michael8554

Remarkable combination of heavy engineering and micro engineering. Did Michael Fish make the weather report ? Good explanations for the layman of how telescopes work. Yes, application of a simple audio noise filter would have been good. Michael

I straight-away thought PE, but as you said, the middle image has stars that are separated, not linked. Diff Flexture, the focuser sagging or guidescope flexing seems a possibility - is it me or does focus look off ? "guiding was around RMS 0.60 for the session." The GuideLog would show if guiding was good for every exposure. Michael

"You're so vain, you probably think this (post) is about you............." 😆 Michael

Hi Neil "when I slew manually at a motor rate of 5 or 6, the backlash is 'more or less' gone, however, when at a faster rate, it is quite severe and I can't get rid of it. " In what way are you seeing Backlash in this situation ? Michael

GuideLog for 13th looked good. Similar RA and Dec errors should mean round stars. You could try Binning the guidecam, which will up the pixel scale and increase sensitivity. Which would allow you to reduce the 3 sec exposure time, as MultiStar compensates for "Chasing the Seeing" to a degree. Michael

Coma and Tilt. But you should be looking at a single short exposure, to eliminate tracking/guiding errors. Michael

Bin 2: Will make the camera more sensitive. Will double the image scale. Michael

The LodeStar X2 has a 6.45mm x 4.75mm sensor, so any OAG with a 8mm x 8mm prism will do. Just get one with fittings that match your kit. Some of the premium OAGs look to be identical to the no-name ones 😆 A helical focuser makes focusing the LodeStar so much easier, but the extra length can sometimes make it impossible to match the main image camera to prism distance. Baader make a low profile helical focuser. Michael

What I use with an OAG on a Meade SCT FR'd to 1400mm. Those big pixel aid sensitivity and yield a 1.24arcsec/pixel guide pixel scale. I use the LodeStar SXVR driver. Michael

Hi Phil Looking at the PHD2 Log: 1) The key to Good Guiding is a Good Calibration. So trying to guide with issues Last Cal Issue = Orthogonality can be a waste of time. You might have got a good Cal by clearing Dec Backlash first. 2) The sudden dive of RA and Dec in the GA run. PHD2 was reporting the star position to be moving (without any guide commands of course) as shown in the graph, and the guide star wasn't lost (yellow trace): This can only be due to external influences - a cable snag, the guidescope or camera rotating, Sidereal tracking stopping etc. Focus was reported to be poor. Michael

In the daytime any distant landmark such as a small feature on a pylon or church tower will do nicely. Michael

Being an SSD you don't have to worry about mounting it where it will be shaken about. But my Telrad used to fall off my OTA using the provided sticky tape. The improved Velcro design of the Dual Lock looks secure, but I'd add some rubber bands to reinforce the sticky tape attachment ! Michael

Great result for a beginner. "but had to bin 75% of the lights, due to the star adventurer mini." I'm sure there are many SA users getting better percentages than that. What errors were you getting ? Dec drift due to Polar Alignment ? RA due to Periodic Error ? 180 sec exposures suggest you are guiding, but I don't see mention in your equipment list ? Post the GuideLog, or if not take shorter exposures. Michael

To avoid this confusion, "Camera Backspacing" is often called "Flange Distance". For instance all Canon EF lenses focus 44mm behind the lens's mounting bayonet. That focus distance is fixed, so the camera's Flange Distance has to be 44mm. Unlike a telescope, where any camera can be attached and focus found using the scope's focuser. Michael

So you are using ZWO's recommendation for Back Spacings for two different manufacturer's OTA's with built in FF's ? Does WO recommend 55mm Backspacing? Does Askar recommend 55mm Backspacing ? As I said, "you said the OTA's don't need a Backspacing for best star shape. And cameras don't have Backspacing, so no need for a "55mm Backspacing". That's only necessary if there's a 55mm backspace FF or FR involved. Michael

1) It's impossible to compare the star shapes in these images because they are all 300 secs exposure, so will show differing guide errors. Take one short exposure with each at max gain, stretch if necessary, post a jpeg, 90MB tifs aren't necessary for this analysis. 2) "both scopes didn't require an accurate back spacing as they are both Petzval designs. " "I used a ZWO asi294mm camera (bin1, gain 120, -10 degrees, with suggested 55mm back spacing)" Confusion here. As you said, the OTA's don't need a Backspacing for best star shape. And cameras don't have Backspacing, so no need for a "55mm Backspacing". That's only necessary if there's a 55mm backspace FF or FR involved. Just focus the camera. Michael.

Hi Andrew Assuming you have the mono MM and not the colour MC, I expect that Binning 2x2 should give you Bin 2 mode. Michael

You need to address the soft-tipped screws holding the guidescope in the rings, a lot of the Diff Flex will be due to those. I would favour your first solution, gluing sounds so "last resort". Ditch the short guidescope mounting bar and mount the rings with longer bolts through the new bar. Michael

I assume you're guiding through an Off Axis Guider for that long 1570mm focal length. A colour camera is sometimes not sensitive enough for OAG use, how are you fairing ? The guiding pixel scale is 0.62arcsec/pixel. If you had the mono version you could bin that to a more sensible 1.24arcsec/pixel, and the increased sensitivity would help too. Michael

"JWST spies concentric rings around a binary star" I knew it ! It's really a CIA funded dark mission to spy on aliens ! Michael

This ribbon looks to be slanted in the socket: Michael

Possibly a ribbon not fully reinserted, did you mark a Sharpie line across the ribbons to show how far they have to be reinserted ? Did you correctly re-insert the black pipe into the white receptacle ? Are all the ribbons around that area inserted ? Michael

Hi Roger What do you mean by a "nice bright glow" ? Do you mean you want more saturation ? Do you mean you want more contrast ? Post your image. Michael

1) Use Auto, and correct in image processing. 2) Custom White Balance, read the user guide on how to, I'd say you'll still need to tweak in image processing. If you're using a refractor or camera lens you'll need to add an IR cut filter, to prevent star bloat. Michael

"meat Different,people ?" Would you like to "meat" zombies with a chainsaw 😆 ? Seriously, post some interesting questions and you'll get plenty of replies. Meeting people may be tricky as most SGL members are in the UK, and you're in the USA. Michael