EPs advice for newbie on SCT

[kirkster501]

Hello guys,

Was thinking buying a TV 24mm Pamoptic when I get my F10 SCT (probably a CPC1100).

I see this EP gets glowing reviews. However, I also see that many say that more basic EP's work as well with the SCT and that the TV would be "wasted"???

Do you think, as a beginner with a big scope, to get a Hyperion Zoom for a while and get familar with that before going to upper end EP's? Or maybe get a 8mm and a 24 mm Hyperion?

I have no Ep's at all at the minute and I need to buy something else or I'll only have the 40mm that comes with the scope and I would like to look at planets and Double stars and Globular cluseters. A but of DSO stuff as well.

My thinking longer term (say within six months) was a TV Nagler 10mm, the TV Pan 24 as above and then replace the supplied 40mm with a TV 40mm or so. Also to use 2 inch diagonal for the longer FL Ep's.

But I need somethign else now. WHat shoudl that "something" be do you think?

Appreciate your opinions please. This EP malarkey is more complex than a scope

Rgds, Steve

[Adrian]

The 40mm that comes with the scope is a 1.25" fitting plossl, so will have around a 40 degree FOV. The 24mm panoptic is also 1.25" fitting, and will show the same area of sky, but magnified to a 68 degree FOV. These eyepieces are both showing the maximum true field that a 1.25" eyepiece can.

In order to see more sky you would need to change the visual back to a 2" fitting and get a 2" eyepiece & diagonal.

There are other advantages to the panoptic - it's extra magnification will darken the background and so increase contrast. It should also be very sharp to the edge of the field.

It will also be excellent in any other scope you may change to in the future.

Whether these differences are enough to justify the price, only you can decide, but given the same true field of view, I wouldn't start with a 24mm panoptic.

The 8mm hyperion is excellent, but it may be too much in a C11. I found that it was too much mag in my 10" SCT so I couldn't justify keeping it. A 13 or 17 with the fine tuning rings would be more useful during normal seeing conditions. Haven't tried the zoom myself.

HTH

Adrian

[michael.h.f.wilkinson]

The panoptic should be fine, and has the advantage that if ever you opt for a faster scope, it will still be fine. On a C11, I would get a 2" visual back and diagonal. The 40mm does show the same FOV, as noted above, but the 24 will show a darker background (due to higher magnification). I have seen a few Hyperions in an F/8 scope, and they worked well. You could get a set of Hyperions, and upgrade later to higher-end EPs if you like.

I have a series of TeleVue EPs with my C8, and they are definitely worth it for me. I did go the 2" back + 2" star diagonal way, and visually that is way superior to 1.25" ep with focal reducer (which I used to have). I started out with Plossls, and except at the high power end, where small eye relief is a pain for me, they lasted quite a while. I replaced the 10mm Plossl with a 9mm Vixen LV, and later added a 7mm LV. These have now been replaced by Radians (8 and 10 mm). At the long end, my 26 and 36mm Plossls were replaced by a 22mm Nagler and a 40mm TMB Paragon (the latter came first). These give massive fields of view (for an SCT). The gap in between has been filled first by a 14mm Meade UWA, later a 17mm Nagler. The last addition was a 31mm Nagler. All these EPs are first rate, and some say that is wasted in an F/10 scope. That is wrong. They clearly outperform the (very decent) EPs I had, even at F/10. They also work neatly in my F/6 triplet, and I tried a couple in Olly Penrice's F/4.1 Dob, where they worked beautifully. Regarding an 8mm: maybe a bit, much, but I use mine frequently enough to keep it (smaller scope though). You just need to wait patiently for the rare moments when the seeing is perfect, and the image snaps into focus.

Having said that, I had a lot of fun with the old gear, and only upgraded when I felt I was seeing the shortcomings of the existing kit. Be warned though: Once you replace one EP with really top notch EP, there is no turning back.

[Mr Spock]

For your focal length scope I'd be looking for something around 12mm to start. This would give a very usable magnification for planets.

[kirkster501]

Thanks everyone. Hmmmm, I think I am more confused now then I was when strarting to investigate this subject !! Just so many options !

[michael.h.f.wilkinson]

Thanks everyone. Hmmmm, I think I am more confused now then I was when strarting to investigate this subject !! Just so many options !

There are many options, but few wrong ones. Most of the stuff out there is very good, a lot is excellent, and some is outstanding. Get some decent eyepieces to start observing. Typically you need three:

1. A wide field like your 40mm, possibly replaced by something like my 40mm Paragon (similar design to Skywatcher Aero ED) with its much larger FOV, but that requires getting a 2" back plus diagonal,
   
2. A high power EP, something like 10-13mm for your scope,
   
3. Something in between, say 18-24mm,
   

As you develop more experience, you can add as you see fit. EPs like the Hyperions will be very good starters (BST Explorers also have a good name), and will show you a lot of stuff really well. Once you get going, you will find out what your preferences are, and which additional EPs you want.

