Hi John. I enjoyed this video and Red’s two videos. I know this is late but thought I would share. I have made my own Red’s Double Plossl. Got some tube at work. But I became obsessed with 2 inch outside diameter pipe. Mentioned in my local working men’s club and a pal told me he was throwing out an old glass TV stand, the type that has glass shelves separated by chrome stands or tubes. He gave me one to try. Well, it is like a machined part! The fit could not be more snug. He gave me all the rest for the price of a pint. I have lots to go at. Not sure if 2 inch is standard but worth noting if any are in second hand or thrift shops etc. Cheers.
The biggest issues with 52mm eyepiece that it passes lowest useful magnification for these scopes - they all give exit pupil above 7mm. So basically you reduce aperture of the scope.
@@TheStevecas9860 explain yourself please? Exit pupil = Aperture/Magnification. With 1200mm/200mm scope and 52mm eyepiece you get magnification of x23 and exit pupil of 8.6mm it is larger that largest dilated pupil of about 7mm (for adults even less) so you are basically going to loose some of the light. I don't tell it isn't useful but just to be aware. You can get same field of view with shorter focal length 2" eyepiece as long as they filed stop is the same.
Recently been looking at the Pliedes cluster and the whole of Orion's sword through a 1000mm 120 mm refractor and the view is stunning! Crystal clear all the way across the field of view! Just scanning around the sky is a joy!
As John said you can fit in the Pleiades easily the sword of Orion and Andromeda in one view. On a 1000mm focal length scope it gives you a real 2 and half-real degree flat edge-to-edge field of view crisp clear edge to edge and no chromatic aberration and an eye relief of about 2 or 3 inches so glasses wearers don't have to take them off!
That's amazing Steve! Yes I'd like to buy one but I'm in Australia and shipping from USA to Aus is too expensive for many small items :( But I'd be interested to know the price with shipping cost, I can ask my friends at the NSW amateur astro society if they're interested also, that will lower the shipping cost for me atleast :D
John that is so cool. That wide view should help you find things alot easier. Would love to see the🎉 Pleiades and Andromeda n such in a wide view. I'm envious. Have fun n clear skys.
John says that it gives the "green-fronted eyepieces a run for their money" is an epic statement and I agree! I have a few and they are amazing, For John to say this is to put these eyepieces in that class! Make one for yourself and be Amazed? The lenses I sent were Carl Zeiss Jena excellent optics from 2 pairs of 7x50s,s My next project is to encase them in an aluminium tube to pretty them up? Clear skies folks!
@refractor I am so impressed that you are impressed John and I hope people will make this as it is so easy to do!. Have sent a few out to fellow astronomers and they are loving them. Clear skies John
I bought my first telescope in 2017 for $100. It is a 10 inch Coulter Odyssey Dobsionian from the 80's and it came with just one eyepiece that I had never be enable to identify and it looks just like one of Red Henry's! I'm gonna have to run it by him and see but its still the clearest eyepiece I have in my arsenal. Now ive discovered the joy of ripping old optical equipment apart to make eyepieces any which way! It might sound like overkill but I also test them with a Geiger counter because _ya never know what that glass is made of_ LoL
@@AstronomyGarage I have heard of this but I,m sure they are harmless! if you think about it why make something radioactive that could damage your eyes over long periods?
I regret tossing out my broken binoculars, I want to make a set myself! Pretty cool to repurpose and reuse, less waste and as an be donated to someone starting out.
Hi John just woke up at five am and grabbed my 10x50s .Jupiter nSaturn out. My hands r to schaky .. i also seen the Pleiades nHyades in Taurus.Going to put the 6 incher out tonight. Thanks for the videos
Red's video shows how easy it is (it's a step-by-step video). No machining necessary because the retention rings that come out of the binoculars line everything up. It looks surprisingly easy.
