Ags

If it's any consolation, the weather has hardly been better here in Holland. I remember people talking a decade ago about global warming making northern Europe more Mediterranean, but in practice all that sea evaporation means we're just getting more rain.

As long as it doesn't go negative...

You're too kind!

2021 was a busy year, both for buying and selling items. I was sad to see my ST80 and ASI178MM go, but they were all more than replaced. Between my Zenithstar 66, ASI485MC and 50 mm RACI finder, I don't know which to pick as the best buy of 2021. They all seem essential! I think the RACI wins by the slightest margin, as it has opened up hundreds of new targets for me. Worst buy? I am afraid Worst Buy 2021 goes to the Baader Q Turret. Eyepieces tilted out of alignment and it was always too stiff. What was your best buy?

OK, so I have decided on the ZWO Duo filter for narrowband work. I am now thinking to get the Astroomik L-3 filter' as it cuts more red and blue than the L-2. Not sure however if that is overkill for a ZS66+f6.3 reducer combo.

Yes, I have experimented with front mounting filters. One major disadvantage is the filters are exposed to the elements. But I've sold all my lenses now, so no more such experiments for me

Yes I see that, but remember by area that the highly angled edges are actually most of the aperture. And when you change from F8 to F4 you are only adding the big angles... The light pollution still gets in from those more angled rays (there is light pollution of the right frequency) but your signal doesn't get through. So by using faster optics with a narrow fliter, you effectively only add more light pollution and hardly increase the signal (in extreme cases).

So, I suppose my question is: can anyone recommend me the best of the best UHC?

I think another way of looking at it is: given the above graph, the L-Extreme is passing half the incident Ha at f4 versus f8, but broadband light pollution is not attenuated at all (light that would have been blocked bandshifts into view). So the narrow passband of the L-Extreme is effectively doubled in width, in addition to effective aperture being decreased by a factor of 0.7.

Here is a graph for a broadband versus narrowband filter: https://www.cloudynights.com/topic/737925-l-extreme-or-l-enhance-for-f4/ Seeing as I am imaging at around f4.5, maybe I will go back to the Baader UHC-S, but it leaks IR...

Good catch. But surely this would apply to any interference filter, particularly a narrower one like the Optolong L-Extreme? Why is the ZWO more affected?

I think I will go for the the ZWO Duo filter after all.

I just sold my last two camera lenses so I am in a position to complete my fun-sized setup: CF tripod AZ-GTi ZS66 F6.3 Reducer ASI485MC I desperately need an IR cut filter, and I am thinking about getting the 1.25" Astronomik L-2, which will go close to the sensor via a ZWO T2-1.25" adapter. Is it worth 20 euros over the budget IR cut filters? To enhance contrast on nebulae, I can choose between a Baader UHC-S or an Optolong L-Extreme. In favor of the Baader, I expect it is easier to use as it lets more broadband light through - so easier to focus and frame. And star colors will theoretically be better (not a big fan of narrowband stars). Sky fog would only be reduced by a factor of 3 however. The L-Extreme would reduce sky fog by a factor of more than 10, but I'm just concerned it would be frustrating to use. Has anyone got experience of both? I could also split the difference and get the ZWO Duo filter (like the Bader in blue and green, like the Optolong in red). For IR I think I will just stick with my trusty Wratten #29.

The second looks a bit cleaner to me too. Both very good, better than I have ever done.

I knew there was a But coming... 🤣 I seem to have nearly come to the end of my buying too. I just need a couple of filters and adapters for astrophotography, and maybe one more eyepiece.

The 2" part comes off the 485MC exposung male T2 thread, at least it does on mine.

Even if we only get two or three good nights next year, let's make them good ones and enjoy them. Keep on putting the scope out to cool, because you never know when a clear patch will blow over!

I want to shoot enough good DSOs to make a calendar at the end of the year (14 months, 12 for 2023 and first two of 2024). So far I've got 1.5 pictures 😀 It should make the "perfect" xmas gift for my friends and relations next year... Also on imaging, it's a Mars year so that will be a highlight. Observing - I want to chase down more doubles and DSOs I've never seen before. Writing - finish writing my book on DSOs. Also for writing - I want to generate milky way traces on my charts. Should be a simple matter of generating contours from star density, but the trick is making the contours pretty and not troublesome under red torchlight.

My TalentCell battery might actually work. The Pi runs, and it looks ike there is enough current when the camera is connected to the USB 2 port. I can't however connect to the Pi over VNC when the camera is connected on USB 3. I disabled Bluetooth to save a bit of power, but still couldn't get the camera working on USB 3. Not a problem for DSO imaging. It's still not clear if the TalentCell will still work when it is powering the AZ-GTI too.

Thanks @AstroNebulee. I definitely want to add more data to this one.

I can understand going to dark sites, but this is taking it to extremes!

This might do the trick -2 3 Amp USB ports. https://www.amazon.nl/Anker-PowerCore-Powerbank-Technologie-Smartphones/dp/B00Z9UY65G/ref=asc_df_B00Z9UY65G/?tag=nlshogostdsp-21&linkCode=df0&hvadid=430640613250&hvpos=&hvnetw=g&hvrand=5697410519504224895&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9065148&hvtargid=pla-563106500803&psc=1

This is 90 minutes on M45 at f4.3: 910 x six second subs with an ASI 485 MC at gain 100. AZ-GTi in Alt-Az point-and-track mode. Bortle 8 skies, no Moon issues. Stacked and processed in APP and Gimp. It is the first time I have managed to reveal the nebulosity in an image, and I feel this is a good starting point: to make the image better I just need to improve framing slightly, and shoot a lot more data! Both of which are easy! Another thing that will improve the image: buy an UV/IR blocker! But it looks like the process of super short subs and basic mount is viable My hard drive is filling up nicely though.... Not sure where the halos come from - the only things in the optical train are a f6.3 reducer and the AR window.

I was surprised to see many negative comments online about the use of Ariane. But in reality it is the most reliable launch vehicle in service; it was designed to launch crewed flight after all.

Hi Claire, I watched the launch on tenterhooks too, but the rocket performed flawlessly. the next 30 days are full of risks (probably more risky than the launch) but the good news is I can't stay anxious that long! I feel for the engineers and scientists working on the project and I hope it will all work out in the end.