Bortle 2 dilemma!

[badhex]

Hello all,

I'm going on two separate mediterranean island holidays later this year, and I knew that for the first of these it would be in Bortle 4/5 skies. We're mostly staying in one place we have rented before and I know the situation well etc., so planning to take my portable setup of ZS73 and 4-5 EPs.

For the second trip, we planned to be island-hopping a bit on some smaller islands with a few more days on the final island (also Bortle 4), and had decided that it wouldn't be ideal taking this same setup. Although it's compact, it's quite a lot heavier and by the time you add it all up it's a lot of expensive glass to be lugging about from place to place. I planned to just take a couple of inexpensive EPs, a Celestron Travelscope 70 and a carbon fibre tripod - chuck everything in my main case and not be worried about breakage, weight, (theft even maybe?).

BUT

I just discovered that two of the places we're going on the second trip (total of 5-6 nights) will be Bortle 2! 

Now I'm worried that only taking lower quality gear means I won't be getting the best of a rare opportunity to observe under really dark skies, but taking the expensive and heavier gear is less convenient and there is at least one afternoon I'll have to leave it with a hotel and not in a room.

What do I do?

[City9Town0]

7 minutes ago, badhex said:

What do I do?

You hope that it is not cloudy... anything else is a bonus!

[parallaxerr]

 

26 minutes ago, badhex said:

Now I'm worried that only taking lower quality gear means I won't be getting the best of a rare opportunity to observe under really dark skies

I would actually say quite the opposite. What you will do is squeeze every last bit of performance out of the inexpensive gear and likely will be so impressed with the views that ED glass, for example, wouldn't make much difference.

My very best views EVER were under very dark skies in Southern France using a WO 66mm refractor and a 32mm plossl, that's literally all I took! I ticked off more of the Messier list that night than I had managed before, or since for that matter. Image scale was small but the contrast made up for it!

Edited August 3, 2021 by parallaxerr

[pete_l]

4 hours ago, badhex said:

will be Bortle 2!

I wouldn't put too much stock in that. Sky darkness varies greatly, throughout the night and with the seasons. So if that Bortle 2 was measured estimated in mid-winter, without any tourist facilities open (and their lights on) you may well find that in peak season it is an entirely different situation.

I'd say just treat it as a holiday. Relax 😎

[badhex]

23 hours ago, parallaxerr said:

 

I would actually say quite the opposite. What you will do is squeeze every last bit of performance out of the inexpensive gear and likely will be so impressed with the views that ED glass, for example, wouldn't make much difference.

My very best views EVER were under very dark skies in Southern France using a WO 66mm refractor and a 32mm plossl, that's literally all I took! I ticked off more of the Messier list that night than I had managed before, or since for that matter. Image scale was small but the contrast made up for it!

Well, indeed the options are between a small refractor and a small refractor! I know either way it will be great, and the TS70 does surprisingly well for the cost, but then I would be limited to 1.25“ EPs, and I like the idea of huge swathes of sky not being washed out by poor contrast for once. My "expensive" option is a small 73mm WO refractor, so comparable to your 66mm. 

[badhex]

20 hours ago, pete_l said:

I wouldn't put too much stock in that. Sky darkness varies greatly, throughout the night and with the seasons. So if that Bortle 2 was measured estimated in mid-winter, without any tourist facilities open (and their lights on) you may well find that in peak season it is an entirely different situation.

I'd say just treat it as a holiday. Relax 😎

True, although the place we're staying is an island chiefly composed of volcano and only 1000 people, so I'm assuming it should be reasonably dark. 

[jetstream]

I'd be taking as much aperture as you can and a top quality OIII filter.

[badhex]

3 minutes ago, jetstream said:

I'd be taking as much aperture as you can and a top quality OIII filter.

The OIII was something I have strongly considered as a pre-trip purchase! In this case I would buy the 2" though, which precludes the possibility of taking the cheaper scope. 

[jetstream]

I would only buy a new Astronomik or the new Televue. Check out the North American neb... with and without the filter.

[badhex]

8 minutes ago, jetstream said:

I would only buy a new Astronomik or the new Televue. Check out the North American neb... with and without the filter.

Yeah the Astronomik does keep coming up as the best option in many SGL threads. Wasn't aware that Televue had one as well. Assume its astronomik-al in price though! 

