Author Topic: $500 to spend on eyepiece/diagonal  (Read 426 times)

glyctetabung

  • Active Astronomer
  • ***
  • Posts: 114
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #15 on: January 12, 2018, 12:57:18 AM »
I just placed an order for baader zoom eyepiece and celestron focal reducer. I think this will be a yearly thing from now on. Already start thinking what to get next year with $500...

Chris Jiles

  • Active Astronomer
  • ***
  • Posts: 116
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #16 on: January 12, 2018, 03:10:56 AM »
I can't advise you on diagnals.

I have two zoom eyepieces - Celestron 8-24 and the Baader 8-24. I like them both but the Baader is clearly the superior choice.  Go with it!

chuckgemslerswe

  • Active Astronomer
  • ***
  • Posts: 119
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #17 on: January 12, 2018, 09:14:35 AM »
Quote
Quote

The F6.3 reducer/corrector sounds great in theory and it works well too but you either leave it on or leave it off as it is not a quick change device and each time you change you expose the rear cell to the open air and dust. (Yes an open diagonal exposes too but not quite as directly). If it's windy and dust you don't want to be exposing the rear cell with or without a diagonal and just leave the eyepiece in place and clean it very carefully when you get home.

Plan your viewing before you get there. Is the moon up, what phase? When does it set? What planets are up and when do they rise and set? Kids love planets and the moon through telescopes. As for wide fields many first timers don't understand what field of view they are seeing and usually think they're looking at entire constellations. Just tell them the field of view is less than the width of their fingernail at arms length ( and then watch every kid place they're arm out; it's fun).

I think an 8-24mm zoom would be a great eyepiece for such a field trip. Add a 24/68 or 32mm Plossl for the low power end and that's all you need. A UHC filter is great but it will cost a bit and you will be putting it on and taking it off a bit so weigh that up in your decision. You will likely want to use it with a low power eyepiece only on say the Orion nebula but it is rapidly disappearing in the west. It is not an essential item, I think for this trip.

Whatever you choose, enjoy!

Great suggestions on planning. Also agree about the UHC filter.

I've been putting on and taking off the R/C for about 25 years.  It goes on for star hopping and extended objects. It comes off for planetary or other high-power work.  I can make the switch in less than a minute, and it really has never seemed that much of a hassle to me (and you can cut the switch hassle factor almost in half by buying an extra visual back). Nor have I ever worried about leaving the rear cell open for five-ten seconds at a time.  Newts are open all the time you are observing (and not just a 38mm hole). Even if there is wind, it only matters if it is blowing directly at the back of the scope, and if that is the case, I make a rather effective windbreak (far too effective these days...).  If I lived where it was dustier, maybe I'd feel differently.
.
I went to a star party once where a someone had a large SCT. It was windy and dusty at times and the user was afraid to even swap eyepieces and made a point of it and I guess this is where it got into my head. I had not owned anything but a Newtonian at the time. Now I have a Newtonian, refractor and SCT and I think the point of keeping dust getting in is that it is a lot harder to get it out with a refractor and SCT whereas a Newtonian is easily cleaned.

As for the f6.3 R/C it is a nice piece of gear but I soon got tired of unscrewing it and screwing it back on also fearing to I would wear the threads out too but mainly I just found it a pain to swap. I went the 2" visual back path but I'm tempted to go back to the 1.25" either with R/C left in place or removed for an given evening of viewing as I'd rather work closer to the design focal length. YMMV.

trigitsipo

  • Active Astronomer
  • ***
  • Posts: 136
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #18 on: January 12, 2018, 10:41:57 AM »
The baader zoom is a good choice. Next year get better quality EPs at specific focal lengths. The ES 68 24MM recommended by jallbery is a great choice as is ES 82 11mm.

Maybe look into good UHC filter or OII filter for next year to get better views of nebula for the group. Chance for a specific viewing session.

ithoclirans

  • Active Astronomer
  • ***
  • Posts: 123
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #19 on: January 13, 2018, 06:41:28 AM »
Quote
From all the suggestions, seems like aF6.3 reducer/corrector is a good buy for this event. Can someone post a link for the recommendedF6.3 reducer/corrector?

I highly recommend the Celestron as it is both reducer and corrector. I use it often during star parties to provide a great wide view.
I originally purchased another brand and I didn't care for it all. You can often see this listed in CN, for cheaper than the list price here: http://www.highpoint...corrector-94175

NOTE: I am not a vendor, but I do often purchase items from the site I listed.

