Tuesday, October 4, 2022

Finally Dark Enough

I rolled Big Bertha out.  I took some one minute videos of the Moon.  1800 frames should stack some awesome images.

Jupiter never ceases to amaze me through this 17.5" f/4.5 scope rebuilt by DobStuff.  Not just the brown bands in the upper and lower temperate latitudes but all the subtle curlicues that are just on the edge of resolution at 222x.  It was getting late enough that I just wanted some still photos and video of Jupiter and satellites.  Unfortunately, eyepiece projection put too much weight at the front and in the dark I could not find the counterweights I hang on the back for this purpose.  Maybe tomorrow night.  But I will have pictures tomorrow morning!

Tomorrow morning: As fast as this new laptop is, Registax is still taking a while processing 1800 frames!

Registax alone on 1800 frames.  This was I think at 1/100th second exposure per frame.

Then with GIMP unsharp mask:

And here was a still image ISO-100 1/80th second unsharp masked with GIMP.

As you can see stacking 1800 frames produces a better image than even a very short exposure.

Jupiter's satellites.  Jupiter is washed out because I was using a long exposure time (1/100th second?  not included in the EXIF block) to get the satellites.  I will use a shorter exposure and eyepiece projection tonight to get details on the planet.  That long exposure time might be showing tracking errors, or more likely maybe the alignment to north was inadequate.  Jupiter is not that oblate and the satellites are a bit smeared.  

Okay, this was a shorter exposure per frame, 15 seconds.  It still needs eyepiece projection to get more detail.  I cropped it a bit to increase scale.

If you are considering buying an equatorial platform for your Dobsonian, you will not go wrong with the Crossbow.

I found the additional balancing weight for eyepiece projection.  All the way in the back of thhe shed.

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