Have I made a mistake

[michaelg]

Ok I have a 250px Dob and decided to upgrade the standard 10 & 25mm plossi eyepieces I bought a 13mm badeer Hyperion.

Here's the thing the conditions have been rubbish over the last few days since I bought the baader however I took the scope out tonight as it was clear in parts it's was about 10pm and only stars to look at but what I found really surprised me. I noticed that the views of the stars was better with my 25mm plossi than it was with the baader.

Please tell me that I will get better planetary views with the 13mm baader than I will with the standard plossi that came with the scope

To let you know I bought the fine tuning rings for the baader which gives me a 10.8 a 9.2 & 8.1 but due to my vast inexperience not sure when to use what.

Please tell me I have not just wasted £120

[John]

When you say the view was better with the 25mm plossl, could you say what you preferred about the plossl / disliked about the Hyperion ?.

The Hyperions will show some distortions towards the outer parts of the field of view in a fast (F/4.7) scope like yours but the central area should show a very nice view - noticeably better than the eyepieces supplied with the scope.

Have you viewed any planets with the new eyepiece yet ?

When you do you will want to use a bit more magnification than just the 13mm eyepiece. 200x (a 6mm eyepiece) should be quite usable on a decent night.

Edit: One more thing, did the scope have a chance to cool down before you used it ?

[michaelg]

Hi John

When I say the views were better I saw more stars with the 25mm plossi than I did with the 13mm baader

I let it cool for 30 minutes

I have not managed to view planets with it yet due to conditions you say I need to use a greater magnification like 200x (6mm) how do I achieve this

[John]

The standard eyepieces supplied with the scope are not plossls as far as I know. They are lesser quality eyepieces just designed to get you going. If you actually have plossls then those would be non-standard.

The 25mm should show a slightly wider true (ie: how much sky) field of view than the 13mm Hyperion so you will see more stars, in terms of the amount of sky shown. The Hyperion will focus at a slightly different place than the 25mm so you will need to adjust the focus to get a sharp image (sorry if you know that already !).

As you know, you can use combinations of the 28mm and 14mm fine tuning rings to get more magnification from the Hyperion. At the longest (both rings) it will be in effect an 8.1mm eyepiece which will give you 148x. Jupiter and Saturn will look nice at that power but you should be able to add a bit more power and you will need either a good quality 2x barlow lens to use with your 13mm Hyperion (making it a 6.5mm eyepiece) or a 6mm eyepiece, to get around 200x with the scope.

30 mins cooling should be OK this time of the year but you may need more when the nights get cooler.

Don't forget to use low magnifications too with the scope - the 25mm eyepiece or even getting a 32mm would be nice to see the larger deep sky objects like M31 (the Andromeda Galaxy).

One more point, the planets never look really big through a scope, even at 250x - 300x. The key is to get a sharp image of them, even if it's a bit smaller. Sharp images will show the features whereas a large but mushy image won't.

[LukeSkywatcher]

The rule of thumb regarding the cooling of scopes is 5 mins per inch. aperture...............

It really does not matter what EP you have or how expensive it is. Its all down to the scope optics being the same ambient outside temp as the l;ocal conditions.

A 250mm scope needs the best part of an hour to cool down. The longer the better.

[Qualia]

When I say the views were better I saw more stars with the 25mm plossi than I did with the 13mm baader

I don't know if I've got the right end of the stick - probably not - but the 13mm will narrow your field of view, so for pure aesthetic pleasure of a more open field of stars, the 25mm will 'look' better. You're running something like a 90x with the 13mm which in my own case would be used for relatively smallish open clusters, nebulae, and that kind of thing.

Hope that helps.

[michaelg]

Hi John

I have just checked the standard eyepieces and they are 10 & 20mm super plossi not sure if they are considered good or not

Do you with your knowledge think my 13mm baader may have been a bad buy as I did take advice from the guy at the telescope shop in Rotherham and they are meant to be quite good.

I told him I wanted a good eyepiece for planets as I am new to the hobby and he suggested the 13mm with the rings was I given bad advice

Thanks for you help with my questions John

[brantuk]

When you align on a planet compare the 10mm with the 13mm Hyperion then you'll have a closer like for like match. You'll soon see the differences. The bigger the difference in eyepiece size the less you'll be able to compare views cos they are totally different. The advice was good but you just need to use and understand a few more eyepieces of different focal lengths and magnifications

[JamesM]

The true test will be when you test the Baader eyepiece on a planet! Their eyepieces are very good and they handle contrast really well so you will certainly see some detail - trust me. Investing in a barlow is a good idea and although there are those who will argue the virtues of single eyepiece (which I don't disagree with) if you are on a bit of a budget, barlows certainly have their part to play.

