TheSkySearchers

Hi Mike,

If you want something that packs easily and compactly and that can be reasonable on DSO's, I agree with others a 5"-6" aperture SCT or Mak is probably the go. Both 127mm f12.5 Maks and C6SE f10's have 1500mm focal lengths. If you go smaller than 5", the maximum eyepiece size will drop to 1.25" and this severely limits the available options for wide angle long focal length eyepieces.

Even though the cores of large bright DSO's are easily visible, a dark sky is best for seeing the faint outer regions of large DSO's, nebulae, faint outer arms of large galaxies such as Andromeda and M33. For these you need the widest field you can squeeze out of the instrument. Even the biggest globulars are only about 1/2 deg so you don't need the big field for those.

You probably already have a selection of other eyepieces for your other scope. Just make sure you also have or buy a decent 2" 40mm eyepiece with a 65-70 deg AFOV. This will give you a 1.6-1.8 degree field of view with a 38x magnification and a 4mm exit pupil giving great wide field views for large nebulae, galaxies and galactic star fields. You do not need to go to the top of the market (eg Naglers/PanOptics etc). These are necessary for fast newts but an f10 SCT or f12 mak is very forgiving on eyepiece design.

Even the mediocre GSO SV42mm Superview eyepiece would work. Although they claim a 68 degree field in advertisements, in reality, they are only about a 52 deg field. I have one and in a long f ratio instrument they are ok but not great in a Newt. An SV42 will give you a 1.4 degree FOV at 36X but if you can go up market a little, you'll be much happier with the view. There are a number of good 40mm 68-70 deg eyepieces, eg Vixen, ES.

A 50mm eyepiece would be even better with a 5mm exit pupil but the choices are limited and generally poor. All 50mm eyepieces are Plösl's with <50 deg FOV's. Televue make a 55mm plosl. The 2 examples of the TV55 I have seen weren't much good, GSO make a 50 mm similarly very average. The only really good 50mm eyepiece I've ever looked through is a Takahashi LE50 but they come at a very hefty price.

Joe

.

Unfortunately most of the 125 or 150 SCT's (like the Celestrons) or Maks have 1.25" diagonals as standard. The ETX has an internal flip mirror system with 1.25" eyepiece holder. This of course limits the real FOV and eyepiece choices considerably: the biggest TFOV is obtained with a 32mm plossl (like the Televue one)...

Something else to consider!

DeanD wrote: ↑Sun Oct 29, 2023 6:45 am Unfortunately most of the 125 or 150 SCT's (like the Celestrons) or Maks have 1.25" diagonals as standard. The ETX has an internal flip mirror system with 1.25" eyepiece holder. This of course limits the real FOV and eyepiece choices considerably: the biggest TFOV is obtained with a 32mm plossl (like the Televue one)...

Something else to consider!

The SW 127 has a 2" eyepiece holder and I'm pretty sure the C6SE does too.

My 6"f7 has a small 3.5% diagonal and I only fitted it with a 1.25" focuser. Not much point doing anything more. My 21mm Denkmeier 65 degree eyepiece gives me a 1.3 degree field with a 3mm exit pupil. I have an old Unitron 40mm Kellner (35 degree AFOV) that also gives 1.3 degrees but with a 5.7mm exit pupil. Both have excellent optics. Although the Unitron 40mm is like looking into a tunnel, some objects pop out much brighter because of the much bigger exit pupil than in the 21mm Denk.

Joe

Good to see the Skywatcher SW127 has a 2" diagonal. Sadly the Celestron 6SE comes with a 1 1/4" one.

Just for interest, what do you mean by "a small 3.5% diagonal"? Is that a typo?

All the best,

Dean

SCT 5" and 6", and Mak 127mm baffle opening is 27mm, which is the same as max field stop of 1.25" EP. This means that even if you have an option of putting 2" diagonal on, 2" EPs will be vignetting since they have larger field stops. Vignetting is not a hard stop, so you will be able to use shorter FL 2" EPs but performance of longer FL 2" EPs will be degraded.

This is trade off for small size and weight of small SCT and Maks.

OzEclipse wrote: ↑Sun Oct 29, 2023 4:55 am A 50mm eyepiece would be even better with a 5mm exit pupil but the choices are limited and generally poor. All 50mm eyepieces are Plösl's with <50 deg FOV's. Televue make a 55mm plosl. The 2 examples of the TV55 I have seen weren't much good, GSO make a 50 mm similarly very average. The only really good 50mm eyepiece I've ever looked through is a Takahashi LE50 but they come at a very hefty price.

Joe

I would not agree with this assessment. There are quite few good choices of ~50mm Plossls from affordable Garry Russell optics

https://www.russell-optics.com/two_inch.html

to TV 55mm. Even standard Plossls from Meade, GSO etc perform nicely in slow scopes. There is no advantage of more complex EP designs at 50-55mm FL since the max FOV is limited in this case by 2" EP barrel. Just by the laws of optics you can get FOV wider than ~50 deg.

