes, PA can never be adjusted to be "perfect", but anything better than 5arcmins is easily guided. That and the Backlash result suggest the Dec axis may also have Stiction. You really should return the mount again, with a copy of the GA result. Michael

Yes Mark, though I'd describe it as the front edge. But according to the Altair spec, 55mm is approximate: Spacing of approx. 55mm to Sensor, which can be fine-tuned with our T2 spacers. Suggesting you tweak the 55mm to get best star shape in the corners of the image. Michael

Hi Herrman Yes if you don't have a permanent setup, or disassemble at the end of each session, you will need to Calibrate every night. ASIAir similarity to PHD2 may mean the logs are in a folder called PHD. Or use the Windows File Search facility to find any files that include GuideLog in their filename. Michael

After the GoTo slew, check in the handset what RA and Dec position the mount thinks it's at. If RA and Dec are correct, then you have the mount set to the wrong location, date, or time. Michael

Hi Pete You should tidy up those cables catching on the mount and dragging on the ground. Michael

Not familiar with the mount, all I know is 0.20x is too low, based on the number of Cal Steps. Yes, 0.80x is actually 12arcsec/sec, my bad. Sidereal is 15arcsec/sec, not 1arcsec/sec, I expect that you made a typo. Michael

Ability to slew at 8 indicates power to the mount is adequate, but to be sure try at the highest setting, that may be the GoTo speed too. Monitor the voltage reading in the menu while slewing. If those tests pass, the handbox showing "Slewing" but the motors not running suggests a software issue. Maybe try a handbox Reset ? Michael

The Review Calibration image shows that the RA and Dec Guide Speeds are set too low - 0.20x. So set the Guide Speed in the mount to at least 0.80x (or 8arcsec/sec or 80% depending on the mount). Then the number of steps in the Cal should be more like the expected 12 or so, instead of 51. Also you were Calibrating at Dec = 72.6, it's best to Cal near Dec = 0 and near south. A read of the PHD2 Instructions would help ? Michael

Focus in the centre is slightly off (or is it slight dew ?) The corners have coma. Michael

Looks like the first image has a much longer exposure than the second image. Michael

Possibly the RA guiding is worst at the peak of the Periodic Error ? Michael

So you want to use this Svbony Guidescope as a Finder, with a correct image diagonal. You might succeed with the helical focuser removed and the correcting diagonal inserted:

Once you've got both cameras in focus, it's best to keep the whole OAG / image cam / guidecam setup assembled, then focusing the image cam will always focus the guidecam too. Mono imaging will be as Elp describes, unless you have the filters before the OAG, but then some filters could attenuate the guidestar too much. Adding a helical focuser to the guidecam doesn't alter the focal plane, that is set by the prism to imaging cam spacing, so hasn't altered. It just pushes the guidecam sensor further away from the focal plane. If the imaging cam is already as close to the OAG as it can be then a helical focuser isn't workable. Michael

If guidecam rotation was the cause, I think it would have to be considerable to get such a large translation between the axis. I'm not clear whether this is a new or ongoing situation ? What Dec was the Cal and GA at ? Michael

Hi Jon As you said, RA and Dec guiding is off during a GA run. For SGL readers, the PHD2 guys suggested that between Cal and the GA run, the guidecam rotated. Then every move of the mount had a RA and Dec component, as registered by the guidecam. So the RA PE would show as Dec movement too. Michael