How to process

[astro mick]

Linking to an already interesting thread,i think there is a gap in this imaging forum for a step by step Tutorial for processing an image.

This may or may not assume the imager has aquired his images,and perhaps even calibrated them.

Its the next step where a lot of people including myself fall down.

A lot of Tutorials assume wrongly that people know their way around such programmes as Photoshop,and say things like create a new layer,or blend the opacity at such a level.This really does,nt help.

If some kind Knowledgable imager could do a simple step by step,and i mean a slow walk through the process,maybe even with

photos,exactly how they process an image.(It would be a great help)

I know there are a lot of variations,such as blending in of H-Alpa,an such but that could come at a later stage.

I have looked for such programmes,but they all seem to fall down in some respect,and start to get too Technical

Thats not to say we dont understand,but i think a really good step by step instruction would be helpful.

If you dont agree,please say so,or you may know of a really good Tutorial that would help someone on this path.

I can take the Criticism.

Mick.

P.S.

I think creating a step by step Tutorial of a LRGB image would really get the jucies flowing.

[gbealnz]

Good request/suggestion Mick.

In my case, I have tried a variety of software packages, and have settled on Images Plus for some reason. OK, the main reason is that others didn't like more than about 8 or 9 of my M25C subs, the aged PC choked.

With respect to Images Plus, there are very good user tutorials provided and are accessible on the web as well.

Maybe toss into the suggestion the software package you are looking to use, it will likely make a difference to your answers.

Gary

[steelfixer]

I for one second your wish for a step by step tutorial as I struggle with the likes of Registax let alone Photoshop.

[shaunster]

Theres is loads and loads of advice on here for processing

Look here Imaging - Tips, Tricks and Techniques - Stargazers Lounge for loads of processing primers including LRGB, use the search function as there are people linking to very good places elsewhere for photoshop guides and tutorials

When I first started the absolute best online resource I used was starizona's guide to CCD imaging, it covers a lot of ground including photoshop. ALl the information you request is already available!

Starizona's Guide to CCD Imaging

Starizona's guide to photoshop covers so much more than can be covered in one tutorial http://starizona.com/acb/ccd/software/soft_proc_ps.aspx

[Psychobilly]

There are quite a few useful "video" tutorials on the Waid Observatory Site...

Waid Observatory - Index of Articles

[Martin-Devon]

I also think there is still a need for more introductory help for beginners into image processing. I've just started this 6 weeks ago, and having watched many of the free tutorials on various websites I'm still struggling in several areas. Like many others I have the various sets of "actions" for Photoshop, and without doubt I over-rely on these to process my images. MartinB and others have put together good sets of tutorials on SGL - some of which I find useful, others don't do what I expect or I get stuck because it is assumed I know my way around Photoshop more than I actually do. Many times at the moment I'm struggling to bring out subtle detail in an image and only seem to amplify coarse features. If the levels/curves, actions, or 1-2 basic filters I know don't do this them I'm totally stuck!

I've been looking to see if there are any actual day or weekend courses on Photoshop processing for astro-imaging and so far have found none. Does anybody know of one? Like several others I've also purchased a Photoshop astro-imaging DVD - I have the Don Waid one - and although some parts are good, many other parts are either dated and/or surpassed by the action buttons now available. The DVD is also fairly selective in content and is certainly not an A-Z on how to process various images.

I would have thought that a few very detailed examples, as Mick suggests, using a couple of nebula and galaxy examples would be very helpful. The steps before even starting Photoshop also deserve attention since these can significantly affect what/how Photoshop has to work on. For instance I only have experience of one very elementary way to combine my initial images in Maxim and generate a FITS file suitable for Photoshop, and I'm sure there's a lot of scope here for improvements as well, but I don't have a clue what to do. Likewise at the moment I have no idea how to subtract flats from my image using Maxim.

I think it's clear that for many folks at the beginner & intermediate level there is a real demand for more guidance on processing. This could encompass problem solving by highlighting examples of errors/artefacts and how to overcome these.

The complication will come from the fact that folks are using several different software packages now for initial alignment and subsequent processing - and what is relevant for one is not for the other.

As a beginner in astro-imaging though I would definitely welcome more introductory and simplistic step-by-step image processing tutorials where it is assumed the user has either minimal or no previous experience of Maxim or Photoshop.

