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ASI120mm - The Sun in Ha

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The BBC's weather forecast said that the sky was set to be clear - well if clear is defined by giant clouds broken by occasional blue sky, then they got it spot on! If the clouds weren't enough of a hassle, the strong wind just added to the "fun" of it all.

These images are first light images taken with the ASI120mm, a camera that everyone is raving about due to it's very sensitive monochrome CMOS and relatively low cost.

The camera suffers from Newton Rings, much like any CMOS camera does when imaging Ha light, and I've yet to receive my tilt adapter from Germany. Despite the Newton Ring issue, they weren't so prominent as to ruin the images entirely.

Weather didn't allow me much experimentation time, and whilst processing the full disc, I noticed an interlace pattern which I had to remove with a "de interlace" filter.I suspect my shutter speed of 0.065ms might be a cause.


The two large towering proms where fascinating to watch, over time I saw them twist about each other, and if the wind had not been there, I would have done a time lapse sequence.


The following video is straight from the camera, no processing, and gives you a sense of what fits within the telescope/sensor combination.

Technical Information

Location and Time: April 8th 2014 | 13:55 GMT | Mansfield, England

Conditions: Strong Wind | Mostly cloudy | Seeing 3/5 dropping to 2/5

Imaging Train: Coronado SolarMax II 60 BF10 | Meade 2x Shorty Barlow [Proms Image Only] | ASI120mm

Imaging Settings: Shutter=0.065ms | Brightness=0 | Gain=50 | Gamma=50 | Duration=9s | Frames captured=428 | ROI=1152x672

Processing: Registax | Photoshop [sharpening | Levels | Masking | Colour]

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indeed.  Excellent image of the proms.  Are you sure you didn't dig that first photo out of a family album from the 70s though? :D


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1972 to be exact! :D

Thanks, the proms I could have watched for hours if it wasn't for the darn clouds :D Hoping to get some time in the coming week to look at the interlace issue and perhaps photograph whatever else the Sun throws out!

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Nice full disk and great proms. I got a patterning effect on the sun with my ASI130MM, so now I use a DMK21 for H-alpha (works but you need a massive number of tiles). Not sure the ASI120MM should show this effect

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Excellent images of the massive proms, an animation would have been great as perhaps they were solar tornadoes :) :) :)

Haven't you got a more up to date picture of your scope? :lol:


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