Focal Length and expensive EP,s

[great_bear]

Maybe its just a different set of design choices favoured by different designers.

Oh, for sure: Tele Vue's big thing is prioritising edge-of-field sharpness above everything else. Certainly the Tele Vue Panoptic 24 has enough pincushion that you'd probably not want to use it in daylight on terrestrial targets.

[michael.h.f.wilkinson]

Oh, for sure: Tele Vue's big thing is prioritising edge-of-field sharpness above everything else. Certainly the Tele Vue Panoptic 24 has enough pincushion that you'd probably not want to use it in daylight on terrestrial targets.

One reason to opt for the TMB Paragons: very little pincushion distortion and excellent edge sharpness (granted, in my F/10 scope, but you would not want to use a 40mm on anything much faster than F/8)

[beetlejuice]

The SWAs and UWAs are very well-liked - some focal lengths more than others - but I've never seen anyone claim that the 5000 Plossls are special in any way...

Well, true but they are not true plossls as they have 5 elements. some 6 (Masuyamas?). But anyway, there performance is very favourable when compared to TV Plossls.

[great_bear]

Well, true but they are not true plossls as they have 5 elements.

Well neither are the Tele Vues, since they're 4-element Symmetricals - but it's been common to call 5-element Erfle-esque eyepieces "Super Plossls" for some time.

Apart from the Clave, I don't really know of any "True Plossls" in modern history. I suppose one could argue that a Brandon is geometrically-speaking a backwards True Plossl, but without knowing the glass types even that's dubious.

[michael.h.f.wilkinson]

So it looks like Plossl has become a name for any decent-performance, mid-price EP with rather short eye relief at short focal length.

[spaceboy]

I have to agree that better advice should be offered or label on the product. A better educated beginner will enjoy their telescope more. A person who enjoys their telescope in turn sells the product to his friend who is also interested in getting a telescope. The friend buys one and so forth. Or you get the quick sale and the customer goes away not realizing what they have let themselves in for. With in a month they are wishing they hadn't bothered as the experience and views just weren't what they thought is was going to to be and they can't get rid soon enough. They advise their friend not to bother and so 1 less telescope gets sold.

No-one in this world wants to spend their hard earned cash on something to find out they have to spend double the amount to get it to work efficiently. Given the opportunity people would rather spend that little bit more knowing thats it! and they can get on with observing.

Due to all the factors involved with visual observing IE: weather, seeing conditions, light pollution astronomy is a reasonable small market and because of this, prices of quality eyepieces, telescopes and other accessories are high. If a small company has 7 people to make eyepieces and only 3 eyepieces sell a week, the cost of the eyepiece is naturally going to be higher to cover costs. If 50 eyepieces a week go out the door prices can be lowered as costs are easily covered. The more you make of something the cheaper materials can be purchased and better production can be set up. I would assume the first ever plossl at one time cost £100 but now you can pick them up for £10-40. It makes sense for a company to get their product out in the market place as quickly and as cheaply as they can to encourage growth and in turn profit. Although a Nagler may cost £12 to produce. The costs have to be covered. IE: Nagler parts =£8 Joe bloggs on production =£3 p/hr Joe bloggs supervisor =£5 p/hr supervisor's boss =£8 p/hr the manager =£10 p/hr over heads on the factory inc electric, rent, public liability, blah blah blah..... I'm sure you all get the idea. BUT costs don't stop here, there is moving the shipments around, there's people and sales teams handling the items all around the world and ever time the cartons are touched there is added value to the eyepiece, everyone makes their own little profit. The difference between the plossl and the nagler is that the development and production of the nagler is newer compared to the plossl. The plossl is well established in the market place. It is established only because it's production is efficient allowing the costs to come right down. You put 2 EP's in front of a beginner and say give me a days wage for this ep.. you will see the rings on Saturn...or give me a weeks wage for this ep and you will see the rings on Saturn and a couple of moons.. If you just paid £300 pound out of you monthly wage of £400 what eyepiece do you think they would buy.

In ten years the cost of Naglers will be the equivalent of todays plossl. It's the same with any commercial product.... plasma and LCD TV's cost around £5000 when the first came out but as more people buy the cheaper they become and now one can be picked up for a couple of hundred pounds.

My point is for something to become cheaper you need to sell more of them. To sell more of them you need to get more people interested in the 1st place. This is where I think people need to be better advised about telescopes.. after all lets be honest there is a few different types, focal lengths etc out there. If you get people regretting their choices thats when the ripple slowly becomes the wave. I recently purchased a 250 dob from someone who'd bought it new 1 month earlier, the reason for sale was he didn't realize he'd have to go into the expense of quality eyepieces. ( guess what? neither did I ) Having made a loss of £100 after only 30 days I doubt very much he would be looking to make another telescope purchase. I am already touching on regret with my purchase as I don't have the money to be slashing out either. The only advantage I have is that I already know what the heavens have to offer and I could not even dream of owning an equivalent sized SCT so it may be a price I have to pay for having a larger aperture. The way I see it though is the eyepieces will remain mine no matter what telescope I purchase in the future.

The secondhand market is also a catch 22 for all astronomers. Most of us cannot afford new so we have to buy secondhand. But if we were all to go out and by new the prices would eventually fall and then better eyepieces and telescopes would be more affordable.

People not enjoying their first telescope and the secondhand market all lead to the lack of demand. The lack of demand leads to poor profit margins. Poor profit margins leads to high prices.

[Moonshane]

some good comments there Nick. Personally, I am absolutely positive that many people would be awestruck with cheaper eyepieces and not miss the expensive stuff. for me though it's worth paying the extra for the better quality and I'm lucky that I can get a 'new to me' EP every now and again.

the way I do it is build up slowly, buy a cheaper alternative like one of the TMB clones or a TV plossl and then use that for a while ensuring I will use it regularly. assuming I do then I start saving for the 'real thing' whatever that may be and then get it when possible.

I have set myself a 'strict' 6 eyepiece rule (I don't use a barlow); the exception to this is that I am beginning to see the advantage of a few Plossls/Orthos sprinkled at various focal lengths to use with my planetary dob for eg when my wife's using the bigger dob to 'skyscan' - I live in hope.......

[Earl]

Is say that the first consideration has to be your viewing condition's.

if you have average skies, then imo its pointless spending big bucks on EP's as you will not be using them to there potential.

Televue Plossl are good, and although a little higher that other options, are fine eyepieces.