Laurin Dave

the other thing that might help is to increase the "Search Region" in the PHD2 Advanced Setup Guiding Tab

I think you need to increase the Dither scale in PHD2 by the ratio of the focal length of the SW200p to 162 mm ie about 6 to get the same actual dither movement in your imaging camera..

Brilliant!!.. Great idea extremely well executed. Well done Dave

Yes like that but will it screw further down towards the sensor

That looks right although I’d turn the filter round if possible so that any anti reflective coatings are facing the right way.. as for a 2” filter I don’t think it will work between the flattener/reducer and camera but if you look on the scope facing side of the flattener/reducer there may be a thread you can screw one in to

A guess but maybe encoder conflict.. are they in polite mode? Or whatever Steve has in the manual? Also need supervisory threshold set to 10 deg.. all from memory Helen

With the camera came a threaded ring that will screw into the 21mm extender, screw the filter into that .. it needs to be as close to the sensor as possible to minimise vignetting ..

Presumably the effect of the reducer... without it the sensor will be at the scope's native focus position, with it I'd assume it moves further in

As Skipper Billy says .. and as per ZWOs guide yes...

yes that gives the required 55mm ... See link.. https://astronomy-imaging-camera.com/tutorials/best-back-focus-length-solutions-55mm.html

yes it is .. that and the other two extenders are all you need

I assume then that you don't have the 11 mm female to female T2 extender.. which makes up the distance and reverses the threads ie the black ring on the front of the camera

Should be like this for ZWO (I think) … Flattener M48 (I assume) .. 16.5 mm T2- M48 extender... 21mm T2 extender... 11mm T2 extender (on the camera already so not shown as an accessory) then camera... giving 55mm backfocus

That's easily good enough not to cause any issues so I wouldn't worry about your PA being the cause of our woes... also just checking my PHD settings I have hysteresis at 0.3 and min mo's of 0.2...

Adam Looks like that's to do with the "failure to settle" report and some sort of re-setting .. its showing a general drift owing to Polar alignment and the PE shows as the small sinusoidal overlay on the downward drift.. Dave

Hi Adam I'd suggest longer is better as short exposures will chase the seeing.. Had a look at your settings and can't see anything obviously wrong although it is these I would suspect .. also a quick look at your logs .. the calibration steps at 1200 mm look to me as if the guide camera (or something else) may still be a bit wobbly (on the basis that my OAG at 1070mm returns calibration points on a straight line) ... and on some of the graphs the corrections on Dec are in the wrong direction.. Some suggestions for fault finding .. take SGPro out of the equation to isolate that as a cause ... guide via ST4 (ie On Camera) .. also try the guiding assistant for a couple of PE cycles (ie 10-20 mins) through the 225mm without SGPro - this should give you the PE.. and as an experiment/ test just attach a guide camera to your reflector (ie in place of the imaging camera) and see if that works... (will rule out wobbly OAG) HTH Dave

Pretty sure SGPro will tell PHD to use the profile that is set in the Equipment Profile or Control panel ( so long as the guide camera and mount are the same ).. so if it’s using 225mm focal length with the OAG the calibration movements will be so far from what it expects that it fails . Could also explain why the PE appears to be 4 times bigger (ratio of focal lengths) than it should be .. Dave

Inspired by @PhotoGav's post yesterday evening I thought I'd have a go at comet imaging .. here's the result from 2hrs of 5 and 10 min subs through my Esprit150/SX46 and 2 hrs of 1 min subs through my piggybacked Esprit100/ASI1600. Processed in Pixinsight (using the comet alignment routine) APP and Photoshop where comet RGB and Luminance were manually aligned. Subs captured between 9:30 and 24:00.. Comet position is at 24:00 thanks for looking Dave Comet C 2019 Y4.mp4

A single 10 minute lum sub on the 150... have switched to 5 min as the head looks rather elongated .. also doing RGB on the 100 at 60secs.. Dave

I’ll let you know Gav

Hi Gav.. great video and idea.. imitation being the sincerest form of flattery I’ve just started on it myself! Dave

Adam... these settings may help .. copied from Sara.. you probably have reverse guiding checked in two places.... I did at first and this sorted it Dave Sitech PHD SGPro Settings - Sara Wager (004).pptx

Thanks .. the background is a bit lumpy

From unexpectedly clear skies on Tuesday night.. Globular cluster Messier 3 in Canes Venatici was discovered on May 3, 1764, and was the first Messier object to be discovered by Charles Messier himself. Messier originally mistook the object for a nebula without stars. This mistake was corrected after the stars were resolved by William Herschel around 1784. This cluster is one of the largest and brightest. It is made up of around 500,000 stars, is 90 light years across, estimated to be 11.4 billion years old and is located at a distance of about 33,900 light-years from Earth. It is also 31,600 light years above the Galactic plane and roughly 39000 light years from the centre of the Milky Way. (Wiki) Also visible is NGC5263 a type Sc spiral galaxy about 200 million light years away and many more distant galaxies some visible through the clusters halo. Esprit150/SX46 2hours per channel RGB. Processed in APP Pixinsight and Photoshop. Thanks for looking Dave

What does the Ha you've got so far look like Dave? They're quite weak compared to the general Ha in the core and inner arms