[jetstream]

The new Televue is made by Astronomik and is my favourite OIII filter, out doing an older, excellent Lumicon. Either one will be top notch but I'm partial to the TV. You will see the veil no filter as well, you taking the 80ED?

[badhex]

 

1 minute ago, jetstream said:

The new Televue is made by Astronomik and is my favourite OIII filter, out doing an older, excellent Lumicon. Either one will be top notch but I'm partial to the TV. You will see the veil no filter as well, you taking the 80ED?

Good to know, thanks. The choice is between the WO ZS73 or a cheapo (but still surprisingly good) Celestron TS70. I had been planning on keeping it simple with the Celestron until I realised how dark the skies will be. 

[Highburymark]

I couldn’t pass up an opportunity like that. I’d take the WO, and the minimum number of good quality EPs and filters to make the absolute most of the skies. You could also insure it against loss or damage for peace of mind.

The advantages of an ED scope over an achromat will make a big difference under dark skies in my view. The first year I took my old Equinox 80ED on holiday to Spain I must have seen 40-odd Messiers. Amazing what small ED scopes can do in the right location.

[JeremyS]

2 hours ago, badhex said:

True, although the place we're staying is an island chiefly composed of volcano and only 1000 people, so I'm assuming it should be reasonably dark. 

It should be…unless the volcano erupts 

🤣

[JeremyS]

For really dark skies I like nothing better than binoculars. And if the Milky Way is on view, some of those vixen ultra wide field opera glasses

Vixen SG 2.1 x 42

[Victor Boesen]

2 hours ago, badhex said:

Assume its astronomik-al in price though!

I too was looking for a "budget Astronomic/Lumicom filter" some time ago and ended up with the Castell OIII filter, which I've used a lot for observing the veil, dumbbell, orion neb and etc. Looking at the following transmission spectrum from other filters the castell looks very identical to the Astronomik which was one of the reason I went for it.

Unfortunately the Lumicon OIII isn't a part of this comparison.

As for your original question, I think you'll be very happy with low magnification Milky Way sweeping with your WO73 refractor under such dark skies. It's only in these cases you benefit from large exit pupils which would otherwise result in washed-out views in areas with more light pollution. Perhaps bring some medium power eyepieces as well for planetary nebulas and star clusters. Wouldn't see the need for high power eyepieces since you'd be stupid to be splitting doubles all night under such conditions😅

Have a nice holiday! It sounds like a great trip, and I'd love to hear some reports from there, weather permitting

Victor

[jetstream]

2 hours ago, Highburymark said:

The advantages of an ED scope

My SW120ED has excellent transmission and contrast on DSO. The list is long for targets in truly dark skies. The H130 is my perfect companion for ultra quick views and holds mag really well, up to 270x on the moon. SW ED scopes really perform on DSO IMHO.

Under truly dark transparent skies its shocking what most any scope can do. I wish I had the Tasco refractor I had as a kid to try now with more knowledge.

3 hours ago, badhex said:

I realised how dark the skies will be. 

I'm excited to hear your reports!

[badhex]

11 hours ago, Highburymark said:

I couldn’t pass up an opportunity like that. I’d take the WO, and the minimum number of good quality EPs and filters to make the absolute most of the skies. You could also insure it against loss or damage for peace of mind.

The advantages of an ED scope over an achromat will make a big difference under dark skies in my view. The first year I took my old Equinox 80ED on holiday to Spain I must have seen 40-odd Messiers. Amazing what small ED scopes can do in the right location.

Thanks. As it goes, I'm pretty much insured up to the hilt so I guess it's not my main concern. I guess if I don't take the WO, I might be always kicking myself afterwards. It's just a fair bit less convenient, and at maximum I might only get 3 or so nights under the very dark skies. 

[RobertI]

Take the ZS73 and a good pair of binoculars - you’ll be in astronomy heaven! Last year I scanned the Milky Way with my 10x50s, holding an OIII filter up to one eyecup and a UHC filter to the other - it was like having X-ray vision, the emission nebulae just popped into view! 

