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Problems with processing image - andromeda


snursaba

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Hi 

 

I've tried to take a shot at andromeda from a fixed tripod - I've seen several posts online that it's possible to do so? But I've tried a few times and have not been successful unfortunately.

 

The following image is a final stacked image using DSS. I've used 695 light frames (~400 light frames at 250mm, 2s each, the rest at 300mm at 1.6 s each), I've also included about 40+ dark frames and bias frames. my ISO is at 3200 (it's the highest my camera can go - I'm using nikon d40x), and the arperture is f/5.6 (again, it's the fastest I can go).

 

I've tried processing with photoshop after stacking but the image gets worse.

 

Is there a problem with the camera settings do you think, or is it the processing?

 

Any help is much appreciated! :)

 

 

andromeda_final.TIF

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I think and i am no expert but due to the exposure time being so short then it is very hard to pick up the fainter parts of the galaxy therefore only being able to see the center if the galaxy. I've tried to process my images of andromeda from a fixed tripod at 140mm but my exposure was too short DSS could not pick up enough stars to stack. Hope this helps. I've wasted a lot of data from this simple mistake.

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Yes I agree with the post above - at 2s you are only capturing the core of M31 and M32. The fainter parts of the galaxy cannot be distinguished from the read noise of the camera sensor. If you try exposures of around 30s you may get better results. Also, have you tried to calibrate your images using dark, bias and flat frames? This will help improve the quality of the final image. There are plenty of posts about how to calibrate your images if you are not sure.

Dan :happy7:

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Hi

Thanks for your replies!

I've used dark and bias frames, but not flat ones. Ok, I'll venture into using flats as well. 

For longer exposure timings, I suppose I'll need a tracker for that - I have an ioptron cube, the cute alt-azimuth one - perhaps worth a try though I've never used it for astroimaging :D 

Clear skies! 

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