I know that's a lot to think about - but think about it . I been thinking about that for a while . Great job nice slow and simple way of explaining . Opened my mind up for a wider view - Ha
One question, how do you know when an eyepiece quality surpasses your main telescope quality and then you get no additional advantage on getting a more expensive eyepiece ? I'll give you an example, I have a Celestron TrailSeeker 80 Spotting scope and a 114 LCM and I attached an Omni Ploss Celestron EP and I liked the quality of the image , however, I wouldn't know at what point an EP would be overkill ? In Celestron lineup would the limit be Omni , Ultima, Luminous? I'm kinda confused and I'm just very new to all of this
With a wider field of view and average seeing with a given telescope, does that mean you should opt for higher magnification eyepieces than you would with a narrow field of view? I am looking at a C9.25 and am opting for the 41 and 27 Panoptical, plus 21, 17, and 13 Ethos lenses. Geez, the eyepieces are nearly double the price of the scope!
A 9.25 inch Schmidt Cassegrain telescope is going to have a long focal length (2350mm to be exact, at least in common Celestrons) and that means that high magnification eyepieces (under 10mm) will only get use on nights with the best seeing conditions. Here's the set I would want for a 9.25 SCT. 31mm Nagler Type 5 - The undisputed king of both wide true and apparent field. One of the best finder eyepieces. Would give 75x magnification in the C9.25. 17mm Ethos - Great medium power and super wide apparent field. Very sharp eyepiece. Would give about 138x in the C9.25 10mm Ethos - Good high power eyepiece for a long focal length scope. Would give 235x in the C9.25 And that would get you through nearly all the observing demands you'll need and will cost less than your initial plans for a 5 piece set. On the rare night where you get pristine calm air in the skies and you can push the magnification to 300x or more, you could either get a shorter focal length eyepiece or use a focal extender/barlow lens with your eyepieces to essentially double your three eyepiece set into 6!
Your telescope is f/10 which means it'll be pretty easy going on the eyepieces you use. I would consider the Explore Scientific range as they are a lot more affordable than the Tele Vue range. I'd go Tele Vue if I was using a faster telescope, say below f/5.
I am totally sold on the quality of Televue eyepieces. I have owned a variety of Plossls, Radians, Naglers Ethos, and Delos. All are outstanding. Outstanding presentation!
So the eyepiece is like a microscope 🔬 for seeing that floating image? Hence the importance of quality optics.....then can we conclude that a telescope is a 2 part system ? The telescope itself and the eyepiece?
All I know is this company makes some of the best telescope eyepieces you can buy. I'm a fairly bright guy, but there was a lot he said I couldn't follow. Still, I appreciate an expert like him trying to teach us about eyepieces, it's kind of like listening to Spielberg speaking about filmmaking if you want to be a director.
Dave, that's the best explanation I've had on the oculars of my life. Thanks Dave and see you soon at NEAF! Merci Christophe pour ce grand moment passé avec ce Maître Opticien
This guy emanates a passion about his field of expertise. A rare find in today's socio/economic climate. Absolutely the most helpful and informative explanation on eyepieces I've found after doing hours of research on first purchase advice for new telescope and accessories purchase. TeleVue products are pricey, but you get what you pay for; I'm sure it will be money well spent. Thank you sir.
He inherited it from his father Al, very lucky to be endowed with such a life and business. I wish them the best of success, and will personally vouch as a happy TV customer. Clear skies from NOLA
Just ordered what may be the last Nagler 22mm 2” in stock. Should have it Saturday. It will replace the stock Plossls that came with my Evolution 8. Very excited!
Because it will likely be fuzzy, a 5x isn't made for wide field much above 60 degrees. Let's say your scope can max out at 400x with perfect seeing conditions (never happens btw) and you use that 5x Barlow, better use very very good eyepieces and keep the magnification under 300x for the best view. Only photographers tend to use those 5x Barlows for planetary pics. Might be good with an orthoscopic 18mm or larger. I have a 25 Fujiyama with a 45 degree fov, but for zooming in on Saturn I use a 3x Barlow and I had my mirror refigured to near perfect focus. My rule of thumb is use 75% of double my aperture. 235x through ED glass is very detailed.