I just made a 2X Barlow from a converted camera teleconverter lens I bought on eBay for $4 using Red Henry's instructions. I am about to start dismantling some old binoculars I had laying around too. I found it's easier to use the throwaway EP bodies that come with cheap scopes instead of buying and cutting tubing to fit. Most cheap EP's have screw in lenses that are simple to take out.
That is awesome! Its been so dry and dusty out here in NE Texas. I've been hesitant to bring my 12-inch dob out for fear of having to clean the mirrors when done.
@@AstronomyGarage Yes. I probably need to add some dirt or sand around our foundation or face a huge repair bill down the road. Just got a new roof on all of our buildings. Same weekend my daughter broke her leg just below the knee and doesn't have insurance. Don't need no more billable lessons.
Well I made a 50mm double-plossel. Used 3:1 Marine Grade black 50mm heat shrink...stretch it a bit with slipjoint pliers, it will fit just fine. Eyepiece is SIMPLY AMAZING in my 102mm long focus refractor. I used a 7x35 binocular eyepiece and a .965" barrel and made a GREAT eyepiece for my 1960s vintage 76mm refractor.
I've seen the video on how to make them - which is surprisingly easy, and I should be able to make one soon - the 52mm RDP attracts for giving a full M45 fov...it will be hugely fun. For NZ$50....
Folks what John didn't mention is that the field of view is flat all the way across the eyepiece. as mentioned in Red Henry's video if you care to look at how to make it! I am so grateful that I found my friend Red he is sharing a game changer on how to make inexpensive eyepieces that perform incredibly! Clear skies folks!
Following up here. I watched Red Henry’s videos and made one of his Double Plössl from two unfixable binoculars. It ended up with a focal length of 58 mm with an AFOV of 47°. I acknowledge the limitations of using such an eyepiece on a fast dob, but I tried it anyway. I was impressed with the sharp wide field free of defects. It may not be suitable for observing DSOs but I can see circumstances where the low-power wide field would be nice to have.
Thanks for comment - I'm glad it worked out for you. With a focal length of 54mm on a typical Dob, you're delving into the world of the "rich field" telescope... essentially not much magnification. But with a dark sky, such views can be spectacular.
@refractor John let us know when you have a chance to use the 52mm at a dark sky site with your 12-inch Newtonian? Clear skies to thee oh Master from your padawan!
What about a 35 mm camera lens reverse mounted so you're looking in the out glass? It seems like a quality 28 or 35mm lens in an undesirable mount could be a good eyepiece.-
That very well could be excellent. The second-hand eyepiece group uses lots of different lens sources - I think binoculars are the most popular just because they are extremely cheap.
@@TheStevecas9860sorry for the delayed reply! A 50 mm eyepiece in a 1000 mm gives a magnification of 20x. If the true field of view is 2.5° then the AFOV if the eyepiece is 50°.
Great video John, thanks for informing us about this! I recently threw away a wonky 70x15 binoculars and now I'm regretting it :( Is there any way we can purchase these eyepieces? And I had issues with coma with a 40mm 68 degree FOV eyepiece on my 12 inch F5 reflector, But you tested on your dob (which I think is also F5) and found little coma.....thats incredible for a homemade eyepiece!
I've used my home-made eyepiece several times so far and haven't run into any chromatic aberations or pin cushioning. It's sharp all the way out to the edges. I suspect it may be due to the binocular lenses being optimized out the wazzoo for perfect visuals.
Great video, John. These are indeed amazing eyepieces. I have two 1.25" eyepieces and a diagonal Red Henry sent me when I was starting out a few years ago and they are incredible performers. Shout out and a thank you to Red and Steve for what they do! 🙌🏽
Is there such a thing as “too low” a magnification? A 50 mm eyepiece on a 300 mm (12”) f/5 Newtonian gives 30x, but the exit pupil is 10 mm. The pupil of your eye (let’s say 5 mm) can’t take it all in. In other words, your ‘scope is effectively a 6” f/10. I hope you will follow up with a dark-sky test.
