ollypenrice

They are more like shoes than socks, though and they last forever. At least, I know the mits do because I've had a pair for forty years. I also noticed that a lot of mendacious outlets sell poly-cotton socks which they call Dachstein. If it ain't shrunk wool, it ain't Dachstein. Olly

A very good imager indeed. Olly

Crocs are lethal round here. You'd end up with something sharp and pointed right through you foot in no time. Olly

The key thing about any socks, from a warmth point of view, is that they need the shoes around them to be large enough, which is likely to be a size up on your regular size. Thick socks in tight shoes don't work, they restrict circulation when what's needed is the opposite. If you want the warmest socks on earth, I'd suggest Dachstein wool. I'ts a shrunk, felted wool of remarkable density. https://www.sweaterchalet.com/dachstein-woolwear/dw-5111-adult-socks/ Olly

The truth is that M31 does not contain strongly contrasting colours. When you see strong dstinctions between reddish core and blue-ish spiral arms with patches of Ha, this is not false, it's just exaggerated or emphasized. Olly

Transformed! A really good M42, now. Point of interest: the bottom half of the nebula, in this rendition, is brown and dusty. In most renditions the red emission still dominates in the lower half. In some, there is a strong colour transition, but in the reds, where yours turns into brown dust. I find your version perfectly credible and am simply interested in the emission/reflection balance, brown dust being reflection. Essentially, I think your image may be onto something. Olly

Very nice indeed and, as Alan says, subtle. I do think it could stand a little more colour intesity but not by bosting saturation. That's a noise monster. Olly

The most important thing about observing is where you do it. Almost all deep sky objects are impossible from cities, though the moon and planets can be observed. Do you intend to go out to darker sites than Melbourne? If so, portability will be important. An excellent starting point would be an 8 inch Dobsonian. This is a Newtonian reflector with a simple but very stable and intuitive mount. Bang for buck, they can't be beaten. They do sometimes need optical adjustment and if this worries you (though it isn't very difficult with an appropriate tool) you might go for a refractor instead. https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html Olly

That's my carelessness in using it, though. It would be easy to avoid this. Olly

A year of change, for me, collaborating with Paul Kummer and a joint RASA/OSC CMOS/Avalon Linear rig under Paul's robotic control. I'm just the on-site mechanic and do the post-processing. The RASA has opened up new targets (very faint ones) but the best we've done, technically at least, is this widefield Pleiades. It's a large image so, to see the real point of it, you'd need to follow this SmugMug link, go to full screen and then click to enlarge. https://ollypenrice.smugmug.com/Other/DUSTY-DARK-AND-MILKY-WAY-TARGETS/i-RXwsZdg/A Huge thanks to Russ Croman, author of StarXterminator, BlurXterminator and Noise Xterminator, software packages which have transformed post-processing. Olly

There are so many variables in this game that I agree with Alacant: a pragmatic approach works because you are working with all your own variables built into the data. Trying to anticipate or quantify all those variables from theory is, in my view, effectively impossible. Olly

Paul rebuilt our widefield M45 mosaic (linear data) after running them through BlurX at default settings. In doing the post processing I felt it held more delicate detail and the stars were easier still, using StarX. Full size is enormous but here's a link to a fairly large one. Be sure to use the full screen icon, upper left, and click to enlarge the image. The partial screen sometimes creates artifacts. https://ollypenrice.smugmug.com/Other/DUSTY-DARK-AND-MILKY-WAY-TARGETS/i-RXwsZdg/A Olly, and Paul Kummer.

I would rather give up wine than watch anything by an 'influencer.' The very word makes me want to throw the sofa through the window... Regarding imaging tutorials, the questions I'd ask are: Where are the images taken by this person and are they any good? Rob Gendler, Adam Block, R Jay GaBany, JPM, RBA, Warren Keller and many others have no difficulty passing this test. Does the person know what they are doing and why, or are they thrashing about grabbing this slider and that one? The minute I hear, 'I just adjust these sliders till I get what I like,' I switch off and both the sofa and the window start to feel nervous. lly

An honour to be the first to comment! This is simply magnificient. What a joy to see it with the stars under control. (I reprocessed mine through StarX as well, though not from scratch. The improvement was spectacular, one of the best StarX successes for me, along with The Hidden Galaxy and the Fireworks Galaxy. In each case the originals look - embarrassing! Image processing will never be the same again. Olly Edit: I wasn't wide awake when I posted this. Ooops!!!! 🤣