Let me also thank Mick for kicking off this thread.

[roundycat]

This is a tricky one, not just because of the many different s/w packages out there but because to write a detailed and simple method of calibrating, aligning and combining twenty sub frames and then working on it in, say, Photoshop would take something the size of a book.

I am retired and know my way around the image processing business but the never ending backache from the time sitting in a chair doing all this does not exactly motivate me. (in spite of having the time to do it).

I would recommend the following;

1. Don't try to learn Photoshop using an astro image. Start with something a bit easier.

2. Don't rely on free s/w or 'easy to use' actions that seem to do everything for you. Learn it from first principles.

3. Have a look here and see if anything helps. Mono to RGB

Dennis

[astro mick]

Roundaycat.

I can appreciate what your saying about the time spent laying this out.

I could tell you what i do in about 10mins,but i know its not correct,and i would be shot to bits.

But i thought it was a question worth asking,as the Thread has already demonstated an interest.

Mick.

[Darth Takahashi]

http://www.harrysastroshed.com/pixinsighthome.html

VIDEO TUTORIALS ARE BEST, try the above link, it based on PixInsight but a lot of the basics translate well for other programs as well.

If SGL is going to take this on then I would also advise two routes;

1, Using FREEWARE

2, Using the most common commercial software (A vote could be taken to decide this section since everyone has their own preference)

Real RAW image data could be submitted by SGL members, preferably with common defects like gradients etc... Definitely NOT PERFECT CLEAN DATA which is all to easy to process.

Then you could split the processing into the following steps designed to build upon each other.

1. Basics (Image basic calibration, stretching and conversion into other formats)

2. Intermediate (Advanced calibration, Stretching, RGB creation, final image manipulation for 8bit JPEG format with noise reduction)

3. Advanced (Deconvolution, Wavelet sharpening, Masking and various defect correction techniques along with LLRGB or HaLRGB and narrow band imaging)

Maybe finally using a common reference book so that there is NO DEBATE regarding the content "http://www.willbell.com/aip/index.htm" The Hand book for Astronomical Image Processing would be my first choice as the BIBLE / REFERENCE BOOK.

Neil.

[mark7331]

I think I have to agree with Mick here. I've spent countless hours over the last year processing my data and, to be honest, getting it wrong most of the time. Only now do I just about understand the steps and variations in calibrating, registering and stacking and that's just the start of the process.

I agree that it's a complicated area, as Denis says, and maybe part of the problem is that the software producers just don't provide enough documentation (PixInsight for example).

So I think that a "how to..." on the basics for the most popular programs (free or not) would give a beginner an real advantage and isn't that what SGL is about?

Just my 2p worth

Mark

[roundycat]

I frequently refer to AIP but my edition, bought in Feb 2002, is, I think, the latest. Has it reached issue 2? It is good for basic technical info but the processing is years behind. They also tend to make endless references to what are now very small chips and no mention is made of DSLR's, the weapon of choice for a great many people now. There is far to much math in it for the average imager who cares about his pictures, not the math behind it all.

Mark mentions the dearth of info available for image manipulation programs. Forgive me for mentioning it but when you look in bookshops for Photoshop info the books stretch as far as you can see.

When you consider what (how) the real experts are doing you will not find DSS, ImagesPlus, AstroArt, CCD Soft, StellaImage, Mira AP and Pixinsight in wide use. I should think something in the order of 95% or more of astro imagers use MaxIm and Photoshop. Many complain about the expense (you should see the rows I have had with Adobe in spite of having taught Photoshop for years) but it should be regarded as a legitimate expense, all part of the astro imagers budget. You do not need to constantly update this software. I still mainly use MaxIm v4 and I just bought CS3 for windows for £130. You do not need CS8 or whatever it is up to now.

Many consider standardising their equipment such as cameras and mount fixings to make things easier and the same consideration should go into what software you use. Don't be misled by the type of person that might insist you use Linux because they hate the amount of money Bill Gates is making. Don't be tempted to use Mac instead of Windows because your trendy graphic arts friend said the Mac is better. The best trick here is to run with the pack.

