Lee_P

Brilliant!

It's got "The Sky Guide" for December 2021, if that's what you mean? It's a 16-page pullout.

This was a toughie. A bit crazy to attempt it from Bortle 8 with an OSC camera, but I like proving that these things are at least possible! Full details on my website, and capture details below. * Nov - Dec 2021 * Bristol, UK (Bortle 8 ) * Telescope: Askar FRA400 f/5.6 Quintuplet APO Astrograph * Camera: ZWO ASI 2600MC-PRO * Filter: Optolong L-eXtreme * Mount: Orion Sirius EQ-G * Guide: William Optics 32mm; ZWO ASI 120MM Mini * Control: ASIAIR Plus, ZWO EAF * Software: PixInsight, Lightroom, Topaz DeNoise AI * 540 x 120 seconds ------------------------------------------------------------ Total integration time: 18 hours ------------------------------------------------------------ By Lee Pullen

vlaiv's suggestion there is excellent. I've just written a review about that very telescope over on AstroGear Today. It's below your budget, so you could bundle it with the book Turn Left at Orion and a red LED torch, and it's a Merry Christmas all round!

Looks great, especially for a short integration time. Keep going, add in as much good quality data as you can! It could probably handle being sharpened a little more during post-processing, if you're concerned about it looking a bit soft.

Could you cycle your R G B filters regularly throughout an imaging session so you have an even number of them regardless of when the cloud runs in?

This is interesting because actually given that mono collects data faster, battling clouds is a point in favour of mono rather than OSC. What I find in practice though is that data acquisition is sufficiently simpler with OSC that I personally find it easier to rack up integration times -- typically 20+ hours per image, even from cloudy Bristol. I think that discussions about mono vs OSC tend to focus on quite technical aspects, but really the most important factor should be what a person would find more fun to use. The answer will be very dependent on the person, and may well change over time as their personal circumstances change as well. Mono has the potential to give a better end result, but what if someone has a torrid time actually reaching that point? And on the flipside, what if someone has an easier time with OSC and produces a stunning image, but feels that they've sold out by fudging together a Sulphur-II channel in order to recreate the Hubble Palette, for example?

I've made an example price breakdown in this article about Mono vs OSC. Ballpark figure is that mono plus required filters is likely to be about 1.5x the cost of an equivalent OSC. But of course it varies hugely based on what kit you go for. To answer the OP's question, mono has the edge over OSC in many ways, so there are certainly still benefits. But OSC with a dual-band filter is capable of producing excellent results while being cheaper and (depending on what you want from the hobby) potentially more fun to use. Lots of OSC image examples are here in my gallery. and all from light polluted city centre skies.

Consider me very interested in the L-uLtimate! 🤩

Welcome to SGL 😃

I'm slowly reviewing all the astro kit I've been using for the last year or so. Now it's the turn of the William Optics 32mm Slide-base Uniguide Scope. The review is here: https://urbanastrophotography.com/index.php/2021/11/24/review-william-optics-32mm-slide-base-uniguide-scope/

Nice review! I've used this telescope as well, and think that it's an excellent choice for beginners. Here it is set up at Stonehenge for a stargazing event I was running:

I'm a refractor guy so am not that clued up on collimation, but my guess is that your collimation is out of whack to such an extent that your autofocus routine can't work properly. So if I were you I'd first spend time getting the collimation spot-on; then I expect your autofocus will work much better.

A tiny toy telescope I was bought as a present when I was a child! Cost about £15 I guess. Terrible optics and horrendous to use, but when I saw the Moon... 🤯

I've just taken a look at your Crescent data using PixInsight. Collimation / focus is off. Still, here's your data straight out of integration: And with a very quick edit:

Just five minutes of editing on your version 2. The longer integration time has really helped!

@Iem1 I had a quick edit of your data so far. You're off to a good start, just gather more subs and get your focus as tight as it can be 👍

There are three main things you can do to combat noise: 1. Longer total integration times. The more good quality data that goes into your stack, the better your signal-to-noise ratio will be. Here are some tips. 2. Take calibration frames (Darks in particular). Having a cooled camera sensor does help to reduce noise a little, but the real benefit of a cooled camera is that you take set it to a particular specific temperature and then create a library of calibration frames that can be reused. Calibration frames are still important with a non-cooled camera like a DSLR, they just take a bit more effort to produce. 3. Noise reduction during post-processing. What you can use depends on the software that you're using. I find that Topaz DeNoise AI can work well, particularly on starless images (you then add the stars back in afterwards).

I appreciate that this is a controversial opinion, but I shoot both narrowband (using an L-eXtreme) and broadband (with no filter) regardless of what the Moon's doing. I just don't factor the Moon into the equation. It works out fine -- example photos here. Full Moon, New Moon, if the skies are clear I'll be imaging whatever project I've got on the go. If the subframe quality is really bad, PixInsight's SubframeSelector will flag that and I'll remove it from the stack. But tools like DynamicBackgroundExtraction and NormalizeScaleGradient work really well at making even images with strong gradients usable. I expect other software packages can do similar. I do aim for long integration times mind you -- 20+ hours -- so won't ever be producing an image from just a night or two when a target was close to the Moon. I consider this comment to be gold quality, bearing in mind I'm under Bortle 8 skies:

Lots of good advice here already. This will likely be a tip for the future, but I find that PixInsight does a good job of removing gradients from a bright Moon, and its NormalizeScaleGradient is useful too. Also, here's an OSC Iris Nebula from Bortle 8.

I use Topaz DeNoise for almost all of my images. It can be really good. I've found it works best on starless images, and then I add the stars back in afterwards.

That's a great collection!

Thanks, I appreciate the comment I have a pier in my garden, but I keep the telescope in the house when I'm not imaging. So fairly permanent, but not to the level of a dome or roll-off roof shed. As a point of interest, I'm in Bristol, so not far from you, and collected the 28 hours over 15 nights. Actually I collected a lot more, but weeded out the low quality subs. I've written an article with tips on getting long integration times here. Edit to clarify: those were 15 consecutive nights, and most of them were cloudy!

Presenting The Lion Nebula (Sh2-132), taken with a small refractor and OSC camera plus L-eXtreme filter, from Bristol city centre. This is the latest in my series trying to push what can be achieved with my kit under such light-polluted skies. I might do one more faint target before moving onto the brighter delights of Winter! More info on my website, but if you just want the capture details: * October to November 2021 * Bristol, UK (Bortle 8 ) * Telescope: Askar FRA400 f/5.6 Quintuplet APO Astrograph * Camera: ZWO ASI 2600MC-PRO * Filter: Optolong L-eXtreme * Mount: Orion Sirius EQ-G * Guide: William Optics 32mm; ZWO ASI 120MM Mini * Control: ASIAIR Plus, ZWO EAF * Software: PixInsight, Lightroom, Topaz DeNoise AI * 840 x 120 seconds ------------------------------------------------------------ Total integration time: 28 hours ------------------------------------------------------------ By Lee Pullen

This photo appears in the December 2021 issue of Sky at Night Magazine 😃