Cheap eyepieces

[HnrKS]

Hello. I have a small question: has anyone compared cheap chinese eyepieces with original ones? For example, I'm interested in this cheap chinese eyepiece and celestron eyepiece (celestron I can get at a local shop, I wouldn't buy it from aliexpress). They have the same specifications, but price is differs quite a bit. So my question is simple: has anyone tried them and what difference in quality to expect?

[John]

31 minutes ago, HnrKS said:

Hello. I have a small question: has anyone compared cheap chinese eyepieces with original ones? For example, I'm interested in this cheap chinese eyepiece and celestron eyepiece (celestron I can get at a local shop, I wouldn't buy it from aliexpress). They have the same specifications, but price is differs quite a bit. So my question is simple: has anyone tried them and what difference in quality to expect?

They are probably made in the same factory or to the same design so the performance is likely to be the same. You can get pretty much the same eyepiece branded as Skywatcher, Telescope Services and a number of others as well. The Telescope Services ones had slightly better coatings but otherwise was the same thing. I suspect that there are a number of chinese manufacturers making this design now. Some supply the big brands and some are sold unbranded.

 

[ronin]

As John says they are very likely made in the same place and simply the name on the side differs. However that would imply no checking or QA internal to the factory production line - basically they are made and boxed and what is in the box in terms of performance is simple chance.

However what if as they are made they are put on a conveyor and get to a check point that shines a laser up through the eyepiece, produces a simple interferogram and each is graded into A, B or C by a camera and a reference pattern. Then you have the "same" eyepiece graded into 3 standards.

Everyone talks as if they are just a random collection of eyepieces so the Celestron ones are as good/bad as others off the production line. However if checked then the question is who is selling the Grade A' and who the grade C's ?

Similar scenario: 2 parked cars externally identical - which has the bigger and smoother engine ? One could be defined as better then the other but by just looking at them you cannot tell.

Usually with eyepieces you get what you pay for, and also ignore the descriptions to a fair extent. If they perform poorly do you actually expect the seller to say so ? I have yet to see an eyepiece described as "Reasonable but not good central sharpness, edge views are distorted.". However I have used some that fit that description.

[RT65CB-SWL]

Oddly enough I was looking at the unbranded one a few days ago... I do have 2x 6mm Ortho's*, 1x 6mm Plossl, 1x 6mm Radian & 1x 3-6mm zoom.

Do I need another 6mm eyepiece?

 

* one is 0.965" c/w 1.25" adapter and the other one is 1.25".

[BeerMe]

These eyepieces are referred to as gold-line eyepieces for obvious reasons :-)

They are very well thought of on the Telescopes Reddit board, although not the 6mm so much (if I remember correctly, it suffers from poor eye relief).  The 9mm though seems to be universally accepted amongst users on there as being a very good EP for the price.  The longer focal lengths aren't great either, 9 or 15mm seems to be the sweet spot with them.

It appears to be that the quality control of the cheaper, unbranded versions (the gold-lines) is less stringent than on the same eyepieces from brands like Celestron, etc but if you bag a good one then you'll get a very good bargain.  I'll be buying one myself once I get a new scope :-)

[HnrKS]

Ok. Thank you, guys, for answers. I'll give a cheaper option a shot. I've been observing with worse eyepieces (that came with telescope (25 and 10 mm)), so I shouldn't be very disappointed.

[Charic]

15 minutes ago, HnrKS said:

I'll give a cheaper option a shot

You won't know until you try. My favourite eyepieces are available in no less than 6 different brands,  depending on the retailer, and I think their all based on the astro-tech paradigm eyepiece. My particular brand and retailer was also reported as being the cheapest in the style at the time ( you would need to search and check every detail to see if thats still the case! ) making my decision even easier back then. You can click  the title banner on this forum to see the Starguiders in question, which FLO have recently stocked, with some special deals.  Their still highly regarded by many  on this forum. 

