chubster1302

Evening all. Looking for suggestions for the above. I want a dedicated, cooled, one shot at the best price possible. I can't afford £1000+ plus unfortunately.

It will be paired with a WO Zs73iii and will be used under Bortle 3 skies. 

I'm thinking maybe a ASI 533MC Pro bit are there any better alternatives for the same sort of money?

Anyone come across red solar lights for the garden that they can personally recommend?

At our home in Southern Spain and forgot to bring main camera so thought id try the phone. Just a 7min exp in Astro mode. 

Would that even work? 

Let's say, loads of us got together, agreed a target and stacked everything as one 🤔

1 hour ago, Rodd said:

I can't download the data either.  For what its worth, I will say that the data looks very good.  And you have to keep this in mind...In my opinion, you are attempting one of the most unforgiving and difficult tasks in all of astrophotography...broadband nebulae....and with a DSLR.  Not an easy thing to pull off well. I don't know what your sky is like, but if its anything like mine, you need boat loads of data.  Also, for the lack of a better analogy, we all have internal sliders--expectations of how we think the image should look.  These internal sliders can get out of whack.  A perusal of my early images will reveal my unwilling internship at Disney, or Looney Tunes....I could not understand why I was creating cartoons, while the same accomplished imagers who have toyed with your data produced realistic "nebulous" looking images.  And THAT was with narrow band!, which I personally find much easier.   Even so, I have color mottle quite frequently with narrowband, which I attribute to LP--multiply problems (of any sort) by at least 10x with broadband.  So I think you are headed in a pretty good direction.

It is a good think to play with slider to see what they do.  Don't forget, it is often that how multiple sliders work in unison that is important (and how multiple sliders in different tools work in unison).  The best way to learn this IS through playing with them (with a eye on theory as well--documentation on what they represent).  I know it's not much help, but the following should be.  Great advice from Olly..."leave 10% of the image on the table" (It might have been 5%--can't recall).  This will be a natural check on the propensity to cross the threshold into cartoon land (which can happen all of a sudden.  Suddenly, the Rubicon is a mile behind you. Coupled with this gem is realizing that the slightest change in an image--the smallest tightening of edges, or the slimmest increase in dynamic range between background and nebula can radically change an image.  Combining very small incremental changes builds an image.  The goal is to render a nebula that appears to be floating in space, with a color palette that draws you in to the faintest details, as oppose to blinding you with chroma.  This can happen quickly, much like a giant slab of rock hanging by a thread from some precipice can be made to break free and plummet by the addition of a single grain of sand dropped from a bird's foot.

One last bit of advice.....WALK AWAY (Now!!! Run!!! And drop the camera in the nearest waste bin!).  Just kidding (sort of).  But do walk away...you will be amazed how different an image looks the next morning, or even an hour later.  Its akin to editing your own writing.  Nothing is better for an essay or story then to spend a day or two in the drawer.  I think its like IR that builds up in some cameras that need a pre-flash to clean out the signal (older technology) --Our brains need a break, a shift, to wash away the conceptions we build into them.  Not sure why, but every time I have come back to an image, I find I can improve it.

Finally--space is not black, stars are not like colorful diodes, brightness steals color (and curving down brightness enhances it), and nebula are rarely like a barrier reef community in vibrancy.  Somehow, the reef world does not look like a cartoon. Or maybe it does, but for some reason that is OK.  But an astro-photograph with the same definition and palette most likely would.

Rodd

Looking at the plot in siril I don't think the data was that good, but it was all I've be able to get from my location in weeks. Still need to add more subs.

To be honest I didn't even realise IC 1396 was a broadband target, It just happened to be in the right place....but, I like a challenge and if i can nail that as good as poss then the "easier" targets should be a breeze. Hmm 🫣

I do get the whole walk away philosophy, even if I have been sitting here at 3am still looking at data, when I have to be up at 6am 🙈😀 

Some amazing advice in here, thanks everyone. 

@wimvb 

I didnt know about the data repository, many thanks I will check that out. 

