Seelive

I assume the camera still works OK with the normal battery but not with the adaptor? As @powerlord said, the battery compartment lid needs to be fully closed for the camera to work so it's necessary to feed the adaptor cable through the small slot on the side of the battery compartment so that the battery compartment lid can be closed. My Andoer dummy battery is rated at 7.6V / 2A and works fine (and also looks exactly like the one quoted by@malc c)

I assume that when you are moving the axes by hand you are also moving the stepper motor via the preceeding gears. Depending upon the gearing ratios, where you try to turn the axis can make a big difference to the apparently required torque. Ideally, you need to 'feel' the torque needed to turn only the worm and wheel when the axis is balanced (and as the RA axis wheel will have more teeth, it should always appear to be 'easier' to turn?)

But when we do get a clear sky at least we rejoice rather than 'oh no, not another one...' 😆

I did wonder but I assumed you had a Dew Controller with auxiliary 8V output. You will need to buy an AC/DC adaptor with an output voltage between 7V and 8V such as this one https://uk.farnell.com/multicomp-pro/mp004759/adapter-ac-dc-7-5v-2a/dp/3497087

The 78xx is a series of (old) linear voltage regulator IC's. The 7805 provides a 5V output but a 7808 version is available that provides an 8V supply which would be suitable for a Canon 750D. It would operate OK from a 12V input supply but you would also need to include input and output decoupling capacitors as well as something to dissipate the heat generated in the IC and I'm not sure if the maximum 1 amp output rating would be enough.

These are crops of an unprocessed M31 image taken with my 200D and a 400 mm lens and saved as JPG images. On the left is a 'zoomed-in' view of the full 6000 x 4000 pixel image, on the right is a 'zoomed-in' view from the 3 x 3 binned 2000 x 1333 pixel image. I know which I would prefer, but without zooming-in ('pixel peeping') you probably wouldn't notice any difference of the un-zoomed images on a PC screen.

I use this one https://www.amazon.co.uk/Andoer-ACK-E18-Battery-Adapter-Charger/dp/B076CK6JPF. It's available from several different suppliers.

Wow, I wonder how many metres off the centre line you could be to catch one of those and how fast would the video FPS need to be to ensure you captured it on at least 1 frame?

Agreed, I worded that poorly. My understanding is that darks are intended to remove the 'correlated' noise from the lights (but will still increase the uncorrelated random noise) and that in the absense of darks dithering with a sigma clipping algorithm will have a similar effect. However, in the absence of dark flats (or flat darks), I though that only the bias is used to calibrate flats, not the darks?

I wonder if you actually need to take Darks? At this time of year, the sky doesn't get really dark from the UK so if the natural (or unnatural if you're imaging from a light polluted location) 'sky noise' exceeds the camera noise then I would have thought that using Darks wouldn't add much benefit if you're dithering (intentionally or not) and stacking with a sigma rejection algorithm.

If you look here http://skywatcher.com/product/heq5-synscan/ it says "Power Supply: 11 to 15 V DC 2Amp (Tip positive)" but I'm sure most people would recommend at least 3Amp minimum capability.

Not sure why you would need to do either. OK, so I've got a EQ-35 but I'm sure they're not so different. My polar scope unscrews from the rear of the RA axis (if you really need remove it to clean it) so no need to remove anything. To calibrate I just raise the east and west tripod legs to the maximum leaving the north leg at minimum and then adjust the mount altitude until I can find a distant object in the polarscope near the horizon (obviously with the north leg pointing roughly towards the object!). That way you can comfortably sit down whilst aligning the polarscope.

The odds of capturing one by chance are somewhat minimal. Look at https://transit-finder.com/ to find out when a solar or lunar ISS transit occurs at (or near) your location.

Low, high? I've always thought that the first number refers to the desired standard deviation and the the second number to the number of iterations to try to achieve it (I'd guess that 1 is normally sufficient in most cases) but I suppose the definition could vary between software.

