Clear nights compared to previous years.

[WolfieGlos]

3 hours ago, 900SL said:

I've just bought a 533mm pro from FLO, on the basis that there are so few clear nights here. So if the moon us up at the same time, I can shoot narrowband

I’m thinking about getting an astrocam at last, and I’m thinking of the 533mm pro with all accessories (RGB filters and a filter wheel), but it comes in at a similar price to a 2600mc. I’d be interested in seeing what you make of it when you get some clear skies 🙂 

Edited December 29, 2023 by WolfieGlos

[wookie1965]

I have had one good session since June with health and weather but this winter from October to today has been rain rain rain. 

According to the BBC weather app next clear sky is the 9th from 5pm until 10pm but I will not hold my breath. 

[Bugdozer]

1 hour ago, ONIKKINEN said:

17h is with twilight included so not a useful estimate on usable night sky time, right now we have 13h of astro darkness according to Stellarium and Hastings has 12, so not that different.

The numbers were just made up as an example, my overall point being that there are as many hours of astronomical darkness per year in both locations, they are just concentrated into a smaller number of days the closer you are to the poles. 

The cloud cover is a separate issue. 

[F15Rules]

55 minutes ago, Alan White said:

It must be that time of year and this topic comes up.

I have missed as many observing opportunities due to other commitments and life in general this year as much as any other.

I have had a number of great observing sessions and will not grumble.

 

I tend to agree Alan, except for the last paragraph..I've had very few sessions since August..

However, this has been partly my own fault, and I think for 2023 Im going to have to be less picky and choosy about when I get the scope out. For example, I may need to be willing to get up very early to see a morning sky or more willing to tolerate the cold etc.🤭😏😂

Dave

[Merak]

3 hours ago, Elp said:

I'm starting to wonder whether building a micro obsy with a Seestar within might be the way to go going forward. You could even keep it in a wheely bin. Next to no setup time and doesn't take much space at all.

I have thought about getting a seestar but that'll have to wait because I've been told that we need a new sofa...

[John]

I have had quite a few sessions over the past few months but most of them have been quite short, some very short indeed. It seems ages since I had a really long observing session (ie: several hours) covering numerous targets. 

To balance that, the outer planets have been much better placed this year and some of the views of Jupiter in particular have equalled some of the best I have seen in many years.

I'm fairly sure that I'll stick at simple observing though. I don't fancy that EAA is for me and I don't feel drawn to imaging. 

 

 

[900SL]

55 minutes ago, WolfieGlos said:

I’m thinking about getting an astrocam at last, and I’m thinkiof the 533mm pro with all accessories (RGB filters and a filter wheel), but it comes in at a similar price to a 2600mc. I’d be interested in seeing what you make of it when you get some clear skies 🙂 

I went through the same process. I was going to get the 2600MC for the APSC format, but I already have the 533MC Pro (similar specification) and whilst I am generally happy with it, I think I can get better SN and greater flexibility with the 533MM. I'll post up results if I ever get clear skies..

[ONIKKINEN]

1 hour ago, Bugdozer said:

The numbers were just made up as an example, my overall point being that there are as many hours of astronomical darkness per year in both locations, they are just concentrated into a smaller number of days the closer you are to the poles. 

The cloud cover is a separate issue. 

Not sure how you came to this conclusion, because it simply is not true.

Some rudimentary back of the napkin calculations point to the average amount of darkness per day (for a whole year) being 9,5h on the equator, 7 ish at 50 degrees and more like 6h for 60 degrees. Higher latitudes just get less darkness overall.

[WolfieGlos]

41 minutes ago, 900SL said:

I went through the same process. I was going to get the 2600MC for the APSC format, but I already have the 533MC Pro (similar specification) and whilst I am generally happy with it, I think I can get better SN and greater flexibility with the 533MM. I'll post up results if I ever get clear skies..

I just can’t justify the cost of a 2600mm for APSC format in mono, but also unsure how I feel about a square sensor being a DSLR user. I’m not thinking until much later in 2024 so hopefully you (and everyone else) get some clear skies by then… 

[Elp]

The 533 square isn't bad, in fact it's the perfect shape for even field illumination because your optics project a round circle. What you loose in width you gain slightly in height. It's usefulness depends on your framing options via your optics, my main issue is if I need to match the data to my 183 with the 533 I'd have to either crop to suit or mosaic the 533, in this case it's better to use a larger sensor if available. The lack of amp glow looks nice, but I find it makes little to no difference after calibration.