Beginner Question Incoming : Can we use a 3-6 mm Zoom Tele Vue Nagler in combination with a 3X Barlow Tele Vue - on a Orion XT8 Dobsonian ? Would it work ? Is it worth ? Is it an overkill or inefficient ? I feel a bit overwhelmed .. so much to learn and catch up too . Thanks for your help and content!
XT8 is 1200mm Focal Length. Here's your mags with the 3-6mm Nagler Zoom: @ 6mm = 200x - With a 3x Barlow = 600x @ 5mm = 240x - With a 3x Barlow = 720x @ 4mm = 300x - With a 3x Barlow = 900x @ 3mm = 400x - With a 3x Barlow = 1200x Overkill for the most part as you may go up to 400x when the seeing allows, but that all depends on how good the figure of your mirror is, how good you have collimated your telescope, if it is cooled, etc.
Hello Mr. David. Gabriel Corban is here. I wonder if I talked to you on the phone today, from Europe (Jan. 6 2023 in the morning), about the thread for the I101 NP IS cover. If so, I feel very honored. You were very kind and gave me an absolutely brilliant idea to solve. The clip here is also excellent. Thank you very much and congratulations on everything you do for astrophotographers.
I can second that Tele Vue are among the finest eyepieces available and they have the best customer support out there (as in it's not unheard of to call in and get Dave or Al on the phone), they will fix and repair your eyepiece in the USA should it ever need attention and also let you know if it's safe to self-remove any parts from the eyepiece (like the lens barrel) without any lenses or retainers falling out.
Bonjour Francois-SK. L’intérêt est de ne pas ajouter de tirage derrière la barlow/powermate et donc s’utiliser la powermate au grossissement prévu. Si tu fais ça avec une barlow 2x, tu auras quelque-chose comme une barlow 3x... Je crois aussi que la powermate sera plus propre pour applanir correctement le champ. Christophe
I would say your max power is 300x XT8 is 1200 FL % 5mm = 300x So yeah look for something around 5mm for your max power. I’m not sure how much use you’ll get out of it. 300x is your limit
uh lol the next day I’m reading this post and realize the math is off. My XT12 1500FL / 5 mm = 300x The XT8 is 1200 fl / 5mm = 240x My recommendation is still 5mm at 240x. Anything above 250 things become distorted. You’ll still see Mars at 240
@@cdlc48 oui biensur, je l'ai visionnée d'abord en français puis ensuite en anglais, comme ça je connais le contexte si jamais il y a des passages que je ne comprends pas 😉
Great job David Nagler
Eyepiece optics explained by the man himself! If you don't understand it after this, well... Thank you for sharing this!
You’re welcomed! It was an honor and a pleasure to meet him!
I know that's a lot to think about - but think about it . I been thinking about that for a while . Great job nice slow and simple way of explaining . Opened my mind up for a wider view - Ha
Thanks very much Adam!
I expect to shoot a second part with David Nagler next time he'll come in Paris (2020 I guess).
Regards.
Christophe
So informative thank you
Excellent explanation
One question, how do you know when an eyepiece quality surpasses your main telescope quality and then you get no additional advantage on getting a more expensive eyepiece ?
I'll give you an example, I have a Celestron TrailSeeker 80 Spotting scope and a 114 LCM and I attached an Omni Ploss Celestron EP and I liked the quality of the image , however, I wouldn't know at what point an EP would be overkill ? In Celestron lineup would the limit be Omni , Ultima, Luminous? I'm kinda confused and I'm just very new to all of this
EXCELLENT video! Thanks.