Quote

A third problem which many beginners make, is that they are too impatient. Rather than learning what individual steps in a workflow, or the individual processes in a software package do, and how to use those that are available, they jump from one software to another trying to find quick fixes. Hence the popularity of ever new software (EZ suite in PI, Topaz sharpening, graXpert). Choose one software, and learn that before you mix other software in your workflow.

While you learn the art of image processing (despite being highly technical in nature, it is an art), you also need to learn the other half of AP, data acquisition. For this, have a look at this resource. It is dated, but the principles still hold.

https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

I am currently using Siril + PS CC and I dont have any plans to change yet, I do have some experience in PS, Camera Raw and LR so at least im not starting from stracth. "Luckily" for me, my "brain" is as such, that it needs to know exactly how one thing works before moving onto the next, the frustrating bit is not really knowing what effect early editing decisions may have down the line, if at all, and there is always the, just because of the lack of knowledge...."what if I did that first" scenario. Yeah, I know this isnt life and death but it just bugs me 😀

I have the book you mention and that has helped me get to where I am currently, a good read 👍

Quote

The number one problem with beginner's data in my experience, is the lack of it. Beginners generally underestimate the amount of time it takes to gather good quality data. When I started in AP (and others have confirmed it was the same for them), I started out as a space tourist, shooting as many different targets as possible on a single night. (Like tourists visiting as many places as possible during their short vacation.) Now, I try to capture at least 10-15 hours of data per object, sometimes spending several weeks collecting that data.

Yep, whilst reading many posts and watching many vids that is one thing I knew from the start....lots of subs. Im currently only working on two targets

25 minutes ago, Elp said:

Personally, to save on doubling up, get a smaller mount and carbon fibre tripod and an on board computer controller whatever make that will be. You'll end up in four figure sums very quickly trying to double accommodate. Or, just enjoy the sunshine.

Which would be the "better" mount to take and leave at Spain. Im assuming, maybe incorrectly, that the EQ5 would give me a better guiding experience overall. But then the seeing in Spain, is going to be better than at home so perhaps that doesnt matter? Would the AZ-GTi fit the bill as a smaller mount ? 

....cant really afford it right now.

Dilemma...We have a place in Southern Spain, 360 degree views, under Bortle 3 skies, currently we go over there about 4 times a year. I have a EQ5 pro, WO ZS73iii, D5300, guide cam and scope. Should I just take everything over there and leave it there,  or just haul everything back and forth each time. 🤔. Im considering the Sky-Watcher AZ-GTiX, as a second mount, that should be able to handle the equipment I have, no? That would just mean taking the scope and bits and pieces back and forth, which would easily go on as hand luggage. Then "if" i go down that route which mount would you keep where? Id still like to practice in the UK, when and if I can. I have no PC in Spain, so would probably get something like the Asiair Plus for control.

Decisions, decisions.....what would you do 🤔

1 hour ago, ollypenrice said:

I can't donload a file that size but I think the most important thing is that you have pinpointed the problem in the the phrase above.  We live in a world in which people post u-tube 'tutorials' in which they actually say 'I just play with the sliders  till I like what I see,' as if this were a sane way to proceed.

In effect, you answer your own question in posing it: understand the sliders.  Actually, I think there's a degree of back and forth between two approaches to learning how to process.

1) Know the tools at your disposal and understand what they do. 

2) Learn to look ever more analytically at an image and say to yourself, 'What does it need?' Once you've decided on this, go to the tools you have. Just don't go to a tool till you know what you want to do with it.

What I would like to have tried with this image is go to Photoshop's Selective Colour and move the top slider in Reds to the left to lower the cyan in red. This usually boosts Ha signal.

Olly

I have a rough understanding of what the "sliders" do, but the problem with following tutorials is that  9 times 10 whatever they are doing will not work, or give widly different results on your image. Interpretating how to apply the correct tools is the hard bit. I used to have a fine art pet photography business so have spent a fair bit of time in LR and PS, but with those "targets" I knew the dog was black, the grass was green etc....

