Dark Site Tips

[Zane]

Perusing this site, amazing the thoughtful help the community offering!

I recently bought a vacation home in a dark site area in the eastern Oregon desert and seeing the unbelievable naked eye star viewing decided I had to get a telescope and jump into this hobby. I have a Nexstar 8SE and a Baader 8mm-24mm Zoom eyepiece on the way to get started. Even though portability not the biggest concern, opted for the GOTO SCT for ease of use, expecting to be fairly incompetent to begin with.

I have a general and a specific question. As I'm expecting really outstanding seeing conditions much of the time, what should I do to take good advantage of that? Specifically had thought about a 3, 4 or 5mm eyepiece for planetary viewing thinking I could expect good results with high magnification. Is that going to be hard for a newbie? If not, how aggressive an eyepiece should I consider?

All input appreciated!

 

[happy-kat]

Welcome :-)

What eyepieces come with the kit?

[rockystar]

I think your scope has a focal length of 1500mm? So a 5mm will give you x300 - in the UK, that would be too much and wouldn't get much use. I think this would be a good match for your scope and skies. 3mm will give you x500, which will be too much for any sky.

[laudropb]

Hello and a warm welcome to the SGL.

Even given your excellent seeing 1 think the 3 and 4 mm eyepieces will be a bit too aggressive . Normally the maximum usable magnification is given as 2x the aperture of the scope. In your case that gives a value of 406. To find the magnification of a given eyepiece in your scope divide the focal length of the scope by focal length of the eye piece. For example for your scope this is 2032/4 = 508 for a 4mm eyepiece. Also do not get too hung up about magnification. Quite often 200 to 250 X is more than enough to give good detail on the planets, especially Jupiter. The Moon will take higher magnification quite well, but it is always dependent on the seeing conditions.

[jetstream]

Seeing is a measure of sky "steadiness" so to speak ( great for lunar/planetary) and dark transparent skies are good for faint objects- good seeing and good transparency don't always go hand in hand. You obviously have dark, transparent skies so I would also recommend a low power widefield eyepiece with an exit pupil of 4mm at least and a UHC or OIII filter. With these you will be able to see nebulae very well.....

The SCT members can advise you on which low power eyepiece will work well in your scope.

[Putaendo Patrick]

Baader make a x2.25 Barlow specifically for use with their zoom, allowing it to work in the 3.5mm to 10.5mm range. This would allow you to test out different magnifications and see which work best in your location. Further down the line, you could consider getting fixed EPs for the magnifications you use most.

http://agenaastro.com/baader-2-25x-hyperion-zoom-barlow.html

[Charic]

Start with low power eyepieces ( larger number ) and then work your way up to the higher magnifications ( low number on the eyepiece ) to vary your magnifications,  your zoom should give you some approximation as to what is achievable, and the type and style of the eyepieces  themselves, can be suitably selected to offer better fields of view and varying degrees of eye-relief, all dependent on the users requirement?

Your initial description of the sky sounds good, so don't dismiss wide angle binoculars either! two eyes are better than one, and binocular views are  stunning, providing much more than your eyes alone can see. They won't offer the detail that your scope will provide on the likes of say Jupiter, but wide field  views of the larger constellations, and  the ability to follow  and see more satellites than your naked eyes can see,  is just an amazing sight. Welcome to the SGL.

[glowjet]

Hi Zane and welcome to SGL.

Even though you have a location with really dark skies, you will find the visual clarity of the atmosphere will vary throughout the year, in other words the seeing may not be constant every night. 

From the previous foregoing threads, you should now have some idea of the useful magnifications your scope can handle, by all means have an eyepiece in your kit that will extend the magnification a little beyond the scopes capabilities, especially where the Moon is concerned and for those special nights of exceptional clarity, but it is best to stick with eye pieces that give you a magnification offering the best resolution and clarity your scope can provide. More often than not, you could find this may not exceed 250x, which in itself should provide you with some excellent observations of subjects in our local system. Enjoy the forum and your new telescope  

[Zane]

Thanks everyone for the quick replies. True instant gratification. Looking at my focal length of 2032mm, sounds like I may not need to add anything for awhile and starting with the Barlow to go with the Baader zoom maybe a good option to start exploring with higher magnifications. The scope comes with a 25mm eyepiece. All too easy to get excited about the kit at the expense of the activity itself.

Appreciate the comment on high quality binoculars, as there's also a lot of wildlife in the area for daytime viewing and my 2 kids may not be patient enough for the telescope.

I'm sure those nights of exceptional clarity will correlate to temperatures at -10C, so goose down may be the most important accessory of all.

 

 

[faulksy]

3 hours ago, rockystar said:

I think your scope has a focal length of 1500mm? So a 5mm will give you x300 - in the UK, that would be too much and wouldn't get much use. I think this would be a good match for your scope and skies. 3mm will give you x500, which will be too much for any sky.

dont agree sorry, i have used 500x here on planets, a few years ago seeing was ace for weeks saturn and mars loved it. i have used it recently as well

[rockystar]

Just now, faulksy said:

dont agree sorry, i have used 500x here on planets, a few years ago seeing was ace for weeks saturn and mars loved it. i have used it recently as well

fair enough, guess I've just not been lucky enough for skies that good.

[ngwillym]

I'd consider a 32mm or 40mm for wider views

[jetstream]

5 hours ago, faulksy said:

dont agree sorry, i have used 500x here on planets, a few years ago seeing was ace for weeks saturn and mars loved it. i have used it recently as well

I've cracked 475x razor sharp on the moon in my 15" which was jaw dropping, 400x on Mars in the 10"... Best to be prepared for excellent seeing, fleeting as it can be... you don't want to miss these chances.

[Aaron F Johnson]

Times of great seeing happen more often and for more extended periods in non light polluted sky's as I have spent years observing in both...I currently live on a peninsula with a 10,000 acre lake on one side and equal acreage of state forest on the other 6 miles out from the closest city providing for some pretty spectacular nights but average is still below 250x and usually less than 200x. Although I have used and keep handy magnifications I won't even mention here because I hardly believe them possible myself...that being said load for bear, expect squirrel...

[cloudsweeper]

Depending on conditions, the max you might get from the 8SE would be about x400 (aperture related), so a 5mm EP would do that.  But as others have said, you don't often go that high, and usually operate below x200, except perhaps for the Moon.  

Low mag/wider angle viewing is very rewarding, and I make much use of 42 and 30mm EPs, which give x48 and x68 in my 8SE.  My full range is 12 EPs from 50mm to 5mm.

Doug.

PS: At a dark site, larger, dimmer DSOs would show well, so you might have to think about a complementray 'scope with a shorter focal length to fit the targets into view!

[Aaron F Johnson]

Clouldsweeper is right on the second scope...I use an f/3.9 newt  for dso newts or dobs work well, short f/ratios resolve low mags better for observing dso's in my opinion as well. Newts and dobs are visually brighter and are great for gathering light wich you will need plenty even in dark sky's. O-lll filter for diffuse nebula and an ultra high contrast filter for other dso will help. I do use a higher f/ratio scope for dso on occasion but results are less pleasing.