Gary

Robert Spencer

  • Active Astronomer
  • ***
  • Posts: 127
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #20 on: January 14, 2018, 01:05:34 AM »
With $500 budget, I bought Baader zoom 8-24mm eyepiece, celestron F6.3 reducer/corrector, and a set of vibration suppression pad. It came out to be just under $500.

Thank you for the input, guys. You are as always, very helpful.

I will post the same question this time next year! Have fun at night time!

Nick Ellis

  • Active Astronomer
  • ***
  • Posts: 140
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #21 on: January 18, 2018, 03:08:22 AM »
From my perspecitve Zooms are a CN fad...not popular among members of my club, and as for me, the one I had I got rid of.   The focal reducer is not a good idea because it will gray the sky (loss of background sky contrast) and it defeats the purpose of the zoom. For a visual observer, why lower the magnification to jack it back up again? Crazy. *There is no net gain in field of view* with the focal reducer. Any way you do it, 1.2 degrees is all you're going to get out of a c8. Sky contrast will be better with the Pan 24.

In 1.25 inch format the 24 Pan Optic will give you maximum field of view for the instrument with its current visual back and diagonal.  The 24 Pan and a 10 to 14 mm are all you need to show off deep sky and planets. In 1.25 inch format you'll be limited to about 50 arc minutes field of view, a bit better than a C14. (In other words, FOV in a c8 in 1.25 inch format is pretty narrow).  In two inch format you'll get close to 1.2 degrees. It's a lot more sky real estate.

I disagree with spending money on a 1.25 diagonal. The one you have will be fine and the replacement should be part of a coherent plan to move up to 2" format.

Given the long string of prior posts I think the (poor, IMO) decision for a focal reducer has already been made, but in the end, anything you buy can be re-sold, and the c8 is a nice observing platform.

Good luck,

Greg N

Tye Paez

  • Active Astronomer
  • ***
  • Posts: 131
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #22 on: January 18, 2018, 04:41:15 AM »
Quote
From my perspecitve Zooms are a CN fad...not popular among members of my club, and as for me, the one I had I got rid of.  The focal reducer is not a good idea because it will gray the sky (loss of background sky contrast) and it defeats the purpose of the zoom. For a visual observer, why lower the magnification to jack it back up again? Crazy. *There is no net gain in field of view* with the focal reducer. Any way you do it, 1.2 degrees is all you're going to get out of a c8. Sky contrast will be better with the Pan 24.

In 1.25 inch format the 24 Pan Optic will give you maximum field of view for the instrument with its current visual back and diagonal.  The 24 Pan and a 10 to 14 mm are all you need to show off deep sky and planets. In 1.25 inch format you'll be limited to about 50 arc minutes field of view, a bit better than a C14. (In other words, FOV in a c8 in 1.25 inch format is pretty narrow).  In two inch format you'll get close to 1.2 degrees. It's a lot more sky real estate.

I disagree with spending money on a 1.25 diagonal. The one you have will be fine and the replacement should be part of a coherent plan to move up to 2" format.

Given the long string of prior posts I think the (poor, IMO) decision for a focal reducer has already been made, but in the end, anything you buy can be re-sold, and the c8 is a nice observing platform.

Good luck,

Greg N

How does having a focal reducer defeat the purpose of a zoom? The purpose of a zoom is to offer a wide range of magnifications without the need to change eyepieces.  If you thought it had another purpose perhaps that is why you got rid of yours.As for zooms I would agree that they have not been especially popular in my club either. But I would not call them a CN fad, I would call them a growing trend, especially around newer users who don't have a ton invested in older eyepieces. Over the past year the usage and purchases of zooms in my club seems to have been increasing.

The Baader Hyperion Zoom and the Celestron Zoom are the two that seem to be getting the most activity.

The Celestron has typically been the "giving it a try" purchase and for those who are typically buying lower end eyepieces such as those adding to the eyepieces that they got with their first scope. That is when I purchased mine and that is when I fell in love with it.The Baader Hyperion Zoom is the one that people are upgrading to or for those who are typically using higher end eyepieces. There are people who have more or less standardized on this zoom. I provide links to discussions about this earlier. High end users who start with the zoom and only pull out the single FL eyepieces where their slight advantage would be beneficial.  I to do this when I start getting over 200X. I can barlow the zoom or pull out my ES 82s.  Most of the time the zoom or zoom + barlow stays in the focuser. It is not an either or situation.  For me it is picking the right tool for the job.

