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Uraranium.

Thanks,yes thats very helpful,as is the link.Any video instrution i think is worth its weight in gold,as you can have your image in its work station,and also follow the instruction as per video.You can pause,go back,and double check you are doing it right.

I think a good video talk- through at an amateur pace,is what a lot of people are really looking for.

If Olly finds the time great.if not i think it might clarify what may be needed.

Yes i did get my RGB merging wrong,thaks for pointing out.

There is some good stuff comming out here,so it would be a shame if the thread closed.

Regards.

Mick.

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Hi

I hope someone does do some photoshop vids as My pixinsight ones have been popular ;) as they are aimed at the newbie

But as I have found its not a 5 min job doing them ,a little video can take hrs of work , but please do not let this put anyone off :(

I look forward to olly vids :BangHead:

Harry

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Neil, steady on. Bawling in capital letters will not make your voice louder than Dennis's. Rather the opposite. You said on another thread that you had been thrown off a Dutch forum for some reason that I was unable to understand. Please, come on, we are all talking about something we care about and I like to think that the 'something' is the beauty of nature in the night sky. No one comes onto SGL in order to watch an arm wrestling contest with a pile of raw data.

I'm sorry to be so blunt but I don't feel you left your readers much choice.

Olly

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OK.

I agree as a newbie that some tutorials for different software would be great. However: We all use things differently, you cant do the same as I do to get the same image from different subs.

If you are really keen to learn Astrophotography you wont spend tens of thousands of pounds on software and programs: Learn how to use it!

I have spent the last 4yrs getting to grips with Photoshop: And I teach it at A level!!!! You always learn something new and as a dedicated Astronomer you will learn what you want it to do.

When I post an image on SGL I am looking for comments/criticism. Sometimes I listen sometimes I don't. What is important is what you hobby brings!

If I am happy with an image, I'm happy!

My 2p worth

Jamie

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First off, Paxo, why pull the thread. That really is spoiling the ship for a half-pennyworth of tar.

Remember, spare the rod, spoil the child.

Mick, you listed your basic process, here are some points where I think you might benefit.

Six darks are not enough. Take fifteen to twenty to see the difference. Any number of darks add their own noise, the idea is to reduce the added noise as much as possible. Thirty takes the added noise down to around 2%, usually well within the noise from readout and sky background.

The main use for Bias is for scalable darks but they can lead to artefacts buried in the data, not visible until you stretch it. The second use is to do a quick calibration on your flats. They must be dark or bias subtracted or they will be inaccurate. If you do not use flats you can expect various artefacts in your pictures, some easy to see such as dust and some not so easy such as fixed pattern noise. If you can get your mount to dither reliably you can do away with darks but you still need to subtract bias from each sub.

To cut a long story short I recently bought PS from an Amazon dealer for £130. This version is plenty good enough but I seem to recall PS6 would not do 16bit layers which makes it useless.

I suggest you use Levels only to bring out the basic detail. A gamma shift of 2 two or three times will do this. For Curves pick a dark area in the picture and Ctrl Click to place an adjustment on the curve. Then do it again at a brighter point and shift the second point up the graph using the arrow keys. Up to a point Levels and Curves do the same thing. But if you pull the algorithm too far they will differ quite a bit.

Using just a centre point adjustment in Curves will lighten the background too much and limit the contrast you can pull out of the mid-range. In my view you always need two points and sometimes three or more depending on what you are trying to do.

Regarding the number of exposures the answer is as many as you can get. The length of exposure is best determined by trial and error. You need as long as you can get without blooming or bloating of the bright stars. I can’t recall the stacking options available in AIP but you should use at least a Median combine and preferably a sigma reject routine. Combined with dithering this will knock out nearly all the thermal pixels as well as cleaning up the background noise. (sat and con-trails, cosmic ray hits etc). If you have good camera control software you can measure the sky noise, calculate the read noise and base your exposure on a new but not very different optimum.

