ollypenrice

These old ellipticals don't have much by way of interesting structure and, since we're looking out of the plane of the Milky Way, there's nothing much in our own galaxy to provide foreground interest. 'The Eyes' galaxies probably provide the most rewarding detail, with their tidal interactions. Paul Kummer and I have it in an 8 inch RASA, so comparable with the Hyperstar. It's a wider field mosaic so it's on the enormous side as an image but here it is. You can do the clicks for the full res if you have the patience. I think the interest in this region lies in cruising the field in search of little surprises like irregulars and little spirals. It will never be attention-grabbing eye candy, so to speak. https://ollypenrice.smugmug.com/Other/Galaxies/i-kTDJC88/A Olly

A famous portrait painter once had a very dissatisfied customer who strongly insisted that the likeness was false. She had a more than averagely asymmetrical face and the artist realized that she was used to a mirrored view of herself, so he altered the painting to a mirrored view and she was satisfied. I'd much rather not have the moon mirrored but put up with it because the rather basic erecting prisms I've tried really clobbered the image resolution. I've never tried a good one. Olly

Nothing wrong with that. René was here, he said, to see it and photograph it, perhaps for the last time. He was in his eighties and had too much LP to see it from his home on the other side of the country. Olly

Lovely shot. I had the pleasure of being host here, for a week, to Dr René Dumont whose doctoral thesis was on the zodiacal light and whose article on the subject is the very last in Moran's Astronomy and Astrophysics Encyclopedia. It was a delight to be enlightened on the subject by a professional astronomer and world authority, especially since he was such a truly nice man. (He and his wife were particularly attached to our affectionate dog and asked after her on subsequent Christmas cards. ) Olly

I hadn't thought of actually venturing down the tube to do this. An input fan on one side and an output on the other would be more comfortable... lly

Have you tried blowing air across the surface of the mirror? There's an argument which says that this is the best way to break the boundary layer. I've never tried it and no longer have a Newt. Olly

That's great, packed with things rarely seen. Paul Kummer and I had fun in this region in broadband. Olly

For an objective measurement I checked the background brightness per channel in two places using the Ps Colour Sampler Tool (eyedropper menu.) I check these values regularly when processing. It gave R40 G30 B19 and R38 G29 B19. A neutral sky would have parity in all channels though personal prefences also apply. However, the numbers do say 'red high and blue low.' Olly

Super project. Your background sky is looking decidedly brown on my monitor so a background calibration might be in order. Olly

Whatever they are (and I can't help with that) they are extremely interesting. I wonder if the circular loop, probably a spherical shell, above SNR G206.9 2.3 is associated with the much larger loop which no doubt continues above the region you've already captured. Keep going! Olly

Nice. Certainly a conversion issue, then. Olly

Very strongly magenta on mine, too. Oly

Incomparably better, with crisp details curling right into the core of the spiral. The core is less blown out and there is more faint stuff, the background and stars are better, it's win-win-win. Olly

I don't normally see any degredation between here and my view of an image in Photoshop. Are you're in the right colourspace? The internet standard is sRGB. (I process in ProphotoRGB for its better gamut and then go into Photoshop's Edit-Convert to Profile to choose sRGB. Don't confuse this with 'Assign Profile.') Olly

Hardly anybody uses wedge-mounted alt az mounts, not because there is anything wrong with them in principle, but because the ones on the market are really not up to the task. In most cases we are talking about the American SCTs. The mounts are lacking in stiffness, precision and backlash control and this is particularly problematic because the focal lengths are long, giving high resolution image scales which are extremely intolerant of tracking error. I struggled for a while with a wedge-mounted Meade SCT and gave up on it, switching to a German Equatorial. Olly

Lovely job, Francis. Olly

Maybe type the eyepiece make, model and focal length into Google and see if any pictures come up which would give you a clue. Olly

Much better background and now you have that tail showing decisively. Olly.

It's very good. I don't think a focal reducer would add anything, though. The other way to get the same effect is to use bigger effective pixels. At bin 2, you are still highly oversampled so the trick would be to stack to give a still larger effective pixel size. You can also resample downwards before doing any processing. When I process our Samyang 135 data I know it is optically limited in resolution so I resample it downwards till the image scale matches the available resolution. In your case you will be seeing limited but you can still do the same. In a nutshell, it is much better to downsample before processing than after, when you discover that presentation at full size is not a good idea. Olly

Have you tried Noise Xterminator? It's what I use to control the ultra-highly stretched regions in our images over the last year or two. It removes only the noise. In order to find out what's lurking, unseen, in my initially stretched data I run it through Photoshop's Equalize routine (in Image-Adjustments.) This is a diagnostic filter but it tells me what's in there and, once I know it's there, I'll move heaven and earth to get it into the final image. Olly

I think the tolerance of guidescope offset is related to the precision of your polar alignment. If you are polar misaligned, the guider will cause the imaging scope to describe a circular path around the guide star during the sidereal day. The position of the guidestar relative to the centre of the image determines the size of this circle - or so it seems to me. In reality you can point the guide scope considerably off axis. That's what adjustable guide rings are for. They are not there to let you align the guide scope with the main but to search off-axis for a guide star. This used to be necessary when guide cameras were far less sensitive. Just remember that, if you change the guide scope position, you will need to recalibrate the guiding. Olly

That should sort it. It really is a stunning chip. I'm using it in two OSC iterations, a ZWO and a generic Telescope Service variant. I think it tends to be more sensitive in the blue but it's clean, fast and vice-free. Olly

Thanks and, yes, that's a good idea. Olly

Very good separation of the reflection nebulosity. Olly

Welcome back, Martin. I don't think it's at all blingy. On the contrary, it has a subtle and natural look. Are you sure about the chip distance, though? Three corners show elongation. Olly