Knight of Clear Skies

6 minutes ago, Ryan Adams said:

So in your opinion is the jump in quality between the NEQ6 and the HEQ6 worth the extra £200? 

Think you mean the HEQ5?

As I understand it, it depends what scope you put on it. The NEQ6 doesn't necessarily track more accurately but has a higher payload capacity, whereas the HEQ5 does track better than some cheaper mounts. Both mounts require guiding (guide-scope + camera) to achieve long exposures.

2 minutes ago, Ryan Adams said:

Sorry if this is obvious but what is the difference between the mounts as you increase in price. I know that they are better but in what aspects? 

Essentially, tracking accuracy and payload capacity.

1 hour ago, Ryan Adams said:

I would much rather do deep sky astrophotography but I’ve read that it can be challenging so I thought planetary imaging would be better for a beginner like me. However, if it isn't too difficult to do deep sky astrophotography then I would rather get a scope for that rather than planatery imaging.

Thanks, 

Ryan

It's a learning curve, certainly. Looking at your budget and if you'd prefer to image DSOs have you considered DSLR imaging with camera lenses? There are some large targets up there and everything is more forgiving at short focal lengths. For example, here's my latest effort with a couple of 135mm lenses.

Another NA & Pelican I'm afraid but this one was taken with a 60s vintage camera lens. It's a bit of a proof of concept. For reasons I've never been able to determine I've always got better starfields out of my 135mm Takumar f3.5 than any of my more modern lenses, so I'm planning to use it to shoot RGB while I shoot Ha with the Samyang f2. I'd like to build some big mosaics in the Autumn but I have some hurdles to overcome first.

It's about 40 minutes in RGB, enough to pick up a bit of dust, and 22 minutes in Ha with the Samyang and 1600mm cool.

Looks like a calibration file problem to me. Failing that, Noel's actions for Photoshop (horizontal banding noise reduction) can remove most of it.

Further noise reduction would also help clean-up the background.

A big question is what you want to image. I see you've tagged the post with both 'planetary' and 'deep sky' but the scope and mount requirements are quite different I'm afraid.

If you want something within your budget a lightweight mount like a Star Adventurer, DSLR and camera lenses is the way to go. For example, this is The Heart & Soul at 135mm focal length (RGBHa).

(This is with a modded DSLR and clip-in Ha filter, capture details are here.)

Nicely framed and plenty of depth.

Thanks Pieter, got it now. Looks like I just managed to pick it up as a faint ring in my DSLR image but unsurprisingly it shows no detail at 135mm focal length.

Very interesting object, formed in an outburst of some kind? I'm assuming it's one structure but the region is so busy I guess that's not certain. There also appears to be a star cluster to the right of it, I wonder if that is catalogued.

That ZWO duo-band would be ideal for my DSLRs, a shame no clip-in version is available. I'm guessing ZWO won't make one either as it would encourage competition with their cameras.

Very nice, that inclined ring structure is striking, as are those streaks at upper right. Thanks for showing us something new, these filaments in Cygnus are often overlooked in favour of the more famous objects. I can only assume they are the result of multiple supernovae and stellar winds from massive stars.

If anyone is wondering where this is, I found DWB145 on Aladin (you may need to zoom out quite a bit). I'm not quite sure where LeDu2 is in relation to it though. @pietervdv, can you help us please?

42 minutes ago, pietervdv said:

Thanks to Nicolas Outters for the inspiration!

The discoverer of the Squid Nebula in Sh2-129 if I'm remembering correctly.

On 25/05/2020 at 08:16, andrew s said:

Our best theory has the Universe in a very hot dense initial state. It was and remains spatially infinite (or very close to infinite) .  It  has been expanding and cooling ever since. 

Just to add, we have very good evidence for this from atomic physics. We can measure the ratio of elements present in early universe from the CMB. This matches up with the ratio we'd expect to form from a hot, cooling plasma - hydrogen, helium with a splash of lithium. We then have a good idea of how heavier elements were formed and dispersed in stellar furnaces, as the nuclear reactions happen at energy levels we can reach in a lab (on a very small scale at least).

Personally, I find the idea that universe had a beginning equally absurd as thinking that it did not. Some things are simply beyond my comprehension and likely to remain so, although that doesn't mean we shouldn't try. Our local universe appears to have had a jump start but who knows what exists 'before' or 'outside' it, or if those are even sensible concepts.

Very nice, can just make out jets from Herbig-Haro 555. 

1 hour ago, pietervdv said:

Always great to see nice B/W images like this. This is a very handy reference image to pick some potential new targets from! 

Pieter

Thanks. I have an even wider view which might be useful, taken with an old 35mm lens.

Another good resource for planning shots is https://www.mdwskysurvey.org/, they are attempting to map out the entire northern sky in Ha at considerable depth.

Shot on the night of the 13th/14th, here's a two panel mosaic of central Cygnus.