After Uranium’s comment I feel I should say again, use Levels initially two to four times until you can just see the object and then stay with Curves. There is nothing to be gained by constantly switching between the two and Curves give you the control you need for delicate stretching, Levels does not.

Dennis

Edit for the second time; I am having a very extended senior moment. With all these messages appearing, disappearing and just randomly moving about I don't know if I am coming or going anymore. Apologies for my confusion.

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I have a few Photoshop videos up on my site including a basic one, although I would be happy to do a few even more basic to explain where things are in Photoshop and how to do things like layers and masks with a focus on astrophotography. I sent out a request when I was doing the videos a month or two ago for what else people wanted and got very few responses. If you would find it useful I should be able to work on some later this week although my internet connection is completely worthless at the moment so might take a few more days on top of that just to upload them.

Here are the ones I currently have:

Enterprise Astrophotography: Shooting the stars | Videos

Although, as someone said, it could take several volumes of books to cover EVERYTHING possible in Photoshop - I find new ways to do stuff almost every time I start playing around in it. However, since it seems as if there are several that would really like a REALLY basic how-to, let me know if you would like me to get working on a couple.

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Hi

This is a good thread with plenty of good advice for what is actually a difficult question to answer, let me explain

"How do you like your eggs?"----Fried, boiled, poached, boiled (soft or hard), scrambled, coddled, baked, pickled, etc.

This may seem a bit daft but I see astro imaging and processing in the same way, ie there is more than one way to process an image depending on the result you want to achieve, your skills, the type of imaging that you are doing and so forth. Personally I think the best way to learn is through forums such as this. From a personal point of view I think videos teach you how to process according to someone else's methods, so if you get the Adam Block videos you will process your images in the same way is he does rather than develop skills and techniques of your own, there is nothing wrong with this but are you actually learning anything?

All the techniques that I use in my imaging and processing workflow have been learned through a combination of trial and error, following tips and advice on forums and discussion with people who have a lot of experience in particular fields eg Richard Crisp in the case of narrow band imaging.

For what it is worth here is my work flow in brief from acquisition to end result

1. Select subject

2. Focus, focus, focus and focus (needs to be checked during the night especially with temperature changes)

3. Frame the subject

4. Calibrate auto guider and start tracking using dithering between each exposure

5. Set exposure time (30 minutes per frame)

6. Start imaging

7. I do one filter per night

8. Repeat the same process for subsequent filters, I use cross hairs on the screen to get the framing right each night

9. This is all done with Maxim DL, the telescope is controlled by The Sky 6

10. All raw frames are calibrated with darks and dark subtracted flats, I don't use bias frames as I don't scale my darks, the flat frames are taken with an electro-luminescent panel

11. The calibrated sub frames are then stacked and use sigma reject in maxim to do this using auto star matching to align the frames

12. I then align and colour combine the three master frames in Maxim DL, the reason I do this is because I do most of my imaging in narrow band and I find that the weighting compensation in Maxim easy to use and I can see what effect it is having on the colour instantly.

13. I then stretch the image using a gamma stretch with a value of 0.1 and maximum pixel value, this ensures that none of the information is lost and the gamma stretch gives the best overall results especially for nebula

14. I then save this as a 16 bit tiff file using a linear screen stretch so that when I open it in photoshop it appears exactly the same as where I left it in Maxim DL

15. When I open it in photo shop the processing is surprisingly simple

16. I start with some desaturation of the magenta which is only present in the stars as a result of boosting the OIII and SII channels, a couple of iterations of levels using only the mid range slider and adjusting the black point after each iteration.

