SCT & Newtonian shootout!

[arad85]

Perhaps another member will spot this and give us both some advice!

Perhaps this will help you: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/3090155/page/0

[philsail1]

Hello "arad85,"

Well, what can I say! Many thanks for the link to "Cloudy Nights" Question & Answer section.

It was very, very useful. It seems that a short focal length 8" Newtonain (especially with an excellent mirror) is always going to be quite a bit brighter, and with a significantly bigger field of view than an equivalently sized SCT.

I didn't know about "Field Drop Off" in illumination, or "vignetting" when using a focal reducer and wide field eyepiece (above 35mm).

Many of the contributors seemed to think that the use of a good wide field eyepiece in an SCT would achieve about the same brightness and field of view as using a 6.3 focal reducer with 1.25" eyepieces of the same focal length.

Reading the above, has "fired me up" to using my next observing session to compare (more in-depth than I have previously) the views I get when using wide field eyepieces. Fortunatley I have two wide field eyepieces - an unbranded 2" x 38mm eyepiece, and a Meade Series 4000, 2" x 35mm wide field eyepiece. I'll put the 35mm in the Newt and the 38mm in the C8i - then vice, versa. I'll try and get some photos to compare views.

Thanks again for that link "arad85." It's one I will re-read in depth.

philsail1

[arad85]

Thanks again for that link "arad85."

You're welcome

[therockfrog]

My first scope was an Orion 8" Newt and I just sold a C8-XLT. Personally, I liked the views better in the Newt. Yes, ease of setup and use came with the C8 but I have other scopes so having to set up the Newt for me occasionally wouldn't be a big deal. Also, the image shift, the cool down, the focuser was awful to me being used to crayfords...I just really didnt like the C8 that much. I would have had to buy a motofocuser and a reducer for AP...

In fact, I'm now going to buy another Orion 8" Newt for AP use with a Baader MPCC.

If I could only have ONE scope, I'd get the C8 but OMG...I bought 7 scopes in 6 months..sold most of them, but I just cant have just one scope....the wife of course disagrees!

[philsail1]

Thank you for your reply "therockfrog."

It is a hard decision to make, but I've got to do it soon.

Each scope is excellent in it's onw right, and I know that as soon as I let one of them go, I will regret it!

All I can do is try each scope as much use as I can over the next few weeks. I do enjoy the bright, wide field (and crystal clear) views of the Orion Newt, but the ease of set up and use of the C8 is a very attractive feature!

I'm also going to decide on the mounts too. CG5 against CG5 with "GoTo."

Same situation here. Motorised CG5 is quick and easy to set up. CG5 with "GoTo" finds things!

A tough decision, but everyone's comments have been, and are very useful in pointing out things that I may not have considered.

Regards,

philsail1

[The Warthog]

Excellent comparison. I am thinking of making a Celestron 9.25" SCT my retirement scope (when I get my retirement gratuity...) This hellps confirm my thinking. I have looked through SCTs, and found very good views indeed.

[philsail1]

Thanks "Warthog!"

I've just had a three hour session with the two scopes this evening - looking at the Moon and Saturn. Tried various eyepieces and Barlow combinations on both scopes.

The views are better in the Orion Optics 8" Newt, but I'm still coming back to the "ease of viewing" with the C8i SCT!

It's such a shame we cannot have the best of both worlds in a single scope - perhaps there is such a scope out there?

I hope you find an SCT to suit your needs "Warthog."

Regards,

philsail1

[arad85]

I've just had a three hour session with the two scopes this evening - looking at the Moon and Saturn. Tried various eyepieces and Barlow combinations on both scopes.

The views are better in the Orion Optics 8" Newt, but I'm still coming back to the "ease of viewing" with the C8i SCT!

One other variable that I don't think has been mentioned, is that with the SCT, you have an extra mirror in the path - the diagonal. I have a C9.25 and was observing sitting down tonight. Looking at one of the Messier objects in the eyepiece, it was really uncomfortable, so I removed the diagonal and placed it in the exit hole of the tube. FAR crisper, brighter and nicer views. I've no idea how much better it was, but putting the original diagonal back in, the view dimmed quite a lot and lost a tad of focus. I know my next purchase wlill be a decent diagonal.