Good question. They worked great in my two Dobs that I tested - those were 1200mm and 1500mm. I do have a 300mm refractor, but it's for 1.25" eyepieces and I think the internal baffling would fudge with the view "cone" via the baffling. I would say if there is a limit, it's due to the baffling structures. I'll let Steve answer that since he has way more experience.
Well, there’s a comet that’s currently between the orbits of Jupiter and Saturn that could become as bright as magnitude -5, but it’ll only be here in late 2024.
I don't get it, if these are so nice and big and easy to make why aren't the big name brands making their own versions of these wonderful eyepieces?...i would buy one just so i wouldn't have to make it from old binoculars spare lenses. I'm old and tired of making stuff, hopefully other manufacturers will start selling these. 🤞
I'm not sure if they could do it profitably. These take advantage of big binocular lenses, so the raw materials are, at a minimum, about $50 if bought new.
Here is another review from another astronomer Andy Moony. I Now Pretty them up incasing the lenses in an Aluminum tube th-cam.com/video/7_AdypYuSzA/w-d-xo.html.
I promise that it's wrapped very solidly. No wobbly bits. I think that this electrical tape wrapping is standard procedure for the home-made eyepieces.
@@AstronomyGarage John I only use the electrical tape now because if I used super glue it tended to bleed over onto the eyepiece and it was a pain to remove using acetone.
@@TheStevecas9860 I was worried about how runny super glue can be when I watched Red's video, but I think he was using it instead of epoxy just for demonstration sake.
@@AstronomyGarage I don't use super glue as I have found the fumes tend to bleed through onto the lenses and it has to be cleaned off with acetone. I just use the insulation tape
As others have said, FACEPALM! Folks, please learn to understand about exit pupil. I love me some 50mm to 56mm goodness. But i dont use them in dobs, they are for slower focal ratio systems. SCTs and slow refractors. The reason deep space objects looked like crap is because larger exit pupils actually AMPLIFY the light pollution, and you are also LOSING light by exceeding the 7mm exit pupil, and since you are likely over 50, your pupil is probably 6mm or even 5mm. So many "experts" in this hobby fail to grasp or understand this crucial concept, and basically, most "are doing it wrong", and more importantly, "thinking it wrong as well" There are those basics that we are taught, but if we apply them universally, we are frequently not optimizing our views. I facepalmed at an outreach where a guy with scts, hence the need for a 55m plossl, was using it to show people stuff, probably the moon (this was a long time ago), in his 10" dob, that's right, an 11.7mm exit pupil! And I double facepalmed when he kept referring to it as a "55mm nagler". Dont bother with a 52mm eyepiece on any telescope faster than f8, and even then, only in dark skies, or when going for the veil with an OIII filter , but I dont think that eyepiece has filter threads. I did find red Henry's double plossl interesting, and the claims of it having good edge correction in fast scopes also interesting. However, it is at a focal length that is not practical for said fast telescopes. But if you have an SCT, have at it, it would be an excellent view of the bigger objects, in dark skies. 5.2mm exit pupil is still too big for light pollution unless used with a nebula filter.
@reflactor don't need to be a professional astronomer to learn about exit pupil. But many in the hobby don't unfortunately. And most professional astronomers never even come near an amateur telescope in their work ;)
Hi John. I enjoyed this video and Red’s two videos. I know this is late but thought I would share. I have made my own Red’s Double Plossl. Got some tube at work. But I became obsessed with 2 inch outside diameter pipe. Mentioned in my local working men’s club and a pal told me he was throwing out an old glass TV stand, the type that has glass shelves separated by chrome stands or tubes. He gave me one to try. Well, it is like a machined part! The fit could not be more snug. He gave me all the rest for the price of a pint. I have lots to go at. Not sure if 2 inch is standard but worth noting if any are in second hand or thrift shops etc. Cheers.
That is an excellent tip! My cheap Ikea desk here has 2 inch tubes like that, so I bet these are a great resource.
