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I have recently purchased a 25mm BST eyepiece as I thought that it would be a lot better than the 25mm MA eyepiece that came with the scope. Although it was an improvement, it wasn't as much as I expected.

I was wondering if a 32mm or even 40mm would be better as although I could see hundreds of stars last night, I couldn't work out if they were Messiers and if so which ones. Still trying to get to grips with locating a bright star and hopping to a messier

Jupiter and Saturn looked great through my 7mm X-cel and going to a 5 or 6mm lost detail.

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For the field viewed the 25mm BST will be very similar toi the 32mm or 40mm plossl.

The magnification on a 32mm plossl is less so the objects would be smaller and so potentially brighter.

The alternative is to look at the 2" eyepiece ranges which may be a reasonable option.

So you may gain something however perhaps not what you expect.

You will likely have to get a good plossl, Vixens are one option, TV being the other and on a 10" which I see if f/4.7 I would go for the TV's. You may be in the situation of a big scope that by design has to be fast and so you need good eyepieces, Additionally I guess you may also need a coma corrector for visual also, that mirror will be producing coma on what you see.

Edited by ronin

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Not to sound flippant, but even the great eyepieces won't tell you what is what upstairs...as I found out when I started, you have to learn the skies and practice, practice, practice (or is it practise? I always get confused!) :) Do you use a star atlas or software like Stellarium, Sky Safari etc?

The BST range has a good rep. Me, I'd also go for a 32 (40 if you have a 2" focuser I guess) but star and DSO recognition and hopping, that's a nightly classroom on its own :)

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Hi

The improvements in image from a upgrade will not be staggering. You will notice it more on some targets than others. I would steer clear of the 40mm and probably the 32mm as the exit pupil will be too big to get all of the light captured into your fully dilated pupil. This leads to a washed out view that lacks contrast. The formula is Eypiece mm / Scope's Focal Ratio. Anything above an exit pupil of 6mm is beginning to puch it a bit. My 30mm is about the most that I can manage in my f4.7 10" scope.

Try M57 The Ring Nebula in Lyra next. Nice and bright with a couple of good guide stars.

I use Sky Safari Pro on an iPad to find my way around.

Paul

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As stated above, star hopping takes lots of practice. Like you I struggled for a while, but I found the use of a Rigel and a RACI Finder in combination made things much simpler.

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You also need to spend time at the eyepiece, as you observe the eye dark adapts and you begin to see some extra detail. .

  • Like 1

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I agree with everything already said about star hopping needing to be learned by doing it over and over and over and obviously learning a few constellations along the way. Most DSO's will not jump out at you when you are observing. They are just not big enough or bright enough. It takes time to learn to hunt them down manually. At best..........you are just going to notice a hint of grey wispy smudginess in your field of view. You really have to move the scope slowly or else you might go right past your target.

My personal choice of EP for hunting down DSO's is the Vixen 30mm NPL because this range in my opinion gives fantastic contrast and sharpness. They really do show a difference between the faint grey colours of DSO and the blackness of the sky surrounding them. The NPL are comparable with BST's according to people who have used both. The BST's may be a better choice because they offer better eye relief. 

When you have learned how to star hop and hunt down DSO's then you have to learn the art of averted vision. This is when you see something without actually looking at it. Its very useful for observing galaxies and even comets. You are basically looking/seeing objects in/with your peripheral vision. Objects (some) are brighter and more defined when using this method of observing.

Edited by LukeSkywatcher

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Thanks to everyone for their advice. I found the beehive cluster very easily, but some of the others mentioned on here as easy to find have eluded me. I am beginning to learn the constellations and am finding it easier navigating around the sky and am probably expecting the Messiers to just be obvious to find.

I tend to use iPad apps to find my way around, but they are not always that accurate and tend to keep showing me the wrong view. My laptop is to old to handle stellarium (OpenGL issues) and I will try sky safari

My next purchase will be a telrad Finder so that should help.

My scope can take 2" eyepieces, so that is another option..

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I personally cannot get used using the standard FS. Everything being the opposite to what you think it should be. However I have never looked back since I got my Telrad to hunt down dso's. I think it's my most useful bit of kit along with my Vixen 30mm EP. May fave app is star chart long with stellaruim.

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Going to buck the trend a bit here and say that for most deep sky objects you really don't want that low a power TBH.

When one starts to drift towards 30mm eyepieces in a 10" f/4.5 ish Dob you are actually going into the realms where objects become too small. 

Smaller objects actually become harder to locate because of their now tiny size. I find a 20mm is ample for low power observing in this type of scope.

You will also find that a 20mm won't 'wash objects out' so easily and will provide better contrast and image scale at which to observe.

