Hi All,

I recently started to reuse my Criterion 6 inch Newtonian which I purchased 30 years ago while in college. It's focal length is 48 inches so it is an f8.  The motor does not track well probably because I never aligned the scope correct.  I am looking for an eyepiece which will give me a wide field of view so I can properly learn the sky before I invest in a go to scope.

Suggestions for a good  EP near the lowest mag. threshold?

Orion has the Stratus line of eyepieces that give a wide FOV.  There are others, some cheaper, some pricey.

Good luck

I'm assuming the scope has a 1.25" focuser. A nice clean clear as wide a FOV as you can get is in the 30-35mm eyepiece range. Any longer a focal length won't gain you any wider field. Just get a simple design like the Orion Ultrascopic or the Celestron Ultima and you will be more than happy. They are truely sharp eyepieces.

 There is also the 32mm Televue ploessl. It won't break the bank and these are also extremely sharp eyepieces. I recently bought a couple of 15mm Tv ploessls to put in a cheap binoview for public outreach. From how good they are I'll be using them for more than that.

 Bill

Yes, it has a 1.25" focuser.

Bill,

Thanks for the advice.  I just placed an order with Orion for the 35mm Ultra and a new finder.  When the saleswoman heard the scope was 30 years old she had me speak to a tech guy first.  He agreed with your advice and the limit on the power.  They run a first rate order op.  No rushing and the technician was willing to help. 

Chris 

Hi All,

I received the 35mm Ultrascopic from Orion.  It's a beautiful EP but I am having a big problem.  To get a view I need to be about an inch away and I keep losing the image.  I have done some reading and I think this is due to too much eye relief.  Am I correct that this is what is happening?  Is the cure to get an EP with a shorter eye relief?  I don't wear glasses and am used to getting right up to the EP with my old Criterion EPs.  I notice some ads give the eye relief but the ultra does not.  Is there a way to figure it out or must I depend on the manufacturer.

I will call Orion later today and see what they say.  I really can't use this EP. 

RedSox04:

Hi All,

I received the 35mm Ultrascopic from Orion.  It's a beautiful EP but I am having a big problem.  To get a view I need to be about an inch away and I keep losing the image.  I have done some reading and I think this is due to too much eye relief.  Am I correct that this is what is happening?  Is the cure to get an EP with a shorter eye relief?  I don't wear glasses and am used to getting right up to the EP with my old Criterion EPs.  I notice some ads give the eye relief but the ultra does not.  Is there a way to figure it out or must I depend on the manufacturer.

I will call Orion later today and see what they say.  I really can't use this EP. 

 

 

If you're looking for a low magnification wide field of view eyepiece the Ultrascopic is not the answers. They are not a wide FOV eyepiece only having a 52° AFOV. intended more for planetary viewing.
If you want an affordable wide field eyepiece you want more than 52° AFOV
The Orion Stratus = 68° AFOV

It's not just the issue of eye-relief by itself. There are many long eye-relief eyepieces that don't have that problem. The problem you describe is an inherent problem with some eyepieces that have a long eye-relief and a narrow AFOV. Some people affectionately call it jelly beaning or black out.  Other than Ultrascopics the Orion Epic ED 2 are known for this problem also.

The Stratus comes in focal lengths of 24mm, 21mm, 17mm, 13mm, 8mm, 5mm, 3.5mm. All of them, even the shortest focal lengths have the same size Eye-Lens which is a large 1.25"  diameter.  If you're telescope only has a 1.25" focuser rather than a 2" focuser with a 1.25" adapter, the eyepieces are made to fit both so that won't be a problem.

For low magnification wide field views the 24mm should be plenty if your focuser can only accept 1.25" eyepiece and not 2" also.   You might think because it is only a 24mm it won't give you that low magnification you're looking for, but with the 68° AFOV you will have a much greater TFOV in your eyepiece allowing you to see much more of the sky than an eyepiece of equivalent or even a little longer focal length in a Plössl or Orthoscopic.

If you want any longer focal length than that for lower magnification you're going to have to go with a 2" eyepiece. Then you might consider the Q70s that Orion Has.   Unfortunately if your focuser is only 1.25" you're limited to your choices when it comes to long focal length eyepieces.

If you're looking at the Orion eyepieces because of availability, affordability and reputation, For very competitive pricing and reputation I suggest you also look at the Baader Hyperions which are very similar to the Orion Stratus. And also take a look at The William Optics Swan Series eyepieces which have a 72° AFOV.

Now About that black out problem
Some people when going from a plössl where you need to have your eye right at the eyepiece do the same on new eyepiece that have a long eye-relief.  With a little practice you learn to back off and keep your eye centered over the eyepiece.   Allow the cone to enter your eye where it should.    You will find that you want an eye-patch over the non-viewing eye so that you may relax your eyes to reduce any strain. This helps with seeing detail in many objects. You will also want to block any stray light from getting between your eye and the eyepiece. Sometimes just cupping your hand around your eye and eyepiece helps, but a nice black hood works very well instead.  
With a little time and practice you can overcome much of the black out problem.  Try backing off the eyepiece taking advantage of the longer eye-relief. 

Have A Nice ___________

 The 31mm baader Hyperion in this add can be used as either a 1.25" or 2" as it has adapters for both.

With your scope this will give you about 39X power, and a 1.83 degree FOV, with a 3.81mm exit pupil. This is about the maximum performance you can get in a low power 1/25" EP in your focal length telescope. Take a look!

Hyperion

JJ 

Tim,

Thanks for all the info and explanation of blackout.  It is new to me.

JJ,

Thanks for the suggestion.

Since I'm returning the Unltrascopic to Orion I bought the 24mm Status for an even swap.  The Orion tech guy told me the eye relief on the Ultrascopic was 24mm which is about what I guessed (1 inch).  The 24mm Stratus will cut the relief down to 15 mm which should be fine.  Tim, he agreed with your figures.

Thanks a bunch guys,

Chris

Longmeadow, MA. 

Interesting comment on blackout.  So far, I only have that problem when using my 25mm Sirius Plossl with a 2x Ultima barlow.  It does not do this with the 25mm alone, or with the 10mm plus barlow.  Weird...it does indeed get annoying, though.