The biggest issues with 52mm eyepiece that it passes lowest useful magnification for these scopes - they all give exit pupil above 7mm.
So basically you reduce aperture of the scope.
But it can be useful with SCT like C8 giving exit pupil of 5.2 and x38 magnification
So have you used one in real life?
You are totally wrong!
@@TheStevecas9860 explain yourself please?
Exit pupil = Aperture/Magnification. With 1200mm/200mm scope and 52mm eyepiece you get magnification of x23 and exit pupil of 8.6mm it is larger that largest dilated pupil of about 7mm (for adults even less) so you are basically going to loose some of the light. I don't tell it isn't useful but just to be aware. You can get same field of view with shorter focal length 2" eyepiece as long as they filed stop is the same.
@@artyombeilis9075 Just use one
What fantastic way to repurpose old lenses. Great video and a big shout out to some incredibly innovative astronomers.
Thank you! @deepskymike767
Glad you enjoyed it!
Recently been looking at the Pliedes cluster and the whole of Orion's sword through a 1000mm 120 mm refractor and the view is stunning! Crystal clear all the way across the field of view! Just scanning around the sky is a joy!
And doing that requires a pretty low-magnification eyepiece, like your giant 52mm home-made Plossl!
Yes it does the job @@AstronomyGarage
THANKS JOHN !!
Thanks for watching!
As John said you can fit in the Pleiades easily the sword of Orion and Andromeda in one view. On a 1000mm focal length scope it gives you a real 2 and half-real degree flat edge-to-edge field of view crisp clear edge to edge and no chromatic aberration and an eye relief of about 2 or 3 inches so glasses wearers don't have to take them off!
The 50mm wide lens is about the same width as my eyeglasses - I still take them off just out of habit, lol.
That's amazing Steve! Yes I'd like to buy one but I'm in Australia and shipping from USA to Aus is too expensive for many small items :(
But I'd be interested to know the price with shipping cost, I can ask my friends at the NSW amateur astro society if they're interested also, that will lower the shipping cost for me atleast :D
John that is so cool. That wide view should help you find things alot easier. Would love to see the🎉 Pleiades and Andromeda n such in a wide view. I'm envious. Have fun n clear skys.
Thanks for watching! I look forward to using this in really dark skies!
John says that it gives the "green-fronted eyepieces a run for their money" is an epic statement and I agree! I have a few and they are amazing, For John to say this is to put these eyepieces in that class! Make one for yourself and be Amazed? The lenses I sent were Carl Zeiss Jena excellent optics from 2 pairs of 7x50s,s My next project is to encase them in an aluminium tube to pretty them up? Clear skies folks!
I've enjoyed them quite a bit and look forward to when Orion starts showing up in the evening!
@refractor I am so impressed that you are impressed John and I hope people will make this as it is so easy to do!. Have sent a few out to fellow astronomers and they are loving them. Clear skies John
I bought my first telescope in 2017 for $100. It is a 10 inch Coulter Odyssey Dobsionian from the 80's and it came with just one eyepiece that I had never be enable to identify and it looks just like one of Red Henry's! I'm gonna have to run it by him and see but its still the clearest eyepiece I have in my arsenal. Now ive discovered the joy of ripping old optical equipment apart to make eyepieces any which way! It might sound like overkill but I also test them with a Geiger counter because _ya never know what that glass is made of_ LoL
Thanks for watching! $100 for an Odyssey is a pretty fantastic deal. You have piqued my curiosity - were eyepieces ever made from radioactive glass?
@@AstronomyGarage I have heard of this but I,m sure they are harmless! if you think about it why make something radioactive that could damage your eyes over long periods?
Looks great John I've never heard of home made eyepieces till now very impressed.
I'm very new to them too. It's a great way to get a high performance 52mm at little cost. The view was excellent even in my fast Dob.
@dumpydalekobservitory Make one it will blow you away!
