Synth module question

[puckja]

I used Synth to restore some diffraction spikes from my Newt. The spike usually is too long and bright but I can easily taper it down and blend it really well with my small CCD (image size: 27x36 arcmin).

Today I try to do the same trick on my Orion StarShoot Pro V2 image (66'x100') and I found the spikes were suddenly like puny hairs ??? I tried to adjust the Image Size but has not much effect. One example here:
http://www.flickr.com/photos/95673005@N06/10746423944/

I messed up with this for a long time and wonder if I missed something. For image like this:
http://www.flickr.com/photos/95673005@N06/10747833815/

The big spike (not synthesized) is much longer than I can achieve with Synth module now.

Thanks for the help!

And one more suggestion: would it be possible to save the 1st stage of Synth process since I found myself kept inputing the same parameters and wait a long time for that. If we can save the Synth calculation and directly load and apply, that would be great!

[admin]

I used Synth to restore some diffraction spikes from my Newt. The spike usually is too long and bright but I can easily taper it down and blend it really well with my small CCD (image size: 27x36 arcmin).

Today I try to do the same trick on my Orion StarShoot Pro V2 image (66'x100') and I found the spikes were suddenly like puny hairs ??? I tried to adjust the Image Size but has not much effect. One example here:
http://www.flickr.com/photos/95673005@N06/10746423944/

I messed up with this for a long time and wonder if I missed something. For image like this:
http://www.flickr.com/photos/95673005@N06/10747833815/

The big spike (not synthesized) is much longer than I can achieve with Synth module now.

Thanks for the help!

And one more suggestion: would it be possible to save the 1st stage of Synth process since I found myself kept inputing the same parameters and wait a long time for that. If we can save the Synth calculation and directly load and apply, that would be great!

Hi Puck,

The way diffraction spikes look is a function of your scope's characteristics and the diameter of the image in arc minutes.
Did you compute/approximate the angular size of the scene correctly?

If you need longer diffraction spikes, you can increase the point spread function's precision ('Sample Size'), but I find it is rarely needed if the angular size and scope characterstics are modeled accurately enough.