If you have set your mind on a specific brand and style, then I see no reason why you shouldn't investigate in the cheaper options, but price and brand is not the only factors to consider

There is a belief, in that you get what you pay for, but don't think the most expensive will always  serve you well, just because its got some exotic glass and fancy coatings over the elements. I had the opportunity to buy Tele Vue eyepieces from the outset, but I chose the cheaper option, especially when so many folk had great comments and feedback for the Starguiders, I have no regrets buying or using ANY of my BST's.  If I had just bought the TV's then I would not have known any different, that cheaper options can do just as good a job, but its not just the eyepiece alone, there are so many variables to consider and overcome.

For example, take the seeing conditions, the telescopes set-up, focal ratio/speed of the scope,  the scopes cooling period, having the right eyepiece for the target/task, how efficient is your eyesight,  how healthy are your eyes, are they dark adapted, the list goes on. If any one or all of these are out of place, no matter what the cost of the eyepiece, from £9 to over £300, there's nothing you can do, except correct the issue, or wait for conditions to improve?

Like I said at the beginning of this text, you won't know until you try for yourself. I have owned and sold the original Tele Vue eyepieces that I could have bought at the outset, proof enough for me that you don't have to spend a fortune to get good results. All you need to do is find what works best for you!

[Alfian]

I'm not sure what scope you have but I had the Skywatcher 9mm  version of this. A nice looking, seemingly well made EP, but didn't work especially well in my F5 scope. I never got round to trying it in a longer focal length scope but imagine it would be OK.

[John]

4 minutes ago, Alfian said:

I'm not sure what scope you have but I had the Skywatcher 9mm  version of this. A nice looking, seemingly well made EP, but didn't work especially well in my F5 scope. I never got round to trying it in a longer focal length scope but imagine it would be OK.

They are not great in faster scopes (eg: F/5). The 9mm is probably the best but even that one shows quite a bit of outer field distortion.

I used a set of these in an F/10 schmidt cassegrain and they were really quite good for their price.

[HnrKS]

Mine is 130/900, so almost F/7.

[Louis D]

The 23mm 62° eyepieces direct from China are really good as well in slower scopes.  I use a pair in my binoviewer to maximize my field of view.  By pulling off the rubber eyecup, I can comfortably use them with eyeglasses as well.  Just be aware that the top element is an aspheric acrylic lens and the coating can be rubbed off easily if you try to clean it, so don't get gunk on it in the first place, and you'll be fine.  They have way better edge correction than vintage "Konig" designs of similar design parameters, though they're still no Panoptics.

[Dave In Vermont]

I have a friend who has created a specialized field-of-study out of chasing down the actual manufacturers of eyepieces. He enjoys finding the location of their factories, etc.

Regardless of the branding they may wear.

A new aspect of astronomy was thus born -

Dave

[John]

6 minutes ago, Dave In Vermont said:

I have a friend who has created a specialized field-of-study out of chasing down the actual manufacturers of eyepieces. He enjoys finding the location of their factories, etc.

Regardless of the branding they may wear.

A new aspect of astronomy was thus born -

Dave

He / she must live under very cloudy skies

[Dave In Vermont]

1 minute ago, John said:

He / she must live under very cloudy skies

Yep - just up the lane from you, in the UK.

Dave

[davehawkins]

I have two of these eyepieces the 6mm and the 20mm under the Skywatcher brand name. They work very well in both my scopes but I changed to BST and Vixen SLV because I like twist up eye cups and better eye relief, they are prone to "blackout" if your eye isn't in just the right place especialy with the 6mm. Having said that I still use them and like them and have no plans to replace them. They are excellent value for money, mine were £34 + postage.

[RT65CB-SWL]

On 01/05/2017 at 14:19, HnrKS said:

Ok. Thank you, guys, for answers. I'll give a cheaper option a shot. I've been observing with worse eyepieces (that came with telescope (25 and 10 mm)), so I shouldn't be very disappointed.

Did you get one? - I took a chance on the 6mm and seems to be OK for what it's worth... less than £15.00GBP... and arrived within 14 days.