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High end Barlow lens to use with Hyperion 13mm 17mm 21mm?


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Hi all. Hi Dave, Doug, Mike, Sarah, Jason, John, Pete, Peter Dana, and everyone else out there.



A sincere thank you to a very warm welcome and your collective generosity of all yours offer of help to an old codger like myself through SGL. I am going to take up some of your kind suggestions on my new journey.



I can now operate the scope indoors ok, all seems fairly simple. I chose this scope (Schmitt-Cassegrain?) specifically because I had a nasty back injury and cannot stand for more than a few minutes, hence the eyepiece at the bottom of the scope. Just for the record I have three Hyperions a 13mm, a 17mm and a 21mm. Also have two star diagonals a T-ring (I need an adapter too apparently) a selection of 12 filters, a power supply, which I won't need outside due to the scopes ability to run for 10 hours fully charged and the 'thingy' I spoke of is a 'Starsense Autoalign'. Also have a large due filter, and I can lift the scope when it is off the mount and will move them separately outside.



I have to admit I did dive in at the deep end with a bigish scope as my first, but I am pushing on a bit and I doubt I'll be breaking any longevity records. Whilst the cloudy skies are here I'm trying to read as much as I can and yes, there is a hell of a lot more to learn than I ever thought, but that won't stop me, I'll plough on.



I know it's early days for me, but I was thinking about getting a good quality high end Barlow lens, maybe a three or four element one and with my existing EP's 13mm, 17mm & 21mm and maybe a 3X Barlow, any suggestions guys? This combo would give me a 4.33mm, a 7mm, and an 8.3mm. If I've done my maths right that is.  Budget would be £150.



Thanks again all so much for your help and I do hope I can get up and running properly as soon as I can.



Kindest regards



Simon.



Celestron NextStar Evolution 9.25 with Starsense Autoalign and three Hyperions, 13mm 17mm, 21mm.


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Your scope has a long focal length, about 2300mm I think. So your EPs give a higher magnification. Your 13mm EP gives about x175.

You have three excellent EPs which give a good range of magnifications. In my opinion, what you lack is less magnification for some types of observing, and a little more for lunar and planetary observation.

I personally wouldn't get a Barlow, but instead opt for adding two more good EPs, one in the 8 to 10mm range, and the other maybe 30-32mm.

The maximum magnification of your telescope will always be limited by atmospheric conditions, and most of the time you will effectively be limited to x250 or often less. An EP barlowed to 4.5ish in your scope would give a magnification of over x500, which would be a very difficult challenge even in the best seeing conditions!

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I would agree with the above. I have the 9.25 SCT on an AVX mount, so the same tube.

A 3x barlow would certainly be overdoing it under UK or even many other skies.

At the most I would suggest a 2x.

If you have not got one then invest in a heater and dewshield, ot maube a combination of the two. SCT's are great scopes but that big bit of glass at the front end is a dew magnet.

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As said above, a barlow lens for a scope that already has a "native" focal length of 2.3 metres is really not going to be much use for visual observing.

Get fixed focal length 10mm and 8mm eyepieces then that covers the useable high power range.

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Wow!   Thanks guys. I am really glad I asked the question, you saved me from wasting money already.  Instead of the Barlow, How about the Baader Hyperion Aspherical Eyepiece 31mm? This should give me a slightly wider field of view shouldn't it?

Celestron NextStar Evolution 9.25 with Starsense Autoalign and three Hyperions, 13mm 17mm, 21mm.

Great band John, Great band!

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Wow!   Thanks guys. I am really glad I asked the question, you saved me from wasting money already.  Instead of the Barlow, How about the Baader Hyperion Aspherical Eyepiece 31mm? This should give me a slightly wider field of view shouldn't it?

Celestron NextStar Evolution 9.25 with Starsense Autoalign and three Hyperions, 13mm 17mm, 21mm.

Great band John, Great band!

Yes it will, as long as it's used in 2" mode. With the 1.25" barrel attached the field of view is reduced about 20%. There is a 36mm Aspheric as well which will show a bit more sky again.

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Thanks John.  Would it be possible to use it in 2" mode on my setup do you know?

Regards

Simon.

Celestron NextStar Evolution 9.25 with Starsense Autoalign and three Hyperions, 13mm 17mm, 21mm.

“From out there on the Moon, international politics look so petty.

You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch.’”

Edgar Mitchel, Apollo 14 astronaut, speaking in People magazine on 8 April 1974.

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Thanks John.  Would it be possible to use it in 2" mode on my setup do you know?

Regards

Simon.

Celestron NextStar Evolution 9.25 with Starsense Autoalign and three Hyperions, 13mm 17mm, 21mm.

“From out there on the Moon, international politics look so petty.

You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch.’”

Edgar Mitchel, Apollo 14 astronaut, speaking in People magazine on 8 April 1974.

I you have a 2" diagonal you are good to go. If you still use the 1.25" type you would need to upgrade it to a 2" one. You can still use 1.25" eyepieces with a 2" diagonal because most come with a 1.25" adapter.

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I added a 2" visual back and diagonal to my C8, and that has been a great investment. I can get 1.34° of sky in one FOV using the Vixen LVW 42mm, but more often use the Nagler 31T5 "Panzerfaust" for wider field at 1.25°. This is much better than using a focal reducer (which is OK optically, but a bit fiddly to insert into the optical path.

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