Stub Mandrel

Still looked really puny last night. I was surprised my companions had not heard the news!

But to compensate you got plenty of the faint stuff. Tip, when doing M42, get the main data, then quickly take 20-30 images each a 10 seconds long. That's plenty to give you a 'trapezium' layer to blend in.

Having used the Skywatcher CC for a few years, I think the issues are overstated. Yes, you do get a faint blue patch 180 degrees around from Alnitak when you image the flame and horsey. It's not an issue in narrowband or even with the L-enhance, and I haven't seen the problem anywhere else, not even M42. It's big advantage is that 'it just works' no messing with adjusting spacers, just fit a t-mount + dslr or for an astro cam get the image plane 55mm back. Example with L-enhance and DSLR - no sign of a reflection.

Yes. I managed with an EQ3-2 for a few years before getting an HEQ5.

Turn it off and find polaris, focus sharply, then turn it on.

How about this? I've used an assymetric blur kernel and deconvolution, then extra de-noising.

They are aren't they. Strange, I was getting ~1.14" RMS which is less than the pixel scale of my camera. Time to check my subs... Hmm... they all show that amount of trailing! I did lose guiding a few times that evening, it looks like those are either 5-minute unguided subs or something was moving - but if it was it was very consistent.

On the 6 Feb. 130P-DS & ASI1600. 14 x 300s, Ha.

I wouldn't get over-excited. The dimming is caused by reconfiguration of the Dyson sphere.

Here's my HSO M42. Wasn't sure if it would work, but a few things stand out - there's barely any Oiii in M43, the Sii signal is faint so it picks out eth trapezium really well, and the Ha signal gets a lot more faint stuff than a straight L - at least with my light pollution. Improvements with more narrowband processing experience await...

Are the challenges over? Have we admitted defeat in the face of Perma-Cloud?

Here's something you don't see on this thread very often - the Moon. This shows off the capabilities of the 130P-DS pretty convincingly.

Received wisdom is that it is caused by lack of dither. Personally I can't see how fixed noise can become streaks when I'm guiding and the image drift over a session is far less than the length of a streak... My pet theory is that it is associated with very thin cloud and it follows the wind direction.

Excellent, beats my recent attempt with a UV filter, but the seeing was terrible, I was surprised to get this , certainly no cloud detail...

You should have it turned on. Polaris is not very bright and you will need to get your eye in to spot it quickly. Don't assume that setting the angles will get you roughly aligned on Polaris! Sight along one of the corners of the mount body to get it roughly aligned with polaris, and be prepared to jiggle the mount around a bit to get it in view. To align the reticle you need polaris (or anything) dead centre, and adjust the reticle (gently, carefully!) until it stays central when you turn the mount. This can take ages... I did it in daylight, aligned with a distant TV aerial. Polar aligning is easy with the new reticle if you download the Jason Dale Polarfinder app, then update the reticle (both linked here on my website: http://www.stubmandrel.co.uk/astronomy/123-new-style-reticle-for-polarfinder) All you have to do is set the cross hairs vertical/horizontal and then adjust to get polaris in the same place on the reticle as Polarfinder displays it.

Those should be pretty durable! They don't need to be very tight. It should be possible to replace/repair them, can you post a pic of the worn one some time?

Do you mean the threads have stripped through over-tightening? They shouldn't wear out You can ask a local garage to fit a helicoil insert for you which will restore the thread and make it stronger than before. Or even buy a suitable set and do it yourself, cheaper than new rings. <edit>I assume you mean the threads that fit the rings to the wedge?

Suffer for your art, Rob!

M42, luminance only at 60 and 2 seconds. Final image binned 2x2. Collimation needs a tweak as stars are slightly off, pixel peepers!

An easy thing to (dis)prove. Take a 30s exposure. If the image is delivered directly after the exposure finishes, no dark frame was subtracted. If you have to wait another 30s, you can deduce that it did subtract a dark. Of course, this presumes that the camera did take a true 30s exposure, not a 15s one followed by a 15s dark. But again that is easy to verify by comparing a 30s exposure from the same chip in another manufacturer's camera with the ASI one. I think I can sniff a bovine, here. Definitely wrong Best way to disprove is to look at a 5 minute sub and compare to one with darks subtracted - the very faint amp glow disappears.

Not at all, it's taken me five or six years, but I have benefited by starting with very basic gear and very ordinary skies which forces you to learn how to get the best out of short subs, and adding bits piecemeal so I learn a step at a time. If I dove straight in now with my present setup I would struggle - in fact I am struggling! None of it would be possible without SGL as a source of advice and a signpost to other sources of information - or the encouragement of fellow SGL and RAG club members!

You get an extra like for the 'Who needs Prima Luce anyway?' adaptor!

My first quality scope, stunned me the first times I saw Jupiter and Saturn through it. I still use it as my planetary imager and it's great.

My current guidescope is a 50mm 183mm f/l coated achro lens from Astromedia, in an aluminium body with coarse length adjustment, with a cheap eBay helical focuser, and the lens cell, dewshield and mounting block off a £7 eBay scope. Gives me a 3:1 ratio and as mentioned above I can guide at 0.6" rms 🙂

Ah, the place where bias (allegedly) belongs is master flat = (average flats)-master bias. Unless you use master flat = (average flats)-master dark flat