Zooms may not have been especially popular in the past but I think that is changing.   Just my observation.

I like zooms but they are not for everyone and I feel people should use whatever they like.

Baader Hyperian Mark III Clickstop zoom reviewhttp://www.weasner.c...iece/index.html

Baader Hyperion Mark IV - The current modelhttps://www.cloudyni...-zoom-eyepiece/

Baader Zoom Vs Fixed Eyepieces - This will open your eyeshttp://www.cloudynig...m-vs-fixed-eps/
Baader Mark III discussion
http://www.cloudynig...l=+baader +zoom

ransgesislu

  • Active Astronomer
  • ***
  • Posts: 114
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #23 on: January 18, 2018, 07:48:18 AM »
Quote
From my perspecitve Zooms are a CN fad...not popular among members of my club, and as for me, the one I had I got rid of.   The focal reducer is not a good idea because it will gray the sky (loss of background sky contrast) and it defeats the purpose of the zoom. For a visual observer, why lower the magnification to jack it back up again? Crazy. *There is no net gain in field of view* with the focal reducer. Any way you do it, 1.2 degrees is all you're going to get out of a c8. Sky contrast will be better with the Pan 24.

In 1.25 inch format the 24 Pan Optic will give you maximum field of view for the instrument with its current visual back and diagonal.  The 24 Pan and a 10 to 14 mm are all you need to show off deep sky and planets. In 1.25 inch format you'll be limited to about 50 arc minutes field of view, a bit better than a C14. (In other words, FOV in a c8 in 1.25 inch format is pretty narrow).  In two inch format you'll get close to 1.2 degrees. It's a lot more sky real estate.

I disagree with spending money on a 1.25 diagonal. The one you have will be fine and the replacement should be part of a coherent plan to move up to 2" format.

Given the long string of prior posts I think the (poor, IMO) decision for a focal reducer has already been made, but in the end, anything you buy can be re-sold, and the c8 is a nice observing platform.

Good luck,

Greg N

To move my 8SE to 2" format will require a new mount, which the advance VX costs $900. That is a new telescope to me. I would rather buy a new telescope, maybe a dob, than buying a new mount for my 8SE.
Baader zoom EP will be good for all the first time college students during the camping trip, so I am happy about it. I can't speak for the focal reducer until I use it for a few times, but I genuinely trust the folks here on CN.
Everyone is entitled to their opinion and I appreciate your input.

smarhurtfranoth

  • Active Astronomer
  • ***
  • Posts: 122
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #24 on: January 21, 2018, 04:35:26 AM »
The 2" plan has, in my opinion, a big fault which is called "coma". And a lesser one, called field curvature (which may be somewhat mitigated with some eyepieces).
Extra field of view for sure, but quite messy.

fucheatisu

  • Active Astronomer
  • ***
  • Posts: 105
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #25 on: January 22, 2018, 11:33:49 PM »
Quote
From my perspecitve Zooms are a CN fad...not popular among members of my club, and as for me, the one I had I got rid of.   The focal reducer is not a good idea because it will gray the sky (loss of background sky contrast) and it defeats the purpose of the zoom. For a visual observer, why lower the magnification to jack it back up again? Crazy. *There is no net gain in field of view* with the focal reducer. Any way you do it, 1.2 degrees is all you're going to get out of a c8. Sky contrast will be better with the Pan 24.

In 1.25 inch format the 24 Pan Optic will give you maximum field of view for the instrument with its current visual back and diagonal.  The 24 Pan and a 10 to 14 mm are all you need to show off deep sky and planets. In 1.25 inch format you'll be limited to about 50 arc minutes field of view, a bit better than a C14. (In other words, FOV in a c8 in 1.25 inch format is pretty narrow).  In two inch format you'll get close to 1.2 degrees. It's a lot more sky real estate.

I disagree with spending money on a 1.25 diagonal. The one you have will be fine and the replacement should be part of a coherent plan to move up to 2" format.

Given the long string of prior posts I think the (poor, IMO) decision for a focal reducer has already been made, but in the end, anything you buy can be re-sold, and the c8 is a nice observing platform.

Good luck,

Greg N

The point of the R/C is that you can use it with something like a 24mm Pan and get the equivalent of the 41mm Pan.

