michael8554

ASIAir produces a basic PHD2 style GuideLog that can be read by PHDLogView Michael

I've heard that too-fast exposures (0.025s, 0.001s) with mechanical shutters, as in DSLRs, may show shutter artefacts. Dim the light source until AV exposures come out at about 1 second. AV gives a 50% exposure. Michael

If the RA and Dec guide error figures are similar, then you should have round stars eg RA = 0.90arcsecs, Dec = 0.85arcsecs Then any elongation will be due to a wobbly guidescope (differential flexture). Post your PHD2 GuideLog. Michael

Hi Craig Have I got this right ? You're going to mount the Sigma lens to the Star Adventurer with the Sigma's mounting bracket. Then attach the ZWO ASI533MC-Pro to the lens. Clamp the 78mm ring around the ZWO ASI533MC-Pro. And attach the ZWO mini guide scope onto the top of the 78mm ring ? The Sigma bracket is trying to cope with heavy overhangs on that single attachment point. But might actually work with the Sigma on wide-angle ! If you look at similar setups with scopes: You'll see the scope is attached to the mount with a substantial dovetail The scope is attached to the dovetail with two clamshell rings And the guidescope is mounted over the centre of gravity on the two clamshell rings. Michael

+3, an OAG is not going to make much difference, unless your current guidecam and guidescope scope setup is particularly wobbly (Differential Flexture) Regarding an OAG, the ASI 120 Mini has a 4.8um x 3.6um sensor, so a 8mm x 8mm prism is large enough. Michael

In "standard trim" the OTAs are often front-heavy. Loosen the Dec clutch with a firm hand on the OTA and see if it swings ! Michael

Dithering only occurs between Lights. So your single Light won't show any pixelation due to Dithering, Only the Stacked image will show the improvement due to Dithering. Michael

Looking at your Light I only see about 16 to 20 stars, so DSS detection is correct. And I've managed to get DSS to stack stars with worse shapes ! The Score figures in DSS are very different - best is 38.29, worst is 17.14. Try unselecting the worst Lights and try again. I'm not sure how DSS choses which Light to measure for star count, so try making sure a "good" Light is at the top of the list. Michael

What is the balance like ? Try slewing in Az with the OTA pointing straight up. Unscrew the base cover and have a look for grit or swarf in the worm and worm wheel. Clean and re-lube may help. The worm carrier is spring loaded to the wormwheel, check there is a tiny amount of free-play at all points of normal Az use. Michael

In your PHD2 screengrab there are the guide error figures: RA = 1.32 arcsecs, Dec = 2.10 arcsecs. So Dec error is about 60% more than the RA error = elongated stars. "the Stars in my subs are pointing towards the left" Is that elongation in Dec, I have no way of knowing ? But looking at the guide graph there appear to be roughly equal amounts of north and south deviations in Dec. But without a PHD2 GuideLog it's all conjecture. Michael

Glad you got a result/ Michael

Don't take my word for it, read about guidescope attachment and Diff Flex in the PHD2 Instructions. But you haven't said if the stars are trailing in only session 10 at 23:50, and session 12 at 03:46 ??? Or in the rest of the sessions, which had good guiding. If the trailing is in all sessions then it's Diff Flex. Michael Michael

Fleshed-out descriptions above are good, but I'll repeat, that if your setup is basic ST4, you'll need to Calibrate on every new target. Michael

Mains travel hairdryers are typically 1000 Watts plus. Plugging one of those into a 300 Watt Inverter will release the magic smoke :-< As David said, a 12V hair dryer is perfect for the job. Michael

Hi Peter So if you click on a target in CdC and ask it to Goto, does it succeed, or move the wrong way ? If successful, then there is probably a menu where you can set Manual Slew directions. Michael

In PHD2, if you have a connection that supplies the mount's RA and Dec, then you can Cal near Dec =0, and use that Cal on all your Targets for that night. If the mount doesn't supply RA and Dec, as in a basic ST4 setup, you will have to recal on every new target. Whether those rules apply to ASIAIR's version of PHD2 is something that may be described in the instructions. Michael

