michael8554

I gather you made a stack of exposures that had round stars ? Then that drift in Dec over time is due to Polar Alignment error. Perfect PA is not possible, so guiding Dec would help. But I don't think your mount has Dec motors ? So get best PA and expose for as long as gives round stars, those subs should stack well. Michael

So which "hot mirror" do you to remove ? The # LPF-1 filter passes the visual band and rejects IR, so this remains in place in a Ha mod. If you remove that and the #LPF-2 filter you have a Full Spectrum mod. The #LPF-2 filter is a visual band filter that partly attenuates the Ha end of the spectrum, so only that one is removed for a Ha mod. Michael

"Removal of the hot mirror really does make the red hit you." To avoid further confusion, AFAIK "Hot Mirror" refers to the IR Filter, which remains in place in a Ha mod ? Michael

Hi Bob Depends on what focal length scope you are going to image with. If it's a long focal length such as an SCT you will need an Off Axis Guider, and a premium sensitive camera such as a Lodestar. If it's a short focal length then a separate guidescope and a basic MONO guidecam such as the ZWO ASI120MM range will be adequate. Michael

Nice work Rob ! Most people call that mod a "Ha Mod", the IR filter remains in place. If you had the bandpass and the IR filter removed, that's a "Full Spectrum Mod". Michael

IIRC there's a thread oh Cloudy Nights on sourcing and replacing the display. Michael

Hi Dave This seems to be the reverse of a graph with Dec Backlash. Usually the red dots head off away from the origin instead of following the white line. Then when the backlash has been taken up, the red line starts to run parallel to the white line. Beats me. I would post your image, and a PHD2 GuideLog and PHD2 DebugLog on the PHD2 Help Forum. Make sure the dates in the filenames match. https://openphdguiding.org/getting-help/ Michael

OAG Michael

Hi Tom It would be worth posting this in the Planetary Imaging section, along with a shot of your camera and eyepiece setup. Planetary imaging is not usually carried out by taking single frames. It's usually carried out by taking long duration high-speed video sequences with a Planetary Imaging camera. Or with a DSLR, 5x LiveView video recording. Then software such as AutoStakkert! throws out blurred frames in the video, and Stacks the rest that aren't blurred by atmospheric movement. However, your single image is a typical result, due to the high magnification and atmospherics. Michael

Hi irtuk From your 6th October GuideLog: "Last Cal Issue = None, Timestamp = 24/09/2021 21:09:04" So that's why there's no Calibration data in the Log, because you haven't done a Cal since 24th September ! A Cal from 24th September is probably not going to work very well on 6th October, unless you have a permanent setup. Although I don't think your "Review Calibration" screenshot is from the 24th September Cal, I should point out: "Expected RA Rate: NA" points to a cable or Driver problem, there should be a RA figure reported from the mount similar to "Expected Dec Rate: 13.5" The RA Guide Rate Calculated by that Cal was 3.046 as/s, which is very low compared to Dec. Dec was 12.819, close enough to the "Expected : 13.5" figure. That Cal was carried out at Dec = 74.2, Cals are best carried out near Dec = 0 and pointing near south. Until you re-Calibrate I don't think any of your guiding since 24th September is representative. Except to say that the way the directions of guide graph movements are mirrored in both RA and Dec suggests that the guidcam has been rotated since 24th September. Here are some Guidelines to read: https://openphdguiding.org/phd2-best-practices/ Michael

From the many ASIAir GuideLogs I've seen posted on SGL and Cloudy Nights, it can work very well. But when it doesn't, fault-finding is difficult because of the PHD2 settings that ZWO have stripped out. Michael Your second image - I would remove the Anglepoise from your setup....... 😆

Screengrabs only say so much. A PHD2 GuideLog that includes a Cal would be much more helpful. Michael

Hi Brad 650mm FL and 3.75um pixels gives a image scale of 1.19arcsecs/pixel. Binning would up that to 2.38, IMO a more sensible value. But depends on the guidestar shape. Many setups have less than ideal star shapes. PHD2 seems to cope, but worth testing both Bins on the same night in case Binning makes guiding worse :-< Michael

The GuideLog, if there is one, should show what went wrong. Michael

If you have the imaging and guidecam distances the same, all I can think of is you don't have the prism far enough into the light path. Try with the prism as low as possible, then work out until the prism shadow no longer shows in Flats. Michael

With any brand of OAG: Roughly measure the distance from the centre of the prism to the main imaging sensor. Attach the guidecam that same distance from the centre of the prism. Focus the imaging camera on a distant landmark. Without altering that focus, now fine-focus the guidecam. Don't ever change the guidecam focus - if the main camera focus is now set on stars, the guidecam will always be in focus too. Michael

The media need a "wow" figure to impress the masses. It images much further into the IR, maybe that's the comparison. Michael

My 600D banded too, but only on hot summer nights. Michael

Hi Simon There's a comprehensive User's Guide in DSS that you ought to read before any further stacking. Michael

Just to be clear: Deleted files go to the Recycle Bin, from where they can be Restored. So did you "Empty Recycle Bin" ? Then you will need the File Recovery Tool. Michael

You can see from the spectrum in your link that the CLS rejects 600nm, the Sodium streetlamp frequency, and passes Ha and other ionised gas frequencies in two separate bands. The DSLR Ha mod will further improve the Ha response. However, the main LED street lighting spectrum peak is at 450nm, which is just inside the lower Passband of the CLS. Michael

Note the subtle wording. I suggested you align the finder after centring Jupiter in the eyepiece. If you had already aligned the Finder and Eyepiece views, then the scope instructions are correct. Michael

If I've understood that correctly, that's in the wrong order: GoTo Jupiter. Centre in the eyepiece. Enter. THEN align the Finder. Check Jupiter is still centred in the eyepiece and Finder. Michael

The 6D Mk1 and 5D MkII seem to be similar price used ? Michael

Light leak from the eye-level viewfinder ? Michael