I regret tossing out my broken binoculars, I want to make a set myself! Pretty cool to repurpose and reuse, less waste and as an be donated to someone starting out.
I didn't even know such recycling was possible until just a little while ago. Cool stuff. Thanks for watching!
Hi John just woke up at five am and grabbed my 10x50s .Jupiter nSaturn out. My hands r to schaky .. i also seen the Pleiades nHyades in Taurus.Going to put the 6 incher out tonight. Thanks for the videos
Yup, it's planetary season for early birds. Unfortunately, I'm more of a night owl, lol.
i couldnt built that as that beyond me but nice to see some people do
Red's video shows how easy it is (it's a step-by-step video). No machining necessary because the retention rings that come out of the binoculars line everything up. It looks surprisingly easy.
th-cam.com/video/iEUEvv4s3N4/w-d-xo.html
Joe it really is easy!
Interesting.
I agree. I didn't even know people did this until I heard about Red and Steve.
I just made a 2X Barlow from a converted camera teleconverter lens I bought on eBay for $4 using Red Henry's instructions. I am about to start dismantling some old binoculars I had laying around too. I found it's easier to use the throwaway EP bodies that come with cheap scopes instead of buying and cutting tubing to fit. Most cheap EP's have screw in lenses that are simple to take out.
Congrats on saving money and re-purposing old equipment.
I,m doing the same @ericbarnett6771 some old Tameron teleconverters!
That is awesome! Its been so dry and dusty out here in NE Texas. I've been hesitant to bring my 12-inch dob out for fear of having to clean the mirrors when done.
I understand that. Our yard is pulling away from our foundation despite watering it. These 108 degree days are drying things up quick!
@@AstronomyGarage Yes. I probably need to add some dirt or sand around our foundation or face a huge repair bill down the road. Just got a new roof on all of our buildings. Same weekend my daughter broke her leg just below the knee and doesn't have insurance. Don't need no more billable lessons.
@@strat1960s When it rains, it pours. Be careful out there.
Ill be looking at this option.
Thanks for watching!
th-cam.com/video/iEUEvv4s3N4/w-d-xo.html
Oh good grief! I own 17 pairs of binoculars AND some old cameras...I must try this for myself!!
Be sure to watch Red's video. Just take two identical binoculars and scavenge the main primary lenses. He makes it look pretty easy!
John, I will, and I am immediately thinking of heat-shrink, vs. tape...I will keep you posted
@@markscungio2996 Hi let me know if you find a source for that ?
I would love to see when you make one!
Well I made a 50mm double-plossel. Used 3:1 Marine Grade black 50mm heat shrink...stretch it a bit with slipjoint pliers, it will fit just fine. Eyepiece is SIMPLY AMAZING in my 102mm long focus refractor. I used a 7x35 binocular eyepiece and a .965" barrel and made a GREAT eyepiece for my 1960s vintage 76mm refractor.
I've seen the video on how to make them - which is surprisingly easy, and I should be able to make one soon - the 52mm RDP attracts for giving a full M45 fov...it will be hugely fun. For NZ$50....
Let me know how it goes. I like to keep this one on my worktable for quick access. Steve Case did a good job building it.
What about:
1) apparent field of view
2) off axis performance
3) performance in fast scope
Folks what John didn't mention is that the field of view is flat all the way across the eyepiece. as mentioned in Red Henry's video if you care to look at how to make it! I am so grateful that I found my friend Red he is sharing a game changer on how to make inexpensive eyepieces that perform incredibly! Clear skies folks!
From edge to edge. It's impressive.
Following up here. I watched Red Henry’s videos and made one of his Double Plössl from two unfixable binoculars. It ended up with a focal length of 58 mm with an AFOV of 47°. I acknowledge the limitations of using such an eyepiece on a fast dob, but I tried it anyway. I was impressed with the sharp wide field free of defects. It may not be suitable for observing DSOs but I can see circumstances where the low-power wide field would be nice to have.