James

[umadog]

I had exactly the same experience with a 12" f/5. It's not cooling. The 13 mm Hyperion is a terrible, terrible, eyepiece in fast scopes. It performs worse a cheapo 3-element design (as you have found out). Massive astigmatism in the outer third of the field. It's not going to get any better: just send it back.

[pvaz]

The Hyperiond are generally known to be good mid range EPs. Personally for the price I would (and did) buy some 2nd hand Televue EP as they are specificly designed for fast scopes and you can get a 2nd hand Nagler or Radian for about that price.

Nevertheless the Hyperion should provide a wider view (wider circle) and have a more confortable eye relief then a plossl thus providing a more pleasing view. I would try it a few more times before making my mind about it.

One thing to consider is the eye relief. This is the optimum distance your eye needs to be from the lens. When I bought a Nagler 31mm T5 I struggled with it at 1st. I was used to plossls and was placing my eye too close to the eye lens, which cause dark areas in the view (known as kidney beans). It cost me about 500€ at the time so 1st thing I did was to come in here and show my disappointment. A few sessions laterI learned how to use it properly and it became my favourite EP and kept that place for a couple of years. until I replaced it with the Ethos 21mm (about the same with wider FoV).

[John]

A range of views about the Hyperion posted as you can see. My view is that they are nice eyepieces in scopes with focal ratios of F/7 or slower (eg: F/8, F/10 etc) but would not be my 1st choice in a fast newtonian like yours to be honest. The central part of the field of view (or circle of view as Paulo calls it) will look fine but as you look away from the central part the stars will appear elongated, "seagulls" as some have described it.

The person from Rotherham may not have known the scope that you had perhaps ?

One option would be to see if they would exchange the Hyperion plus rings for something like the 12mm and 7mm Celestron X-Cel LX eyepieces (which I think they stock). They should work better with your scope I think.

Choosing eyepieces for a fast scope is a bit tricky so you would not be the 1st to go down a slight cul-de-sac.

[pvaz]

PS-> Check how much time you have available for a return with full refund. If you really don't like it then just return it.

I would highly recommend 2nd hand market for the following reasons:

• If you buy at normal market prices you can resell for the same price (in case you don't like it or want to upgrade)
  
• People in this hobby generally take really good care of their gear so in my previous purchases the EPs always came as new with just minor scuffs from the regular focusing screws.
  

As where to buy, most people use this site http://www.astrobuysell.com/uk/ and the classified section on this forum. I think you need something like 150 posts to see the classified section here (keeps people from coming here snatching the bargains to resell somewhere else at a profit).

[John]

..... I think you need something like 150 posts to see the classified section here (keeps people from coming here snatching the bargains to resell somewhere else at a profit)......

Good advice re: buying used.

To view our classifieds here you need to have made 50 posts. To post an advert it's 250 posts.

[umadog]

Paulo is correct. Look second hand or look at other manufacturers. When I bought my 13 mm Hyperion I paid $130 for it. I returned it the next day and ordered the 14 mm ES 82 degree for $99. The latter is sharp across the field and the field is wider. Eye relief is lower but still comfortable. You don't need to settle for the Hyperion astigmatism when there are other comparably priced eyepieces out there that don't exhibit it. Sorry if that sounds like a rant and I realise that at larger focal ratios they are reported to work well.

[Qualia]

Great stuff and no rant should be assumed. It is information like this in the thread and on the boards that really helps new-comers and potential buyers. It is part of which makes SGL so special a place.

[Capricorn]

The one often repeated point of Hyperons is that they do not perform well on fast scopes. Yours is f/4.7 and that makes it fast, so it may sinply be a case of the wrong eyepiece for the scope.

No idea where you purchased it from but I suspect that you will have to consider requesting an exchange owing to the above.

You will see more stars in the 25 then the 13, the field of view is close to twice as wide and the lower magnification means that the individual stars will come out a bit brighter.

Concerning general performance, the TV plossl's are specified dwn to f/4 so plossl's can work at f/4.5, will say that usually the supplied items are not great but you may have just got a decent 25mm plossl that is OK in your scope.

If you get a refund then alternatives seem to be:

Celestron X-Cels,

BST/Starguiders.

Places like TS do a flat field eyepiece that are intended for fast scopes - designed to handle the curvature better, well thats what they say. May be worth considering.