Look at it this way-- the cost of a decent 2" diagonal and the R/C is about a wash.  A 24mm Pan costs $310. The 41mm Pan costs $510.  So getting your widest possible SCT view with the RC+24mm Panoptic saves you $200.  Plus you save about a pound of payload (important on the somewhat undermounted 8SE).  As far as greying the sky, the sky won't be any more grey with the 24mm Pan + R/C than it would be with the 41mm Pan. You ought to get a bit less scatter with the 41mm Pan, but you get some additional field correction with the 24mm+R/C combo. AND you get a 24mm Panoptic to use at F/10 for as a bonus.

A 2" diagonal on a c8 adds focal length and small bit of negative spherical aberration. The R/C has the disadvantage of the added hassle of putting it on and taking it off.  Both are valid approaches to maximizing the useful true field of a C8-- they just have different tradeoffs.  I have both. They both have their place.

unoutdethea

  • Active Astronomer
  • ***
  • Posts: 126
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #26 on: January 23, 2018, 06:20:50 AM »
Quote
Quote
In 1.25 inch format the 24 Pan Optic will give you maximum field of view for the instrument with its current visual back and diagonal.  The 24 Pan and a 10 to 14 mm are all you need to show off deep sky and planets. In 1.25 inch format you'll be limited to about 50 arc minutes field of view, a bit better than a C14. (In other words, FOV in a c8 in 1.25 inch format is pretty narrow).  In two inch format you'll get close to 1.2 degrees. It's a lot more sky real estate.

Greg N

The point of the R/C is that you can use it with something like a 24mm Pan and get the equivalent of the 41mm Pan.

Look at it this way-- the cost of a decent 2" diagonal and the R/C is about a wash.  A 24mm Pan costs $310. The 41mm Pan costs $510.  So getting your widest possible SCT view with the RC+24mm Panoptic saves you $200.  Plus you save about a pound of payload (important on the somewhat undermounted 8SE).  As far as greying the sky, the sky won't be any more grey with the 24mm Pan + R/C than it would be with the 41mm Pan. You ought to get a bit less scatter with the 41mm Pan, but you get some additional field correction with the 24mm+R/C combo. AND you get a 24mm Panoptic to use at F/10 for as a bonus.

A 2" diagonal on a c8 adds focal length and small bit of negative spherical aberration. The R/C has the disadvantage of the added hassle of putting it on and taking it off.  Both are valid approaches to maximizing the useful true field of a C8-- they just have different tradeoffs.  I have both. They both have their place.
this is a misconception. A 1.25 diagonal with a 24 pan and reducer corrector will never ever give you the fov of a 41 pan in a 2 inch diagonal on the same scope. OP wants to stick to 1.25.

in the hypothetical that he did move to 2" diagonal he sTill would not equal the 41 pan because the 1.25 inch barrel is the limiting factor.

and fwiw the 41 pan offers one of the finest wide field views in amateur astronomy. It is not going to be easily duplicated with a two inch 30mm and a focal reducer, which is about what you would need to get the field of the 41.

ciomasbure

  • Active Astronomer
  • ***
  • Posts: 125
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #27 on: January 23, 2018, 06:44:46 AM »
Quote
Quote

From my perspecitve Zooms are a CN fad...not popular among members of my club, and as for me, the one I had I got rid of.  The focal reducer is not a good idea because it will gray the sky (loss of background sky contrast) and it defeats the purpose of the zoom. For a visual observer, why lower the magnification to jack it back up again? Crazy. *There is no net gain in field of view* with the focal reducer. Any way you do it, 1.2 degrees is all you're going to get out of a c8. Sky contrast will be better with the Pan 24.
Good luck,

Greg N

How does having a focal reducer defeat the purpose of a zoom? The purpose of a zoom is to offer a wide range of magnifications without the need to change eyepieces.  If you thought it had another purpose perhaps that is why you got rid of yours.

If you're like Rod and have problems with field curvature in 30 to 40mm two inch wide field views I concede the need for an rc. But if you've already cut the outer field with 1.25 format I don't see the point. Since the zooms are medium to short fls there's even less need. If you have the zoom for zooming why negate it with an RC? The widest fov he can get is the 24 pan or the 32 plossl. The pan is a much nicer view in a c8 and the higher magnification for better dark sky contrast.

I've been on CN long enough to have read the paeans to various zooms but it's good to repost them for other readers. As I indicated mine is not the dominant CN view.

