Use decon for bad adjusted telescope?

[TobiasLindemann]

Hi there,

the last days I had a look at the pictures of a friend. Obviously his telescope is very bad adjusted, so the stars are not round at all.


So I had a try with deconvolution to get the stars sharper and more round.


As you see, there is some sharpening-effect in the nebula visible, but there is no much difference in the stars. (The image is still linear)

So I had another try with a starmask and MorpholocicalTransformation.
First I applied a starmask to the image:

Then I tried to do the MT:

The effect is also not what I expected

My question is, what I am doing wrong or is there any other better method to gain better stars?
If you wish, you can download the linear fits image at the following link:
http://www.tracking-station.de/heller/integrationHa2.fit

Greetings
Tobias

[Zocky]

It looks to me like the image is out of focus, so you won't be able to repair the stars.

[TobiasLindemann]

Hi Zocky,
yes it looks like, but unfortunately it is not out of focus. But even if it is out of focus, I think there must be a way to repair the stars.

Tobias

[TobiasLindemann]

Has nowbody an idea?

[Geoff]

Hi Zocky,
yes it looks like, but unfortunately it is not out of focus. But even if it is out of focus, I think there must be a way to repair the stars.

Tobias

You can't get good data from bad data. Throw it away, fix the problem and then take good data.
Geoff

[TobiasLindemann]

ok, this makes sense, thank you for your answer 
Unfortunately I can´t fix the problem by myself, because it is not my telescope. 

[Alejandro Tombolini]

Hi Tobias,

Try MorphologicalTransformation with similar parameter to this example
A good mask here is very important.

Saludos, Alejandro.

[TobiasLindemann]

Hi Alejandro,

thank you for your tip  . Unfortunately it seems not to work on on that image.

Tobias

[jerryyyyy]

Problem is stars are not with same distortion over whole field... so star model cannot correct (one size does not fit all).  This may be a collimation problem with your friend's scope... I speak from experience just fixing my Tak 180ED.  This is the corrected image but i does not cut off all the tails... tails are different top to bottom.