Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Eyepieces - the very least you need.


Recommended Posts

The field stop diameter of an eyepiece will increase as it's focal length increases so a 25mm Kellner (or similar 3 element design) will have a larger diameter field stop than, say, a 15mm Plossl. The Plossl will still have a larger apparent field of view through.

The 25mm Kellner type eyepieces supplied as stock items are often labelled "Super Wide Angle" or similar because their field stop is a little wider than the a normal Kellner would be. So you see a little larger apparent field of view even though it's not going to be that well corrected, especially in a faster focal ratio scope.

These are low cost eyepieces though (you can get them for £5 used) so thay don't do too badly considering that and they do get you started :smiley:

I think Celestron sometimes refer to that AstroMaster Kit 'Kellner' as wide angle, so that slightly extra field stop size was probably what I was noticing. It got me started alright; I started to buy wide angle TeleVue eyepieces lol!

Next, an Ethos I think.  :grin:

  • Like 1
Link to comment
Share on other sites

  • 2 months later...

I have recently acquired a Celestron 130mm Newtonian Reflector. Astromaster 130EQ. I also have a DSLR Olympus E-500. I live a the suburbs and light pollution is visible but not a problem. Is it possible to fix a LP filter, Barlow and digital camera. I know how to fit barlow and camera but have not idea where the filter would go.

Link to comment
Share on other sites

I have recently acquired a Celestron 130mm Newtonian Reflector. Astromaster 130EQ. I also have a DSLR Olympus E-500. I live a the suburbs and light pollution is visible but not a problem. Is it possible to fix a LP filter, Barlow and digital camera. I know how to fit barlow and camera but have not idea where the filter would go.

It should be able to thread into something in the light train. 

Link to comment
Share on other sites

  • 2 weeks later...

I do very little observing at the eyepiece because I'm lazy & can't contort into the required positions to position my eye. However for what little visual observing I do I use mostly either a Televue Nagler or a Baader Hyperion Mk III zoom eyepiece with a barlow integrated if required. I'm no expert on eyepieces but the MKIII smashes the critics negative opinions about zoom eyepieces- it seems very good. 

  • Like 2
Link to comment
Share on other sites

  • 1 month later...

Great post...You hit the nail on the head. For my 114mm f/5 I use a 8 to 24 zoom and the 25mm ep I got with the scope. For a barlow I purchased a 3x Meade, but on good seeing nights I thought a little more magnification was possible and purchased a Celestron 2x but that turned out to be too much for the scope. So I flush sanded a filter case removing the male threads and glued it to the end of the 3x barlow and screwed in the lense module from the 2x barlow. So the 2x barlow is maybe a 1.5 and the field is flat and true. This also helped as the second barlow is now in side the focuser but nowhere close to the secondary. Cool because of this arrangment I am getting my money's worth out of this scope but getting there wasent easy. I should have read a little more on the subject before diving in, I would have gotten to the same place but much quicker...

Link to comment
Share on other sites

  • 3 weeks later...
On 5/29/2009 at 03:45, Doc said:

Under our skies yes but I've read so many times on Cloudy nights that they in the USA can get x600 + from their dobs. Their seeing is far superior to ours but you still need to track, unless they have tracking mounts as well.

 

Link to comment
Share on other sites

How are the Skies in the US any better than in the UK? Not feeling the advantage. Been raining for a week! Arizona is nice though with clear dry skies alot.

600x, wow. That'd be something. I'm hoping one day to get nice views of Saturn and Mars at 317x. That'd be about my limit in an f/7.5 120mm apo.

Link to comment
Share on other sites

1 hour ago, View2 said:

How are the Skies in the US any better than in the UK? Not feeling the advantage. Been raining for a week! Arizona is nice though with clear dry skies alot.

600x, wow. That'd be something. I'm hoping one day to get nice views of Saturn and Mars at 317x. That'd be about my limit in an f/7.5 120mm apo.

It obviously depends where you are in the US, but there are many places known to be better than in the UK, specifically those at high altitude and/or with dry stable air. We don't get much of that around here being on the the receiving end of what comes across the Atlantic!

Link to comment
Share on other sites

On 5/29/2009 at 03:45, Doc said:

Under our skies yes but I've read so many times on Cloudy nights that they in the USA can get x600 + from their dobs. Their seeing is far superior to ours but you still need to track, unless they have tracking mounts as well.

 

Link to comment
Share on other sites

I see, yes I live 80 miles from the Pacific ocean and get the first of any incoming moisture as well. I live in what is called the Pacific Northwest. My favorite spot is at about 4,000ft and a 40 minute drive. But it's dark!

 

Link to comment
Share on other sites

3 minutes ago, View2 said:

I see, yes I live 80 miles from the Pacific ocean and get the first of any incoming moisture as well. I live in what is called the Pacific Northwest. My favorite spot is at about 4,000ft and a 40 minute drive. But it's dark!

 

There's a case in point, I think I'm right in saying that it's not physically possible to be more than 75 miles from the sea in the UK, in the US I guess many hundreds if not a thousand or so is possible.

4000 feet, dark and a 40 minute drive away. Hmm, in England the highest 'mountain' is 3200 feet! In the UK it is 4406 feet and you have to climb up them, so not really practical to carry a scope up!!

So, even though perhaps not as good as some places in the US, I suspect your conditions are still significantly better than anywhere hear. Enjoy them!! ??

Link to comment
Share on other sites

I shall relish the thought of my good fortune then, and stop complaining about the rain. I once drug my 8" down to AZ on the plane, now that was amazing...clear dry skies. Caught a glimpse of OmegaC at near twilight, big! In the deep night there was Cotton overhead like I've never seen since. Took a trip to kit peak too, but not with my scope. Freaking cold up there. I've missed this hobby.

  • Like 1
Link to comment
Share on other sites

12 hours ago, Stu said:

There's a case in point, I think I'm right in saying that it's not physically possible to be more than 75 miles from the sea in the UK, in the US I guess many hundreds if not a thousand or so is possible.

 

So the UK is only 150 miles across if you are bang in the centre? lol

I believe the UK has around 5000 km of coastline, which is the same distance approximately from the US Eastern Seaboard to the Pacific Coast.

Link to comment
Share on other sites

Well, I'm only taking three eyepieces out tonight. A 10mm Celestron Luminos, a 14mm Baader Morpheus and an 18mm AH ortho'. Plus a couple of Barlows. And a telescope. Well, maybe a 20mm Celestron erecting eyepiece for initial target acquisition, although I've just sorted my RACI out, so I'll see.

Link to comment
Share on other sites

14 minutes ago, Mak the Night said:

So the UK is only 150 miles across if you are bang in the centre? lol

I believe the UK has around 5000 km of coastline, which is the same distance approximately from the US Eastern Seaboard to the Pacific Coast.

Sounds like a tropical paradise! 

Link to comment
Share on other sites

27 minutes ago, Mak the Night said:

So the UK is only 150 miles across if you are bang in the centre? lol

I believe the UK has around 5000 km of coastline, which is the same distance approximately from the US Eastern Seaboard to the Pacific Coast.

The UK is about 260 miles across if you measure through the geographical centre which is somewhere in Leicestershire. Nowhere in the UK is more than about 75 miles from the sea.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.