ollypenrice

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

Could you not take a series of overlapping stills covering your 360 degree view and give them to Microsoft ICE to stitch? Or make several panoramas, save them, and, diotto, give them to ICE to stitch? Olly

Since we cannot terraform the Earth I think our chances are not good... lly

Nice job. It does have something of M101 about it. Less lopsided, yes, but still a bit so - and the arms have that angular look. I like curvaceous arms, myself... lly

Another little thought: I have two volumes of Kepple and Sanner's Night Sky Guide, probably the definitive visual observing guides. They have plenty of hand drawn charts and monochrome film astrophotos but no digital images - and I wouldn't want to see any in there. They would just be inappropriate. Olly

Super. So much going on just away from the celebrities. It's great when you suddenly find you have a free mosaic! lly

With more than double the data (Thanks Paul!) it looks like this: Olly

It may be an aritfact, I really don't know. Without capturing the whole section in a single, very short FL frame, I don't think we can ever be certain. Always with these monster mosaics the overall lighting is the hardest part to get right. One issue comes from the stitching and another from a tile pattern which is often latent in the starless image after StarXt. I do my best to cosmetically correct them when I'm confident that they are, indeed artifacts. Since star removal is essential in lens images, to my mind, we must await tweaks to the software. I'm sure the background sky is far less even to the west of Barnard's loop. The successive supernovae which created it have presumably swept the sky in a sphere roughly centred on the Trapezium. I also wonder if the region in shot is being swept by a particle wind from the west. This may have destroyed a western half of the loop and also shaped the Meissa Nebula. Olly

Edit: Please scroll down for 9.75 hour version of this target. This is the lowest of the emission nebulae arcing south from the Rosette. The main purpose of this RASA 8 shoot was to enhance our giant Orion-Monoceros Samyang 135 mosaic. Here we have 4 hours of OSC from the RASA 8, capture and pre-processing by Paul Kummer, my post processing. For a standalone image we might go back and shoot more data but for adding to the big mosaic this is fine. The mosaic, with this used for enhancement, is here: https://ollypenrice.smugmug.com/Other/Emission-Nebulae/i-fL2LTdD/A Olly

A truly enjoyable post to read. There is nothing odd about your enthusiasm. People in dozens of fields enjoy preserving old technologies and old skills. At one extreme, I have a friend who, in association with professional archaeologists, recreates stone age tools and garments, strictly in accordance with what research shows to have been the original methods. In the summer, local villages put on fêtes in which old farm machinery is presented in working displays. In a couple of hours I'll be off down the road to watch a stage of the Historic Monte Carlo Rally. Does anybody care that a modern rally car is way faster than a sixties Alpine? Your rig is beautiful and I can fully understand the enjoyment you must derive from handling it and getting the best from it. The result is not the point. The doing is the point, as GrumpiusMaximus says. Even in the digital AP word, there are already opportunities to be 'old school.' I post process mostly in Photoshop because I like being in Photoshop. As it stands, I can get better results in Photoshop but the day may come when I'd get better results elsewhere. If I don't enjoy working in a newer environment I'll either carry n in Ps or stop. I just don't want to spend my afternoons in Pixinsight because it's not a place I like. Olly

In most circumstances it seems to me that digital is the hands down winner, but not in absolutely all. A well-made slide film image, seen projected, has a scale and intensity, a verisimilitude, a feeling, which digital doesn't have. It's like being under the night sky, only more so. The digital images that I and others make go deeper, contain more information, etc etc - but a projected slide can have a little something else. Olly

I think we must shoot it with the RASA to add to our giant mosaic. Stunning object. It's the only significant object for which we haven't added telescopic data. Olly

Great stuff. I hadn't realized that so much was going on south of the Rosette. It seems there's a lot of OIII in Sh2-284. Olly

I was wondering if, in flat desert areas, there might be successive green flash effects from sunsets at a greater distance from the observer. I've no idea if this is possible but mirages are also necessary. David's explanation above seems more plausible, though. Olly

You're in the wrong loo! This is the Observing section... That's astonishingly good, isn't it. Sharp and clean. Olly PS There's a truly demon trick for OSC users on emission nebulae. In Ps, go to Image - Adjustments - Selective Colour and it opens by default in Reds. Just move the top slider to the left to lower the cyans in red. It boosts Ha signal. You can do this on the standard image or you can make a top copy layer, set the blend mode to luminance and do it. This will boost the brightness of Ha regions but not the colour.