Peter Ward
10-02-2025, 01:07 PM
Having been so impressed with Maurice’s SHG images, I decided to test the spectroheilograph waters for myself.
My MLAstro SHG arrived about a week ago, with this morning being the first time I’ve had a chance to try and work out how to use it.
First problem was my usual solar camera (QHY533m) would not reach focus, due physical contact of the (largeish) camera body and SHG focusing micrometer.
There is a fix for this, but thankfully my older and much smaller Point Grey camera was easy enough to adapt for initial testing without pulling the SHG apart.
I’ve since ordered a newer IMX678 camera to live out its days on the SHG.
SHG’s are definitely not “point and shoot” many subtle adjustments need to be made to get high quality data.
I’m clearly not there yet.
First light image attached. Apart form refining some settings I'll need to use a shorter focal length scope (AP92 should be perfect).
That said, once you have lined everything up, capturing a “scan” is very similar to any solar/lunar/planetary .SER data capture, except you press the RA button to (smoothly) move the solar image across the SHG slit.
The very impressive and intuitive JSol’Ex software does the rest...and its free!
At this stage I don’t think this SHG will ever deliver higher quality/resolution images than my Lunt 90mm etalon.
But at a fraction of the cost of a 90mm Ha double stack etalon (read $ five figures) the Ha contrast of the SHG is simply amazing and you can explore many more lines along the solar spectrum (Ca, Fe, etc.) but simply turning a dial.
In short, the MLAstro SHG one of the coolest bit of kit I purchased in many, many moons.
Highly recommended. :thumbsup:
My MLAstro SHG arrived about a week ago, with this morning being the first time I’ve had a chance to try and work out how to use it.
First problem was my usual solar camera (QHY533m) would not reach focus, due physical contact of the (largeish) camera body and SHG focusing micrometer.
There is a fix for this, but thankfully my older and much smaller Point Grey camera was easy enough to adapt for initial testing without pulling the SHG apart.
I’ve since ordered a newer IMX678 camera to live out its days on the SHG.
SHG’s are definitely not “point and shoot” many subtle adjustments need to be made to get high quality data.
I’m clearly not there yet.
First light image attached. Apart form refining some settings I'll need to use a shorter focal length scope (AP92 should be perfect).
That said, once you have lined everything up, capturing a “scan” is very similar to any solar/lunar/planetary .SER data capture, except you press the RA button to (smoothly) move the solar image across the SHG slit.
The very impressive and intuitive JSol’Ex software does the rest...and its free!
At this stage I don’t think this SHG will ever deliver higher quality/resolution images than my Lunt 90mm etalon.
But at a fraction of the cost of a 90mm Ha double stack etalon (read $ five figures) the Ha contrast of the SHG is simply amazing and you can explore many more lines along the solar spectrum (Ca, Fe, etc.) but simply turning a dial.
In short, the MLAstro SHG one of the coolest bit of kit I purchased in many, many moons.
Highly recommended. :thumbsup: