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Where to find Maskulator?

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7 replies to this topic

#1 sharkmelley

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Posted 20 August 2016 - 01:37 AM

Does anyone know where it might be possible to obtain a copy of Maskulator?

 

It was written by Niels Noordhoek, the author of the brilliant Bahtinov Grabber.  His website (www.njnoordhoek.com) is no longer available and looking the final version of it on the Wayback Machine reveals the following very sad news regarding Niels:

 

http://web.archive.o...jnoordhoek.com/   (Changed from jpg image to link, in line with CloudyNights ToS)

 

Unfortunately, neither Bahtinov Grabber nor Maskulator can be found on the Wayback Machine.

 

I am very interested to run some diffraction patterns to better understand the aperture vignetting "black wedge" artifact in bright stars on many refractors, discussed here:

http://www.cloudynig...n-bright-stars/

 

This is an example of what Maskulator is able to achieve.

http://www.cloudynig...-what-to-avoid/

 

 

Regards,

 

Mark


Edited by sharkmelley, 20 August 2016 - 03:50 PM.

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#2 entilza

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Posted 20 August 2016 - 08:06 AM

What a cool program! Love those examples.

#3 telfish

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Posted 20 August 2016 - 11:51 AM

Here ya go. I found it.

 

https://www.dropbox....1AjlVjGoma?dl=0



#4 sharkmelley

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Posted 20 August 2016 - 04:02 PM

Here ya go. I found it.

 

https://www.dropbox....1AjlVjGoma?dl=0

 

Thanks for that.  I can't get it completely working though.  Running fresnel.exe, loading one of the example masks and hitting calculate seems to do nothing.  I'll play around a bit more and try it out on different machines.

 

Mark



#5 telfish

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Posted 20 August 2016 - 04:18 PM

 

Here ya go. I found it.

 

https://www.dropbox....1AjlVjGoma?dl=0

 

Thanks for that.  I can't get it completely working though.  Running fresnel.exe, loading one of the example masks and hitting calculate seems to do nothing.  I'll play around a bit more and try it out on different machines.

 

Mark

 

 

 

You are right I did not try it. I am using a Windows 10 system, will try on a Windows 7 later.



#6 sharkmelley

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Posted 20 August 2016 - 04:23 PM

I've just tried it on 3 different machines.  It ran perfectly on Windows XP but not on Windows 7 nor on Windows 10 (even in a Windows XP compatibility mode).  Maybe it's a 32 bit vs 64 bit issue, maybe something else.

 

In any case I'm happy I can get it to run at all :)

 

I managed to get quite a nice result:

http://www.cloudynig...tars/?p=7388127

 

Mark


Edited by sharkmelley, 20 August 2016 - 08:09 PM.


#7 sharkmelley

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Posted 21 August 2016 - 01:44 AM

For anyone interested, I've now managed to get it to run on 64 bit Windows (both Windows 7 and 10) using instructions found on the archived version of Niels's site: 

http://web.archive.o...hoek.com/?p=376

 

The trick is to download the 64 bit version of FFTW from here:

ftp://ftp.fftw.org/pub/fftw/fftw-3.2.2-dll64.zip

 

Extract the files from the zip file into your the Maskulator folder overwriting the previous ones.  Hey presto it should now work :)

 

Mark


Edited by sharkmelley, 21 August 2016 - 01:46 AM.

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#8 neuperg

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Posted 23 October 2016 - 03:37 PM

I have done some hunting on the web for how the Maskulator innards work but have come up empty on this.  

 

Does anyone know how Maskulator calculates the out of focus diffraction pattern.    I understand how to do both the defocused and focused  general case with brute force (computationally costly) EMAG superposition of (apodized, windowed... ...masked ) field across the aperture and was getting set to do that when I discovered Maskulator earlier today.  .  

 

But I do see that Maskulator uses a Fourier transform DLL 

 

But with Fourier transform using plane wave mask pattern as input,  you solve only the far field Fraunhofer (in focus) pattern.    How does Maskulator  solve for the out of focus case?    

 

Did Niels use some sort of transform or phase modification of the complex field at the mask and then just crank it through the Fourier transform.

 

If so what is the transform or modification to the mask complex coefficients?  

 

As simple as applying spherical wavefront phase apodization function to the mask?    

 

Regards

Frank




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