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Auroras, Cocoons, Horseheads and Deer...


Ships and Stars
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8 hours ago, PeterW said:


What is the R^2 of your regression? Interesting stuff. I’ve seen notes about the variation due to different effects like the milkyway. Be interesting to see your time series data.

Peter

R^2 is around 98%, and the sqrt(sum-of-squares) of the residuals-from-modelled, the quasi std-dev, is 0.34 mags for this model. (This model is for "Moon Up" data. I run a different model for "Moon Down" excluding the moon's properties of course, which gives a quasi-SD of 0.12 mags. And another for "All together" which gives 0.41. All 3 R^2 are 98-99%).

I'll compile my data and send it to anyone who's interested. I also have a similar series for my London location, a 19.05 site, so opposite ends of the LP spectrum so to speak.

Apologies to @Ships and Stars , sorry I don't mean to hijack your superb account and thread.

M

Edited by Captain Magenta
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On 25/11/2020 at 12:58, Captain Magenta said:

Apologies to @Ships and Stars , sorry I don't mean to hijack your superb account and thread.

M

No problems all! Thank you @scarp15 @PeterW and everyone else who has commented as well. That's why I'm here, lots to learn. I am especially interested (bordering on obsessed!) in light pollution and SQM-L readings I'll have to dust off my calculator, though that still doesn't mean I'll know what to punch in ;)

Family things and work have been flat out past two days - I've just popped on here for a minute but will try back later this evening if I get a break.

PS tripod fork mount arrived today from TS Optics for the big obsy bins - it's a work of art!

 

Edited by Ships and Stars
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Link for the mount, sounds interesting! SQM-L, just make lots of measurements, recording the location, the date and time and sky conditions.... that’s what Captain Magenta has been doing, enabling him To do some fitting. I reckon urban locations would not be less variable from the Milky Way etc, but I’ve not tried. More data is more better. Don’t know if any Cairngorms dark sky date collection.... if you want a challenge....

Peter

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1 hour ago, PeterW said:

Link for the mount, sounds interesting! SQM-L, just make lots of measurements, recording the location, the date and time and sky conditions.... that’s what Captain Magenta has been doing, enabling him To do some fitting. I reckon urban locations would not be less variable from the Milky Way etc, but I’ve not tried. More data is more better. Don’t know if any Cairngorms dark sky date collection.... if you want a challenge....

Peter

I'll take a note of what readings I get. I have a baseline of sorts from previous readings but not much in the way of notes, etc.

Here's the fork mount - this is the cheap one! They seem like a lot of money for what they are, but everything works so much better than what I was using. My DIY forkmount was never completed, didn't have the time but I prefer the TS Optics as it mounts on a Vixen dovetail. 

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p6384_TS-Optics-Binomount-DX---stable-fork-mount-for-binoculars--telescopes-and-spotting-scopes.html

More pics to come of that in action!

PS my Quantum 5.1s are 7.2kg and the mount holds them just off zenith no problems. I've just tried it indoors, chasing children in circles at the moment!

Edited by Ships and Stars
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I was looking at this sort of  one if I ever went bigger. Be interesting to know offset of the pivot and bracket from the tripod connection. I was going to attach it to the top of my EQ6 tripod (can get a 3/8” adapter), but worried the tripod leg angles would cause the bins to be stopped from getting to the zenith and that I might need a tripod pier extension (I had one but sold it - wouldn’t be the first time I regret selling stuff). 

 

Peter

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11 hours ago, PeterW said:

I was looking at this sort of  one if I ever went bigger. Be interesting to know offset of the pivot and bracket from the tripod connection. I was going to attach it to the top of my EQ6 tripod (can get a 3/8” adapter), but worried the tripod leg angles would cause the bins to be stopped from getting to the zenith and that I might need a tripod pier extension (I had one but sold it - wouldn’t be the first time I regret selling stuff). 

 

Peter

Hi Peter - the fork mount arrived yesterday from Germany in under 48hr! Amazing. It's quite nice overall for the price, this was by far the cheapest one at around £202 with exchange rate commission and DPD shipping, these things are a bit dear. The anodising/powdercoat is a little thin perhaps compared to the higher end fork mounts, APM etc, but they cost 2x to 4x more and I've not seen them in person. I'm using it for now on a trusty old Velbon Sherpa medium duty alloy tripod with a 1/4 to 3/8 camera thread adapter and an 80mm Vixen rail. There are no interference issues when viewing at zenith, but while it's stable, the balance point is set back a bit far for my liking, I'd prefer a larger tripod soon but my main viewing position with be sitting down on a very short stool so the tripod will only be 2/3 extended, about 1m high.

I think you might be able to get away without a pier on a SW steel tripod, but can't say for sure at the moment, I can take some measurements from the centre of my tripod once it's all set up.

I'm doing a minor repair on one of the tripod legs with some JB Weld, so waiting for the epoxy set before I mount it again this afternoon. 

Digital scale shows the fork weighs 3.43kg. It holds altitude with the 7.2kg bins very nicely and seems quite stable. So that's around 10.7kg for the bins and fork mount.

I'll post more when I've set it all up, work is pretty hectic at the moment but I might do some lunar this evening to test it out...

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IMG_20201127_093601391~2_1.jpg

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