Astro specific software might have some interesting routines but when you are at the stage of post processing you are dealing with pixels. Not galaxies, not stars, not nebulae. Just pixels.

Dennis

[astro mick]

As a starter this is what i do.

I aquire my images using AA3.I take 6 Darks of 15mins each.I do not take Flats,as i never get good results.I dont take Bias frames either.

I take 2 15min subs of LRGB,(all the same).

Done.

I load into AIP where i calibrate and stack.(Too many programmes so if someone would like a step by step instrution as to how i do this,please PM)

I then export as 8bit tiff file into Photoshop.(Again i can let you know how i do this.)

In Photoshop,the images are usually dark,but if i can see the Neb/Galaxy.i dont bother with levels.

I open Curves(Menu/Image /Adjust/Curves.

If the image is not visible i open Levels.(Menu/image/Adjust/Levels.

I adjust the centre slider until the image just starts to show,then stop.

Using Curves i usually position the start point about centre of the graph,and gently pull the graph to a curve to highlight the object.

I do this a few times to keep bringing out more detail.

If i want to keep the background dark,but enhance the Neb/Galaxy,i click on the background sky,and note where the point is on the Graph.Then i click on the graph at that pont to create an anchor point.This then allows me to keep the background the same,but enhance the object.

This info applies to the Luminance channel,which i then save as a PSD.

Then comes the RGB data.

If you think this sort of description is helpful,please let me know,and it can be continued.

This is my basic way of doing things,which to me helps get a reasonable image.

Let me know what you think.

Mick.

[Glider]

The one thing I notice about the way you do things is that you, "export as 8bit tiff file into Photoshop". I used to do this to get data into GIMP, which is free but only 8bit. Photoshop will take 16 bit. Can your camera capture 16 bit images?

Don't you loose a lot of resolution doing that at such an early stage.

[shaunster]

Mick,

6 darks, no flats or bias frames? Thats not good for a start. Properly calibrated images are much easier to process. What is it you dont understand about flat fielding and bias frames? You also want more than 6 darks, the more the better but after 50 the benefits are minute, if possible aim for 20-30.

2 15 min subs of LRGB? Not enough, aim for more subs per stack, also you dont need 15 min RGB subs, your using an L channel and thats were your detail comes from so take many more but shorter RGB subs. The more subs you have the easier it will be to process and create a better final image.

Export as 8bit? Why?

I use maxim for calibration and stacking/alignment, its easily the best program for the job out of the ones I have used

[astro mick]

Hi Guys.

This is good. Because our weather is so unpredictable,i thought spending any longer than say 30mins on each Filter,would not allow me to complete an imaging run in one night.So thats why i set this limit.This could be a mistake!!

My flats never seem to turn out well,i usually do the White T-Shirt method,and expose until it saturates,then i just half the exposure,which usually results in me seeing Doughnuts.But the appllication just doe,snt seem right.

Bias Frames i could never be bothered with.(Perhaps another mistake.)

I used to import 16bit images into Photo-Shop(My camera is a 16bit starlight-xpress MX716.

I could process the Luminance as 16 bit,but Photo-shop 6.0 cant handle 16 bit colour,or my version cant.Therefore i have to convert the RGB to 8 bit so i can then merge the channels.

To overlay with the Luminance i have convert the L into 8 bit,change to RGB then copy onto the RGB image.

Then in layers i change the blend mode to colour.I then play around with this image to get the finished article.

Perhaps a good starting point would to sugest exposure times for Darks/Flats/Bias,and finally image.Also how many should you take.

I thought if you have good Tracking longer is better.

I think this initial info would be a good starting point for us amateurs

then when we have the correct exposures,take it further.

Mick.

[p1taylor]

I think a simple step by step and no complicated bits that just say do this but dont tell you how, just complicate it.

peter

[ollypenrice]

[quote name=

I've been looking to see if there are any actual day or weekend courses on Photoshop processing for astro-imaging and so far have found none. Does anybody know of one?

Yes. I offer free imaging tuition to guests and if you check out Ian King's website you'll see that he runs pretty regular weekend courses. I have seen his course notes and they look good to me. He's a nice guy and organized so I bet the course is good. There have also been SGL workshops, too, which are no doubt excellent. Shame I can never get to them!