17. This is followed by several (anything up to 10) iterations of mild 'S' shaped curves (this brings out more detail by increasing the contrast)

18. If the brighter stars start to become bloated I use the colour select tool to select the brighter stars and increase the selection by 2 pixels and then feather by 2 pixels and then invert the selection, this has the effect of selecting everything apart from the brighter stars, this allows me to concentrate on the nebula without worrying about over bloating the stars

19. When I have got the nebula appearing as I want it I generally do a final colour balancing to ensure the histograms are roughly the same and in order to tone down the sometimes garish colours associated with narrow band imaging I use selective colour to shift the balance to the generally more acceptable appearance of the Hubble palette

20. If there are any stacking artefacts on the edges I will crop the image and the final thing I do is to use the clone stamp tool to get rid of any hot pixels or gamma ray streaks

21. Finally I use the save for web function to save as a jpeg for my website and posting

This may look daunting but in reality it takes me a maximum of about 3 hours from calibrating to the end image. You will notice that I don't use masks, sharpening, noise reduction, RGB star layers, etc. Although I have Noel Carboni's tools for photoshop I no longer use them as I have found that getting good data gives the best results and makes the processing easier. I find that if the data is sufficient and good quality then you don't need it. Also when I used sharpening and noise reduction in the past it left visible artefacts in the image. I use layers but purely to check each stage of the processing.

This is my way for doing narrow band images, other people will have different methods

Best wishes

Gordon

I forgot to mention and I think it was mentioned elsewhere, you need as many sub frames for each filter as possible, typically I aim to get between 9 and 12 sub frames of 30 minutes each, occasionally I will go as low as 6 but at least that is still giving me 3 hours per filter. As far as the calibration frames are concerned the same applies

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Dennis.

Thanks very much for that detailed explanation,i had,nt realised that so many darks were required,to me a dark was a dark.I must pay more attention to my calibration,so understanding the taking of Flats is a must.

I do try to use Levels as little as poss,and make more use of curves.Photo-shop 6.0 is way out of date,but its become familiar to me,hence my sort of comfort with it.

I do have a copy of CS4,but never really got into it.That must change.

Anna.

This is what a lot of people would like to see,i,m going to work through the Tutorials,and would greatly appreciate any more you can provide.

If i may add at this point,i,m not a complete novice at imaging,but have become a bit of a Dinosaur at processing,and honestly thought my images were adequate.

I hope i am speaking for a lot of people out there,that are struggling to achieve a decent result,and if all this info helps,bring it on.

Thanks to all who have contributed,and please continue.

Mick.

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Hi all,

My 2 pence worth is as follows. I've been imaging for about a year and in my eye's anyone can go rush out and spend a couple of grand on scopes and ccd's point them at the sky and take pictures, in fact I was chuffed to bits when I managed to get my first "Mobile phone camera through the scope picture of the moon" and from that point I was hooked.

There's all the headaches of setting up the scope then getting it to work with your DSLR or CCD, getting guiding right (if you use it) finding a target, then realising something is not plugged in correctly or is refusing to work and not to mention the weather etc etc the list can be endless BUT to me this is the easy part, easy but frustrating.

The hardest part of imaging for me anyway and others it seems is processing the data. Up until the processing everything is done automatically, though just reading back over what I have just typed I've missed one vital point! You need to collect good data.Lots of bad data won't give you a good image no matter how much stretching/noise reduction or hundreds of pounds you spend on software if you have a pile of **** it won't matter how much glitter you sprinkle on it...it's still a pile of **** :BangHead: I know because I've done it and it wasn't until I listened to people more knowledgeable than myself that I realised I was just sprinkling myself with glitter :)

So acquiring good data will help in in cutting down processing time and obviously a better image. Look at the top imagers on the forum, check how long there total image time is etc if these are the kind of images you want to acquire then they are the standards you aspire to. I say this honestly "THERE ARE NO SHORT CUTS IN ACQUIRING GREAT IMAGES" again I have realised this because I have tried ;)

So onto processing, a dark art in itself and by far the hardest part of Astroimaging though for me the most fun! (I say fun in the loosest terms because if I had hair I would have torn it out by now). For those of you just starting out and I know this will be really really difficult....start with ONE target, I know it's hard, there's so much up there, I used to try and get four maybe five in one session just try and stick to one, give yourself a reasonable time limit say 3 hours for sake of argument if you are using a dslr and maybe an hour each filter for RGB just so you can get into the habit of taking enough "good" data so you can get a good image :( Also get into the habit of taking darks/flats/bias if you don't strip your camera/ccd from your mount your flats can be used again and again and they don't take long to take (I use an open notepad page on my pc monitor for the light source)There are plenty of tutorials on the net (google is your friend).

