First light on the Optolong L-Extreme filter

[AMcD]

First, a caveat about these two stacked but unprocessed images.  The pictures do not constitute an absolute comparison.  The first, unfiltered, image of the Rosette Nebula was taken on a night with a full moon.  The second, L-Extreme filtered, image of the Rosette Nebula was taken on a night with a waxing crescent moon.  The first image was captured on a still, cold night that had a degree of haze.  The second image was taken on a warmer, windier night following heavy rain, meaning that there was likely less haze.  

Both pictures represent approximately 2 hours exposure time comprising 5 minute sub-frames taken using a QHY8  on a Celestron C8 with Hyperstar mounted on a Losmandy G11.  The images were stacked with dark and flat frames in Deep Sky Stacker using the "average" setting for each of the light, dark and flat subframes.

Notwithstanding the significant caveat set out above, the Optolong L-Extreme has immediately made a huge difference to the quality of the data I am able to achieve from my city center location, which includes an old sodium street light that shines directly into my back garden observatory.  The quality of the data has also allowed me to identify that my Hyperstar assembly is urgent need of collimation!

[JemC]

wow! that's some difference  

[AMcD]

On 19/02/2021 at 12:05, AMcD said:

First, a caveat about these two stacked but unprocessed images.  The pictures do not constitute an absolute comparison.  The first, unfiltered, image of the Rosette Nebula was taken on a night with a full moon.  The second, L-Extreme filtered, image of the Rosette Nebula was taken on a night with a waxing crescent moon.  The first image was captured on a still, cold night that had a degree of haze.  The second image was taken on a warmer, windier night following heavy rain, meaning that there was likely less haze.  

Both pictures represent approximately 2 hours exposure time comprising 5 minute sub-frames taken using a QHY8  on a Celestron C8 with Hyperstar mounted on a Losmandy G11.  The images were stacked with dark and flat frames in Deep Sky Stacker using the "average" setting for each of the light, dark and flat subframes.

Notwithstanding the significant caveat set out above, the Optolong L-Extreme has immediately made a huge difference to the quality of the data I am able to achieve from my city center location, which includes an old sodium street light that shines directly into my back garden observatory.  The quality of the data has also allowed me to identify that my Hyperstar assembly is urgent need of collimation!

This is the processed version of a stack of the images taken through the L-Extreme (I had to re-do the stack above as I had messed up the flat frames to the extent that they introduced an unwanted and complex gradient into the stack, born of the Hyperstar's notoriously uneven field illumination and not helped by its current lack of proper collimation).  It is so much easier to deal with processing in Photoshop when not having to wrestle with light pollution...