Building an eyepiece collection

[FenlandPaul]

I've come to realise that I've very much neglected the importance of good quality eyepieces in my setup and I'm a little overwhelmed about how to build a sensible collection.  When I bought my 12" dob, I bought a cheap Revelation-branded eyepiece kit, which is fine and great value but there's no point pretending they're premium glass!  I have a TeleVue Plossl 32mm, which I think gives lovely pinpoint stars but in my scopes it seems to give a lot of pincushioning.

I've done some looking around the web and struggled to find a decent readable guide to selecting the best range for a particular set of requirements.  An Al Nagler article in Eyepiece looked promising, but ultimately felt like a school text book.  Does anyone know any good readable guides?

I have three scopes: a 12" f/5 dob, a 6" f/5 frac and a 5" f/9 frac.  None are top-end optics.  The dob gets its outings on moonless nights and hoovers up galaxies and nebulae.  The AR127L is mainly for doubles, planets and lunar.  The ST150 has been great for deep sky from a dark sky when it's tricky to take the dob.  In the future I've got my eye on either a 120 ot 150 apo of some sort, but that's a good year or so off.

I wear glasses for short sightedness and I have astigmatism.  I am toying with the idea of getting contact lenses.  

Any ideas on where I should  start?  I want this to be a long term investment, built up over a few years, so I'm happy to spend a bit of money for the right glass, although clearly the more I spend the longer it will take.  It seems that eyepieces of a certain quality hold their value reasonably well.

Look forward to any thoughts...

Paul

[John]

I'll have a think about some good reading resources but I came to a similar conclusion quite a few years back and gradually built up an eyepiece collection that, I feel, will perform excellently in virtually any scope that I might own.

My choices are centred around Tele Vue and Pentax and favour wide and ultra wide field eyepieces because my scopes are all on undriven alt-azimuth mounts but others will have their preferences too.

My scopes range from 12" F/5.3 to 4.7" F/7.5 and my eyepiece set covers focal lengths from 31mm down to 3mm. I've chosen now not to use barlows or tele extenders mostly to keep things simple - one less expensive thing to drop in the dark !

I've found that I can happily live with reasonable gaps in the focal lengths until I reach 6mm and then the spacing gets more tightly packed so that I have choice at higher powers to find what suits the conditions / target best.

While really good quality eyepieces do cost a fair bit, there is some reassurance and satisfaction in having the confidence that the eyepiece is going to be showing you everything that the scope and conditions can

Good luck with your quest !

 

[Piero]

Hi Paul, 

First of all, I think it would important for you to define how much money you intend to spend on this. Then I would select the eyepiece focal lengths depending on your interests and so that they are not too close or distant. To me, the x1.4 factor works very well. After that I would select the best brands with the ergonomics and features of interest (e.g. eye relief, field of view etc). Second hand market as first place to go unless you find good deal from a shop. 

Having three telescopes makes things a bit more complicated, but two of them actually have the same focal ratio (so the eyepieces will have the same exit pupils). It seems to me that in the long term you will keep the dob 12" and get an ED frac. So, I would probably focus on eyepieces for the dob 12" right now, which anyway will work fine on your F5 frac. 

The spectacle thing can be a constraint. If you really need them, Deloi / Pentaxes are the way to me. If you get contact lens, you could also look up for Ethoi, assuming you are comfortable with their cost. 

For what is worth, when I was in your situation after some study, I ended up with a few notes which eventually built up the following thread:

 

 

[Tinker1947]

I started with a Revelation kit, its still in the shed not been opened for years, so sorting out what i needed for a reflector seemed easy buy  good EP's and i should be set up, so over a period of maybe a year i brought the Pentax XW's  5mm to 30mm and added a few years later a 17mm Naglar and a 41mm Panoptic, i'm very happy with them and in years to come they may well sell for a good price......

[Louis D]

Target magnifications around 30-50x, 75-100x, and 150-200x and then locate Pentax XLs or XWs or TV Delos that hit those sweet spots with the most scopes.  The low end will probably require Panoptic or ES/Meade 5000 SWA eyepieces above 27mm to yield sufficient eye relief for you.  Shop used if possible.  Put out want ads and see what turns up.  Buy one at a time, starting with your most used magnification range.  Don't be afraid to mix and match eyepiece lines.

[YKSE]

Many good points mentioned above.

As a very simplied guideline, I'd like to believe that you need tight spacing of EPs around 1mm exit pupil for Moon, planetary and double stars, for other DSO, in the low power end, EPs with 3-4mm exit pupil if you observe in light polutted backyard, up to 6-7mm exit pupil if in dark site. around 1.4x EP focal length jump (equal to twice brigthness difference) in low power end is just fine.

Multiple scopes with different focal ratio makes EP choice more difficult, since scope and EPs work together, therefore it'll be much better to take your time, think over the whole package.

I'm not a big fan of trying out many different scopes and EPs, just want to use them as observing tools. I had decided my potential scopes ready some years ago, and built my EP collections afterwards. I have only a potential 12"/f5.3 scope in a few years, as far as I can see, my EP collection doesn't need to change the time I get the scope.

[scarp15]

Building an eyepiece collection can become an evolving and gradual journey, that might determine periodic changes, particularly if replacing or including additional scopes. In terms of wearing glasses, most certainly as stated, Pentax and Delos with their 20mm eye relief.  I have a 10mm Delos, 5mm Pentax XW and until very recently, a 6mm Delos in which each are quite excellent. Combining buying used with new (especially when there are periodic discount codes) coupled with a long term approach makes it possible. 

[Brasspoodle]

Lots of great advice so I thought I'd share my failings. 

I reckon I started out slightly in the wrong direction with my lineup. I filled in gaps between the 'not so great' eyepieces I had. What I'd wished I'd done was determined and then upgraded the most useful magnifications first.

I wished I'd tried more varieties of eyepiece before getting stuck on one brand or style. In pursuit of ever greater apparent field of view I'd collected the 82° and 100° Explore Scientifics but on buying a Delos 17.3mm (72° AFoV) I was stunned by the comfort of the eye relief and the immersive feeling the large lens offered. It wasn't that it was necessarily better than the Explore Scientifics it just gave me an experience I valued more than the shorter eye relief large AFoV. I've still got my ES 82° 30mm and ES 100° 20mm (both benefit hugely from a Coma corrector in my 12" f5 Dob) as maximizing FoV at this end makes sense to me. I've replaced almost everything else with Delos and Pentax XWs. Vixen LVWs are also very good on ER and are worth considering. 

When adding to my eyepiece lineup I was often trying to buy eyepieces that performed better in poor conditions. The money spent on premium glass to reduce reflections or eek out some Galaxy hiding in light pollution would have been better spent on getting to a dark site. It's only a slight flaw I think as a lot of my observing has to be done from my backyard with family responsibilities being a priority. When I'm under dark skies I often don't care what eyepiece I'm looking through!

Finally my biggest fault is giving into Gear Acquisition Syndrome (G.A.S.)! I was really happy with just a Delos 17.3mm, Delos 10mm and Pentax 7XW :-/

[Highburymark]

The best guide to eyepieces (in fascinating, exhaustive detail) I've read is 'Choosing and Using Astronomical Eyepieces' by Bill Paolini, a sometimes contributor to this web forum. Published by Springer - and thoroughly recommended.