JSeaman

Exposure time varies depending on your target and equipment. If you are running a 'dumb' mount just tracking then you may be limited to something like 1-2 minutes. If you are guiding then you will likely to be able to get longer exposures (typically something between 5 and 30 minutes). People don't tend to do more than 10 minutes most of the time for a number of reasons such as aeroplanes / mount issues / clouds etc. spoiling a lot of data and the fact that this will normally give you all the detail you need If you are shooting something really bright like M42, you may only want 1-5 minutes and you will also likely want some much shorter (between 3 and 60s) exposures on the core The stacking software should deal with field rotation no problem

I couldn't quite get what I wanted on this one, plagued with issues again and only managed a little in G/B but here it is 72x5 minute HA (6 hours) 54x5 minute red (4.5 hours) 3x5 minute green 6x5 minute blue

It was a bad one for sure, I'm hoping new Lindy cables and IP rated Ethernet will make the difference, should know by tomorrow!

Well, thirty minutes on blue and only 15 green so really not enough but I lost the battle last night and figured I would just use what I have. Hope you have more success than me!

I eventually got everything set up and left it going last night, I came down this morning excitedly expecting 6 hours of data ... it stopped after 30 minutes. Definitely one of those nights, I think I give up for now, this is as much as I managed

At least something good has come of it then! Eventually (6th effort) I plate solved and the scope has magically moved by a decent amount in both RA and DEC since it was tucked away a few days ago in a locked observatory. I also just lost all comms for no reason at all and then my phone died while I was setting the shut down timers. Suffice to say, a terrible night but I have just started taking my first picture ... in time for the moon to come bounding in like a mischievous rogue to ruin what little consolation was left of imaging. PAH! Stupid hobby

Now back to slewing in the wrong place:

I just need an hour of blue data. That's all. So I set everything up, slewed to my target in CDC and it was offset by a good margin on the starmap, tried another target and got the same. Synched the time to make sure everything was good, same issue. Opened up the "Setup"-->"Date/Time" to make sure BST was enabled and it jumps to the target all of a suden. Close the window and it jumps back. Then after a few minutes it seemed to sort it's life out and jump back again. During all this, at no point was the camera seeing the star it was supposed to be on. So I decide I'll plate solve on where I'm pointing - astronomy.net, 4 attempts, 4 failures after >10 minutes. Doesn't seem to be working. I downloaded all sky plate solver - it now wants to install 4GB of maps before it can plate solve. Everything has been perfect for a little while, BST comes along and it all falls down. Something has cocked up for sure, I think it is CDC but it's going to be a pita tonight!

Maybe these: Leo Triplet, M101, M51, M81/M82

That is a blown out trapezium? This is a good example of it now blown http://skyandtelescope.org/wp-content/uploads/Trapezium-Hubble.jpg

That was very rough and ready and mainly in PS, it's good data and you can go far with it. Just process it forever until you're happy with the result

"From what I've read 1200mm is about the limit after which an off-axis guider is essential" I'm running 1,500mm without OAG for info

I can only add from my own experience - I am running a 300PDS on an NEQ6 Pro (1,500mm rather than the 1,200mm of the 250 PDS). It weighs an awful lot more but I manage it just about on the limits of the mount with all my other equpiment on there. It does work but I wouldn't dream of setting it up each night, I would definitely damage something. The magnification is superb, I was actually too close for imaging most things so I changed my camera to an ASI 1600mm and the FOV is now much better. Changing the focal length (or sensor size) changes the field of view so you can get up close and personal on those targets. In terms of guiding, I use an ED80 with an ASI 120mm which to try and get less than 0.88" accuracy which was just about doable. I have recently switched to 2x2 binning and that makes things a lot more palatable though.

I don't think that's a bad job from the data you have. More data is better and lower ISO if you can for noise reduction. And no moon of course!

That was just a quick process so you should be able to get something better out of it. If I were you, I would treat it as a learning exercise by gathering the exact same data on a moonless night and see what difference it makes

With a crop, smoothing, green reduction and levels/curves you can clearly make out the horsehead and flame

Just a background extraction and stretch showed this:

Simon, what are you using to stack them? If you're using deep sky stacker (dss), you simply open each type and it will do all the work for you. It will combine each into a 'master' and then apply it James

I only managed <1 hr of data this year on it but I stitched together a few legacy photos to remind myself how far things have come. I should get a good picture next year hopefully

No there are no artefacts

I don't understand what you're getting at?

Everything usb-c is bidirectional

0.06 on the panel, 0.01 last time I used the sky

I found it excellent when it first came out but I don't know what has happened of late, it has been off the mark a lot. I use Clear Outside and the metoffice, if either of them say it's cloudy then that one is right normally. The detailed metoffice forecast of cloud cover is useful. I think it's time to pack up and move to Mt Teide