[CGolder]

Hello,

I am an avid sct user and have televues, i would say having a 24 pan is not that essential as you will soon fit you want to break free and upgrade to a two inch diaganal to get around the small fov, the 24 is important to max your fov in scopex with 1.25 but with a decent size sct i am sure your want more, objects like double cluster need way wider eyepieces to fit in the fov like a 35 or 41 panoptic

I find televues (not plossls) are still notivebly better at f10 that others but if i hadnt looked though them for a year or so i probably wouldnt have noticed

To start i would recommend some nice plossls or bst explorers until you know what you want

Sent from my A101IT using Tapatalk

[damnut]

HI Kirkster501,

Where are you??.whilst I do not have the posh tv's I do have in 2" -

40mm, 32, 30, 25 , 15 and an ed Barlow. If you would like to come over and have a look through them on 10"Sct drop me a pm. Before spending hard earned dosh :-).

1.25" have 4.8, 5,8,12.5,16.8,26,32 (not all used on the sct!)

Cheers

[LukeSkywatcher]

So if i am reading this correctly, the FOV in a SCT is 40 degrees (when using 1.25" EP's)????. I have read a few times it has a narrow FOV.

Ive had an EP before with 40 degrees FOV and didnt like it.

Should i/could i upgrade the 1.25" back and diagonal to 2" on the 8se that is on route and then use an adapter (2"-1.25") to get use out of my 1.25" EP's???

Like this:

http://www.firstlightoptics.com/adaptors/2-to-125-eyepiece-adaptor.html

[Adrian]

So if i am reading this correctly, the FOV in a SCT is 40 degrees (when using 1.25" EP's)????. I have read a few times it has a narrow FOV.

No, the apparent FOV of a 40mm 1.25" plossl is around 40 degrees in any scope. The 1.25" barrel is acting as the field stop and limiting the view. Sorry for any confusion.

A 32mm (and shorter) plossl will show ~50 degree apparent FOV (as normal) in an SCT.

Personally, I don't see the point of a 40mm plossl when the 32mm shows the same area of sky, but magnified more.

[CGolder]

the max fov will depend on if you have a 1.25" or 2" diaganal and normal machanics of focal lengh, scts are generally all f10 so have longer focal lengths so less fov, the max fov will be eyepiece fov/magnification, if its a frac sct or newt it doesnt matter

[CGolder]

for an eight inch sct you max fov is 1.39 degrees at 2" and 0.83 in 1.25 (without any reducers)

[michael.h.f.wilkinson]

With a 2", 40mm super wide angle EP (68-69 deg field of view) I get a 1.36 deg true field of view in my C8. This allows me to see the double cluster nicely framed, and the Pleiades just squeeze into the FOV. In a C11 you get 0.99 deg true FOV with the same EP.

[LukeSkywatcher]

No, the FOV of a 40mm 1.25" plossl is around 40 degrees in any scope. The 1.25" barrel is acting as the field stop. Sorry for any confusion.

A 32mm (and shorter) plossl will show ~50 degrees as normal in an SCT. I don't see the point of a 40mm plossl when the 32mm shows the same area of sky, but magnified more.

I'm with you now. Yeah the EP i had was a 40mm E-Lux. All my EP's have a 50 degree FOV and i will still get this in the 8se?

Good to know.

[Mr Spock]

With my C9.25 I get 1.29° using a 42mm 72° eyepiece, and that's the maximum for that scope.

[faulksy]

i no or think i have asked this before but what true fov do i get with my 2" BURGESS 38mm.

[michael.h.f.wilkinson]

1.13 deg true FOV (70 deg apparent FOV divided by 61.8 (magnification)).

[faulksy]

1.13 deg true FOV (70 deg apparent FOV divided by 61.8 (magnification)).

so im short on my max field of view, thought i was, right what ep would cure this ?. cheers sorry to spam admin:)

[michael.h.f.wilkinson]

so im short on my max field of view, thought i was, right what ep would cure this ?. cheers sorry to spam admin:)

Not by much, the LVW 42 mentioned by Mr Spock has a 72 deg AFOV, yielding the 1.29 true FOV. You should wonder if that small increase is worth EUR 298 (Teleskop Service) or GBP 298 (FLO). Excellent EP by all accounts. Unlike the other LVW EPs it has 72 deg FOV (whatever the TS site says) rather than 65. It would give me a 1.49 deg FOV (now I am tempted to replace my Paragon 40)

[faulksy]

quite expensive then lol. so realy i need a 72deg ep obviously in 2" format am i right

[Dellis]

I have a CPC 1100 and use 8, 13, 17 & 21mm Hyperions with the 8 only being of any real use in excellent seeing, the 17mm probably gets the most use but they all work well with the scope. I also have 32 & 38mm Panaviews which suit the CPC very well, the 38 mm gives a 0.95 deg fov which is close to the limit for the C11.

Dave

[kirkster501]

Hi Dellis, which panaviews do you have (make) and what diagonal are you using please?

Rgds. Steve

[Dellis]

Hi Dellis, which panaviews do you have (make) and what diagonal are you using please?

Rgds. Steve

Both my Panaviews are Skywatcher and very good, in fact I've asked Father Christmas for a 26mm Diagonal is a Revelation Astro 2" and it is very good. Check the links.

Dave