Hiding in the dust to the left of the Butterfly is the Cygnus OB2 association, home to some of the most massive and luminous stars in the galaxy, which can be seen as a faint star cluster. If you find the small snaking nebula to the left of the Butterfly, it's above it and to the right.

Stitching the two panes was a bit of a nightmare as I couldn't get the flats to apply (yet again), nor would Microsoft ICE stitch them together. In the end I aligned manually in PS and adjusted levels/curves to get a fairly close match on the second pane.

Each pane is 26x2 minutes with the Samyang 135mm, modded canon 100D and clip-in Ha filter. This combination gives just enough resolution to make out the pillar in the head of the Pelican but not enough to do it justice.

I also shot these two panes in colour the same night but I'm not confident they will match up that well.

Here's a wider but shallower view of the same area, which was made by stitching together 2 minute exposures in ICE.

What are the capture details for this please, and what is the target? HD 200019 is a designation from a star catalogue.

42 minutes ago, andrew s said:

Are we all not star dust? Regards Andrew. 

Even pigeons? In the spirit of the times, I demand a recount!

There are pictures on the internet of the injury the poor woman sustained.

There are also reports of a meteor hitting a Chinese city in 1490 and killing thousands, probably an air-burst. Historians generally believe the accounts to be reliable but cast doubt on the actual death toll.

"Stones fell like rain in the Ch’ing-yang district. The larger ones were 4 to 5 catties (about 1.5 kg), and the smaller ones were 2 to 3 catties (about 1 kg). Numerous stones rained in Ch'ing-yang. Their sizes were all different. The larger ones were like goose's eggs and the smaller ones were like water-chestnuts. More than 10,000 people were struck dead. All of the people in the city fled to other places."

4 minutes ago, andrew s said:

My dad was driving home with the window open he felt a glancing  blow to his head. When he got home there was a recovering pidgeon on the back seat.

Interesting anecdote but I'm not completely convinced that pigeons are of extraterrestrial origin.

Thanks for the suggestions. I'll remove the diagonal next time and see if I can get focus. If I still have the rings I'll try a cling-film flat and if that doesn't work I'll look at a tilt adaptor. I guess this one would be suitable?

Good question, I also noticed it was particularly bright last night. I found an explanation here.

"The phenomenon is called earthshine. It tends to be brightest between April and June, though it does occur at other times of the year. "

"Earthshine varies in strength throughout the year, since the light reflected from the Earth varies. Earth’s reflected light (albedo) is brightest in the Northern Hemisphere spring with a second, slightly smaller peak in the Southern Hemisphere spring.

Satellite measurements of energy reflected from the Arctic provide a picture of why earthshine peaks in the spring. During this period, the Northern Hemisphere is tilted towards the Sun and winter snow and ice are still on the ground in the higher latitudes. Because snow and ice reflect more light than vegetation or water, the spring is brighter than the summer or autumn, when there is much less snow and ice. During the winter, the Arctic receives very little sunlight and reflects less light. Clouds and sea ice contribute to the peak in the Southern Hemisphere."

You were thinking along the right lines but ice is the biggest factor. (So I guess in coming decades it will be less bright.)

Thought people might find this useful. I've never had much success stacking fixed-tripod shots using Deep Sky Stacker. Had another search for stacking tools last night and found recommendations for Sequator, first attempt with it looks promising.

This is the core of the Milky Way from Caradon Observatory. Kit Hill is on the left, the big light dome in the middle is Plymouth. Taken with the 6D and Samyang 14mm f2.8, somewhat cropped. 31x20s at ISO 6400.

There is a good walkthrough on the Sequator site. I used Composition: 'Align stars'/'Freeze ground', Sky region: 'Partial' and Reduce distortion effects: 'Auto'

I guess another question is: are you interested in deep sky or planetary/lunar imaging? the scope and mount requirements are quite different.

Have you considered the Samyang 135mm f2? I tend to recommend it over a scope for people looking to get into deep sky imaging. Everything is more forgiving at short focal lengths, reducing the mount requirements, and at f2 it's very fast.

Probably my last deep sky target this side of Summer, taken Sunday night before full astronomical darkness.

Each panel is a single 2 minutes exposure with the Samyang 135mm f2, modded 100D and clip-in Ha filter. Stitched together in Microsoft ICE and processed in PS using Noel's actions.

This was a test run for what will hopefully be an Autumn project, to shoot each pane with more depth in RGBHa. Framing was tricky as only the brightest stars can be seen on liveview with the filter in place. I'll think about dual mounting the two DSLRs, shooting RGB at the same time would make the framing easier.

The Ha->colour version was made using Noel's actions. It gives a good idea of what each sub looked like on the camera screen, in the dark any signal really stands out.

3 minutes ago, GuLinux said:

It's quite visible in this picture, the centre is quite sharp, while the borders are visibly out of focus, and the illumination is quite uneven.

I found a simple PS tutorial here which may help with the uneven illumination.