With a wider field of view and average seeing with a given telescope, does that mean you should opt for higher magnification eyepieces than you would with a narrow field of view? I am looking at a C9.25 and am opting for the 41 and 27 Panoptical, plus 21, 17, and 13 Ethos lenses. Geez, the eyepieces are nearly double the price of the scope!
A 9.25 inch Schmidt Cassegrain telescope is going to have a long focal length (2350mm to be exact, at least in common Celestrons) and that means that high magnification eyepieces (under 10mm) will only get use on nights with the best seeing conditions. Here's the set I would want for a 9.25 SCT.
31mm Nagler Type 5 - The undisputed king of both wide true and apparent field. One of the best finder eyepieces. Would give 75x magnification in the C9.25.
17mm Ethos - Great medium power and super wide apparent field. Very sharp eyepiece. Would give about 138x in the C9.25
10mm Ethos - Good high power eyepiece for a long focal length scope. Would give 235x in the C9.25
And that would get you through nearly all the observing demands you'll need and will cost less than your initial plans for a 5 piece set. On the rare night where you get pristine calm air in the skies and you can push the magnification to 300x or more, you could either get a shorter focal length eyepiece or use a focal extender/barlow lens with your eyepieces to essentially double your three eyepiece set into 6!
Your telescope is f/10 which means it'll be pretty easy going on the eyepieces you use. I would consider the Explore Scientific range as they are a lot more affordable than the Tele Vue range. I'd go Tele Vue if I was using a faster telescope, say below f/5.
Don't you mention the fact that orrhoscopic are the best eyepieces?
This is the kind of information you have to digest more than once to understand. Very technical. P.s. David is a cool guy. 👍
I feel much smarter now. Thank you for sharing a small bit of your hard earned knowledge. We need more of this kind of info.
I am totally sold on the quality of Televue eyepieces. I have owned a variety of Plossls, Radians, Naglers Ethos, and Delos. All are outstanding. Outstanding presentation!
Thanks very much!
Brilliant discussion, consistent with the quality of their eyepieces and their telescopes.
So the eyepiece is like a microscope 🔬 for seeing that floating image? Hence the importance of quality optics.....then can we conclude that a telescope is a 2 part system ? The telescope itself and the eyepiece?
Exactly! A good eyepiece is important!
Christophe
All I know is this company makes some of the best telescope eyepieces you can buy. I'm a fairly bright guy, but there was a lot he said I couldn't follow. Still, I appreciate an expert like him trying to teach us about eyepieces, it's kind of like listening to Spielberg speaking about filmmaking if you want to be a director.
Dave, that's the best explanation I've had on the oculars of my life. Thanks Dave and see you soon at NEAF!
Merci Christophe pour ce grand moment passé avec ce Maître Opticien
Bro..you just knocked over a mortgage payment! be careful man.
Lol!
Nope. Don’t worry. We have 2 Televue’s eyepiece and 2 televue’d barlows... all bought as second hand.
Christophe
This guy emanates a passion about his field of expertise. A rare find in today's socio/economic climate. Absolutely the most helpful and informative explanation on eyepieces I've found after doing hours of research on first purchase advice for new telescope and accessories purchase. TeleVue products are pricey, but you get what you pay for; I'm sure it will be money well spent. Thank you sir.
He inherited it from his father Al, very lucky to be endowed with such a life and business. I wish them the best of success, and will personally vouch as a happy TV customer. Clear skies from NOLA
Just ordered what may be the last Nagler 22mm 2” in stock. Should have it Saturday. It will replace the stock Plossls that came with my Evolution 8. Very excited!
let us know what you think of your purchase!
So why don’t I just go lower power huge field and step that up with a 5x Barlow?
Because it will likely be fuzzy, a 5x isn't made for wide field much above 60 degrees. Let's say your scope can max out at 400x with perfect seeing conditions (never happens btw) and you use that 5x Barlow, better use very very good eyepieces and keep the magnification under 300x for the best view. Only photographers tend to use those 5x Barlows for planetary pics. Might be good with an orthoscopic 18mm or larger. I have a 25 Fujiyama with a 45 degree fov, but for zooming in on Saturn I use a 3x Barlow and I had my mirror refigured to near perfect focus. My rule of thumb is use 75% of double my aperture. 235x through ED glass is very detailed.
