Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep29_banner.thumb.jpg.da7f3b163f7bd35187cb558b0346baf6.jpg

Recommended Posts

Posted (edited)

Hi, 

I'm just wanting some advice on the eye relief and the quality of the 6mm Omni ep. I have a Nextar 127slt MAK. Can someone please tell me if I should buy it?

Thank you,

Spacecake 

Edited by Spacecake2

Share this post


Link to post
Share on other sites

I would not. The eye relief will be small and it is too powerful for the telescope.  The quality will be OK, and anyway a Mak with its long focal ratio is not demanding of eyepieces. An 8mm eyepiece would be more suitable.

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

The 6mm Omni is about the limit of useable magnification on a 127 MAK. Max magnification is normally given as twice the objective diameter, so 2x127 = 254. A 6mm eyepiece will give a magnification of 1500/6 = 250 on your scope. Whether the seeing conditions will allow that may be more problematic. The eye relief on the 6mm Omni is 5mm, so no use if you wear spectacles, but probably OK if you don't, although a little tight. 

On the other hand, they are dirt cheap if bought from China, and the quality is excellent - they are aluminium bodies with fully multi-coated glass lenses. I have the 4mm, 32mm and 40mm Omnis and they are all good, although the 4mm is too much for the MAK.

https://www.aliexpress.com/item/32754506897.html?spm=2114.12010612.8148356.33.41e07ff7cjx4SK

Rats - that's another impulse buy added to my cart.

David

  • Thanks 1

Share this post


Link to post
Share on other sites

With my 127 Mak, a 6mm EP is indeed near to the limit, as MrFreeze says! Needed though for Saturn for example to really bring out the ring detail. You will only be able to use it when the seeing is excellent or better. I had an old Plossl 6mm but bought a (much better) 6mm Baader Ortho. Beware though, the eye relief is small and you will find yourself cleaning the outer surface of the lens to remove eyelash grease.

Chris

  • Thanks 1

Share this post


Link to post
Share on other sites

It is odd that there are so few 6mm eyepieces available - a very usefull focal length. I was viewing mars night before last, using my Hyperflex zoom and wanted a bit more manification, so tried a 5mm BST Starguider, and it was much worse - I could have done with a 6mm then.

There is a 6mm TMB planetary eyepiece available, which has 16mm eye relief, but I haven't tried any of these yet. (I have an 8mm in the post from China - couldn't resist at £19 from the hilariously named 'Safety Burglar Store')

David

  • Thanks 1

Share this post


Link to post
Share on other sites

I have the 6mm TMB dont use it a lot but is really good on a good night 

Share this post


Link to post
Share on other sites
8 hours ago, MrFreeze said:

It is odd that there are so few 6mm eyepieces available - a very usefull focal length.

There's the 6mm TV Ethos and Delos, Vixen SLV and NPL, Tak Abbe Ortho and Starbase Ortho, Orion LHD and Edge-On Planetary, Antares Speers-Waler Series 4, Astro-Tech Hi-Grade Plossl, Fujiyama (KK) HD Orthoscopic, Burgess Optical Ultra Mono, Vernonscope Brandon, Baader Classic Ortho, Altair Lightwave LER, Smart Astronomy Sterling Plossl, many 58 degree TMB-type Planetaries, many 66 degree Expanse-type wide fields, and many 50 to 52 degree Plossls.  So, agreed, there's not much to choose from at 6mm. 😉

Share this post


Link to post
Share on other sites

I find 6mm an extremely useful focal length but it's probably not as useful in a 127mm mak with a focal length of 1500mm.

Mine is a 6mm Ethos.

  • Thanks 1

Share this post


Link to post
Share on other sites

I have and use the following 6mm e/p's... 

  • 2x Ortho's (one is a 0.965" + 1.25" adapter... the other is a 1.25" Circle-T).
  • 1x TV Radian. 
  • 1x 'generic' UWA.

...and used in my Celestron C6/SCT-xlt & 'remodded' ETX105, 6mm is pushing to the max.
Of all of them, the TV Radian can just about cope under a steady night sky and eye placement.