What got me off the ground was instruction from our guests, most notably Tom O'Donoghue who was about nine months ahead of me. Once you get the basics you can start to invent techniques of your own and that is one of the best bits of the whole game.

If someone will first point me towards an explanation of how to make video tutorials I will gladly spend some time on it this winter. It won't be before then because we are seriously solid and Monique and I have a wee event planned as well...

Olly

[shaunster]

I thought if you have good Tracking longer is better.

.

Not really! If you take 2 15min exposures you will quickly be overcome with noise, if you take 10 5 min exposures you will see better results IME. As for your long colour subs, its not needed as in an LRGB image no detail is coming from the RGB section so long subs are not needed. Also unless your under great dark skies 15min luminence channel subs will be swamped with LP gradients and it will be even harder to tease out the detail.

If your aspiring to produce images of the very high quality we see on this forum then you will need to compose an image from data captured over multiple nights, obviously aligning the camera up again each night is the problem here so it helps a lot if you dont touch the configuration, or if this isnt possible you could mark it so when you setup each night the camera goes into roughly the same position, this will make it much easier on your stacking software, however DSS will stack data together taken on any night regardless of camera orientation (its only plus point IMO!)

Couldnt be bothered with bias frames? they are the quickest and easiest to take

I would suggest reading about flats and how to take good ones, simply saturating your camera and then halfing the exposure is not accurate enough.

I cant comment on your problem regarding 8/16bit images as I have CS4ex and dont encounter these problems, sorry

When you blend the luminence dont choose blend mode of colour, choose blend mode of luminosity instead.

I hope this helps, I think as you can see we already uncovered some problems in your routine

[harry page]

Hi

To find out what software people use it would be nice to see a official SGL poll would not be to hard to sort out

It should be left in place so you could see software trends

Now Olly lets see some videos , I use camtasia very excellent piece

of software:D

Harry

[Martin-Devon]

Couple more comments from me - firstly I don't see any tutorials on how to use Maxim in the SGL section on "Imaging - Tips, Tricks and Techniques" - since so many folks use Maxim, and many like myself have little clue how to use it other than for a very basic combine, stretch and conversion to a FITS file - so maybe a simple tutorial on how to use Maxim would be helpful.

Secondly - in reference to the course that Olly mentions, I attended the Ian King imaging for beginners course in Rugby a few months ago. It was useful, but really only touched the periphery - there were no detailed talks on Maxim or Photoshop methodology and many of the short talks covered mainly the different types of equipment, and options on DSLRs & CCDs. I see that Ian also does an advanced imaging course, usually later in the year - maybe that one covers more image processing stuff & is better? There were about 150 attendees though for the beginners course, so it shows there is a demand out there.

[Darth Takahashi]

I frequently refer to AIP but my edition, bought in Feb 2002, is, I think, the latest. Has it reached issue 2? It is good for basic technical info but the processing is years behind. They also tend to make endless references to what are now very small chips and no mention is made of DSLR's, the weapon of choice for a great many people now. There is far to much math in it for the average imager who cares about his pictures, not the math behind it all.

Mark mentions the dearth of info available for image manipulation programs. Forgive me for mentioning it but when you look in bookshops for Photoshop info the books stretch as far as you can see.

When you consider what (how) the real experts are doing you will not find DSS, ImagesPlus, AstroArt, CCD Soft, StellaImage, Mira AP and Pixinsight in wide use. I should think something in the order of 95% or more of astro imagers use MaxIm and Photoshop. Many complain about the expense (you should see the rows I have had with Adobe in spite of having taught Photoshop for years) but it should be regarded as a legitimate expense, all part of the astro imagers budget. You do not need to constantly update this software. I still mainly use MaxIm v4 and I just bought CS3 for windows for £130. You do not need CS8 or whatever it is up to now.

Many consider standardising their equipment such as cameras and mount fixings to make things easier and the same consideration should go into what software you use. Don't be misled by the type of person that might insist you use Linux because they hate the amount of money Bill Gates is making. Don't be tempted to use Mac instead of Windows because your trendy graphic arts friend said the Mac is better. The best trick here is to run with the pack.

Astro specific software might have some interesting routines but when you are at the stage of post processing you are dealing with pixels. Not galaxies, not stars, not nebulae. Just pixels.