[900SL]

15 minutes ago, WolfieGlos said:

I just can’t justify the cost of a 2600mm for APSC format in mono, but also unsure how I feel about a square sensor being a DSLR user. I’m not thinking until much later in 2024 so hopefully you (and everyone else) get some clear skies by then… 

I've found a bunch of advantages with the square sensor.. which means set up is much easier and you can get on with imaging rather than chasing down issues

Field flatness and corner issues are much less of an issue compared to APSC 

Backspacing is straightforward, and tilt has much less impact  

Files are smaller, data transfer quicker, storage less and processing faster

The 533 is more forgiving of scope image circle restraints, compared to my APSC and full frame Nikons

Filters and filter wheel are way cheaper 

[Ratlet]

57 minutes ago, 900SL said:

I've found a bunch of advantages with the square sensor.. which means set up is much easier and you can get on with imaging rather than chasing down issues

Field flatness and corner issues are much less of an issue compared to APSC 

Backspacing is straightforward, and tilt has much less impact  

Files are smaller, data transfer quicker, storage less and processing faster

The 533 is more forgiving of scope image circle restraints, compared to my APSC and full frame Nikons

Filters and filter wheel are way cheaper 

Love my Altair 533 hypercam.  I think the square shape works well for framing loads of DSO depending on the focal length.

My imaging requirement is basically slightly above EAA so i basically just picked up cheap 135mm, 200mm and 300mm prime lenses (about £100 all in) and with the 130pds I can get pretty much everything framed nicely.

With the benefit of hindsight I should probably have just got an uncooled one and saved a bit.

On the subject of clouds, this year does feel worse, but the winter has been much worse.  In the summer a cloudy night costs me nothing as I have no astronomical darkness from April to the middle of August.  In winter a cloudy night costs me 12 hours.

Another related observation is that what clear nights I do get seen to be +/- 3 days around the full moon.

Not missing it too much.  I image to share with others.  My true love is visual (fortunately).

[Bugdozer]

3 hours ago, ONIKKINEN said:

Not sure how you came to this conclusion, because it simply is not true.

Some rudimentary back of the napkin calculations point to the average amount of darkness per day (for a whole year) being 9,5h on the equator, 7 ish at 50 degrees and more like 6h for 60 degrees. Higher latitudes just get less darkness overall.

I am happy to accept that, if you can tell me a date after the autumn equinox but before the spring equinox, on which a location of your choice in Norway gets a shorter period of astronomical darkness than a location of your choice in France. My understanding is that doesn't happen, but I will accept I might be wrong. If we were to take today as an example, Norway has a greater length of astronomical darkness than France does. 

[ONIKKINEN]

7 minutes ago, Bugdozer said:

I am happy to accept that, if you can tell me a date after the autumn equinox but before the spring equinox, on which a location of your choice in Norway gets a shorter period of astronomical darkness than a location of your choice in France. My understanding is that doesn't happen, but I will accept I might be wrong. If we were to take today as an example, Norway has a greater length of astronomical darkness than France does. 

Well now we have moved the goalposts quite a lot in favour of the equal darkness argument, and yes in that case obviously Norway would be darker for the winter months. Compare the full year between any location in Norway and any location in France, and France will be darker. The time it takes from sunset to sunrise is the same everywhere on Earth, if averaged over an entire year, but the time it takes from sunset to astronomical darkness is not the same, and the further we are from the equator the longer it takes just because the apparent arc that the Sun appears to move in is shallower.

[Gerr]

Worst year of cloud, rain and wind I can remember!  Only two decent nights since August (I live on Anglesey, North Wales).  Now looking at widefield portable set-ups to take on holiday to get my astrophotography fix!! 

[Daf1983]

I have imaged about 3 times this year in North Wales. Like many I don't set up unless the forecast in good enough to confidently leave my set up out all night. Also, work and young children limit available nights. It's frustrating, but I feel it's still worth it for the excitement of a crystal clear night when everything comes together. However, I feel I can't justify spending much on astro gear these days

[Bugdozer]

46 minutes ago, ONIKKINEN said:

Well now we have moved the goalposts quite a lot in favour of the equal darkness argument, and yes in that case obviously Norway would be darker for the winter months. Compare the full year between any location in Norway and any location in France, and France will be darker. The time it takes from sunset to sunrise is the same everywhere on Earth, if averaged over an entire year, but the time it takes from sunset to astronomical darkness is not the same, and the further we are from the equator the longer it takes just because the apparent arc that the Sun appears to move in is shallower.

That’s not moving the goalposts. That's what I suggested from the beginning. In the summer half of the year, the time to reach astronomical darkness is greater nearer the pole than towards the equator. In the winter half of the year, the time to astronomical darkness is less great nearer the pole than towards the equator. These balance exactly for any given latitude, the only difference with latitude is the magnitude of the effect, being greatest at the poles and smallest at the equator. At least, that is my understanding. If that IS the case, then you can see why I remain unable to understand why the poles would have more daylight and less darkness overall, which was your original assertion. As I said, I am happy to be proven wrong, but so far no explanation of why my understanding is incorrect has been given. 

