80 mm short focal length refractor & best eyepieces to use.

[Guest]

I have a Skywatcher Equinox 80 mm. At f6.2 and 500 mm focal length. I have found two much older Plossl eyepieces hidden deep in one of my astro bits n pieces box.

They are 25 and 40 mm. I am going to try them out tonight. They certainly are not glamorous compared to modern exotic eyepiece designs. I have Explore Scientific 82° eyepieces and a 22mm Televue. These serve me well. I remember looking through a 25mm Televue Plossl some time ago. I was impressed.The view was sharp with great contrast. But a narrower field of view.

I have wider field eyepieces because I observe with a  manual mount. They help to make it easier to track celestial objects. But would eyepieces with narrower field of view and with simpler designs give a better or alternative viewing experience. Perhaps just adding one or two Plossles to my collection would be the way to go. I would be interested to hear the experiences of others.

Edited May 15, 2020 by Guest

[Peter Drew]

Nothing really beats wide angle viewing than********** wide angle long focus eyepieces, it's what they are designed for.  When it comes to planets and double stars, wide field is not such a consideration, optical quality, colour correction and light throughput become more important with the shorter focus versions.     🙂

[cloudsweeper]

I had a thing about WA EPs, and they do of course serve a useful purpose.  But more basic EPs do have a place in a collection, and I went for some Plossls and Celestron XCels to satisfy the requirement for good, contrasty views without the wide field.  I wouldn't be without them now!

Doug.

[bomberbaz]

read a few reviews recently on sgl regarding various eyepieces and types, one by astrobaby on narrow fov ep's. On it she reviewed several eyepieces including vixen npl, celestron x-cels and bst's plus one other whose name escapes me. 

To cut to the chase the vixen npl's were the one's she liked the best for the contrasty views and the sharpness accross the fov.

[DaveL59]

My set is mostly TAL Plossls both older and recent with a couple kellners (42,15) in there too. Also have a Vixen NPL 20 & 10mm. No WA EP's but I'm quite happy with the ones I have. The Vixens to give a brighter image in the main, or perhaps just a little easier to use so seem that way. My mounts a couple can track (EQ5-synscan and EQ2+RA motor) the others are manual (EQ5 and TAL) but I don't find that an issue.

[John]

Todays high quality wide field eyepieces using the latest glass types and coatings give little away to simpler designs I find 

They do cost quite a lot though

[bomberbaz]

6 minutes ago, John said:

Todays high quality wide field eyepieces using the latest glass types and coatings give little away to simpler designs I find 

They do cost quite a lot though

I concur

[Louis D]

I've read of observers using narrow field eyepieces to observe dim objects such as the Horsehead nebula located near bright stars.  It helps to block the stray starlight from ever entering the field of view to improve contrast.

[mikeDnight]

First of all I think the Equinox 80 is a fantastic scope. When I bought mine around six or seven years ago, I quickly found myself spending more time under the stars than I had done for years. At the time I was using the 31 Nagler as my lowest power eyepiece along with several other Naglers, Ethos and Pentax XW's.  I used a binoviewer with a 2X barlow and a pair of cheap 16.8mm orthoscopics for observing the Moon and planets, and the views were amazing. It wasn't until I'd bought a 100mm Tak that paulastro loaned me a 26mm Meade plossl to try. I was insulted, first because it was a plossl and second because it was a Meade. What I saw that night though had a major impact on how I viewed eyepieces. I had all this high end and expensive kit, and here was a 26mm (5element super plossl) offering greater transparency and on axis sharpness than the worshipful Televue's and Pentax. The 26mm plossl gave roughly the same true field as my 20mm Pentax but it has a clarity about the image that wasn't quite as good in the XW. On axis the 26mm was every bit as sharp if not sharper than the XW, and although there was some edge of field distortion it was no worse than that shown in the XW.  I couldn't get that experience out of my mind, and as the weeks went by I researched the eyepiece design that Meade used for their super plossl. It is commonly known as a pseudo Masuyama, made in the 1980's under various brands, and are no longer in production except the 35mm Eudiascopic sold by Baader, but they come up cheap regularly second hand. Today, all my eyepieces are pseudo Masuyama's with the exception of my high power planetary Vixen HR's, and they never fail to impress me with their clarity and sharpness.