Dennis

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YOU ARE SO WIDE OF THE MARK IT IS UNBELIEVABLE

HANDS UP WHO BROUGHT PHOTOSHOP?

And please enlighten us all where we can buy Photoshop C3 for 130 Pounds?????????

I have a company license that I’m entitled to use and that’s the only reason that I use it because if I had to paid for it… well its not going to happen… and as the global marketing manager for a international company I’m not short of the necessary funds.

Forget the telescopes I have Canon cameras in excess of 10k and I still wont buy Photoshop.

And as for Linux, take any hardware 6 month or older and compare how it runs with the WINDOZs or Linux? Here another fact for you, performance will be at least 40% better with Linux…FACT. I dislike Microsoft because of the crappie BLOATWARE that they make and it all start with their crappie OS and to think they charge you good money for this rubbish.

In fact, just run any new hardware you wont and the Linux OS will out perform it every day of the week and 2x at the weekend.

MAC and OSX is way better, nice graphical interface and underneath you have the stability of BSD Linux, simply brilliant. And by the way Scientist around the world use Linux and MAC’s not just graphical artist.

UNFORTUNATELY WINDOZ’s is the number one OS because it allows idiots to use PC without knowledge and that’s unfortunately another fact of life.

The hand book of Image processing is the Bible and that’s the end of that. Chip size doesn’t matter one bit!!! Since all CCD are arrays of pixels which can be of any size ultimately.

The only thing we actually agree on is that a section on DSLR’s is needed

FINALLY A CHALLENGE – I CAN ACHIEVE ANY RESULT YOU CAN, STARTING WITH THE SAME DATA AND USING ONLY FREE SOFTWARE…

FROM VERSION 2.6 GIMP SUPPORTS 16BIT TOOLS

I'M READY WHEN YOU ARE!

[shaunster]

Oh dear.... Neil... Your rant above, how pointless

CS3 here, http://www.amazon.co.uk/Adobe-Systems-Inc-Photoshop-CS3/dp/B000O17CQ0/ref=sr_1_4?ie=UTF8&qid=1311013787&sr=8-4 £135

Show me a free program that has anywhere near the functionality of photoshop?

[astro mick]

Hi Shaun.

I do have fairly dark skies,as i am on the coast,with open land to the E/S/W,thats why i take longer subs.

No i am not aiming for image of the month.TBO i could never justify the long hours some people will go to to achieve a good image,(and well done them)but thats not my style,and will admit it.

But i would like to progress a little more,say into H-Alpha,which i know is a different kettle of fish.

Olly that would be great,if you can find the time,but my computer skills cant help,but i,m sure someone will step forward at the right time.

BTW.You may have guessed i am retired,so i can spend a fair bit of time tapping.

Mick.

[Uranium235]

This is where I learnt to stretch and curve properly:

Tutorials to help with your Astroimaging

Its basically the same tutorials from MartinB, except with the illustrations. I found it a brilliant read and if you do what it says to the letter, you cant go far wrong. I even copied the curves used and saved them as 5 stock curves. One standard, 3 curves of decreasing strength, then the last one to bring out the really faint stuff. Halfway through the process I throw in a little NR and then a bit of noels actions to boost the star colour (so often lost when stretching).

The workflow for narrowband (my most used imaging method) is usually Curves, curves, levels, curves, levels, curves, levels, curves, levels. Though I have suspicions that other people may be more gradual than this, depends on what target youre working on I guess.

For merging your luminence, I think you must have been confused as to which way round its done. I always copy the RGB into the luminence (mode changed to RGB) and blend as colour. Though theres nothing stopping you doing it the other way round (Lum into RGB, blend as Luminence).

My stock curves are below, hope you find them useful

[RikM]

The thing that really made the difference to me was Ian's (Lunator's) talk on stress free imaging, and then MartinB, RobH and Peter Shah's workshop / talk on data capture and image processing at the SGL5 star party last year. Rob put up a couple of overheads showing the effects of stacking different numbers of subs and then someone ran through a basic curves/levels workflow. It was fantastic. Martin and Rob also have great tips / tutorials on their websites.

Hand on heart I can say if it hadn't been for that talk, I wouldn't be in the game now.