  • Thanks 1

Share this post


Link to post
Share on other sites

Omni Plossls are ok in the longer focal lengths, wouldn't go below 12mm. I had an omni 4mm once and it was terrible, I wouldn't even sell it on so it got binned. If you need a reasonable 6mm the SW planetary is good. Longish eye relief and a 58 degree AFOV, not bad for around £35-£40. I prefer to use a 2x barlow with my 12mm BST for the same mag as a 6mm.

 

  • Thanks 1

Share this post


Link to post
Share on other sites

This morning I received my 6mm Omni eyepiece that I bought from the link further up the thread. I must say that it's a really nice eyepiece, and was a bargain at only £10. The eye relief is short, but not really that bad, and it is very sharp and crisp. It has a narrow FOV as you would expect from a short FL plossl. In general it performs very similarly to a 6mm Circle-T ortho that I'd forgotten I had, but the ortho has a slight edge in clarity. Then again the ortho cost nearly 4 times a much, and that was second-hand.

I'd also forgotten about two 6mm UWA 'gold line' eyepieces tucked away in the same box, which seem to perform much better than I remember - they can be fussy about eye position and 'kidney bean' far too easily. The FOV is huge though compared to both the ortho and the Omni. I recently also got a TMB Planetary II clone 6mm, and I must say it was awful. Maybe I got a bad one, but it's easily the worst eyepiece I have ever used. It gives a very 'soft' image as if the lens has been smeared with vaseline - it hasn't - I checked. It has a large FOV, similar to the gold line eyepieces, but unfortunately without the clarity.

David

Share this post


Link to post
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.

  • Similar Content

    • By gstallichet
      In market for a good quality, reasonably priced long focal length 1.25 eyepiece to increase fov and help locate and view large objects. Celestron makes a 32mm for @$45.00. Is it any good? Price seems too good to be true. What are good quality/price options?
    • By JamieHardcastle
      Hi everyone,
      My other half bought me (us) a Celestron 130 for my birthday recently.
      I have watched tutorials and done a lot of reading about collimating and various other tips since alongside several hours peering through the telescope.
      I can achieve a very crisp image of the moon which is awesome. However, trying to get a decent focus on Mars/Jupiter Saturn is proving very frustrating. The only non-blurred image of any of them is a single white-point, non dissimilar to what I can see via the naked eye. 
      i’ve tried both the 20mm & 10mm lenses and adjusted the focus in and out all the way.
       
      Any advice would be gratefully received.
      thank you, in advance.
    • By MountainDog
      I have just encountered an error message which says "NO RESPONSE 16" when I power up my 130slt. Has anyone else experienced this issue?
    • By NightSky_Wanderer
      Hi,
      I am hoping someone here may be able to offer some help or advice. I have submitted a support ticket with Celestron but I am still waiting for a reply and would really like to get this working ready for the next clear sky!
      I recently brought a starsense but have not been able to use it because it comes up with the following errors,
      Err: Model Num
      The telescope model could not be read and initialization cannot proceed.
      Critical error!
      File: ..\source\mo
      Line: 1468
      An unexpected error occurred that may cause the HC to not opperate normally.
      When updating the controller and camera it finishes succesfully but when I check for new updates it proceeds to install the same one again and again.
      I can still control the mount and I think the camera tried to do an alignment in my room.
      I have a Celestron Nexstar 6SE.
      Thanks
      Adz
    • By Sky-searcher
      BST Starguider & Olivon Branded 60 degree ED eyepieces. Best upgrade from standard plossl eyepieces. 16mm eye relief, large 21mm diameter eye lens & suitable for f5 scopes & above. All eyepieces in excellent condition. Only reason for sale is now using Baader Morpheus eyepieces.
      Starguider 8mm with original packaging £38 inc UK postage. SOLD
      Starguider 15mm with original packaging £38 inc UK postage. SOLD
      Olivon 5mm, 12mm & 18mm set & case. £100 inc UK postage.
      Payment by PayPal F&F or fees paid by buyer.
       Thanks Andy.





×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.