StarTools

Hello all
I have been trying to understand and work with ST using some already obtained images. They are basically calibrated/partly calibrated in most cases (bias sub, sometimes flat corrected but not all). I have been trying to get anywhere at all using a 'raw' image of M42 that is ~30 mins total subs all bias corrected and stacked. I find myself at a complete loss to know what to do. I ***really*** need to be able to plod through a manual. I saw the suggestion about selecting autodev first (though nothing to explain much else) but it produced a very white image without the info that the notes said it would give. I wanted to try to reduce the brightness but none of the options (no tool tips) did anything to help. The colour tab made a significant difference but I could not get it to reduce the bright blue cast (where it should be red), so I eventually closed the program in frustration.

I could really do with some guidlelines to get me started. The Youtube tutorials have not so far seemed helpful to me as a complete beginner. If anyone can point me in the start direction that would be appreciated. My apologies.

Lawrence

Lawrence. If you have a fully calibrated image, bias darks and flats, try Devel first. Darken, if needed with the dark anomoly slider and readjust the brightness to the eye. Keep and open Wipe. Try Vignetting 85% and a dark anomoly of 2. I find these settings good for a quick look.

If you are still struggling go back to your image set and see if you can improve on calibration . I find this helps more often than not.

Hi Rowland

Thanks for replying. I am one of those people that like to read a comprehensive manual first and learn what all the options and processing sequences are before touching the keyboard. This is really the problem. I cannot find anything that fits (unintended pun) this description. That is not to say that there isn't one - its just that I haven't found it. I want to know what the options mean and how they work. Once I have read a manual I then feel more confident about going through the sequences. Whatever I select on the main page (which incidently I find very difficult to see because it is very dark (grey on black?)) then up pops a set of sliders (not all of which work) but no explanation of what they mean. Maybe I am supposed to know from other software - but I don't. I have been using Maxim DL for everything for some years but I decided to abandon it several months ago for various reasons. The only remaining section that I need is image processing - hence StarTools. FWIW I have been doing astronomy since 1961 so I am still a learner/newbie but I love learning new software.

Lawrence

Hi Lawrence.

I suspect it may be better to ask Ivo directly. I am a hands on type of guy and any explanation provided will amount to experience without necessarily providing the detail you require. You will have found the Modules and Tracking links from the home page and be familiar with the ? tool tips associated with each slider.

Are you using the stable version? I use the Alpha version for bug reporting. Do you recall which elements are not working. I'm sure Ivo will want to know. He is very good with feedback and is usually quick to respond.

As a basic workflow - I do the following;

- Bin 50% (DSLR - reduces noise) - optional
- AutoDev to illuminate areas to be cropped - optional - for me anyway - we know that good images start with good acquisition and proper calibration.
- Crop
- Devel 90% - dark anomaly until image will darken no longer (white balance)
- Wipe defaults (or as in my previous post)
- Devel - as above - reset the full range of data (akin to normalisation)
- Color - Scientific for a bit of luminance retention.

Essentially the core processes to produce a decent image. There is lots more of course, but these are the must use modules.

Not sure if this will encourage you or send you heading for the hills.

Lawrence wrote:Hello all
I have been trying to understand and work with ST using some already obtained images. They are basically calibrated/partly calibrated in most cases (bias sub, sometimes flat corrected but not all). I have been trying to get anywhere at all using a 'raw' image of M42 that is ~30 mins total subs all bias corrected and stacked. I find myself at a complete loss to know what to do. I ***really*** need to be able to plod through a manual. I saw the suggestion about selecting autodev first (though nothing to explain much else) but it produced a very white image without the info that the notes said it would give. I wanted to try to reduce the brightness but none of the options (no tool tips) did anything to help. The colour tab made a significant difference but I could not get it to reduce the bright blue cast (where it should be red), so I eventually closed the program in frustration.

I could really do with some guidlelines to get me started. The Youtube tutorials have not so far seemed helpful to me as a complete beginner. If anyone can point me in the start direction that would be appreciated. My apologies.

Lawrence

Hello Lawrence .

On the front of www.startools.org at the bottom (middle right) you should try and click on the icon labeled PDF document. Behind it is the start of a written manual. It is not completely written finished as there is make a reference to page 145 so you will see is still missing at least 1/3 pages.

I am also looking forward to its being finished and will be complete.

Bedst regards Leif.

Hi Lawrence,

Sorry I'm a bit late to the party, but some good replies here already (thanks Leif, Rowland).
Indeed, if you're looking for a manual, the website is a manual and the manual is a website; you can convert any section (or the whole website) into a PDF manual. As Leif indicated, the best section to convert into a PDF document is "Module features and documentation". A sub-section of "Module features and documentation" is "Quick Start Tutorial: a quick generic work flow", which you may find useful.