And there's the rub. We might want to make objective assessments of the results of this program but, even if we could, what would be the point? We are all going to observe the image subjectively once it's finished, so a subjective discussion is, in fact, the most logical one to have. Olly

I've been inputting PSFs generated by PSFImage but haven't yet come to any conclusions worth sharing. Olly

Regarding the need for short subs, simply look at your linear (unstretched) long sub stack. If an object is not saturated (exposed to the camera' full brightness limit) you don't need shorter subs, you just need to stretch with care, possibly even blending two different stretches. Olly

Colour? Come now, that is precisely what a camera can capture. These are natural colour RGB. Olly

OK, in my 14 inch I would, ideally, like a range of 13mm to 40mm. At the moment I have only 13 and 26. (Members please note that my birthday is Feb 12th. ) With 3 EPs I would have, say, 13, 26 and 40mm. If I were to narrow the gaps by adding another three, what would they be? I do have a good 15mm in my box but it's not as good as my 13mm Ethos and I just don't use it. So how about 20? This would be a DSO eyepiece. Is it worth finessing on DSOs between 20mm and 26? Not for me, personally. The same applies to the gap between my 26mm Nagler and my (imaginary) 40mm Pentax. I'll concede that planetary buffs (which I'm not) would like a fine range to locate the optimal maximum magnification. I'd go for the simple life, 13, 26 and 40. That's the good news. The bad news is the price of the 13, 26 and 40 in question! 🤣 Olly

Depends mainly on 1) the speed of your system. This is not simply determined by F ratio. It is determined by the amount of light you put on each pixel. If you put bigger pixels in the same scope, each pixel will receive more light and you will gain speed and, possibly, lose resolution. 2) the sensitivity of your camera. That's an easy one. 3) your level of skyglow. At a dark site you can expose for longer than at a light polluted one whose ambient light will soon overwhelm your camera. 4) your camera read noise. You get one dose of read noise per exposure, so CCD cameras benefit from long exposure because they have high read noise. A CMOS camera has low read noise so it does no harm to take more and shorter exposures. 5) the brightness of your target. The faint stuff takes a lot more time to capture. 6) the quality you want to achieve. You need to increase your total exposure time by four in order to double your signal to noise ratio. Quality is, alas, subject to diminishing returns. 7) the precision of your tracking. 8 ) whether or not your camera is cooled. I've been typing at the same time as Vlaiv, here, and I agree with his advice. Experiment, find a suitable sub exposure time and stick with it. Very, very occasionally there is a need to shoot short exposures for very bright parts of an image. M42 is the obvious example. You'll also need to find a way of combing them using a high dynamic range technique. (There are many.) Lots of beginners shoot a random assortment of different exposures on the same project. Don't, it is a bad idea. Olly

Marc Bretton. He founded an astronomy centre nearby, on a rather different scale to mine! A good guy. https://www.obs-bp.net/ Olly

As Deadlake says above, the TEC140... You are within price range on the used market. It is a triplet but oil spaced, so there is physical contact between all objective surfaces, making cooldown fast. TEC QC is second to none, and I mean none. (As someone who hosts robotic telescopes I can tell you that Takahashi QC is abominable. If anyone feels inclined to burn me at the stake as a heretic for this, PM me for chapter and verse. Believe me, I'm ready.) The TEC objective is optimized for visual observing (which you'll like) but, with flattener, it is also the best refractor - the best set of optics, in fact - that I have ever used for imaging. The focuser is Feathertouch rack and pinion. You will never beat that. I bought mine second hand about ten years ago and it performs, in all respects, as new. We might remember that, when it appeared, it was presented as a slightly 'sub-premium' Apo with a clever design, and clever aperture choice, designed to take on the finest Apos and beat them on price. The fact that it is now regarded as a full-on premium Apo indicates that it proved capable of living with the best and, sometimes, beating 'the best.' I would swap mine... but only for an AP175. Olly

Welcome! Olly

How would you distinguish between OIII and Ha in the mono capture? You'd get them both but in one channel. If you used this as a luminance channel the Ha and OIII would be applied equally to all three channels, destroying any colour differentiation. Olly

All right, how about this: on a given occasion, does a premium eyepiece of a compromise focal length beat a budget eyepiece of the perfect focal length? My answer is, Course it does! lly