Star Tools Question

[Zuts]

Hi,

In StarTools you can create a star mask so that only star colours are processed in the Colour module.

My question is will the following work?

1. Create StarMask, use colour module to get star colours correct.
2. Save
3. Invert mask, so Stars are not processed, use colour module to get nebula colours correct.
4. Save

In step 3 will it keep the colour data for the stars calculated in step 1, or will it apply the new colours calculated in step 3. I.e. can you use multiple masks in a module?

The same question applies to HDR, Wipes etc. Can you apply different masks to different regions and have for example a HDR of equalize in one region then save and then a HDR of lessismore in another.


Thanks
Paul

[Startrek (Martin)]

Paul,
It’s yields better results in most of your images if you create a Star mask just after your Wipe ( Startools recommendation )
I use this procedure for every workflow and image
Select Mask
Then Auto
Depending on the density of your Star field I usually select Stars instead of Fat Stars
The only Star Mask settings you need to tweak is Feature Size and Filter Density ( default settings don’t always work ) then usually Shrink and Grow to finally set up your Star Mask to your satisfaction , then Save
Invert your Star Mask so Stars are white ( remainder of image is Green so will be sampled during modules ) and Keep
Saved Star Mask should be used for Contrast, HDR, Sharpen, Deconvolution, Life to avoid Stars being blown out and in Colour to separately colour your star field. Star Mask should be cleared when you stop tracking and use Final Noise reduction ( Wavelet Noise)
You can create another Star Mask if you use Shrink and other modules after Noise Reduction
To Colour your Star Field separately ( I usually do that Last after I’ve coloured the main object )
Assuming you have your Star Mask set and inverted ( Stars green background normal )
Select Colour
Keep Mask
Adjust your colour settings ( I like Scientific for Star field in Straight Luminance or RGB ratio ) select as required
If using a NB filter and OSC camera you will have to reduce green bias quite a bit , don’t know about Mono cameras )
Once your happy with both Main object Colour and Star field Colour press Keep
Then before you switch off Tracking , clear your Star Mask and then Keep
Just remember in any Mask , “Green” means it will be sampled during a Module so invert and keep as required
Also any change you make in a Mask you have to press Keep to save it or clear to delete it and try again

Hope the above helps

Cheers
Martin

[Startrek (Martin)]

Originally Posted by Startrek

Paul,
It’s yields better results in most of your images if you create a Star mask just after your Wipe ( Startools recommendation )
I use this procedure for every workflow and image
Select Mask
Then Auto
Depending on the density of your Star field I usually select Stars instead of Fat Stars
The only Star Mask settings you need to tweak is Feature Size and Filter Density ( default settings don’t always work ) then usually Shrink and Grow to finally set up your Star Mask to your satisfaction , then Save
Invert your Star Mask so Stars are white ( remainder of image is Green so will be sampled during modules ) and Keep
Saved Star Mask should be used for Contrast, HDR, Sharpen, Deconvolution, Life to avoid Stars being blown out and in Colour to separately colour your star field. Star Mask should be cleared when you stop tracking and use Final Noise reduction ( Wavelet Noise)
You can create another Star Mask if you use Shrink and other modules after Noise Reduction
To Colour your Star Field separately ( I usually do that Last after I’ve coloured the main object )
Assuming you have your Star Mask set and inverted ( Stars green background normal )
Select Colour
Keep Mask
Adjust your colour settings ( I like Scientific for Star field in Straight Luminance or RGB ratio ) select as required
If using a NB filter and OSC camera you will have to reduce green bias quite a bit , don’t know about Mono cameras )
Once your happy with both Main object Colour and Star field Colour press Keep
Then before you switch off Tracking , clear your Star Mask and then Keep
Just remember in any Mask , “Green” means it will be sampled during a Module so invert and keep as required
Also any change you make in a Mask you have to press Keep to save it or clear to delete it and try again

Hope the above helps

Cheers
Martin

Paul,

To answer the last part of your query
I always use a mask in Wipe when processing Nebula and larger Galaxies so that the Wipe doesn’t mistake gradient for good pixels whilst cleaning up the image
I usually select Lasso at the bottom which allows you to draw around the main part of the object , then invert so the area you want excluded is normal and the remainder of the image is Green which will be fully sampled by Wipe
Once Wipe is finished you can clear your mask and press Keep and the on to the next module , but before that you can then create your Star Mask which can be used all the way through until your ready to switch off Tracking and do your final noise reduction

Cheers
Martin

[Zuts]

Hi Martin,

Thanks for your reply, however I am really asking the following (i should just try it)

If you look at my two Horsehead Images you can see one has lots more nebulosity but vthe stars are blown out. So I am asking the following.

Can I create a mask just for a small area of nebulosity that is very dim and then use HDR on that mask setting equalize. Then save the result of the HDR action.

Then create another mask for another area (not including the previous area), run the HDR module again specifying a different option. Then save that HDR result.

In this way you could have different HDR options or wipe options or colour options for different parts of the image by running the module many times with different masks.

This would only work if it kept the values from the previous options when applying the new option with a different mask.

[Startrek (Martin)]

Originally Posted by Zuts

Hi Martin,

Thanks for your reply, however I am really asking the following (i should just try it)

If you look at my two Horsehead Images you can see one has lots more nebulosity but vthe stars are blown out. So I am asking the following.

Can I create a mask just for a small area of nebulosity that is very dim and then use HDR on that mask setting equalize. Then save the result of the HDR action.

Then create another mask for another area (not including the previous area), run the HDR module again specifying a different option. Then save that HDR result.

In this way you could have different HDR options or wipe options or colour options for different parts of the image by running the module many times with different masks.

This would only work if it kept the values from the previous options when applying the new option with a different mask.

Paul,
Firstly you should only run Wipe once !! ( refer Startools manual )
Secondly you can mask areas on your image just to sample certain modules only, I have tried HDR a few times to enhance parts of an image but your stars will need to be masked as well or else they will blow out , so it’s a tricky procedure to keep a a Star mask and add a masked area also , but can be done using invert etc... I haven’t done it for 6 months and didn’t keep a procedure so you will have experiment a bit
NB: Some modules won’t allow you to mask and only sample the designated area , they sample the whole area irrespective of the mask eg Life module less more
So a bit of trial and error ( I’m still finding out things 3 years into Startools)

Martin

[Zuts]

No problems, I will try a few things and see how I go. Thanks for your replies.

Cheers
Paul

[Startrek (Martin)]

Paul
If you want to reduce Star halo and glare etc in some of the larger bright stars ( eg Alnitak in the horse head ) you can create a Star mask on that Star and invert so it’s Green or to be sampled , save it and then use the Shrink module with 1,2 or 3 pixel size reduction using Shrink or Tighten parameters
Shrink is only available after tracking is switched off and final noise reduction is completed
Repair is another module as well

Martin