ollypenrice

Project with Peter Woods and Paul Kummer. Didn't the IFN use to be faint? My first attempt had over 20 hours, using a Tak 106 and Atik 11000 CCD. This new version is demonstrably deeper, demonstrably cleaner, about 4x wider, and took 3.4 hours in a piddling little camera lens! Times change. Samyang 135 at F2, Avalon M Uno, TS 2600 OSC CMOS camera. Ha in the Cigar comes from an old telescopic image, not that it makes much difference. For some reason the poor stars in one corner of the lens have gone away. On this run they were very good. Olly

I've used a sack truck to move a large SCT. I had it mounted permanently on a palette under which I could roll the platform of the truck. I then had a 'safety belt' round it higher up. Very simple and effective. Olly

Agreed. I had a review copy for Astronomy Now and thought this was a tremendous read - though not one which does any favours to the memory of certain celebrated scientists with mysoginistic tendencies. Olly

All data was shot here, Carole, but, as usual, I work with others who are here either physically or 'virtually.' All the widefield data was done on a jointly-owned robotic rig based here, the other party being Paul Kummer. He programmes the captures and does the stacking, I do the mechanical stuff at the rig and the post-processing. The high res NGC1333 uses old data from the days when I used to stay up all night. Alas, the Doc told me to stop doing that! Olly

Glad you like it, Rodd. The crop was a deliberate choice to bring the colourful part to full screen without a zoom. I do like a challenge, so here's a slightly wider view ... Still a bit cramped? Let me see, what do we have in stock at the moment? This might do it, though I'll have to give you a discount since I can't run to the full rectangle... Olly

The best advice I can give is to look through your optics and not at them. An occasional clean with common sense is all they need. Olly

Super. Seriously good and with outstanding star colour. Did you use star removal and replacement? If you did, I'd be inclined to push its possibility further. Olly

I hope you're joking! There are a couple of places where my punctuation would differ from yours, but I'm not a pundit. Quite often I'm attracted by more than one way to punctuate what I write and I simply sit back and think, How will my reader read this? Obviously, I cannot know - so I make a guess. Your piece reads well. Voila! Olly

Good call on the background sky, not too dark and nicely flat. Olly

When I reprocessed the old ODK14 data yesterday I knew I was missing something. Today I realized what it was: I also had a deep set of TEC140 data from when we had a twin TEC rig going. So this version has more hours than I can remember... Olly

We've had three iOptrons arrive here. Two dead on arrival (one with spares out of stock) and one which went soft on the tracking within a year. You'll forgive me for not being interested in any more! I'd go for one of the EQ sixes. They don't change spec every five minutes so you can always get the bits and the online help. Olly

An update on a form of Photoshop masked stretching I posted a few years ago. This assumes you have done two things first, to the linear image. 1) Given it a reasonable stretch in Levels. I stretch until the stars are about the size I'd like to see them in the final image, or maybe a little bit bigger. This will not be a full stretch, therefore. 2) Removed the stars. I use StarXterminator but Starnet is an alternative. At this point, using a masked stretch is now a breeze because you won't be stretching the stars. - Create copy layer and add a Layer Mask. - Copy the image onto the layer mask. - Equalize the layer mask. (Image-Adjustments-Equalize.) This gives a kind of hyper-exaggerated stretch with radical extremes of contrast - just what we want. We must now use some judgement in looking at the equalized mask, remembering that white is transparent and black opaque with grey in between. When we stretch the top layer a little more, the stretch won't be applied under the blacker parts of the mask and will be applied under the whiter parts. You can use the contrast tool or 'Edit-Fade Equalize' to adjust the extremity of the mask's contrasts. It is also vital to give it a big Gaussian blur, probably 3 or 4. - Stretch the top layer gently and watch the faint stuff rise out of the background. So simple. Olly

The RASA is a kind of Hubble Deep Field instrument in the sense that it turns an 'empty' starfield into one full of nebulosity, apparently wherever you look. This is a Godsend for imaging the comet, though we were lucky with the way the dusty shapes work nicely with the tails. Olly

Comet C/2023 E3 passes the IFN (or other dust.) Project with Paul Kummer, RASA 8/Avalon Linear/ASI2600MC. Capture and stacking done remotely by Paul on a rig based at my place. My post processing. The image is composite, consisting of a stack aligned on the comet and then placed over a background sky stack shot after its departure - but carefully aligned. Olly

The captures are 10 years old or so, using Yves Van den Broek's ODK14-SX H36-Mesu 200. It's a fine object, though, so when a friend asked for a print I thought I'd rebuild it from scratch. New software tools make quite a difference. Olly

Just pick a moderately bright star, high in the sky, centre it and focus on it. About 100x magnification is recommended but isn't compulsory at this stage. Now rack it inside focus and outside focus. When you do so, you should see concentric circles rather than shuttlecocks. These are the bare bones of the 'star test' which, surprisingly, is a brutally demanding test of optics because its underlying value is the wavelength of light - which is very short indeed! If you get ovals out of focus, you are somewhere near. The trick is to refine them into circles. Olly

This link https://fedastro.org.uk/fas/members/members-location-by-county/ will take you to a comprehensive list of UK astronomical societies. (I'm not certain that you are in the UK but you write without an accent. ) I'm sure that, if you went along there, someone would sort out your Newt in no time and show you how to do it. Olly

Very nice, Martin and clean as a whistle, which isn't easy when parts of the scene insist on moving about! Olly

So what is the endgame of these laws? Nobody allowed out after bedtime? Does camping only happen at night? Would it be OK to lie down and sleep during the day and to walk at night? Can camping be meaningfully defined? Olly

That's one to bear in mind! lly

I haven't tried M42 with a CMOS. I'm sure you're right about the longer exposures: no need to go beyond 3 mins, but how about the Trapezium and its colour? Olly

For M42 it's essential, I think. With a CCD I used 10 secs, 50 secs and 15 minutes. To be useful, though, there needs to be a vast difference in sub length. The difference between 2 mins and 3 mins won't fix dynamic range issues. Olly

Decidedly possible and good news if correct. Olly

I like the M31 with its dramatic and atmospheric colour. I think the HDR routine has worked only moderately well on the Trapezium. There's some control of the brightness but the colour has been burned to white. Bleached out colour is common when the signal is very high. The real solution is to shoot a few short subs for the Trap. Because it's so bright you don't need many in order to have a good SNR. When I blend long and short subs in Photoshop I invariably have to boost the saturation of the short, bright ones to draw the colour inwards. Olly

We got comparable arc-like curves when shooting M45 in the RASA. In the case of the RASA there's a lengthy discussion online but stopping down the inner edge of the optics around the central obstruction seems to work for some. This wouldn't be applicable in a reflector but edge blackening or some mild stopping down might help. Sometimes reducers just do this on bright targets. I'd certainly ask the supplier to comment. Alternatively, the fairly easy fix is to shoot some subs with the image moved in the frame so that you still capture the part under the arc but the new arc will be in a different part of the image. You then use the second image as a patch. You don't need a full set of subs just for an arc. You can get away with a short run and a good dose of noise reduction. This can also help if you get a shaft of flare from a star out of shot. Steer the scope towards the star and as close to it as you can before shooting the patch panel (which obviously has to cover the flare in question.) These flares often only appear at some distance from the source star. Olly