To simulate the difference, put the SCT diagonal in the Newt...

[philsail1]

Ah! good point "arad85."

I'll give that a try.

I recently purchased a "Williams Optics" 2" prism 45 degree star diagonal for the SCT, and I have noticed that the prism does give marginally crisper views than the WO mirror 90 degree mirror diagonal.

I will try removing the diagonal from the SCT and see how it performs withour. And yes, I'll put a diagonal in the Newt to what difference it makes.

The more I'm comparing the scopes in actual "set up and use" scenarios, the more I'm becoming convinced to keep the SCT - purely on the basis of ease of use.

Thanks for your comments.

philsail1

[Rob]

I've owned 2 C8's in the past. And yes on 3 particular obs sessions the views of Jupiter were mind blowing around x220 magnification!.. however, to achieve this result it took 3 hours cool down and an ice covered OTA (actually went out to dinner and came back to the scope).

There were so many down sides to the C8 to be honest. Cool down is a real issue if your pressed for time. I found 1.5 hours min to get best results out of this optical system.. The softness of the image can also be a turn off at higher mag's. Our skies here in the UK are not great for this type of scope design. We usually get 3 to 4 knockout nights per year in the UK, where the skies can be near 100% and seeing perfect and steady. The SCT can increase bad seeing and put you off sometimes. The focuser is a little iffy with image shift or slop. I bought a Faeather Touch SCT focus knob (if you have an SCT GET THIS!) best £120 I spent.

Plus sides of the SCT. Small design. ease of use. no problem to collimate - a dream in fact!. the Feather Touch focus knob is dreamy. a 30mm UWA Moonfish is no1 for DSO's. Don't get me wrong. I still had a mini love affair with the SCT for its ease of use and being an all rounder. But there was a trade off.

I now have the SPX200 8" Newt, wow what a scope. The images at high mags are stunning, and very different to the C8 f10. Rings on Saturn, well you could almost cut your finger on them!. The detail I've managed just on Saturn low in the sky is staggering.. miles away from the C8. Planet bands, the divison from planet to rings.. even ring detail while being this tipped. I have to say I cant wait for Jupiter.

Rob

[philsail1]

Thanks for your input Rob. I can see that many people are enthusiastic about the benefits of owning and using an "SCT" scope. It is very easy to set up and use. I find the viewing position is comfortable - I can sit down to view things! I had the scope out at 3.25am last Saturday. "Cool down" time was about 30 mins - the scope is stored in my garden shed. Had some nice views of Jupiter - even though it was quite low down. Also, the Moon too.

My C8i is fitted with a "Feartherlite" dual speed focuser, so image shift is only noticeable at high magnifications. Achieving a sharp focus is very easy with the featherlite. Yes, I think a "Featherlite" is a must for any SCT over about 6". The Williams Optics 2" "Prism" diagonal definately gives sharper views than the WO mirror diagonal. I tried removing the diagonals and fitting the eyepiece directly into the WO extension. First thing I noticed was that the field of view was much wider, and a bit sharper! Definately an imrovement - but viewing position is only reasonably comfortable if Tripod legs are extended so the scope is raised more towards eye level. I've got to try some "afocal" photography with this set up and compare photos.

I had the Orion Optics 8" Newt out at 4.30am on the Sunday! Again, lovely views of Jupiter and Moon. Much brighter, and yes, a tad sharper in the Newt. Viewing position was all over the place - until I slacked off the tube rings and swivelled tube around. HAd to stand up to view. Also had to get a chair so I could view my "digicamera's" screen when taking photos. Also, Orion Optics own make "Crayford" focuser leaves a lot to be desired - it's nowwhere near as smooth as a "Moonlite!" and reaching a sharp focus is not as quick and easy as with the SCT's featherlite.

I would agree that biggest difference between the SCT and Newt, is that the Newt does give the slightly sharper - and much wider field views. I personally didn't notice any difference in "cool down" times, as both scopes are stored in my garden shed. Set up time is definately easier with the SCT. I'm not "wrestling" with a long tube! I can rest the SCT in the mount dovetail slot, steady it with one hand and turn the clamping knob(s) with the other. With the Newt, it's a bit difficult to even see the dovetail slot because I have to hold the tube with two hands, then hold the tube in place with my body and one hand whilst "feeling" for the clamping knob(s).

