Classic Telescope Eyepieces - Kellner / RKE / Ortho / Plossl. Are they still relevant TODAY???

[@jeffpittel6926]

The University Optics green band Plossl's are pretty good.

[@AVTAstro]

Thanks for the feedback!

[@k.h.1587]

I've had both the 28 rke and the 28 plossl version, i never could see the disappearing eyepiece thing, i was more impressed with both the 26mm smoothside super plossl and celestron 26mm vixen silvertops. Unfortunately your 28 rke's days are numbered, the coatings are going bad when they haze up like that

[@BrettSucks]

Yes the 26mm Meade smooth side is better than the RKE

[@freeman10000]

I mainly use Naglers, Panoptics and DeLites nowadays but my 16mm Meade 3000 series plössl I bought back in the Ninetees is one of my favourite eyepieces and is used everytime I take my scopes out. I also quite often use my 6mm Fujiyama ortho for critical viewing.

[@AVTAstro]

Very cool, sounds like you have a nice EP lineup👍

[@jacekniec762]

Meade any MA Meade are good on Moon.

[@Buzzygirl63]

I still like my Plossls and Abbe Orthoscopic eyepieces. They provide a smaller FOV compared to modern eyepieces, but they provide nice sharp views on planets and double stars so I use them mostly for those tasks.

[@AVTAstro]

Very cool, yup they can provide some awsome views!

[@brentjablonski3730]

Great video, thanks. I've had a 28mm RKE since 1980. Still one of my favorites. The view is a little bit magical. I also still get a lot of use out of my University Optics and Baader orthos. As you said, nothing wrong with the views through any of these, just narrower than newer designs. And they are all so lightweight that you never have to think about effect on balance or focuser.

[@AVTAstro]

Very cool! Yeah the 28mm RKE is something. I actually own a pair for my binoviewers!

[@Sergey_Sergeev]

Thank you very much for showing them all and for reviewing each of them.

[@AVTAstro]

Glad you liked it. 👍

[@keithletourneau7305]

Nice collection.

[@AVTAstro]

Thanks

[@Astro_Ape]

Dude I just ran across your ad on AM for these. I had to stop and do a double take whenever I saw this video thumbnail cause I knew I'd seen that pic before lol.

[@AVTAstro]

Lol, yes it is indeed the same image. Having all these eyepieces out on the table was kind of what inspired the video. LOL.

[@markihde4381]

I have a few Brandon Flat Tops that I use with my slow f/12, 6" refractor. Sharp eyepieces but I'm not positive what the design is. Orthoscopic, perhaps? I also have a 48mm Brandon that I use for making the main tube do double duty as a finder scope.

[@AVTAstro]

Not sure what design they are. I have used them in my former Questar and they did work well with the slow scope.

[@markihde4381]

@@AVTAstro The barrels have the letters E F L so maybe that stands for Erfle. Thanks for making the videos.

[@AVTAstro]

It may be. I know they have been made for quite some time!

[@k.h.1587]

I think they are plossl derivatives, or symmetrics. Efl might stand for eyepiece or effective focal length. I know they are 4 element designs at around 50deg field. And many desired the 48mm 2"

[@deepspacehunter]

Naglers are good but are limited to certain scopes and/or focal legths. You have to be careful with the exit pupil. Plossles, on the other hand are much more forgiving across a wide range of telescope types and focal legnths. I love my views through my Meade series 4000 plossles and series 5000 HD60s. The plossle is highly attainable as opposed to a $800 Nagler... is the view better through a Nagler? Perhaps. Is it $750 better? ..NO...

[@AVTAstro]

Well most of what you say is somewhat helpful as far as price is concerned. There are no $800 Naglers though. Exit pupil does not have anything to do with how wide the EP is though. If for you plossls are plenty good, then nothing wrong with that👍 Just like a Ford is plenty good for a lot of folks but a Mercedes will only do some. Nothing wrong with that.

[@k.h.1587]

​@AVTAstro he is probably referring to the kidney bean effect, which is more pronounced at certain exit pupil ranges because it has to do with being perfectly centered on the exit pupil and at the right distance to avoid blackouts, and the different scope focal ratios had different levels of this. It was also influenced by sticker shock nagler resistance and early astronomy forums, back then probably mostly on university arpanet email lists, early usenet and BBS's, or magazine articles

[@MountainFisher]

I acquired all my Kellners from buying telescopes except for Celestron and Explore Scientific who each gave me a Plossl, but my Zhumell and even my Sky Watcher SkyMax 102 came with a 10mmKe and a 25mmKe. The Zhumell had a 10mm and a 17mmKe which I use in my 6" 750mm Newtonian for the Moon with a filter, super sharp. I did buy a Starbase Takahashi 20mm Kellner which is my sharpest AND brightest eyepiece, even beats out my Ortho Takahashi EPs. Something to be said for only having three glass elements even though it is only 45° fov I use it quite often. I do like my wide view eyepieces especially my 25 ED for finding objects, but I often will switch to an Ortho for a better view and I can just make out the Horsehead Nebula with a broadband filter in that 20mmKe. I need to get a proper filter, but they're really expensive, but it would be neat to zoom in on the Horsehead. My most expensive eyepiece is the Celestron Zoom 8mm-24mm I just bought this morning for my Max.

