Is it MaximDL that has a Make stars rounder function?

[g__day]

I remember doing this once - but not sure what software package I used (I think it was MaximDL v4.6) but not sure if it was a plug-in.

Anyone know what to use to address (correct) coma using software?

I thought it might have been Rod Wodaski's DeBloomer for MaximDL - but it crashes for me (Subscript out of range) so I can't tell for sure - http://www.newastro.com/downloads/products.php

Thanks,

Matt

[Alchemy]

not sure , but jase says .... or my interpretation of what he said was..... that digital development gives that effect

might have to do a search to confirm that though.

[jjjnettie]

MaxIm DL has the debloomer.
You can get the Star Rounder plugin for PhotoShop.

[jjjnettie]

AstroPlugins "Star Rounder" v1.03 2005 James Ryan
That's the one I have.
Find it here
http://www.grekalova.com/photo_Astroplugins.html
along with other goodies.

[g__day]

Thanks - Debloomer crashes and Star Rounder doesn't seem to do anything :(

[jjjnettie]

Here's an example of what Star Rounder can do.
I moved all the adjustment sliders to the far right to fix this pic.

[g__day]

Hmmm it did something. Moving all the sliders to the right helped - but 1/3 of the fainter stars then disappeared!

[jjjnettie]

Ooops.

[g__day]

In fact look at your two shots - some stars disappear and some almost disappear!

[jase]

Sorry, just saw this post...been busy with work.

:lol: Before I digress, we should all acknowledge that there is no magical smoke and mirrors algorithm to make shotty stars look perfect. We are talking about pin point sources of light which are best controlled through good optics and guiding amongst other things. Manipulating stars in post processing should ideally be an act of enhancement not recovery. Try not to get into the situation of the latter.



Close... MaximDL has a Kernel Filter which can be invoked by deconvolution or Digital Development function. You can configure the "User Defined" Kernel filter to sharpen stars in a non uniform manner. This can be used to alter edge to centroid mapping. A word of warning, from experience this method can be a little hit and miss. There is an assumption that all stars across the field have the same problem - common with guiding errors - difficult for optical errors such as off axis coma. There is no "selectiveness" in the routine - all stars are given the same treatment. However, you can work around this by creating different Kernel filters and integrating them into a single image using masks. You'll pull your hair out in the process - not for the faint hearted. More information is available here; http://www.princeton.edu/~rvdb/images/deconv/deconv_MaximDL.html (http://www.princeton.edu/%7Ervdb/images/deconv/deconv_MaximDL.html)

[g__day]

Jase et al - many thanks!

I think I am back to reposition the rotten focal reducer in the Lumicon OAG to see if I can kill this coma - shots where perfect (coma-wise) before this arrived.

Lumicon say it shouldn't occur - but my OTA has a 3" long Meade electronic focuser before the OAG - maybe that is moving the focal range to a position they just didn't test well enough. Maybe the focal reducer just doesn't sit in the OAG absolutely correctly - who knows?

If a star looks streaked at the edges of your shot I'm suprised a custom plug in doesn't detect this and make coma affected stars more round. Worse before a PC crash and software re-load I believe MaximDL use to do this and do it well - it would grab suspect stars then process and leave egg shaped stars more round.