Knight of Clear Skies

Has a nice ephemeral quality to it, and it looks like the prom is still attached in Ca-K.

Very nice, like a candle flame but bigger.

Splendid and nice work on the flick-book presentation, would like to see more of that.

First proper light today for the Quark Chromosphere, using my WO zs71 and ASI 290MC. Shows a great deal of promise but also gives me some idea of just how much work goes into putting together those splendid full-disc mosaics. I shot a few panes but can only get some of them to stack. Was also very lucky to catch a big prominence, just don't ask me where as I have no idea which way around the camera was mounted. The first image is showing good detail but there are some prominent ringing artefacts. Does anyone know what's causing this please, and how to remove them? Both captures were 80 out of 800 frames stacked, I don't know what's sensible in terms of capture length and frame selection. Used PIPP to select the best frames and Registax to stack and sharpen them. The top image has a little curve stretching of the green channel to give it a red-orange hue.

Did a bit of math on this to check the angular sizes and I'm more confident that I've got the image scale right now.

Glad you like it, took a lot of hair-pulling to knock NGC 1499 into some kind of shape. Future archaeologists will likely refer to this as the Hasbro or Fischer-Price age.

It's surprising what you can sometimes get away with. We have an outside switch we use as a wifi extender, it's inside a wooden box and has some plastic over it. It still works after several years but I wouldn't recommend doing this with anything you value.

Here's a composite image showing NGC 1499 to scale with the foreground, with a closer RGBHa inset taken with 135mm and 200mm lenses. At centre bottom you can just see the imaging rig pointed straight at the nebula. I wondered why the California Nebula was so bright, it turns out that Xi Persei is one of the hottest stars in our galaxy. More of a write-up here if anyone is interested.

Nice idea and good luck with this. Given the subject matter would an announcement in the 'Getting Started with Imaging' forum be a good idea?

That's a good start on M42, what was the exposure time please? I'd recommend Deep Sky Stacker, Regisax is more geared up towards planetary imaging. At 2,000mm focal length or 1,260mm with the reducer it would be very challenging without a beefy mount and well-tuned guiding. This event on Sunday might interest you. The presenter is Steve Richard, his book on imaging is often recommended by forum members.

I put together this composite image showing the Kit Hill Memorial and Jupiter to scale for a short article on the Caradon Observatory website. Trouble is, I'm not entirely sure I've got the scale correct. The same camera was used in both cases, an old Philips webcam, but for the Jupiter shot I used an ED120 & barlow back in May 2016. I think it was a 4x barlow and have scaled the image appropriately (AstroMaster 114 focal length is 1000mm and the ED120 is 900mm, or 3,600mm with the barlow). Unless I'm misremembering and it was a 2x barlow, or if I scaled rather than cropped the original image before uploading to Flickr. Is there anyone who could give me a sanity check on this please? I also need to work on the text of the article to avoid misleading anyone. I was careful not to inadvertently recommend the AstroMaster 114, the scope itself is decent enough but the mount and finder are dreadful.

Think that's a good plan. Do you have any lenses for the D750? If your existing mount is motorised you might find they work well with it up to about 200-300mm focal length. Many camera lenses need stopping down a bit (50mm are generally good about f4), but focusing on a star a third of the way in from the edge of frame gives better focus than using one in the centre. I like the lunar shot, nice detail, contrast and crisp without being over-sharpened. Is that from a stack of images or is it a single frame?

I'd suggest taking a step back and thinking again, given your budget its highly probable you could achieve far more with a smaller scope. Starting with too big a scope is a common regret for people looking to get into imaging. Searching on Astrobin there are very few images on there taken with an LXD55 SN10. I'd recommend having a quick browse of this thread, the 130pds is designed as an imaging scope. Despite its small size and low cost it's more focal length than many people would want to take on. In the right hands it's capable of taking truly great images. It sounds good in theory but without accurate guiding it's highly unlikely you'd be able to make full use of the focal length on offer. Also, does the LXD55 image circle cover a full frame camera? (Does it reach infinity focus without modification? Many scopes don't.) I had a go at unguided imaging with a reduced ED120 (765mm focal length) the other night, before a battery problem cut my session short. Even with 15 second subs it looks like I'd be throwing away quite a lot of data. But mostly I've been imaging with camera lenses, for example this is Simeis 147 with a 135mm lens. Long focal length isn't required for many targets. Hope that's some help anyway.

'Toy' needs to be put in perspective, Galileo would have bitten the arm off a cardinal to own one of those. But the light grasp from a small refractor is going to be limited and I'm not sure about the mounts. Would a table-top dob be more practical and effective?

Yes, the disk is a straight plane in reality. It's result of the projection in Microsoft ICE, it's not possible to display a (roughly) 180 degree panorama without distortion.

z=3.25 - is that over 12 billion light years away in lookback time?

Thanks, something like this might be a better bet then? (Under the circumstances, a jump-starter would be a good thing for me to have anyway, my car has been sitting around a lot for weeks.) Looking at the 1600MM cool specs it suggests that it only needs 0.5A to cool 30 degrees below ambient, so the adaptor above might still be useful. (But set the cooler too low and it might fry, so probably not a good idea.)

Had some problems with a power pack recently which wrecked a couple imaging runs. Was trying to power a Vixen mount and my 1600MM cool and the cooler cut out on me, even though I had the power pack plugged into the mains. Was wondering if I could power them with a lithium battery pack and 5v->12v adaptor like this one. Does anyone have experience of this please?

I believe the term was first used by Henry Fox Talbot in 1835 when he accidentally captured the Fourth Countess of Lincoln emerging from a dip in Lake Windermere.

Glad you like it. At some point in the future a trip would be worthwhile but I'm not sure quite where to go, I'd prefer to stay away from the villages so I don't disturb anyone. I don't really mind the LP in the panorama above as the Milky Way arches above it, but I suspect it's going to make Rho Ophiuchi very difficult to process.

The 1200D should be fine, all the Canon DSLRs for the last ten years or so have been pretty good and I'm not aware of any particular problems with it. I believe the 130P won't reach focus with cameras as it's not really designed for them. Some people get around this by modifying or replacing the focuser, hopefully someone else can advise you. For shots of the Moon you could try putting a barlow lens in front of the camera, as the element is closer it should then reach infinity. The easiest way to test this is in daylight. Hope that's some help.

Hi, can you change the colours of your post please? The dim blue is not that comfortable to read.

While looking up details on Rho Ophiuchi off the back of this thread I came across this image of Antares taken with the VLTI. There is also an artist's impression of this data on the ESO site. The convection cells on red giants can be enormous compared in proportion to those on the Sun. I believe this may have been the reason for the recent dimming and brightening of Betelgeuse, can anyone confirm that please?

Sorry to hear about this, time, money and hassle you could do without. At least it sounds like it can be repaired from the tips above. Can the neighbour send you a pic so you have some idea of what to expect?

Probably not the right place to share this but I've just found out that Antares was imaged by the VLTI. "Using ESO’s Very Large Telescope Interferometer astronomers have constructed this remarkable image of the red supergiant star Antares. This is the most detailed image ever of this object, or any other star apart from the Sun." I might have a go at scaling the above and pasting it into my image when I've finished processing it (making sure I credit it properly to ESO/K. Ohnaka).