The TS HR Planetary's are reported as good, just not sure how good in an f/4.5 scope as I have never read of anyone using one in a scope such as yours.

[Qualia]

Relevant to the discussion the Spanish magazine, Astronomía did a few reviews of some fast end scope EPs (f/5). Here is their general recommendation. It appears that what you pay for is kind of what to expect: Nagler, Paracorr, Ethos, Panoptic, Abbe Orthoscopic, Explore Scientific (68º), GSO Superview, good set of quality Plossls and x2 barlow, and curiously enough, my own opinion is coming around to the idea that any true Russian made eyepiece is going to be the business.

Hope that helps.

[mart rich]

The beauty of SGL is how much you learn just by reading about other peoples experiences.

Before now, I had never heard of Hyperions being a poor choice for fast scopes, and being a satisfied owner of a Hyperion Zoom and an F5 reflector, I wouldn't have been ay the wiser until reading this. The retailer I bought the Zoom from certainly didn't mention anything at the time and I know I discussed the type of scope I have. I thought I had read around the subject quite a lot before buying the eyepiece.

But I have never had the chance to compare different eyepices . The only way to have done that would have been through buying from the second hand market as described above. Seems like good advice!

Martin

[Qualia]

If you get a refund then alternatives seem to be: Celestron X-Cels, BST/Starguiders.

On the strength of many favourable reviews here and on Cloudy Nights, I decided to go for a few X-Cel LXs (by all accounts a significant improvement on the old X-cels) but with that said, they are used with a forgiving f10. I think they are wonderful eyepieces, well corrected at the edges and have been tested down to about f4. Here are some discussions:

On the strength of them I've even decided to try out the x2 barlow LX. It was a little more expensive than a shorty and just a wee bit cheaper than the longer type televue (which to be honest I feared might have problems with my diagonal). It's a shame I can't lend you a couple to see how they are.

[cantab]

Hi John

When I say the views were better I saw more stars with the 25mm plossi than I did with the 13mm baader

This is normal, the richest starfields will be at low magnification, even though increasing power lets you see fainter individual stars by darkening the sky background.

[Eastridge]

To be fair to the retailer you asked him for an eyepiece for planets. I use a Hyperion ( albeit 10mm) for planets in my fast scope & it's fine because the issues it has are at the edges & I view planets in the centre.

For the money and range of focal lengths you have with the FTR's ( as I do) I find it a god deal.

But if you also want to use it viewing things that will be at the edge of your field of view then people here are right and you could do better, although not with such a wide FOV without paying quite a lot more.

Horses for courses I think rather than a sweeping 'it's a bad eyepiece'

[pvaz]

To be fair to the retailer you asked him for an eyepiece for planets. I use a Hyperion ( albeit 10mm) for planets in my fast scope & it's fine because the issues it has are at the edges & I view planets in the centre.

For the money and range of focal lengths you have with the FTR's ( as I do) I find it a god deal.

But if you also want to use it viewing things that will be at the edge of your field of view then people here are right and you could do better, although not with such a wide FOV without paying quite a lot more.

Horses for courses I think rather than a sweeping 'it's a bad eyepiece'

Valid point about observing planets.

However for that price there are other options with wider FoV, such as the explore scientifics 82º or the Skywatcher Nirvana that retails the 16mm and 7mm for 145 and 135. Both of this have great reviews on fast scopes and compete directly with Televue and Pentax stuff without having such a heavy price tag.

You can also find 2nd Hand Televue Radians for about 120 or less (There's a 10mm Radian going for 100 in the classifieds and a few others on astrobuysell). I have also seen 13mm T6 Nagler going from 120 up to 180 (though a Nagler for 120 is not that easy to find).

[x6gas]

To be fair to the retailer you asked him for an eyepiece for planets. I use a Hyperion ( albeit 10mm) for planets in my fast scope & it's fine because the issues it has are at the edges & I view planets in the centre.

For the money and range of focal lengths you have with the FTR's ( as I do) I find it a god deal.

But if you also want to use it viewing things that will be at the edge of your field of view then people here are right and you could do better, although not with such a wide FOV without paying quite a lot more.

Horses for courses I think rather than a sweeping 'it's a bad eyepiece'

But if you want a planetary EP then you don't need a wide field of view, surely?

[brantuk]

Have a play with this - it'll give you a good idea of different eyepiece sizes with different scopes and you can put your own equipment details in. It also illustrates the differences between cameras. It's not entirely accurate but is a good guide what to expect:

http://www.12dstring.me.uk/fov.htm