Thanks for comment - I'm glad it worked out for you. With a focal length of 54mm on a typical Dob, you're delving into the world of the "rich field" telescope... essentially not much magnification. But with a dark sky, such views can be spectacular.
@refractor John let us know when you have a chance to use the 52mm at a dark sky site with your 12-inch Newtonian? Clear skies to thee oh Master from your padawan!
Will do. Given the weather, it's going to be a while.
What about a 35 mm camera lens reverse mounted so you're looking in the out glass? It seems like a quality 28 or 35mm lens in an undesirable mount could be a good eyepiece.-
That very well could be excellent. The second-hand eyepiece group uses lots of different lens sources - I think binoculars are the most popular just because they are extremely cheap.
Another cool vid.
Thanks! But Steve Case did all the hard work - he actually built the eyepiece. :) Clear skies!
Fascinating video. What does something like this normally cost?
Cost to build about £50 $60
@@TheStevecas9860 that's incredibly reasonable. Very nice.
Cool! What is the apparent field of view of the big eyepiece?
With a 1000mm focal length scope 5 to 6 moon diameters 2 and a half degrees real field!
OK so the AFOV of the eyepiece itself is 50°
@@DavidMFChapman Can you explain how you work it out?
@@TheStevecas9860sorry for the delayed reply! A 50 mm eyepiece in a 1000 mm gives a magnification of 20x. If the true field of view is 2.5° then the AFOV if the eyepiece is 50°.
@@DavidMFChapman I was going by how many moon diameters you can see and fit in with it with a 1000mm f length telescope!
I'm surprised there are no plans available to 3D print eyepiece cases for the used binocular lenses.
That's a good point. Steve Case is now making casings for these that make them look super professional.
Great video John, thanks for informing us about this! I recently threw away a wonky 70x15 binoculars and now I'm regretting it :(
Is there any way we can purchase these eyepieces? And I had issues with coma with a 40mm 68 degree FOV eyepiece on my 12 inch F5 reflector, But you tested on your dob (which I think is also F5) and found little coma.....thats incredible for a homemade eyepiece!
I've used my home-made eyepiece several times so far and haven't run into any chromatic aberations or pin cushioning. It's sharp all the way out to the edges. I suspect it may be due to the binocular lenses being optimized out the wazzoo for perfect visuals.
I was in the middle of asking you if it would be better to make it a Crayford focuser. Then the last minute of the video played.😅 Great idea though.
Thank you for watching. :)
How's the eye relief?
I tested it tonight and I'd say it's about 20mm. It's a pretty enjoyable eyepiece.
Great video, John. These are indeed amazing eyepieces. I have two 1.25" eyepieces and a diagonal Red Henry sent me when I was starting out a few years ago and they are incredible performers. Shout out and a thank you to Red and Steve for what they do! 🙌🏽
Thank you
I would send you one at shipping cost from the UK?
@@TheStevecas9860 oh wow, that would be awesome! Thank you!
Thank you for your appreciation @NanHernanadezP the 52mm is a game changer for wide sharp fields of view
@NanuHernandezP Thank you and clear skies!
I hope you can use them in a dark sky.
Thanks! I hope so. Our astronomical society has a dark site to go to. It takes planning though because it's far away.
Is there such a thing as “too low” a magnification? A 50 mm eyepiece on a 300 mm (12”) f/5 Newtonian gives 30x, but the exit pupil is 10 mm. The pupil of your eye (let’s say 5 mm) can’t take it all in. In other words, your ‘scope is effectively a 6” f/10.
I hope you will follow up with a dark-sky test.
Trust me they work great on all telescopes!
Good question. They worked great in my two Dobs that I tested - those were 1200mm and 1500mm. I do have a 300mm refractor, but it's for 1.25" eyepieces and I think the internal baffling would fudge with the view "cone" via the baffling. I would say if there is a limit, it's due to the baffling structures. I'll let Steve answer that since he has way more experience.