DeanD wrote: ↑Sun Oct 29, 2023 11:21 am Good to see the Skywatcher SW127 has a 2" diagonal. Sadly the Celestron 6SE comes with a 1 1/4" one.

Just for interest, what do you mean by "a small 3.5% diagonal"? Is that a typo?

All the best,

Dean

No typo. Perhaps I should have said the diagonal is 3.5% obstruction by area. 18% by diameter

Joe

Mike Q wrote: ↑Sat Oct 28, 2023 8:08 pm

StarBru wrote: ↑Sat Oct 28, 2023 7:35 pm I believe Bigzmey's recommendation of the Celestron Nexstar 6SE to be the best choice for your criteria and for just $99 more than your $1000 budget, totally worth the amount spent! As mentioned by SkyHiker (Henk), that scope has a good reputation. Also, I would recommend this focal reducer for observing your DSO's, which you can always add later.
https://agenaastro.com/celestron-f6-3-r ... 94175.html

I use a Meade f/6.3 focal reducer on my Meade 2045D 4" F/10 Schmidt Cass, and I love it!

So in reality it is almost 300 over the budget lol.

Yep, $300 over the budget! Sorry about that. Anyway, you have some good advice from everyone here! Looking forward to see what you decide.

Bigzmey wrote: ↑Sun Oct 29, 2023 5:10 pm

OzEclipse wrote: ↑Sun Oct 29, 2023 4:55 am A 50mm eyepiece would be even better with a 5mm exit pupil but the choices are limited and generally poor. All 50mm eyepieces are Plösl's with <50 deg FOV's. Televue make a 55mm plosl. The 2 examples of the TV55 I have seen weren't much good, GSO make a 50 mm similarly very average. The only really good 50mm eyepiece I've ever looked through is a Takahashi LE50 but they come at a very hefty price.

Joe

I would not agree with this assessment. There are quite few good choices of ~50mm Plossls from affordable Garry Russell optics

https://www.russell-optics.com/two_inch.html

to TV 55mm. Even standard Plossls from Meade, GSO etc perform nicely in slow scopes. There is no advantage of more complex EP designs at 50-55mm FL since the max FOV is limited in this case by 2" EP barrel. Just by the laws of optics you can get FOV wider than ~50 deg.

I tried to get an eyepiece from Garry Russell once. However, due to the vagaries of the US postal system he wouldn't sell me one for export to Australia. He said that his local post office didn't send stuff overseas(!!!???), and he would have to drive 40 miles to another town to find a post office that did, so it wasn't worth his while...

StarBru wrote: ↑Mon Oct 30, 2023 5:28 am

Mike Q wrote: ↑Sat Oct 28, 2023 8:08 pm

StarBru wrote: ↑Sat Oct 28, 2023 7:35 pm I believe Bigzmey's recommendation of the Celestron Nexstar 6SE to be the best choice for your criteria and for just $99 more than your $1000 budget, totally worth the amount spent! As mentioned by SkyHiker (Henk), that scope has a good reputation. Also, I would recommend this focal reducer for observing your DSO's, which you can always add later.
https://agenaastro.com/celestron-f6-3-r ... 94175.html

I use a Meade f/6.3 focal reducer on my Meade 2045D 4" F/10 Schmidt Cass, and I love it!

So in reality it is almost 300 over the budget lol.

Yep, $300 over the budget! Sorry about that. Anyway, you have some good advice from everyone here! Looking forward to see what you decide.

It will be a bit. The wife kinda sprung this on me...yes i am blaming her for this. Honestly while i know a SCT or Mak is probably the way to go, I just keep thinking i would rather have a frac. Time will tell

Nothing wrong with a frac. I'm finding I like them more and more!

Mike Q wrote: ↑Mon Oct 30, 2023 9:06 pm

StarBru wrote: ↑Mon Oct 30, 2023 5:28 am

Mike Q wrote: ↑Sat Oct 28, 2023 8:08 pm

So in reality it is almost 300 over the budget lol.

Yep, $300 over the budget! Sorry about that. Anyway, you have some good advice from everyone here! Looking forward to see what you decide.

It will be a bit. The wife kinda sprung this on me...yes i am blaming her for this. Honestly while i know a SCT or Mak is probably the way to go, I just keep thinking i would rather have a frac. Time will tell

If you have a preference for particular design, go for it. This is about enjoying the hobby after all. I would recommend a combo of AT102ED frac

https://www.astronomics.com/astro-tech- ... r-ota.html

and

SW AzGti mount

https://agenaastro.com/sky-watcher-az-g ... 21110.html

I have a very similar setup, which is one of my favorites. I have upgraded the legs on the mount for better stability, though.

