Stub Mandrel

Just don't do what I did this week and use Sharpcap's automatic dark subtraction. And subtract your master dark flat from all your lights...

No 0.9x option for Barlow/Reducer - that's the Skywatcher Coma Corrector lots of us use with the 130P-DS so ought to be there. Minor point 130P on list but 130P-DS isn't (although both have same aperture f/l).

Ignore it, no point trying to do better than that! I used to get 0.6 and results were spot on. New setup and now struggling to get these levels, I've just written out all of my old settings to copy across. (Edit) Hopefully I've found it - backlash compensation was switched off, also minor differences that probably wouldn't cause issues, but I've changed them to the 'known good' values anyway.

If you set things up the same (especially camera orientation) then the flats should get rid of (or at least greatly reduce) the vignetting. They may not remove all dust spots, but they will be less intrusive.

Welcome home Galen! I've found that 99% of the time its really a case of being careful with stretches. Use curves not gamma and keep the upper part of the curve from levelling off. That way I've always managed to keep Alnitak separate from its companion, even with 5 minute exposures. Of course it's easy with a Ha filter...

Posted this elsewhere, but after some serious rework I'm happy to add this to the thread, despite a few disasters on data collection. Binned 50%, Ha Sii Oiii, ASI1600 mono.

Get them, you'll be glad you did, there's detail hidden there but you need to correct with flats before stretching. If your rig is still set up, or it can be 'recreated' just photos of an out-of-focus plain wall using Av setting will be fine.

I've gone back to the start with the Oii and Sii, I stacked them using the Ha as a reference so alignment stands up to papixel peep now. I remembered a technique for pulling out faint nebulosity that rescued many of my early images that saved the Oiii layer. I got more defined colours, then used the original Ha as a luminosity layer as it included all the O and S areas. Now, I'm starting to feel happy with this.

Thanks, I think I can improve the alignment even more by using a Ha reference frame.

Here are the Oiii and Sii layers so you can see how bad they are! Just jpegs to save room. You can see the remains of amp glow on the Sii (because I used the wrong dark) and how feeble the data is, but it does add some features, I've outlined them in yellow.

Last night I got my first OIII and SII data, enough to try combining with my Ha froma few nights ago. Both runs were spoilt more than a bit because I used automatic dark subtraction but the system loaded the 'dark flat dark' of a afew tens of milliseconds instead of the 500 second 'dark dark' 😞 For some reason half of the OIII subs were very dark despite having the same settings, and I got better results just stacking relatively few, but they weren't too bad. The SII subs were incredibly dark, and it took a lot of stretching and some quite scurrilous star mask and blur to get anything usable, but it does pick up some wispy bits at the left of the image. I won't pretend these are either pefectly aligned or well processed, but I'm treating this as 'throw away' data to just find out how it/if works. These are my first attempts at false colour (Ha-red, SII-green, OII-blue) and 'Hubble' palettes. No Pixel-Peeping allowed!

My current setup a week or so ago 🙂

Agreed, start a new thread in the camera forum. This is a question I wrestled with, it depends on what scope you have to some extent.

For all those I used a polarscope with the new-style reticle.

So polar alignment is now an international competition? I see you can even share your PA on social media... "Global ranking 414 Defeated 38.8% ASIAIR Users" I woudl be interested except it still doesn't work with ASI120MM/MC 😕

Made me go a-googling Alan: https://plutotrigger.com/products/pluto-trigger?variant=26846149383 It's very impressive, there's no individual function that's particularly innovative - except they've packed EVERYTHING you might want for automated photography into small box at a reasonable price.

good to revive this thread a s more people should be aware of this option!

Another amazing display of France's capacity to place vegetables in orbit...

Just missed it, but worth watching again for the auto translate...

Pleased with this, I think I'm getting the hang, although with only 12 5-minute frames I would like to get 2 or 3 times the data to control the noise. First though, I'm going to cut some teeth on OIII and SII. Combined with some RGB for a few years back as L.

I think I found the problem. Looks like I had dark subtraction on in Sharpcap when I took the lights, but not the flats (or the flats had additional subtraction of the wrong dark). Last night I took my lights with dark subtraction, then took flats with correctly timed darks subtracted and stacked without darks or bias and it worked fine 🙂

60 seconds to two minutes if you don't pixel peep and you have it set up nicely. Al;l my images on this thread up to June 2017 are unguided, some of them use 120s exposures. These are both 130P-DS, unguided on an EQ3-2, 120s exposures:

I got one of these, gives really nice views of the moon and yes you CAN SEE SATURN'S RINGS!

I almost forgot to process these, about 55% of 70-odd jpegs taken with my bridge camera. Filling in the gaps in my moon collection, I have very few from the last quarter. The sky still had colour to it, so I didn't convert to mono. Nothing to write home about, but a pleasant image with minimal processing after stacking, just light deconvolution and gentle curves.

Nadolig Llawen - a Merry Christmas to one and all 🙂