"Staff" modest😮
Thanks!
Beginner Question Incoming : Can we use a 3-6 mm Zoom Tele Vue Nagler in combination with a 3X Barlow Tele Vue - on a Orion XT8 Dobsonian ? Would it work ? Is it worth ? Is it an overkill or inefficient ? I feel a bit overwhelmed .. so much to learn and catch up too . Thanks for your help and content!
XT8 is 1200mm Focal Length. Here's your mags with the 3-6mm Nagler Zoom:
@ 6mm = 200x - With a 3x Barlow = 600x
@ 5mm = 240x - With a 3x Barlow = 720x
@ 4mm = 300x - With a 3x Barlow = 900x
@ 3mm = 400x - With a 3x Barlow = 1200x
Overkill for the most part as you may go up to 400x when the seeing allows, but that all depends on how good the figure of your mirror is, how good you have collimated your telescope, if it is cooled, etc.
Great explanation. Thanks for the video and getting David to talk for so long :)
Awesome interview! Thanks for putting this together
Thank you very much!
Hello Mr. David. Gabriel Corban is here. I wonder if I talked to you on the phone today, from Europe (Jan. 6 2023 in the morning), about the thread for the I101 NP IS cover. If so, I feel very honored. You were very kind and gave me an absolutely brilliant idea to solve. The clip here is also excellent. Thank you very much and congratulations on everything you do for astrophotographers.
I have an 1.25 focuser and my scopes f5, so why'd yall stop making 1.25 paracorrs?
Thanks for these clear and sharp explanations!
Super helpful.
man they are expensive
Felix Zeng I know.... but they are the best ever!
I can second that Tele Vue are among the finest eyepieces available and they have the best customer support out there (as in it's not unheard of to call in and get Dave or Al on the phone), they will fix and repair your eyepiece in the USA should it ever need attention and also let you know if it's safe to self-remove any parts from the eyepiece (like the lens barrel) without any lenses or retainers falling out.
Best explanation Ive ever heard.
Bonjour
Très intéressant
Pourriez-vous SVP, en dire plus sur le montage powermade sur APN ? Les intérêts, les défauts?
Bonjour Francois-SK.
L’intérêt est de ne pas ajouter de tirage derrière la barlow/powermate et donc s’utiliser la powermate au grossissement prévu. Si tu fais ça avec une barlow 2x, tu auras quelque-chose comme une barlow 3x...
Je crois aussi que la powermate sera plus propre pour applanir correctement le champ.
Christophe
La Chaine Astro - cdlc48 merci beaucoup ! Je suis tenté par la powermate televue présentée dans cette vidéo ! Ça à l’air de bonne qualité !
tout simplement bravo
What lens do I use for 8tx dobsonian High power f5.9 lenses
I would say your max power is 300x
XT8 is 1200 FL % 5mm = 300x
So yeah look for something around 5mm for your max power. I’m not sure how much use you’ll get out of it. 300x is your limit
uh lol the next day I’m reading this post and realize the math is off. My XT12 1500FL / 5 mm = 300x
The XT8 is 1200 fl / 5mm = 240x
My recommendation is still 5mm at 240x. Anything above 250 things become distorted. You’ll still see Mars at 240
merci pour cette vidéo, ça me permet de bosser mon anglais !
william demassias en effet! Même si elle est aussi intégralement en français!
@@cdlc48 oui biensur, je l'ai visionnée d'abord en français puis ensuite en anglais, comme ça je connais le contexte si jamais il y a des passages que je ne comprends pas 😉
I just love Nerds. They are passionate, serious and helpful.
Dude talked for 22 minutes but he said nothing! Get to the point dude