This is just a start of course but it really will help with processing and will consign your box of glitter to the back of the drawer never to be used again!

So what program do you use, MOST use Photoshop but there other programs available like AstroArt, Maxim,Deepskystacker and the new kid on the block PIXINSIGHT! Whatever you chose to use you must learn how to get the best from it, everything is available on the internet there are tutorials all over the place and forums dedicated to most software.Again I really don't think there is a quick way around astroimaging, you've got to sit and do the home work to be able to progress and get the best from your equipment and with all the cloud we have here there's more than enough time to do that.

The length of time I've been imaging I'm only at the tip of the iceberg when it comes to processing I'm just beginning to get my head around using "Masking techniques" and I'm sure the new stuff I learn is pushing the old stuff out!

Though my post seems all doom and gloom it isn't but you will get out of this hobby what you are willing to put in, if you just want a basic image, just learn the basics and be happy with the images you acquire, if you hunger for more then knowledge is power :(

People have already posted enough good links with great information with reference to actual processing techniques that I needn't add to the list. I started with these tutorials and was lucky enough to meet RobH, MartinB and Peter Shah at star parties and picked invaluable tips at there workshops and when talking to them one to one and I can honestly say that them fellas have the patience of gods when it comes to teaching us noobs the basics and have a real passion for imaging that is infectious to say the least.

I'm going to try and make a video tutorial with the basics...it may take time as I work stupid hours and to be honest there's loads of stuff already available to be digested but if there is a need I will try my best.

I don't think my post will directly help your processing but I thought it would pass some time and get my post count up...nighty night all ;)

Matt.

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I like Gordon's point about the eggs!

However, I think that when you start you need some method that broadly works. Mine is indeed derived from Adam Block. After all, you have to get to the stage of having something that looks like an image to start with and some experience of using the software's tools. When you get to that stage you can start to be a bit more creative and create techniques of your own.

I don't have a rigid processing routine. It follows a pattern but varies from image to image. For example, where there is a high dynamic range, often with galaxies, I do two or sometimes three stretches for different parts of the picture and layer them together.

Or, if the DSO and the stars are clearly separated, I will process the starry background separately, not applying any luminance to it in order to avoid cooking the colour. This was based on a two things I picked up on here, one a comment from Rob H and another observation of Harry's. (He pointed out that the middle of my stars were white.True, so I had a think about why.)

More recently I've been experimenting with L layers. Instead of just using the L as L I'm tinkering with extracting an L layer from the colour (if I have a lot) and combining this with the dedicated L layer. I don't have any firm conclusions yet but all this stuff is fun to do.

Dennis's preference for Curves over Levels is all new to me. I'm looking forward to making a hash of this technique on the next project!

It is dead right that more data means less processing. It's a long time since I did a picture in a night.

All good stuff. Keep 'em coming.

Olly

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Neil, steady on. Bawling in capital letters will not make your voice louder than Dennis's. Rather the opposite. You said on another thread that you had been thrown off a Dutch forum for some reason that I was unable to understand. Please, come on, we are all talking about something we care about and I like to think that the 'something' is the beauty of nature in the night sky. No one comes onto SGL in order to watch an arm wrestling contest with a pile of raw data.

I'm sorry to be so blunt but I don't feel you left your readers much choice.