[badhex]

10 hours ago, JeremyS said:

For really dark skies I like nothing better than binoculars. And if the Milky Way is on view, some of those vixen ultra wide field opera glasses

Vixen SG 2.1 x 42

Thanks Jeremy. If I did take the travelscope I would probably take my bins as well, but I've never really enjoyed bins for astro as much as a scope. 

[badhex]

10 hours ago, Victor Boesen said:

I too was looking for a "budget Astronomic/Lumicom filter" some time ago and ended up with the Castell OIII filter, which I've used a lot for observing the veil, dumbbell, orion neb and etc. Looking at the following transmission spectrum from other filters the castell looks very identical to the Astronomik which was one of the reason I went for it.

Unfortunately the Lumicon OIII isn't a part of this comparison.

As for your original question, I think you'll be very happy with low magnification Milky Way sweeping with your WO73 refractor under such dark skies. It's only in these cases you benefit from large exit pupils which would otherwise result in washed-out views in areas with more light pollution. Perhaps bring some medium power eyepieces as well for planetary nebulas and star clusters. Wouldn't see the need for high power eyepieces since you'd be stupid to be splitting doubles all night under such conditions😅

Have a nice holiday! It sounds like a great trip, and I'd love to hear some reports from there, weather permitting

Victor

Thanks Victor! I saw your posts about this filter, so I will have another look and see what works for availability etc. The contrast/large exit pupil issue is definitely one reason for wanting to take the ZS73 - I find under less dark skies the 35mm Aero ED has great views  but can suffer a bit from a lack of contrast, so I'd love to see it under very dark skies! 

[badhex]

12 hours ago, jetstream said:

My SW120ED has excellent transmission and contrast on DSO. The list is long for targets in truly dark skies. The H130 is my perfect companion for ultra quick views and holds mag really well, up to 270x on the moon. SW ED scopes really perform on DSO IMHO.

Under truly dark transparent skies its shocking what most any scope can do. I wish I had the Tasco refractor I had as a kid to try now with more knowledge.

I'm excited to hear your reports!

I do enjoy my 80ED but the mount I had at the time was not sturdy enough and it wasn't portable enough to take to darker sites easily - which is what really drove me to go for a more portable setup. I guess I pretty much bought this setup for trips like this!

[badhex]

3 hours ago, RobertI said:

Take the ZS73 and a good pair of binoculars - you’ll be in astronomy heaven! Last year I scanned the Milky Way with my 10x50s, holding an OIII filter up to one eyecup and a UHC filter to the other - it was like having X-ray vision, the emission nebulae just popped into view! 

This is a great approach - maybe a custom filter holder for binos!

[jetstream]

3 hours ago, badhex said:

I guess I pretty much bought this setup for trips like this!

I can tell you for a certainty that the scope youre bringing will give mind blowing views, if the conditions co operate. You will see Barnards Loop easily, with and without an Hb, go for the shade edge next to M78. Keeping in mind that dark adaptation is a must as is zero alcohol

[ScouseSpaceCadet]

On 03/08/2021 at 17:57, badhex said:

Hello all,

I'm going on two separate mediterranean island holidays later this year, and I knew that for the first of these it would be in Bortle 4/5 skies. We're mostly staying in one place we have rented before and I know the situation well etc., so planning to take my portable setup of ZS73 and 4-5 EPs.

For the second trip, we planned to be island-hopping a bit on some smaller islands with a few more days on the final island (also Bortle 4), and had decided that it wouldn't be ideal taking this same setup. Although it's compact, it's quite a lot heavier and by the time you add it all up it's a lot of expensive glass to be lugging about from place to place. I planned to just take a couple of inexpensive EPs, a Celestron Travelscope 70 and a carbon fibre tripod - chuck everything in my main case and not be worried about breakage, weight, (theft even maybe?).

BUT

I just discovered that two of the places we're going on the second trip (total of 5-6 nights) will be Bortle 2! 

Now I'm worried that only taking lower quality gear means I won't be getting the best of a rare opportunity to observe under really dark skies, but taking the expensive and heavier gear is less convenient and there is at least one afternoon I'll have to leave it with a hotel and not in a room.

What do I do?

Use the cheap gear. My first bortle 2 experience was with binoculars. I was so blown away, the Skymax 102 stayed in the tent...

 

Edited August 5, 2021 by ScouseSpaceCadet