I think some confusion is creeping into this Svbony F4 50mm guidescope Focal Length. Total length is quoted as 240mm total length That's not the same as the Focal Length. Further on it's : Focal Length: 190mm F4 x 50mm = 200mm Focal Length. So if you have Plate Solved it to only 175mm, then somebody has got their sums wrong :-< Within this range of FLs you won't see much difference in the quality of guiding, as to an extent PHD2 will accommodate the error when Calibrating. There will be a miscalculation of the Guide Error figures though. PHD2 won't accommodate entering 50mm as the FL :-< The guidescope rings appear to have soft-tipped adjustment screws. Diff Flex is measured in microns, so there's a source straight off. Michael

Do you mean he's disabled LiveView, or doesn't know which button on the back to push ? Look up LiveView settings in the Instruction Manual that came with the camera. Or is a PDF on the software disc. Or you can download from Canon UK. If he's disabled LiveView, settings are in one of the camera menus if you scroll through them. Michael

The RA and Dec figures were very similar on most of your sessions, so should result in round stars. The exceptions were on session 10 at 23:50, RA = 0.33, Dec = 0.53. And session 12 at 03:46, RA = 0.33, Dec = 0.62. The stars in those sessions could be elongated in the Dec direction. If the other sessions don't have round stars then you have Differential Flexture - the guidecam is being well guided, but the imaging camera isn't. Oh and guidecam focus is poor HFD = 5 to 6 pixels. Michael

GPCAM has 2.9um pixels, ASI294 has 4.63um pixels - nearly identical cameras ??? It is not good practice to delete Equipment Profiles. Better to create a new-name Profile using the Wizard, then you have a choice of Profiles at all times. Your connections allow PHD2 to know the RA and Dec of the mount. So you only need to Calibrate once each night, close to Dec=0, and use that for all targets. When you close PHD2 it remembers the Cal, so you don't need to ReCal after opening PHD2 again. Only ReCal the next time you set up. Your first seven Cals were truly awful, not getting past the RA phase, but the eighth Cal was good, no error messages, you could have used that all night. Later you made two more awful Cals at Dec = 29, but the third was fine ? If you know what you were doing wrong on the awful Cals you could save a lot of time. Re the guiding: You ran GA and applied the settings, exposure was 2 seconds, PA was around 2 arcmins. And guiding was sub-1arcsec throughout. So all good but guidecam focus was poor for most of the night, HFD = 6, but was an acceptable HFD = 3.85 on the final run of the night. And since these are colour cams, every little helps, so you should make Dark Libraries for them. Why do you think you had USB problems ? If you believe it caused the poor Cals, then you should upload the PHD2 DebugLog to the PHD2 Help Forum. Using the instructions in the Help menu, choosing files with relevant dates in the filename. https://groups.google.com/g/open-phd-guiding Michael

Don't hold your breathe, he's long gone, he couldn't even be bothered to reply to my suggestions ........ Michael

By "compass" do you mean the Slew Direction buttons on the handset ? Michael

Hi Stu The ED80 Pro has a 600mm focal length. So roughly measure 600mm from the objective, with the focuser halfway through it's travel. The distance from the rear of the focuser to the 600mm point is the distance you need to fill with spacers, minus the 12.5mm Flange Distance of your two cameras. You can alter the scope focuser to allow the nearest standard length spacer to be used. Michael

Hi Stu I'm afraid I don't remember the details, but it was probably a bodge. Michael

A bit thin on specifics :-< What diameter is the whole thing ? What diameter is the female screw hole ? Does it become a male thread on the other side ? So is it a threaded lock ring, or is it a 1/4"-20 adapter that screws onto the top of scope rings, to allow a camera to be attached ? https://photogeeks.co.uk/tripod-screw-adapter-male-to-female-1-4-20/ Michael