Somerled7

Excellent - that answers my question. I have not been able to find a picture of the top adaptor, so I wondered how it works. It's different to the standard tripod which just bolts up tight. I assume the pillar mount will have the same top plate adaptor as your extension tube. Thanks a lot.

A question for anyone with the Skywatcher pillar mount. I am thinking of buying one for my HEQ5 to avoid potential collisions between the scope and the tripod legs. I understand that there is an adaptor with a central bolt that screws into the bottom of the mount head, then the adaptor sits in the top of the pillar and is secured by three bolts around the top of the pillar. How does this work for polar alignment? With the tripod, I loosen the central bolt, perform my alignment, then tighten the central bolt and check that the alignment is still good. With the pillar, the central fixing bolt is not accessible, so does this have to be left slightly loose? I could not find any You-Tube vides that address this point, so any info from an owner would be welcome.

Thanks for all the replies. In the end my night was scuppered not by a computing problem but a mechanical one - my mount was tracking weirdly, and when I opened it up I had a badly deformed belt drive. So I need a new belt and am in discussion with Rowan Engineering about what went wrong. My experience of astro-photography is that everything is a potential problem - it's just a question of which problem manifests itself on any given night!

Yes, I could have tried a more 'manual' approach. However this was only one of several problems on a frustrating night that ended with me giving up! I know what the source of the other problems were, but couldn't figure out the plate solving issue and wondered whether there might be some setting in APT or ASTAP that I had forgotten about.

Thanks Paul - yes, I was more successful the following night, so hopefully a one-off.

I didn't try that as I don't have another plate solver set up - something I should do in case of problems. Anyway, tried again last night and it plate solved successfully, so no idea what the problem was.

Last night I came across a problem with APT trying to plate solve to the Lobster Claw Nebula. I have an HEQ5 connected via the Synscan wifi module and I'm using the ASTAP solver. Usually it works fine, but this time it solved the first image than said it could not move the scope to the new location. Here's the APT log after the solve:- 2023/11/28 23:32:00 (UT 2023/11/28 23:32:00) DBG RelativeGoTo - SRa:23.256415317, SDec:60.174225994, TRa:23.254444444, TDec:60.174166667, RRa:22.345884323, RDec:55.016101837, NRa:24.164975438, NDec:65.332290823 2023/11/28 23:32:00 (UT 2023/11/28 23:32:00) OpErr Cannot slew to coordinates. Exception occurred. 2023/11/28 23:32:00 (UT 2023/11/28 23:32:00) OpErr PointCraft Error: Can't move the telescope. So the solver worked OK and showed the scope was off by about 1 unit in RA and 5 in Dec, but then it failed to move. I tried changing the target Dec to a random value of 55deg and it plate solved to the location no problem, then re-tried the Claw Nebula location again at dec 60deg and the same failure. For some reason, it seemed like it didn't like those particular co-ordinates! Any ideas?

The Crescent Nebula in Cygnus. I have been trying to get into Narrow-Band imaging for about a year, gradually adding a cooled mono camera, filters, filter wheel and electronic focuser to my kit. I have finally got everything working together (almost!) and have something I think is worth sharing. This is an HOO image with 1hr 15min of H-alpha and 1 hr of OIII. I had hoped to get twice that amount but I left the kit running unattended and when I came back the camera had hung up on downloading images, so I lost a couple of hours. I think it was an intermittent USB problem, so still some things to sort out! Equipment: Skywatcher HEQ5 mount, Altair Astro EDF72 scope with 0.8 reducer giving F4.8 at 345mm focal length, Altair Astro 183MM cooled camera, Baader 7nm H-alpha filter and 8.5nm OIII filter. I've used minimum gain and 300s subs to try to avoid saturating the stars, which I find happens very easily with this camera. I think I still need to experiment with the spacing behind the field flattener as the star shapes go off in the corners, but I don't think they are too bad until you pixel peep. Any suggestions for improvement welcome.

Yes. After the 'big 3' of Andromeda, Orion and Pleiades, the next targets like the Heart, North America and Flaming Star are much harder with an unmodified camera.

I've been slowly upgrading my Astro kit for about 18 months now, and the most recent upgrade was to astro modify my little Canon EOS100D camera. I've also bought a Baader 7nm H-alpha filter for use when the moon is up. I'm now experimenting with combining H-alpha and RGB images, starting with the Flaming Star nebula. I managed 11 hours of H-alpha (15min exposures) over 2 nights under a 70% moon. The RGB data is 2 hrs 30 mins (5min exposures) taken a while ago. Unfortunately they were at different focal lengths - 432mm H-alpha and 300mm RGB, and don't even entirely overlap, so the bottom right side is lacking RGB data. I've stacked in DSS and processed in Photoshop, adding the H-alpha as a luminosity layer over the RGB data and manually aligning the stars as best I could! I know I should gather better quality RGB data at the matching focal length/orientation, so that's the plan for the next clear moonless night, but any other advice/feedback welcome. Camera: Modified Canon EOS100D, Scope: H-Alpha - Altair 72EDF, RGB - Canon 300mm F4L. Mount: Skywatcher HEQ5. H-Alpha Filter: Baader 7nm, RGB Filter: Astronomik CLS clip-in.

Haven't been back to check replies because I've been busy elsewhere. I ended up with different exposure length subs by accident rater than design. Looking for something to image under a bright moon (mainly for practice!) I opted for the Double Cluster in Perseus. As the moon was bright, I took shorter subs than I normally use to avoid over-exposing the sky. I had some older images with longer subs of the same subject, so was looking to see if I could combine them. In the end, I stacked each set separately, then overlaid and combined in Photoshop - interesting to see the noise reducing as the two stacked images were combined.

I've been taking a look at SIRIL for stacking and initial processing, but run into a problem of stacking images with different exposure times. In DSS there are different tabs to group Light files along with their corresponding Dark Files, but I don't see anything similar in SIRIL. Is it a case of throwing everything in and the program sorts it out, or is it necessary to stack each set of images separately then combine the final stacked results? Can anyone advise?

In my first winter of Astro-Photography, I've wanted to at least get decent images of the 'big 3' - Pleiades, Andromeda and Orion. Sounds easy, but it's surprising how much clouds and the moon get in the way - this hobby would be a lot easier to learn if there weren't 4 weeks between each outing! Anyway, here finally is my best effort on Orion. It's only about an hour of total integration time, but ClearOutside was lying when it promised an entirely clear night - after a couple of hours the clouds moved in and by the time they cleared, Orion was sinking behind the neighbours house. 21 x 200s exposures at F6, ISO400, with darks, flats and bias. Stacked in DSS and edited in Photoshop. I've tried extracting the stars with Starnet++ part way through the edit, then re-introduced them at the end. I was quite pleased to start to get some of the darker brown dust showing up. Unmodified Canon EOS80D, Altair Astro EDF72, HEQ5 Mount, QHY5LII GuideCam, Altair Astro 60mm Guide Scope, Pegasus Power Box, Bortle 5 skies.

Thanks for the feedback - you have looked closely! Immediately after posting the image, I spotted the sensor spot directly above the galaxy, but I didn't see the other two. Easy to correct using the Photoshop healing brush, then bring the stars back - we don't want an interstellar incident by destroying someone's star! Point taken on the blues, which I had also noticed when compared to other people's images. I don't think I've got enough detail in the outer reaches to capture much of the blue, though I could adjust the colour balance slightly.

I did use dithering, but just the default levels from APT. Maybe I could look at something more aggressive. Update - Just checked the APT settings, and the default dither level is very small, so I obviously didn't dither enough (though my wife would probably say otherwise!!)