Frky Sherman

  • Active Astronomer
  • ***
  • Posts: 108
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #28 on: January 25, 2018, 12:58:15 PM »
Quote
Quote

Quote
In 1.25 inch format the 24 Pan Optic will give you maximum field of view for the instrument with its current visual back and diagonal.  The 24 Pan and a 10 to 14 mm are all you need to show off deep sky and planets. In 1.25 inch format you'll be limited to about 50 arc minutes field of view, a bit better than a C14. (In other words, FOV in a c8 in 1.25 inch format is pretty narrow).  In two inch format you'll get close to 1.2 degrees. It's a lot more sky real estate.

Greg N

The point of the R/C is that you can use it with something like a 24mm Pan and get the equivalent of the 41mm Pan.

Look at it this way-- the cost of a decent 2" diagonal and the R/C is about a wash.  A 24mm Pan costs $310. The 41mm Pan costs $510.  So getting your widest possible SCT view with the RC+24mm Panoptic saves you $200.  Plus you save about a pound of payload (important on the somewhat undermounted 8SE).  As far as greying the sky, the sky won't be any more grey with the 24mm Pan + R/C than it would be with the 41mm Pan. You ought to get a bit less scatter with the 41mm Pan, but you get some additional field correction with the 24mm+R/C combo. AND you get a 24mm Panoptic to use at F/10 for as a bonus.

A 2" diagonal on a c8 adds focal length and small bit of negative spherical aberration. The R/C has the disadvantage of the added hassle of putting it on and taking it off.  Both are valid approaches to maximizing the useful true field of a C8-- they just have different tradeoffs.  I have both. They both have their place.
this is a misconception. A 1.25 diagonal with a 24 pan and reducer corrector will never ever give you the fov of a 41 pan in a 2 inch diagonal on the same scope. OP wants to stick to 1.25.

in the hypothetical that he did move to 2" diagonal he sTill would not equal the 41 pan because the 1.25 inch barrel is the limiting factor.

and fwiw the 41 pan offers one of the finest wide field views in amateur astronomy. It is not going to be easily duplicated with a two inch 30mm and a focal reducer, which is about what you would need to get the field of the 41.

If you stick a 2" diagonal on a c8, you'll end up with a roughly 2120mm focal-length scope.  A 41mm Pan with its 46mm field stop will yielld about 1.24 degrees at 52X,

Now stick the F/6.3 R/C on that same C8 with the standard visual back and the a 1.25" prism diagonal.  The R/C was designed to work with this setup. You get a 0.63x reduction of focal length.  The R/C does not vignette the rear baffle (it has a clear aperture of 41mm and the baffle is only 38). It creates a steeper light cone, so by the 1.25" diagonal does not cause vignetting either. The effective focal length is now 1280mm. The 24mm Pan eyepiece with its 27mm field stop delivers 1.21 degrees at 53X.

That's close enough to the same field for me.

I don't have a 24mm Pan or 41mm pan. I do have an ES 68 24mm. And I have 38mm Q70 clone in 2". The 38mm q70 has a 45.7mm field stop, which is rather darn close to the 46mm fieldstop on the 41mm Pan. The 24mm+R/C with a 1.25" diagonal combination gives me almost the same true field of view as the 38mm Q70 does with a 2" diagonal.

While I don't have a 41mm Pan, I do have a 1.25" 35mm Ultima. The Ultima is unusual in that it actually has an internal 29mm fieldstop. With 35mm Ultima and the R/C I get 29/1280*57.3 => 1.30 degrees at 37X

Celestron actually used to advertise the 35mm Ultima + R/C as provided the widest possible view on a C8. Don't tell me it doesn't work-- I've been doing it for more than 20 years...It works.

There is no doubt that the 41mm Pan is a fine eyepiece.  But that last couple tenths of a degree of field in a standard C8 suffers from vignetting, coma, and field curvature,  A 2" diagonal doesn't fix any of those problems. If your only scope is a C8, I'm not sure it is worth investing $510 in that particular view. YMMV.  But if you have other scopes that justify having the 41mm Pan-- by all means invest in a 2" diagonal to use it on your C8.

obinspumtou

  • Active Astronomer
  • ***
  • Posts: 116
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: $500 to spend on eyepiece/diagonal
« Reply #29 on: January 25, 2018, 01:11:10 PM »
DuDu, Save the collage $500 and use what you already own, the students will enjoy what ever they see.