adding more images

[alcol620]

A simple question that I am unsure of the answer.

I took 20 of images of M31 a few weeks ago, calibrated them and integrated them into an image (say image A). If I take more images of M31, same setting, and calibrate them, can I register them and integrate these addition images directly with Image A or do I integrate them with the original 20 calibrated images?

Thanks for your help.

[geordie85]

18 minutes ago, alcol620 said:

A simple question that I am unsure of the answer.

I took 20 of images of M31 a few weeks ago, calibrated them and integrated them into an image (say image A). If I take more images of M31, same setting, and calibrate them, can I register them and integrate these addition images directly with Image A or do I integrate them with the original 20 calibrated images?

Thanks for your help.

Stack all the images together which will make a better, less noisy image A

[wimvb]

If you have removed the camera from the scope between sessions, and your camera is uncooled, I would suggest this procedure:

Calibrate frames A with flats and darks A, and bias

Calibrate frames B with flats and darks B, and bias

Stack frames A and B into one new image.

If you haven't removed the camera between sessions, you can reuse flats. If your camera is cooled, you can reuse darks.

[alcol620]

Thanks folks

I have had a go at combining two sets of images using Pixinsight, I registered the images firstly against an image from the set taken last year with an Atik 383 camera on a ED80 scope and secondly against an image from a recent set taken with an ASI1600 mono camera on a TSAPO60 scope. Each registered set was integrated and the two images are shown. Obviously a significant difference in FOV of the 2 images, but it does show as you said, that images of different set ups can be registered and stacked, albeit, stacking images against the wide field registration does lead to a brighter area in the centre of the image where the extra data is intergrated

Any ideas on how you would get rid of this, I have tried a quick histogramtransformation and curves but the bright area does not blend in. Perhaps with differing field of view you can only overlay the wider field onto the smaller??

Comments welcome