ollypenrice

On looking into this idea I found that I have, throughout the 50 years since I took a course in Phenomenology of Religion, misunderstood the term. I understood it to mean the grouping and studying of things according to the phenomena they present, so myths of flood, myths of creation, conceptions of an afterlife, etc. It seems, though, that the term is more concerned with looking at things in terms of the experience they elicit. I'm not sure where that leaves me regarding astronomy, though... Olly

The activity of astronomy is a broad church so no single form of looking can embrace it all - which is good. My point about the small PN at long focal length is simply that you won't find it by 'gazing,' you will find it only through some studious looking. Olly

I suppose starlight nights refers to nights in which there is starlight and starlit nights to ones illuminated by starlight. Since starlight is a noun rather than an adjective it should not, grammatically, be attached directly to another noun but should be phrased as nights of starlight. The adjective starlit can, of course, be attached directly to its noun. However, starlight nights is rather nice, I think, the compression of the discarded preposition and the rhyme (which is both heard and seen) touching it with a whiff of poetic fancy, perhaps? And yes, I think any astronomer calling himself or herself a stargazer is probably doing so self-deprecatingly and ironically, especially if they are British and, therefore, predisoposed to such rhetorical devices! Olly

This is your fault! Language is nuanced. All of the following involve looking: Look, stare, peer, leer, glance, peep, peek, gape, regard, observe, gawp, etc etc. Clearly, though they are not equivalent, each having its own connotations and register. Without going to the OED, I would suggest that gaze has clear connotations which include: Looking without seeing or sometimes even trying to see. He gazed into the distance. Compare this with he peered into the distance. In both cases the person looking may not see anything but in the second case he is actively trying to do so. Looking while lost in reverie. He gazed into her eyes. We can safely say that this is not an optician going about his trade. Or he gazed at the blackboard. This will not endear him to the teacher. Looking with wistful adoration. I used to look at my colleague Sue like that. (I'm using the name Sue because... that was her name.) I suggest that we may sometimes gaze at the stars but that doing so will not enable us to find a low magnitude PN located outside the plane of the Milky Way in a Dob of 3M focal length. In general it misrepresents the way in which astronomers look at the sky and casts them as eccentric romancers unlikely to be able to put a nut on a bolt. In fact they are eccentric romancers addicted to the fantasy that the clouds will part on a moonless night before the month of December the year after next. Olly

This is an old M45 with Baader filters and a head-banging exposure time, the idea being to go as deep as possible in search of dust. The stars are not tight but there are no hard edged halos. Plenty of hot blue stars in this Tak image as well, but still no halos. I know so many people who use the Baader filters, including three whose gear I'm currently hosting, that I'm absolutely certain this is not typical of Baader. I've had three sets of Baaders myself, as well. So what's left? Bad batch, certainly. Have you tried these filters with another camera? A quick search on the 16200 produced a quote from Takman on here: There is still that classic microlensing ‘cross/star’ effect on the bright stars (like the KAF8300, but not as prominent I feel...) I realize that this isn't the effect you're seeing but I wonder if it might be arising from the camera. The chip glass, the microlenses, whatever. Is there anything else in the optical path? I also wonder if there might be an internal reflection visible only in the blue which is, of course, the easiest wavelength to scatter. A separate post on halos with the 16200 might be useful. Olly PS Grrrr.

I certainly don't regard the Baader LRGB filters as entry level and have never used anything else in the last ten years. I have processed Astrodon LRGB and not found anything very significant in their favour. However, all the Baader and Astronomik OIII filters I've tried have been downright lousy, and I've owned or used a few of each. The Astrodon 3nm Ha is fabulous but the Baader 7nm is still pretty good. So... That blue image you posted is incomprehensible to me. It is, obviously, a disaster. Going off your kit signature I'll suppose it's with your Tak 106? I never saw anything like that with the Baader blue in either of the Tak FSQs in our dual FSQ106 rig and I host two other Tak FSQ106 rigs and neither of those produces anything like that either. My Baby Q, before that, was also fine. Something is wrong. Clutching at straws, are you sure that's the blue filter? It looks very like the result I got with Baader and Astronomik OIII. You couldn't have a misplaced filter or a confused filter wheel? Is the filter the right way round? Or, at least, have you tried reversing it? If you are 100% sure this really is the Baader blue, I would contact them. They are a serious company from whom I think you might expect a serious answer. Olly