@@AstronomyGarage I use the 52mm on my 120mm 1000 focal length Refractor and it works like a dream!
Random question: have you ever seen a comet or attempted to see one?
In my entire life? Yes. I saw the Halley's Comet (very dim), the Hale-Bopp which was mind-blowingly big and bright, and the Neowise (also very dim).
Well, there’s a comet that’s currently between the orbits of Jupiter and Saturn that could become as bright as magnitude -5, but it’ll only be here in late 2024.
@@klttrll That's good to know. I'd love for something to approach the brightness and size of Hale Bopp. That was truly amazing.
I bet it was
@refractor I noticed I forgot to blacken the inside of the Aluminum barrel, oops!
No problem. It didn't seem to affect anything. I might paint it if I find the time.
I don't get it, if these are so nice and big and easy to make why aren't the big name brands making their own versions of these wonderful eyepieces?...i would buy one just so i wouldn't have to make it from old binoculars spare lenses. I'm old and tired of making stuff, hopefully other manufacturers will start selling these. 🤞
I'm not sure if they could do it profitably. These take advantage of big binocular lenses, so the raw materials are, at a minimum, about $50 if bought new.
Here is another review from another astronomer Andy Moony. I Now Pretty them up incasing the lenses in an Aluminum tube th-cam.com/video/7_AdypYuSzA/w-d-xo.html.
Nice EP but wrapped terribly!
I promise that it's wrapped very solidly. No wobbly bits. I think that this electrical tape wrapping is standard procedure for the home-made eyepieces.
@@AstronomyGarage John I only use the electrical tape now because if I used super glue it tended to bleed over onto the eyepiece and it was a pain to remove using acetone.
Why are you so negative about it? I and Red are trying to help people all around the world and all you can say is it is wrapped Terribly!
@@TheStevecas9860 I was worried about how runny super glue can be when I watched Red's video, but I think he was using it instead of epoxy just for demonstration sake.
@@AstronomyGarage I don't use super glue as I have found the fumes tend to bleed through onto the lenses and it has to be cleaned off with acetone. I just use the insulation tape
To save you bending over (which can't be very comfy when viewing), why don't you make or buy a small table?
Good question. I have an 18 inch wood box that I usually use, but didn't in this instance.
As others have said, FACEPALM!
Folks, please learn to understand about exit pupil.
I love me some 50mm to 56mm goodness.
But i dont use them in dobs, they are for slower focal ratio systems. SCTs and slow refractors.
The reason deep space objects looked like crap is because larger exit pupils actually AMPLIFY the light pollution, and you are also LOSING light by exceeding the 7mm exit pupil, and since you are likely over 50, your pupil is probably 6mm or even 5mm.
So many "experts" in this hobby fail to grasp or understand this crucial concept, and basically, most "are doing it wrong", and more importantly, "thinking it wrong as well"
There are those basics that we are taught, but if we apply them universally, we are frequently not optimizing our views. I facepalmed at an outreach where a guy with scts, hence the need for a 55m plossl, was using it to show people stuff, probably the moon (this was a long time ago), in his 10" dob, that's right, an 11.7mm exit pupil! And I double facepalmed when he kept referring to it as a "55mm nagler".
Dont bother with a 52mm eyepiece on any telescope faster than f8, and even then, only in dark skies, or when going for the veil with an OIII filter , but I dont think that eyepiece has filter threads.
I did find red Henry's double plossl interesting, and the claims of it having good edge correction in fast scopes also interesting. However, it is at a focal length that is not practical for said fast telescopes.
But if you have an SCT, have at it, it would be an excellent view of the bigger objects, in dark skies. 5.2mm exit pupil is still too big for light pollution unless used with a nebula filter.
I am firmly in the amateur category.
@reflactor don't need to be a professional astronomer to learn about exit pupil. But many in the hobby don't unfortunately.
And most professional astronomers never even come near an amateur telescope in their work ;)