Drizzle

[litobrit]

Hello.
I am a new user of Pixinsight and of this forum. Sorry for my english 
I have made this M16 SHO a few day ago whith a RCGSO8 and an Atik 383 bin2, so the luminance Ha is under sampled.
I have tried the tuto of Juan about drizzle. Everything works fine except the last step when integrating drizzle files. The stars are clearly stretched by more than 10 pixels.
Without drizzle the integrated image has good circular stars as you can seen on the final image :

[Juan Conejero]

I am not sure I understand the problem you are reporting. Drizzle cannot "stretch" stars as far as I know. How many frames are you integrating with drizzle? Which drizzle parameters?

[litobrit]

Hello Juan. I am integrating 15 Ha frames.
Screen captures below :

[Juan Conejero]

No similar problem has been reported so far with drizzle. I can't say anything without having a look at the images. Could you upload them, so I can try to reproduce the issue?

On a side note, you shouldn't enable clip high range with drizzle; see the missing saturated pixel on a bright star in your last screenshot, near the top right corner of the drizzle integrated image.

[litobrit]

Hello Juan,
Clip hight range will be off...
The calibrated frames are here :    https://www.dropbox.com/sh/x33mve6g4nkoujo/AAA8m4LpAnw9whGFYWAtoYewa
Thanks for your help

[Juan Conejero]

Bug confirmed. DrizzleIntegration does not apply correctly the image registration transformations when there are images rotated by 180 degrees in the original data set. I am working right now to fix this bug ASAP. Thank you for uploading your images.

While I fix this problem, the workaround is simply to rotate the necessary images by 180 degrees before StarAlignment. In this specific case:

- Open the ImageContainer tool.

- Select your images from M16-008H_c to M16-015H_c, both included

- In the output template, write: &filename;_r180&extension;

- Open the FastRotation tool, and make sure the rotate 180 degrees option is selected.

- Drag the ImageContainer blue triangle to FastRotation's control bar.

- Proceed to register, integrate and drizzle your files as usual, but use the _r180 images created above.

Sorry for the inconvenience. This bug will be fixed through an update as soon as I can.

[litobrit]

Hello Juan,
Happy to participate to Px improvement.
I have tried this morning with another set of frames without 180° rotation. Drizzle is working fine. Noise is greater than normal integrated images but seems easier to manage. Definition is better.

[Juan Conejero]

I've got good news: this bug is now fixed. I'm preparing an update for all supported platforms, which I'll release later this afternoon. Thank you again for your help and patience.

[Juan Conejero]

The update is now available. Let me know if everything works correctly.

[litobrit]

Working fine.