I haven't tried fitting a diagonal from the SCT onto the Newt to see what the extra glass does to the quality of the views.

I've got to do a few more tests before reaching a decision.

I've had nine different scopes since 2002! (having spent over £2,500!). Although I feel that I've reached the stage where I want to own just one decent scope - and put up with whatever small shortcomings that scope may have - I could still "succumb" to the temptation to buy yet another scope if the finances were available! (I think many of you know the feeling!).

Regards,

philsail1

[PaulG]

Although I feel that I've reached the stage where I want to own just one decent scope - and put up with whatever small shortcomings that scope may have - I could still "succumb" to the temptation to buy yet another scope if the finances were available! (I think many of you know the feeling!).

Regards,

philsail1

I know that feeling very well now Phil, I'm in the same boat in that I have to limit my choice down to one scope (or so I'm told ).

All this is driving me ever so slightly nuts

[philsail1]

You have my deepest understanding "PualG!"

philsail1

P.S. Aaarrrgggggggh! I'm beginning to sway to keeping the 8" Newt now!!!!

[GazOC]

I know that feeling very well now Phil, I'm in the same boat in that I have to limit my choice down to one scope (or so I'm told ).

All this is driving me ever so slightly nuts

Come on Paul, put your foot down!! Everyone knows 2 scopes is the bare minimum needed.....

[dweller25]

Hi Phil,

Hope you don't mind me offering an opinion.

Reading all your posts you value two things :-

1. The sharpness of the newt

2. The ease of use of the SCT.

If I had to choose between the two then I would choose the Newt - Good nights are few and far between and when you do get the chance to observe you should expect the equipment to give you the best possible view.

The view is what it's all about.

Just my two penneth !

[philsail1]

"Dweller25,"

Yes, you are right,

1. The sharpness of the newt

2. The ease of use of the SCT.

The above are the two main points I am wrestling with!

When I think back, the main reasons that I bought the Orion Newt were indeed - "light gathering power," and "crispness of view."

"Good nights are few and far between and when you do get the chance to observe you should expect the equipment to give you the best possible view."

Your comment is a 100% valid point, so I do thank you for reminding me!

philsail1

[Rob]

This is indeed a tricky one!...I too have owned many scopes (17 scopes from 2000 to now) you name it, I've tried it. The OO newt is the over all winner. The other thing is to ditch the OO crayford and pick up an Anatres 1:10 for £100... miles better. Lets be honest OO are not engineers... but they make fantastic mirrors.

[philsail1]

Aye - it is a tricky one Rob! I'm being swayed in the direction of keeping the OO Newt now!

Thanks for the tip about the "Antares Crayford." (I can see you have one on your OO scope). I'll look into getting one.

You are right about the OO "Crayford" focuser - it leaves a lot to be desired! (In fact, it's on the same level as a Skywatcher basic Rack & Pinion focuser - usable, but not brilliant).

Regards,

philsail1

[Rob]

Aye - it is a tricky one Rob! I'm being swayed in the direction of keeping the OO Newt now!

Thanks for the tip about the "Antares Crayford." (I can see you have one on your OO scope). I'll look into getting one.

You are right about the OO "Crayford" focuser - it leaves a lot to be desired! (In fact, it's on the same level as a Skywatcher basic Rack & Pinion focuser - usable, but not brilliant).

Regards,

philsail1

Your not kidding Phil... I have to say my opinion of SPX was slightly trashed when trying to use it. Once that rubbish Crayford was gone, and the Antares was on (small amount of drilling) it was a different scope. I do have a thing for C8's dont get me wrong... its a real tough one.

Good luck with your choice there fella.

Rob

[philsail1]

Hello All,

This poor weather we've been having lately is making it difficult to give my two scopes the comparison tests I need to do before putting one for sale.

At last good weather has been promised this week, so I'm hoping to get both scopes out and continue.

In the meantime - and in readiness for keeping just one of the two scopes - and to get the best performance out of that scope - I would like to ask:-

"What are the best (wide field, planetary, and general use) eyepieces one could buy for:-

An Orion Optics (UK) 8" f4.5 Europa Delux Newtonian.

A Celestron C8i 8" f10 Schmitt Cassegrain Scope.