Olly

Regarding "Astroforum.nl" The main moderator is really an NSB person, look it up if you want. The Dutch are not as tolerant as you maybe lead to believe!!! But that completely irrelevant for this discussion.

Anyway, that's fine with me, I agree, let stick to the subject of Astrophotography and image processing since that's what is really important to us all.

*********************************************************

Hands off Linux and MAC-OSX and free software foundation, agreed?

Unless someone can explain to me why all of the latest supercomputer clusters are using Linux and distributed computer software provide by the free software foundation?

*********************************************************

I'd still like to know how many legal users there are of Photoshop on this forum, I'm one of them with a company license but I suspect that I'm one of the few?

The reason I ask this question is because we are all so focus on Photoshop with the tutorials but if the ADOBE police come calling how many of us could produce a valid license?

Then my point is that we had better include a low cost or free alternative with similar capabilities to Photoshop, right???

Or am I the only one who suspects that a lot of people have an illegal copy of Photoshop??? I'm not expecting people to incriminate themselves by the way!

I just suspect that I'm not the only one who will happily pay thousands for a telescope but will balk at paying 1k for a program, correct?

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"How do you like your eggs?"----Fried, boiled, poached, boiled (soft or hard), scrambled, coddled, baked, pickled, etc.

If a may, a better analogy is GOLF.

Image processing is like GOLF in that if you don't quickly establish a standard setup/routine - the way you address the ball, you will never learn how to improve because you will never know what when wrong!

There are two setups or routines that need to be established.

1. How you capture your data - Telescope, Mount, Camera and control software, here you would fall into the unlimited category, the same as me (+10k worth of equipment)

2. How you then process that data - Computer software and specialized astronomy software and processing steps etc...

Most people are struggling with the second point since there are so many different schools of thought on how this should be done.

I have my own routine which is based on Russell Croman's routine for image processing. The main problem is that for most people this is too much for them to follow, no disrespect intended.

The video tutorials need to follow a predefined sequence, building up the knowledge of the audience to the required level, letting that knowledge sink in and then they can follow the next tutorial.

I to have attended Rob-H and Martin_B tutorials at SGL events and they were fine for me but pitched a little too low. The problem is that the same information was already too much for some. Making the videos solves that problem since we can compartmentalize each of the required sections.

Finally, I don't accept that there isn't a right way to image process, just as there are many different types of golf swing, there are many common elements to the swing itself, we need to focus in on the common element, the good practice of others that should lead to the production of good astro-images.

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Neil it doesn't cost 1k as said you can pick up CS3 for £130, that's cheaper than pixinsight

With all due respect where can I buy it for 130 Pound because I'll buy it today? Even the upgrade price is higher than this!!!

https://store2.adobe.com/cfusion/store/html/index.cfm?store=OLS-NL&

Photoshop CS5 lists for 1000Euro and the upgrade run at over 400Euros

Found it on AMAZON.co.uk https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=Photoshop+cs3&x=0&y=0

And that's excellent value for the money and yes cheaper that PixInsight but 2 version out of date but that shouldn't matter as it will still work good enough.

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I did in an earlier post, amazon..

Adobe Photoshop CS3 (PC): Amazon.co.uk: Software CS3 £129.99 and your protected well buying from amazon dealers

By the way you can also get CS5 for £279 (download, not hard coppy) over at www.buyitultracheap.com , you are going on about computers a lot, well surely you know the software owner/maker is always the most expensive?

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I'd still like to know how many legal users there are of Photoshop on this forum, I'm one of them with a company license but I suspect that I'm one of the few?

I use a legitimate copy of Photoshop elements 7 that was a freebe bundled when I bought my PC last year. I use a free curves plug-in that I don't remember the name of but someone posted the link to it in another thread a few months ago. Before I got that, I used to use the curves and noise reduction features of Canon Photo pro that comes on the EOS utility disk. I work in TIFF as far as possible, then resize and output to jpg right at the end.