[F15Rules]

Hmm... wasn't the original post title "Clear nights compared to previous years"?? 🤔🙄

Dave

[ONIKKINEN]

9 minutes ago, Bugdozer said:

That’s not moving the goalposts. That's what I suggested from the beginning. In the summer half of the year, the time to reach astronomical darkness is greater nearer the pole than towards the equator. In the winter half of the year, the time to astronomical darkness is less great nearer the pole than towards the equator. These balance exactly for any given latitude, the only difference with latitude is the magnitude of the effect, being greatest at the poles and smallest at the equator. At least, that is my understanding. If that IS the case, then you can see why I remain unable to understand why the poles would have more daylight and less darkness overall, which was your original assertion. As I said, I am happy to be proven wrong, but so far no explanation of why my understanding is incorrect has been given. 

Just run the numbers yourself, you'll find that the further north you go the less dark it actually is year round.

I just got the numbers from here: https://www.timeanddate.com/sun/finland/helsinki

Calculated the averages for my location close to Helsinki and Hastings 10 degrees further south.

I simply took the stated "night" time from 1st day of a month and the 15th day of a month from every month, added together and divided by 24 to get an average length of night for an entire year.

For Helsinki, the average is 6 hours. For Hastings the average is 7 hours. I could find a better average by counting all the days of a year but i just cant be bothered because the result will still be roughly the same.

Edited December 29, 2023 by ONIKKINEN

[Bugdozer]

50 minutes ago, ONIKKINEN said:

Just run the numbers yourself, you'll find that the further north you go the less dark it actually is year round.

I just got the numbers from here: https://www.timeanddate.com/sun/finland/helsinki

Calculated the averages for my location close to Helsinki and Hastings 10 degrees further south.

I simply took the stated "night" time from 1st day of a month and the 15th day of a month from every month, added together and divided by 24 to get an average length of night for an entire year.

For Helsinki, the average is 6 hours. For Hastings the average is 7 hours. I could find a better average by counting all the days of a year but i just cant be bothered because the result will still be roughly the same.

Interesting. I also found what causes this effect. Basically I wasn't accounting for refraction or for the elliptical orbit of the earth. This link explains it well:

https://skyandtelescope.org/astronomy-resources/astronomy-questions-answers/daylight-hours/

I think I have had about the same number of clear nights as last year. Including tonight when I was finally able to try out my new 32mm Super Plossl I got for Christmas. 

[mcrowle]

My astro-imaging camera (modded EOS 600D) data is organised in folders by date, so the number of folders gives me a quick count of the nights I did any imaging with that camera. 2023 does feel worse than 2022, especially the last few months, but the actual counts are:

2022: 45 nights

2023: 53 nights

Many of those sessions may have been limited by cloud, rather than being full nights of clear skies. In fact, currently I can't remember the last consistently clear night. Not included in those counts, though, would have been a few nights I did planetary or lunar imaging and viewing, or landscape-astrophotography, and didn't use the 600D.

Regards, Mike.

[ONIKKINEN]

3 hours ago, Bugdozer said:

Interesting. I also found what causes this effect. Basically I wasn't accounting for refraction or for the elliptical orbit of the earth.

Thats not really the thing here nor is there an 'effect' of some kind at play, youre overthinking this way too hard. Its just simply the fact that the Sun takes longer to cross from the horizon to -18 degrees where true darkness begins when the path that the Sun take across the sky is shallower, like further up north.

I'll just drop it, this is going nowhere.

To try and get back on topic: the past few months suck compared to previous years - agreed.

[900SL]

5 hours ago, Bugdozer said:

Interesting. I also found what causes this effect. Basically I wasn't accounting for refraction or for the elliptical orbit of the earth. This link explains it well:

https://skyandtelescope.org/astronomy-resources/astronomy-questions-answers/daylight-hours/

I think I have had about the same number of clear nights as last year. Including tonight when I was finally able to try out my new 32mm Super Plossl I got for Christmas. 

So to conclude: you were wrong, right? 

 

[Merak]

6 hours ago, F15Rules said:

Hmm... wasn't the original post title "Clear nights compared to previous years"?? 🤔🙄

Dave

Yes, it seems in part to have turned in to an astro equivalent of bald men arguing over a comb.

The mods/admin can close or delete the thread.

Edited December 30, 2023 by Merak

[900SL]

1 hour ago, Merak said:

Yes, it seems in part to have turned in to an astro equivalent of bald men arguing over a comb.

The mods/admin can close or delete the thread.

Now you're just splitting hairs 😉

Let's get this back on track. Here it snowed 15cm last night and it's once again solid cloud