I just recall something about the EXOS2GT vs EXOS2GT/PMC8 mount. The former is not a very advanced goto mount, I read some problem reports online. The EXOS2GT/PMC8 mount is an AVX-class mount but costs $999 by itself. So, the combo that I recommended earlier has a less than ideal mount.

Still ES has some other options that are also more portable. There is the lighter iExos100PMC8 mount for $599 that you could combine with a 102 mm frac such as this one for $250. The latter is a "demo" frac and sold out, maybe they are working on the final version.

I noticed that they have 27 fracs (mostly combos) of which 17 are sold out. That's a pretty high number, I hope everything is still OK and that they can still be ordered with a wait time.

Fortunately for me i have plenty of time to decide what to get. There is no hurry at all. I have looked at the AT line of fracs and there are a couple of doublets that would fill the bill nicely. For now i will just keep socking away cash until i am ready to do something. I thank everyone for their imput

Bigzmey wrote: ↑Sat Oct 28, 2023 9:46 pm

Mike Q wrote: ↑Sat Oct 28, 2023 8:08 pm

StarBru wrote: ↑Sat Oct 28, 2023 7:35 pm I believe Bigzmey's recommendation of the Celestron Nexstar 6SE to be the best choice for your criteria and for just $99 more than your $1000 budget, totally worth the amount spent! As mentioned by SkyHiker (Henk), that scope has a good reputation. Also, I would recommend this focal reducer for observing your DSO's, which you can always add later.
https://agenaastro.com/celestron-f6-3-r ... 94175.html

I use a Meade f/6.3 focal reducer on my Meade 2045D 4" F/10 Schmidt Cass, and I love it!

So in reality it is almost 300 over the budget lol.

You can use scope without reducer. Depends on your targets, EPs you have and personal preferences. This package with or without reducer is a great value. The scope matches well payload capacity of the mount and all included accessories while basic are of good quality. What you get often in other packages is that the scope is too heavy for the mount, or legs are too weak and need to be upgraded, or diagonal and EPs are junk.

FWIW it just went on sale for $899 on Agena and Astronomics.

Only 6 in stock at $899? Those are going to go quick!

It came to mind that i never finished this thread off when the new scope came in. The wife and i had been researching and decided that we needed to up the budget after all things were considered. I now have a AT102EDL on a iOptron alt az pro. We have had it a few months now and it has been out a few times, just enough for me to learn how to use it. I dont really have much use for it here at the house as i really prefer the 10 and 16, but as a travel scope for a night under the stars on vacation it will serve its purpose fairly well.

So I have had the 102 out a few times over the last couple months. I have to say when you are used to 10 and 16 inches of aperature, dropping down to 4 inches is a experience. It does the frac thing and the images are nice and sharp, but not that much sharper then either of my reflectors, objects also seem to be dim and small. I should have expected that I guess, being used to lots of aperature spoils a guy. All in all it will do what we want it to do and get us a astro fix while we are on vacation.

Mike Q wrote: ↑Wed Feb 21, 2024 10:44 am So I have had the 102 out a few times over the last couple months. I have to say when you are used to 10 and 16 inches of aperature, dropping down to 4 inches is a experience. It does the frac thing and the images are nice and sharp, but not that much sharper then either of my reflectors, objects also seem to be dim and small. I should have expected that I guess, being used to lots of aperature spoils a guy. All in all it will do what we want it to do and get us a astro fix while we are on vacation.

While there are occasions when I prefer views of moon and planets through my 4" APO over the light buckets, for DSOs aperture is certainly the queen.

Since you already have iOptron AZMP I will put something for your consideration. 8" SCT is a bit wider but in terms of weight ad storage space is close to a 4" refractor, which makes it a great travel scope. It will perform on DSOs closer to 10" DOB.

https://www.highpointscientific.com/cel ... -91024-xlt

Bigzmey wrote: ↑Wed Feb 21, 2024 10:17 pm

Mike Q wrote: ↑Wed Feb 21, 2024 10:44 am So I have had the 102 out a few times over the last couple months. I have to say when you are used to 10 and 16 inches of aperature, dropping down to 4 inches is a experience. It does the frac thing and the images are nice and sharp, but not that much sharper then either of my reflectors, objects also seem to be dim and small. I should have expected that I guess, being used to lots of aperature spoils a guy. All in all it will do what we want it to do and get us a astro fix while we are on vacation.

While there are occasions when I prefer views of moon and planets through my 4" APO over the light buckets, for DSOs aperture is certainly the queen.

Since you already have iOptron AZMP I will put something for your consideration. 8" SCT is a bit wider but in terms of weight ad storage space is close to a 4" refractor, which makes it a great travel scope. It will perform on DSOs closer to 10" DOB.

https://www.highpointscientific.com/cel ... -91024-xlt

You dont know how close i was to going that way. I opted for the frac as it packs away much nicer and will ride on the back seat better. One day i may end up with a SCT, but not just yet