The only saving grace is everything is digital, so if you "get it wrong" you can either undo, or start again 

4 minutes ago, ONIKKINEN said:

Binning is in Geometry-> binning. It wasn't always there, i am using 1.2.0-rc1 and it is. I think it was in the previous version too but not sure if much further back than that so you may need to update if you are on 1.0 still.

Below is an example of the samplers i placed (or something similar)

 

They are a bit difficult to see but i just placed them on the areas that looked least worst in terms of nebulosity. Most of them are on dark nebulosity but in this case since those are the darkest spots in the image they can be used as a sample for a background. Images like this are very difficult to work with for this step because realistically there is no background in this field of view and it is corner to corner nebulosity (and basically all forms of gradient removal also tack onto and remove some nebulosity, just a matter of getting the best compromise). Not very good at this yet myself but i think in these cases its better to have fewer rather than more samplers.

Ah, yes, found the binning option, many thanks ill give that a go. And yeah, I had like the whole background with samples on and just removed the ones around the obvious nebula in the middle. 🙈

1 hour ago, ONIKKINEN said:

Bit late to the party, but here is what i got out of the stack:

Processed in Siril and Photoshop with the following steps:

Siril first: Bin x2, background extraction with just a handful of samplers around the edges, Asinh stretch at 1000, histogram transformation by just moving the black and white point. Export as 16-bit TIFF for Photoshop.

Photoshop: StarXterminator first. Stretched the starless layer a little bit more and applied a boatload of noiseXterminator to fight the noisy nebulosity. Some saturation and manual colourbalance work and a little bit of curves and contrast (this "fiddling" part takes often most of the processing time, no guide for that im afraid). Left the stars rather bright, at least for a typical nebula image. I think the stars being at the forefront can act as distractions from the nebulosity behind which could use some more integration. Only mild work for the stars-only layer including: Smart sharpen, saturation. Added the starless back to the stars-only layer with the Linear dodge blend mode.

Its not bad data, just could use more of it.

That looks awesome, well, to my untrained eye anyways.

Interesting to read your comment regarding the background extraction samplers, this is where i think I might be going wrong early on, watching a few tutorials on it and I know you have to take the samples off the nebula but this whole image seems to be nebula so I am probably leaving way too many on. And when you say "Bin x2", where is that option in Siril ? 

4 hours ago, wimvb said:

I think that's the main cause for your results. Unmodded cameras don't pick up much Ha, and the Elephant's trunk is mostly an emission nebula. I tried pushing the data harder, but ended up with that mottled background. I think you may get marginally better results with aggressive dithering and more data, but in all honesty if you want to capture emission nebulae, you need a camera that is more sensitive to Ha. Larger nebulae are most suited for your telescope's focal length of 440 mm (according to the fits header of your image).

Yep...im sure i will get it modded at some time, and then obviously the next step (I hate this hobby 🙈) a dedicated astro cam but in the meantime, considering the first nights rubbish subs Im quite impressed by the results you have all achieved on this post. Gives me something to aim for

1 hour ago, Fegato said:

I've had a quick go, nothing better than Alan has produced above. Background extraction is a bit of a pain with an image like this as there's so much nebulosity, so I didn't bother, and the end results shows there is a bit of a gradient reducing from right to left! Anyway, a couple of observations:

1. There's a fair amount of noise. You didn't describe your equipment (including filter(s)), exposures and sky conditions - would be interesting to know. Looking at the data, I would guess maybe the exposures were fairly long (stars a bit blown out here and there), but you do need more data?

2. As Alan says - there is a bit of a darkish band across the bottom. If you stretch very hard, there's maybe one across the middle too, but not totally sure. It's difficult to be sure when there is all that dark stuff following a similar path. If it is an artifact of some sort, I don't know what could cause this - assume you have no obstructions in the light path? Anyway, best take some other images and see if it repeats before getting too worried about it.