PS Work on the website/manual content is ongoing. Once it's done the content can be displayed, published and perused anywhere, on anything. For example, I can post/convert the content of the Quick Start Tutorial to something that works on Internet forums;

Quick Start Tutorial: a quick generic work flow

Getting to grips with new software can be daunting, but StarTools was designed to make this as painless as possible. This quick, generic work flow will get you started.
Step 1

Open an image. Processing in StarTools is easiest and will yield vastly better results if the data is as "virgin" as possible, meaning unstretched, not colour balanced, not noise reduced and not deconvolved. Best results are achieved with data that is as close to what the camera recorded (e.g. simple photon counts) as possible.

Do not use any software that may have meddled with the data, such as RAW converters or any software that came with your camera. Make sure that any stacking software that you use is set up to perform as little processing to the data as possible. For example, if you use Deep Sky Stacker make sure that Per Channel Color Calibration and RGB Channels Calibration are set to 'no'.


Upon opening an image, the Tracking dialog will open, asking you about the characteristics of the data. Choose the option that best matches the data being imported.
Image: Giving StarTools virgin data is of the utmost importance. For example, if you are using DeepSkyStacker, make sure 'RGB Channels Background Calibration' and 'Per Channel Background Calibration' are set to 'No'.
Step 2

Launch AutoDev to help inspect the data. Chances are that the image looks terrible, which is - believe it or not - the point. In the presence of problems in the data, AutoDev will show these problems until they are dealt with. Because StarTools constantly tries to make sense of your data, StarTools is very sensitive to artefacts, meaning anything that is not real celestial detail (such as stacking artefacts, dust donuts, gradients, terrestrial scenery, etc.). Just 'Keep' the result. StarTools, thanks to Tracking, will allow us to redo the stretch later on.

At this point, things to look out for are;

• Stacking artefacts close to the borders of the image. These are dealt with in the Crop or Lens modules
• Bias or gradients (such as light pollution or skyglow). These are dealt with in the Wipe module.
• Oversampling (meaning the finest detail, such as small stars, being "smeared out" over multiple pixels). This is dealt with in the Bin module.
• Coma or elongated stars towards one or more corners of the image. These can be ameliorated using the Lens module.

Step 3

Fix the issues that AutoDev has brought to your attention;

1. Ameliorate coma using the Lens module.
2. Crop any remaining stacking artefacts.
3. Bin the image until each pixel describes one unit of real detail.
4. Wipe gradients and bias away. Be very mindful of any dark anomalies - bump up the Dark Anomaly filter if dealing with small ones (such as dark pixels) or mask big ones out using the Mask editor. Use the 'Temporary AutoDev' feature to get a better idea of how Wipe is doing.

Image: In the presence of problems in your data that need fixing, AutoDev will show you exactly what they are. Here we can see stacking artefacts, some vignetting towards the corners and a 'dirty' yellow/brown bias caused by light pollution.
Step 4

Once all issues are fixed, launch AutoDev again and tell it to 'redo' the stretch. If all is well, AutoDev will now create a histogram stretch that is optimised for the "real" object(s) in your clean data. If your data is very noisy, it is possible AutoDev will optimise for the noise, mistaking it for real detail. In this case you can tell it to Ignore Fine detail.

If your object(s) reside on an otherwise uninteresting or "empty" background, you can tell AutoDev where the interesting bits of your image are by clicking & dragging a Region Of Interest.

Don't worry about the colouring just yet - focus getting the detail out of your data first.

Step 5

Season your image to taste. Apply some deconvolution with the Decon module, dig out detail with the Wavelet Sharpen ('Sharp') module, enhance Contrast with the Contrast module and fix any dynamic range issues with the HDR module.

There are many ways to enhance detail to taste and much depends on what you feel is most important to bring out in your image.

Image: Using AutoDev ('redo') again after fixing the initial problems that AutoDev showed us before; stacking artifacts and light pollution were removed.
Step 6

Launch the Color module.

See if StarTools comes up with a good colour balance all by itself. A good colour balance shows a good range of all star temperatures, from red, orange and yellow through to white and blue. HII areas will tend to look purplish/pink, while galaxy cores tend to look yellow and their outer rims tend to look bluer.

Green is an uncommon colour in outer space (though there are notable exceptions, such as areas that are strong in OIII such as the core of M42). If you see green dominance, you may want to reduce the green bias. If you think you have a good colour balance, but still see some dominant green in your image, you can remove the last bit of green using the 'Cap Green' function.
Step 7

Switch Tracking off and apply noise reduction. You will now see what all the fuss is about, as StarTools seems to know exactly where the noise exists in your image and snuffs it out. The main parameters to tweak are 'Smoothness', 'Brightness Detail Loss' and 'Color Detail Loss'.
Step 8

Pour yourself your favourite beverage and pat yourself on the back for a job well done!

Image: The image after deconvolution (Decon), wavelet sharpening (Sharp), local dynamic range optimisation (HDR) and color calibration (Color).
Image: 200% zoom with right part of the image denoised by Tracking supported Denoise, and no noise reduction applied to the left part of the image..