Stunning image. The three dimensionality of the OIII is... total! I feel as if I could walk round to the back of it and look through it. Olly

Certainly true for me. Olly

Rebranding being what it is, this could be almost anything. It isn't a good start when this maker or rebrander uses inches for the aperture and mm for the focal length. Do you have a picture of the instrument itself? Good, modern astronomical telescopes have never been cheaper or better value than they are today. That's where I'd be looking, personally. Olly

I believe it was considerably more than that... 😬lly

It sounds as if you might not have experienced the tile problem, Goran. Lucky you! Here's a section with not much happening in the full version of the present mosaic. Seeing it equalized makes it much clearer, as does using a hard stretch of the faint signal - which I always want to do. It tends to be a bigger problem on mosaics and I've yet to work out why it strikes when it does. The pattern here is not connected with mosaic overlaps which are much larger scale. I do have some thoughts: 1) The pattern is created both in luminosity and in colour, perhaps more in colour, so I wonder if the debayering algorithm might be interacting with SXT. 2) I use SXT in Photoshop. It might be worth trying it in PI. 3) I stretch in Ps so, ditto, I should try something else. I do use 'Large Tile Overlap' when running SXT. Olly Edit. I suddenly wondered if large mosaics run the PC out of enough memory but I just tried destarring a small crop and the tiles were still visible.

One thing I liked about this instrument was that I didn't have to wait till night time to use it. A shadow transit of Jupiter was easy to see on a very bright, sunny afternoon. You need to bear in mind, though, that the 31mm Nagler in use there is the planetary eyepiece... lly

Above IC348 there's NGC1333. Olly

Thanks, I'll show this to Paul when he's back at his desk. The issue was partly one of stitching, partly of irregular contrasts and partly of tile artifacts in using Star Xt. The tiles were the biggest hassle, very insistent in one part of the image. It would be good if Russ Croman could fix this. The wider field would have been of interest if ever we wanted further to extend the Orion-Monoceros image but, when I look up at the night sky and see how far the Pleiades are from Orion, I tell myself to be reasonable... It would be great to have a single panel, short FL image, to act as a template for these monster mosaics. Could this be an excuse to buy a Leica Q??? lly

Nope, can't see it but not to worry! Olly

Capture and Pre-processing, Paul Kummer. Post processing and high res overlays are mine. This is about half of a 24 panel Samyang widefield. I couldn't get the full mosaic to work, so far, but I liked this reduced FOV because it shows all of the dust structures in which the Plaiedes participate, along with Hyades and California. It's an hour per panel plus high res RASA data for California, Plaiedes and IC348. Big version is here: https://ollypenrice.smugmug.com/Other/DUSTY-DARK-AND-MILKY-WAY-TARGETS/i-ZPm459C/A Olly Edit: Minor tweak to the image and addition of telescopic data for tiny NGC1333. You'll only see a difference in the full size in the link.

Probably impossible. There seems to be little or no signal in the dark band to stretch. However, what I would normally do is: Copy layer, top layer invisible, bottom layer active. Curves. Put a fixing point at the level of the brightest background sky and several fixing points above that. Lift the bottom part of the curve below all the fixing points. Top layer visible and active. Erase the dark sections with a feathered eraser. I think that, at some point in your processing, the black point has been clipped in that lower edge. If it has, you need to start again from the linear and avoid clipping. Olly

That's great - but to see a hand I'll need a helping hand! Olly

You can also stitch in Photoshop and other graphics programs. Olly

Anyway, looking at the image again this morning, I think it's fine. Where Tomato's rendition scores is, I think, in having more local contrast in the bright central part of the nebula. This is a product of the stretch, of course. Other than that, I think you've got your 7.5 hours' worth. Olly

Senior moment! Sorry. lly

A noise reduction tool as powerful as Russ Croman's Noise Xterminator, which does minimal damage to resolution, is worth - and now I'm sucking my finger and holding it up in the wind - a trebling of integration time. Worth a try... Olly

'I took 50 x 3 min subs through all 3 filters, 25 hours each filter and 7.5 in total,' Sorry but I don't understand this. 50 x 3 minutes is 150 mins or 1.5 hours and, with three filters, this makes 4.5 hours. Olly

Extremely sharp, as only narrowband can be. Also deep enough to get that extension. The palette is a little limited but that's inevitable since the point of the filter is to restrict it. I guess you're pleased with this? I think it's good. Olly