D5300 unmodded on a William Optics ZS 73iii, no filters. Guiding with PHD2. 3min subs at 800iso. I "thought" the sky conditions were OK but as this graph shows, that really wasn't the case. 🙈

Cheers everyone for the advice and showing me what is there, I still cant get anywhere near the examples above but ill keep experimenting. 

The data for this was taken over two nights, the first session be really bad, just waiting for another clear night to add some better subs. 

2 hours ago, wimvb said:

I played around in PI with your image, and came up with this.

Your image has a common DSLR signature: colour mottle. Tony Halas did a presentation on DSLR astrophotography almost ten years ago, where he discussed this. His remedy: dither aggressively, about 12 pixels at least. Here's the link to his presentation

https://www.youtube.com/watch?v=PZoCJBLAYEs&t=3s

 

 

Interesting watch, thanks. I did dither every 3rd frame when acquiring the subs via NINA, is that the same thing ? 🤔

That's amazing, I have no idea how you managed to bring out so much of the nebula...

I'm using siril to do the initial stacking and stretching, I can see you removed some of the stars, can I ask at what point in the process would you do this. I have starnet++ for Siril

2 hours ago, ONIKKINEN said:

The plot here shows your measured star fwhm in pixels in the vertical direction and the frame number in the horizontal direction. Brutal honesty next: Your first night sucks compared to the second, no way to tippytoe around that. Either seeing was terrible or you were out of focus, or both.

Inen

Many thanks Onikkinen, really appreciate the reply. I realise from the graph that basically anything above the green line might be considered no good and I had come to the conclusion that the first night was carp. So thanks for confirming. 

Where does the green line come from, how is it generated? 

I've been watching loads of processing tutorials but I'm now at the stage where I'm just moving sliders and not really having a clue what I'm doing or trying to actually achieve. Does anyone want to have a play with this and show me what can, if anything, be brought out from this image.  At least then I will have a benchmark to try and aim for 

r_pp_light_stacked.fit

It was two separate imaging sessions which is why "I think"  the result looks the way it does, which sort of makes sense but yeah, its a lot of "guessing" for a newbie to understand. Im not even sure exactly what the green line indicates. What would be an acceptable FWHM for instance 🤔

Has anyone come across any good explanations of how to evaluate the results from the plot tab and its various outputs? I "sort" of get the basics but im not fully understanding it. For instance what exactly is this telling me. Should i be binning all the images on the left hand side of this plot ? 

I've obviously found loads of tutorials online but none of them say "why" to do something or "what to use" in this situation. They are more just watching them do their processing. 

So any really good tutorials you've stumbled across ? 

Anyone done it on this particular scope? Is it an "out of the box" fit or do I need extras ? 

1 hour ago, DaveS said:

I have a completely automated obsy thanks to the ASA software. I can turn the power on remotely too, so I can set up a sequence and go to bed, closing down when the sequence is finished without even getting out of bed.

What obs do you have 

2 hours ago, ONIKKINEN said:

NINA is displaying a 16-bit histogram here for some reason, whereas your image is presumably taken with a 14-bit camera. The max value in a 14-bit camera is 16384, or 16383 if we include 0 as one of the values so fully saturated.

You need to go to the Options->Equipment-> and under the Camera tab set your Bit depth to the correct value which would be 14. This should make the flats wizard work too if there was a problem with determining a nice exposure because of the incorrect assumed bit depth of the camera.

Ok, thanks, it was set to 16 so Ive changed that. So will that make the Histogram "look" the same as the Camera Raw one, or does NINAs histogram work completely differently to every other histogram? CR tells me im well over exposed NNA's says Im well under exposed (when looking at the histograms) 😖

29 minutes ago, Clarkey said:

I think NINA just re-scales the graph to fit the exposure. If you look at the statistics it shows the max, min and mean as 16383 i.e. swamped. What is the problem with the standard NINA flats wizard?

Not had much luck with it to be honest but that s mainly because I don't really understand it. Will give it some more of my time