[@AVTAstro]

What scope are you seeing the Horsehead with? How dark is your sky?

[@Astro_Ape]

If you're wanting good views of the Horsehead you're going to need an Hβ filter, which is going to require a fairly large exit pupil to have enough transmission to get the contrast you're looking for. So you're basically gonna need a really large aperture scope if you're wanting to use much magnification at all. I don't own an Hβ but I know I can't pull out the Horsehead using any other filter I have (DGM NPB, OIII, or LPB) in an 8 inch scope from my Bortle 3.5 sky even with my best Baader and APM EP's which show fairly high contrast.

[@MountainFisher]

@@AVTAstro You know the one. Been recoated and refigured to Takahashi quality?

[@MountainFisher]

@@Astro_Ape Bortle 2 next to Bortle one on a military base and I said I could just make it out. I can see a small bump where it's supposed to be.

[@MountainFisher]

@@AVTAstro Oh I might add, I have an artificial lens on my seeing eye from cataract surgery.

[@Beaver-be8vk]

My first telescope as a 10 year old had a Kellner eyepiece and a orthoscopic. Man I’m old. 😩

[@AVTAstro]

Lol, 🤣🤣🤣

[@ziggyfrnds]

Thanks for sharing Vlad! I have a C9.25 and i've just ordered a Williams Optics branded SWAN 40mm, I should get it early next week. I was using my Explore Scientific 14mm 82 degree on it but that was just too much magnification with the C9.25 for any DSO. Let's see what kind of eyepiece Williams optics have conjured up :)

[@AVTAstro]

Congrats on the 40mm! That should be a good match for your SCT!

[@k.h.1587]

14mm, 1.4mm exit pupil is the perfect eyepiece for globular clusters in your scope. The 13-16mm range. Also planetary nebulae. Not all dso need low powers. And the 1.5mm exit pupil trick works on globulars in light pollution. I showed m13 at many an outreach with my 15mm superview in my 8 and 11s. And on high profile events I would bust out the 14mm es100. A 40mm swan was the most common first 2" eyepiece I would recommend and sell for scts when I was in the industry, but only for when the widest field possible was needed and not all DSOs look best at the lowest powers and 4mm, 5mm and 5.6mm exit pupils that 40, 50 and 56mm eyepieces give in f10 sct. The 1mm, 1.5, 2 and 3mm exit pupils also have their ideal targets The 4 mm and larger exit pupils come in handy with OIII and uhc filters on targets like the veil. That is when you want to go down to eyepieces like the 50mm axiom, 50mm tak LE, and 55-56mm plossls, where the larger exit pupil compensates for the light loss of the filter. This is where fast dobs and televue101 shine because you can do the same thing with a 26 or 31 nagler rather than a 55 plossl. But I kinda liked doing it on my c11 and 50 axiom

[@deepspacehunter]

I believe the plossl is still the industry standard.

[@AVTAstro]

I have no data on that. But it sure is pretty common. 👌

[@Awsimilate]

Well done thanks )

[@AVTAstro]

Glad you liked it! Thank, Vlad.

[@chrisshelton3504]

The unlabeled eyepiece resembles a Jaegers eyepiece. I have one and I have seen the unlabeled ones before.

[@AVTAstro]

Oh cool, thanks for the tip!

[@MarkMphonoman]

What is that little telescope on your window sill?

[@AVTAstro]

That's just a Chinese 4" Mak.

[@miker1721]

12:57 Optical coatings and the glue between the multiple lens do not last forever......

[@AVTAstro]

That is true. But in the 1000's of eyepieces that I have seen this is very atypical.

[@miker1721]

@@AVTAstro yes that one looks horrific! We are just at that period in time now when those eyepieces from the 80’s and 90’s are finally aging out.

[@AVTAstro]

It could be. I have seen a few older SCT correctors with coating issues. I think its a bit of what environment they were in over the years and maybe luck of the draw.

[@amazingsciencevlogs5690]

No hard feelings, but the 13mm Nagler eyepiece is quite Huge, and we get portable Refractor telescope, of the same size Nowadays, Buddy 😂🙏🏻🔭👍.

[@AVTAstro]

Lol, can't disagree. Still a great eyepiece though and a piece of hobby history!

[@k.h.1587]

And the 13mm type 6 is a very compact eyepiece in comparison

[@kmichaelp4508]

Question….

[@MarkMphonoman]

I have two RKE 28mm eyepieces for bino viewers. I am not impressed with my set, not to sharp.

[@AVTAstro]

Yeah it's more about the experience of using the eyepice to me.