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For tracking down those faint fuzzies I wouldn't be looking at a phone or computer screen, you need your eyes to be as dark adapted as possible. Far preferable is a dim red torch and a star atlas, try Sky & Telescope Pocket Sky Atlas.

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+1 for the Telrad. Add a RAC Finder scope (Right Angle to save the back, Corrected to save the brain) and you have all of the bases covered. I am just using a Telrad and my 30mm 82° eypiece to get me where I need to be. Got to get around to sticking the finder back on as well...

Use the iPad apps as interactive zoomable maps. Most have a dim red night mode which helps with preserving night vision.

Stellarium works fine on the iPad. But, spend £15 on Sky Safari Pro. Miles better!

Swamp thing is right. 20mm to 25mm is the sweet spot for max contrast / finding DSO in your scope.

Paul

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Buying eyepieces in hopes of finding DSO is fruitless.  You simply need experience.

However, I'm gonna make your next outing fun...

Point that nice Dob to the right shoulder region of Virgo (hers, not your right) and start driving around.  There are so many galaxies in that particular area that you'll trip over 'em... as many as three at once in the eyepiece.

post-38191-0-93593500-1432384522.jpg

  • Like 4

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Thanks Lowjiber, I will have a look at that area tonight (weather permittng)

I had clear skies last night and was determined to locate a couple of the easy Messiers mentioned on here, but still struggled.

I was looking for M13 In Hercules and found a starting point, but think that my problem is that, I locate a bright star, then start to hop to the messier, but end up seeing a cluster of stars, but am unsure if it's the actual messier. I'm not expecting to see the nice colourful images that people post on here, but what I see doesn't always look the same as pictures online, so I start thinking that it's just a random cluster of stars and not a messier.

For example, last night when I was looking for M13, I drove around a bit until I located a tight cluster of stars in the region where it should be and hundreds of stars around it and my 25mm eyepiece was full of stars, but it didn't look like I expected. Maybe I am expecting the whole cluster to fill the eyepiece, but should concentrate on the tight cluster and magnify that more?

I also had the same experience when looking around Lyra (M56), so maybe I am seeing them, but not what I expect?

M44 (beehive) was easy to find and looks exactly like the pictures

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I haven't read all the replies but finding Messiers is a bit tricky unless you invest in some extra kit, get a Telrad, and download the free Telrad maps, then install Stellarium and turn on the Telrad circles, from here on check the maps with the PC Screen and when you outside things will start to come together, the other tricky bit is getting the experience some Messiers are just a faint grey whisp, a few of the brighter types M51 for instance are bright and easier to find, you can get Stellarium for a Andriod Mobile, having the maps and the mobile next to the scope will help a lot.....Good Luck

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Re M13 and M56

It sounds like you have found M13. In the 25mm it appears as a small circle made up of hundreds of tiny stars. In the center of the circle, the stars are too densely packed to resolve as individual stars. Find it with your 25mm, then get the detail with your 10mm!

Don't worry about M56 in Lyra. It is a fiddly one to spot. Go for M57 which will appear as an obvious little ring of smoke once you get it in view with your 25mm.

Paul

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Re M13 and M56

It sounds like you have found M13. In the 25mm it appears as a small circle made up of hundreds of tiny stars. In the center of the circle, the stars are too densely packed to resolve as individual stars. Find it with your 25mm, then get the detail with your 10mm!

Don't worry about M56 in Lyra. It is a fiddly one to spot. Go for M57 which will appear as an obvious little ring of smoke once you get it in view with your 25mm.

Paul

M13 can take a lot of magnification after you locate it with wide-angle eyepiece.  At around 125x, many more of the stars (there are about 300,000 of 'em in M13) resolve and the cluster does indeed fill the eyepiece.

Edited by Lowjiber

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Re. m13. Agreed. The 8mm Delos at x150 is probably my favourite view in my 10".

Paul

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Thanks. When I found what I thought what was M13 with my 25mm, I did then try a selection of EP's all the way down to a 7mm (Celestron x-cel) and could see the densely packed stars, so it does look like I have seen it. One more to tick off the list

I am planning on getting a telrad finder and have already printed of the maps. Unfortunately my laptop can't handle Stellarium (doesn't have OpenGL)

Is it only the android phone that you can also get it on?

My other planned purchases are a suitable astronomers chair and 90 degree finder scope. My back is beginning to ache with crouching down when trying to see objects very high up. Was trying M51 as well last night, but that appears to be directly above and can't get into a comfortable enough position to locate a starting point. Shame we can't move the sky around to suit our needs

Guess I also need to spend some of my cloudy nights in studying the night sky and get use to the constellations etc..

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