The problem with the plossl in an F6.2 scope, is that you'll get some edge distortion, and though it may not be too troublesom it will be present. But on axis they will give a great view. One way to overcome this would be to use a barlow giving you a F12.4 ratio and a better edge of field performance. But plossls vary so much in quality the cheap as chips Chinese ones can give the design a bad name. If I were you, I'd look to Japan and brands such as Celestron Ultima, Orion Ultrascopic and Parks Gold.

[Louis D]

My biggest problem with plossls in fast, undriven scopes is that the image is super sharp for only a moment before the object passes back out of the center and into the not so well corrected area.  That, and you have to nudge things much more often due to the narrower field of view.  Premium, well corrected wide field eyepieces keep things sharp for a much longer dwell time between nudges.  If you're using a driven scope, then plossls work pretty well for small objects.

[michael.h.f.wilkinson]

The Equinox is a close match for my APM 80mm F/6 triplet, and the 22 Nagler is one of my favourite EPs for great wide-field views. Basically you have a 22x80mm with 3.76 deg FOV. I don't think I have ever had better views om M33 than with that combination, from a really dark site near Olly's place. The 31mm Nagler and Vixen LVW 42mm also give outstanding wide-angle views. Having said that, for lunar observations (which I normally do with the Celestron C8), when I travel, I carry a set of Vixen SLV EPs (5, 9 and 15 mm) which have much narrow FOV, but excelent quality. I also use a MaxVision 24mm 68 deg for wider views. Not a real replacement for the Nagler 22, but excllent views nonetheless. I also tested the cheap as chips 20mm Plössl (15 euro price tag), and found the views really nice as well, but not better than either the MaxVision or the Nagler. For the price, however, it is an excellent piece of kit. The main reason I got SLVs rather than the much cheaper Plössls is not so much optical quality, but eye relief.

[RT65CB-SWL]

If you wish to move up from a Plossl have you contemplated or tried a Radian*?
I use the 6mm with my TV Ranger and at f/6.8, (it is close to the spec of your 'scope), it is very good companion. My mounts, (AYO and Giro), are manual alt-az; so it gives me sufficient viewing time; before a gentle nudge to get my target back in the e/p and carry on observing. For wide-views I use a 13mm Nagler / type 6, and sometimes coupled with a 1.6x or 2.8x Barlow lens.

 

* Radian's are now discontinued, (they do come up for sale from time-to-time)' and has since been superceded by the Delite range.
AFOV for: Radian 60deg - Delite 62deg

BTW - I think there is Radian for sale in the classifieds area.

[bomberbaz]

3 hours ago, Philip R said:

If you wish to move up from a Plossl have you contemplated or tried a Radian*?
I use the 6mm with my TV Ranger and at f/6.8, (it is close to the spec of your 'scope), it is very good companion. My mounts, (AYO and Giro), are manual alt-az; so it gives me sufficient viewing time; before a gentle nudge to get my target back in the e/p and carry on observing. For wide-views I use a 13mm Nagler / type 6, and sometimes coupled with a 1.6x or 2.8x Barlow lens.

 

* Radian's are now discontinued, (they do come up for sale from time-to-time)' and has since been superceded by the Delite range.
AFOV for: Radian 60deg - Delite 62deg

BTW - I think there is Radian for sale in the classifieds area.

I used to have a full set of radians, amazing eyepieces they are, well worth the relatively low 2nd hand price they demand.

Steve

[John]

Used to have the 3mm and 4mm Radians. One I liked and the other I found gave rather odd stray light issues when used to view the Moon. I can't recall now which was which

They were replaced by Pentax XW's in my eyepiece case.

 

 

[bomberbaz]

1 hour ago, John said:

Used to have the 3mm and 4mm Radians. One I liked and the other I found gave rather odd stray light issues when used to view the Moon. I can't recall now which was which

They were replaced by Pentax XW's in my eyepiece case.

Do you still have them John, I liked mine when I had them but at the time I was still trying to view with glasses and despite the good ER,  I did prefer the Delos I owned too. 

[John]

11 minutes ago, bomberbaz said:

Do you still have them John, I liked mine when I had them but at the time I was still trying to view with glasses and despite the good ER,  I did prefer the Delos I owned too. 

Yes, I have the 10mm, 7mm, 5mm and 3.5mm Pentax XW's. I love them

 

[GazOC]

I tend to stick with my 100 Deg eyepieces in my Equinox 80 purely for the FOV. The short focal length of the scope and the wide field EPs are a perfect match for open clusters/ starfields etc, it's hard even going back to the 68 degrees of my Hyperions.

Edited May 17, 2020 by GazOC