With the curves plug-in, PSe7 can do layers, masking, etc. it has most things but not the edit --> fade that is very useful and you can't get Noel's actions, but I am trying to work out how to do those manually anyway.

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Iyou are going on about computers a lot, well surely you know the software owner/maker is always the most expensive?

Yes that's right and just like most I hate being scr&w*d by the software company's like MS and Adobe etc...

I'll give that second site a look, thanks for the information...I had suspected it was just vapour-ware as we call it in the industry, something that you cannot buy!!!

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Can we try and keep this to a friendly conversation folks, any more problems and the thread gets pulled, which would be a real shame as it's raising some interesting points.

Paxo

While we have your attention, albeit for the wrong reasons, how about setting up a software poll so that we can find out what software people are using for their image processing?

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Hi Matt.

Glad you joined the fun.As you know i am a fan of your work,and you know your stuff.(Also a mate)

I have to disagree on one point,yes i agree there,s tons of stuff out there on the net,but i think

thats a big part of the problem.

There,s a lot of clever people out there who know their stuff,but cannot get it across easily.Its like some Teachers,clever but cant really teach.

A lot of the material starts off ok,and your on track,but then the experience of the Tutor takes over,and then it s a case,of watching the cursor fly all over the place,as he conjours up Lassoo,s clone tools,Layers,opacities,blending,masking(need i go on).At that point a newbie will shut down,and struggle on by him or herself.

You yourself said you have had a lot of help from the greats,and i think you said,you have met some of them,and they have shown you.(Invaluable)

But there may be some people who cant do that,or attend star parties,workshops,and meet the great imagers.

As you know, i cant leave my wife for any length of time.

So thats why i think this simple(and yes keep it simple video would help a lot of people,who sit and stare at Photoshop,The Gimp,whatever,and really could do with a start with there precious images.

If they can be shown how to produce a result,then the door is opened for them to take it further.

I am sure people are discarding perfectly good images because they think they,ve messed them up.

Its no good a clever guy/gal pulling stuff from the air or going too Technical if the pupil is not at that level.

Now where,s my image,i,m just going to send it off to S@N,your not the only centre spread on the block.

Mick.

P.S To people like Anna,you are definately on the right track for helping a newbie.

Thanks also to the people who had really helped on this thread and have put a lot of time into it.

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Mick is dead right about video tutorials being too fast and having flying cursors! The tutors forget that they are already looking at the cursor so they know where it is. By the time the tutee's eye has found it the click is often clicked...

Teaching is a skill but not an impossibly difficult one so long as the teacher remembers one simple thing; the audience does not already know what they are trying to explain!

Obvious? 'Course it is, but not many teachers remember it!

Does anyone know where there is a tutorial on how to record tutorials??

Cheers,

Olly

PS The catch with the CS3 packages in the links seems to be that they are not for WIndows 7. Does this mean they won't work on it? I never understand this stuff.

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For what it’s worth I’ve finally found working with Pixinsight is best for me….and principaly because of the excellent video tutorials created by Harry Web, these have already mentioned in this thread by Neil Hankey http://www.harrysastroshed.com/pixinsighthome.html

I guess its more to do with the way people learn, some are great at reading manuals and translating that into practice, whereas I find learning by example much easier. I was struggling to come to terms with Photoshop despite various guides, for me I just couldn’t get my head around it!

I sat down with Harrys videos and played them through and then switching between the videos and some of my data applied the processing steps to my data. To my mind this is as good as attending any workshop and has got me using the application reasonably well.

I like the feel of the application, but I guess that’s fairly subjective. There’s an abundance of processes in the application that I’ve no idea what they do, and I’ll probably never use them…but so far I seem to be getting some fairly consistence results using some of the basic stuff. The DBE tool is wonderful particularly as I seem to always have massive gradients in my images…in fact it was a search for a solution to these gradients that got me onto PI in the first place. I still use MaximDL for image calibration but only because I can’t work out how to do this within PixInsight!

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