When I come to sell one of the above scopes, I'm going to save to buy two or three really good eyepieces, to get the best out of the scope - and partly to comfort my sense of loss, which I know I will feel no matter which scope I let go.

Your advice will be much appreciated.

Thanks in advance,

philsail1

P.S. I've been busy during the poor weather - making a couple of "Table Tennis" tables for two sets of our grandchildren!

[Rob]

Ok Phil,

In order of your question

For the C8 SCT - 2" 30mm UWA Moonfish or clone, 1.25" WO planetary ep's, 1.25" TV Plossls (Japan Made)

For the Newt - 2" Meade 5000 32mm, 1.25" WO planetary ep's, Baader Hyperions

Rob

[philsail1]

Many thanks Rob - I've made a note of your recommendations.

phisail1

[philsail1]

Well, I have at last come to a decision on which scope I will keep.

After a good session last night - and in taking account of all the knowledgeable comments from SGL members, I have finally decided to keep the Orion Optics f4.5 8" Newtonian.

Reasons:-

1. I enjoy the brighter images the Newt gives.

2. And the wider field of view makes it easier to find deep sky

objects.

After having a good think, and writing down all the pros and cons of setting up and using the two mounts I have - Celestron CG5 and CG5 with "GoTo" - I have decided to keep the motor driven CG5, and put the "GoTo" up for sale. Main reason is that I only tend to observe for shortish periods, and as such have found it quicker, and easier to use the ordinary motor driven CG5. (plus I'm a bit of a technophobe when it comes to using computers and the like!).

That's about it really.

I would just like to thank everyone for their help and advice during what had become quite a stressfull time for me. (having made the decision feels like a weight has been lifted from my shoulders - I should not have let myself get into such a state over and innanimate object!

I feel that I've made the right decision n both counts.

Over the next couple of days I will work out a price for the C8i, eyepieces, and CG5 "GoTo" set as a whole, and some prices to allow for splitting the sale into individual items. I will also post some photos of the set up, eyepieces and accessories that will be included. All will be posted in the "For Sale" section.

Many thanks once again,

regards,

philsail1

[philsail1]

The final chapter!

I eventually (and somewhat reluctantly) let my C8i SCT go (with the CG5 GoTo mount and Powertank). I did a partial sale and exchange, with another SGL member.

I have now acquired a Skywatcher 127 Mak! (Did the very thing that I didn't want to do!!).

However, I'm not so stressed up now, as there is such a difference between the 127mm Maksutov, and the 200mm Orion Newtonian, that I can easily choose which one to use on any given night.

Also, you may have seen a post where I'm looking for a suitable "grab-and-go" mount for the Maksutov. Well, I've decided not to bother! I will simply use my existing motor driven CG5 mount.

I would just like to say a big thank you to all who gave me advice - one way or another (but mostly in favour of keeping the Newtonian - which I think was the best way to go in the end). It was very useful to have a fresh perspective on these kind of decisions.

Many thanks,

philsail1

p.s. As you know, I'm trying to decide which DSLR to go for later in the year!

[AztecastroMcJ]

nice comparison Phil , interesting to read ur opinions

wish i had either of ur scopes but being a beginner,

i would favour the ease of set-up and handling, and easier viewing of SCT

(think u could get better widefield shots with focal reducer or other accessories to help maybe)

when viewing ur pic of ur scopes amazing difference in size (again advantage SCT)

noticed u also have Mak aswell (me2) i luv goto aswell for ease of set-up

also noticed alot of people seem to hav a 8-12SCT with APO reflector used for widefield shots thereby u only need one mount

dont know how long or how much ur scopes cost etc but i would suggest selling all 3 LOL including mak and picking up either one Larger aperture SCT say 10-12" (u could always add Apo reflector if u not happy with widefield views of SCT wen funds permit)

or maybe get second hand 10-12" and Apo Reflector together ?

(reasons being size difference of newt n SCT means a larger SCT wouldnt really be an issue for size i presume)

tuff decisions just to make ur decision a bit harder u could also buy larger Newt ?

or

just sell one or two of ur scopes and keep the one u'll get more use out of

which would prob b SCT or the one u get better views with prob Newt

hope this helps with ur tough decision

James