As mentioned above, the sensor temperature can make a big difference to the noise and keeping liveview on will increase the internal camera temperature. You can download EXIFLOG from http://www.covingtoninnovations.com/dslr/exiflog.html that will show you the temperature of the DIGIC chip when the image was taken (not the actual sensor temperature, but probably won't be far off). Ideally your darks and lights should show the same temperature. If their is a large difference (>5°C?), try stacking without the darks. With my 200D I take at least 80 x 180 sec images to get the noise within (my) acceptable limits but that may be due to my Bortle 5-6 sky.

Those are the pixel resolutions in arcsecs, so each pixel of your camera covers 0.74 arcsec of the sky, whereas a pixel of your guide camera covers 2.49 arcsec. The approximate formula is: Resolution = 206 x pixel size / focal length Where resolution is in arcsec, pixel size is in um and focal length in mm.

I have all 3 volumes of Burnhams Celestial Handbook (1978 edition) and I'm not aware of any information I think you are looking for in them. Around the same time I remember buying an excellent book on astronomical mythology, but like so many of my old books, it was consigned many years ago to boxes in the loft. If I get a chance this weekend I'll see if I can get up there and have look for it (but it's more than likely out of print now).

Even with surface mount connectors it should take some significant force the 'pull-off' the connector and would likely result in damage to the PCB lands/tracks and also leave the connector pins bent so based on your photo it looks like a manufacturing issue (dry joints). Personally I would be concerned about the viabilty of the other soldered joints so if you've not had the new PCB long maybe investigate if you can get a replacement before you embark on repair?

When you star aligned were Arcturus and Vega both on the same side of the meridian or was your target on the other side of the meridian? When you get to "Begin Alignment? 1) YES 2) NO" on the HC, if you select 2 does the mount start to track or at least begin moving westwards? (Something you can check in the daylight without having to wait for a clear night!)

To be honest I wouldn't bother. You could get it approximately correct by loosing the 3 graticule clamping set-screws so that the graticule can be rotated to near the correct position (not easily done with the polar scope fitted in the RA axis) but then you would need to go through the realignment procedure so that the graticule is correctly centred around the RA axis (which will probably effect the position of 0). From my (limited) plumbing experience, I've often wondered that, if the 0 was initially clockwise of the required vertical position, the application of some plumbing PTFE tape to the polar scope/RA axis thread would restrict how far the polar scope could be screwed in and therefore leaving 0 in the correct position - but then I don't think I would want to use an adjustable wrench to tighten it to get it spot on 😆

You should be able to download the instruction manual off the web. Looks like you've got the polar scope with the 'clock' graticule so polar alignment is fairly easy with that. First ensure that an object remains on one of the circles when you rotate the RA axis (for best accuracy I personally would try to use a more distant object than that chimney!). Then, when you come to polar align, just ensure that the 0 hr on the 'clock' is vertically upwards (by rotating the RA axis as necessary) and then set Polaris to the 'time' on the gratcule as given by the handset or one of the various polar alignment apps that are available. You don't need to worry/use the 24hr green clock ring unless the want to find objects using their RA and I suspect that it's virtually next to useless for that and just put there for show.

Has anyone used the Canon LP-E17 dummy battery available from Andoer? Their is a significant price difference between their product and the 'official' Canon one!

Last year I made some (rough) measurements of the effect of different stacking methods (I use DSS). I generally try to use at least 80 lights (180s each, so 4 hrs total). I found that using Average stacking the resulting noise closely followed the 1 / ROOT(N) formula and similarly for Kappa-Sigma stacking, but only up to about 30 lights. After that the resulting noise leveled off and occasionally appeared to increase slightly. These days I tend to Kappa-Sigma stack the lights in seperate batches of 20 to 30 and then average stack the results. It seems to give me the same resulting noise as average stacking does but without the satellite trails and hot pixels.

I also first started with the Canon EF50/f1.8 ("nifty-fifty"). Certainly not a bad lens for the price, especially if you stop it down to at least f2.8. On a crop camera you can nicely fit in Orion (like https://britastro.org/observations/observation.php?id=20200227_204500_9630d0caf2b7941a - a bit late for this year unfortunately) and you can get some nice views of the Milky Way (like this in Cygnus https://www.eastmidlandsstargazers.org.uk/topic/18048-milky-way-in-cygnus/ - not long to wait for that).

MotionCo also do a range of pulleys and belts.