ED 100mm, f7 refractor or 150mm f 5 Newtonian?

[Guest]

Hi. I am planning on buying a transportable telescope in the Summer. Or the truth be know, it will be bought as a 60th birthday present for me by the family. So I must choose correctly as it will be a keeper. 

I am looking for it to be quite transportable. Either a 100mm f7 refractor or 150mm f5 Newtonian. 

I was looking at these for visual astronomy only. There are two refractor brands that I like. The WO Zenithstar 103mm ED doublet. Also Altair Astro 102m ED doublet. Altair do a 102mm ED triplet. But not sure if the will be any advantage of an ED triplet over an ED doublet for purely visual. If there is then bring it on. 

The other option is the Orion Optics 150mm f5 with 1/10th wave optics. Light enough to be transportable. 

I am interested in transportable as my area is heavily light polluted. 

Looking for user experiences with these types of telescopes. 

 

[Chris]

With that kind of budget I vote for the 100mm f/7 frac. You can put it in a case for travel, it's smaller in volume, and f/7 will be kinder on EP's. 

Taking contrast into account I think the 100mm f/7 frac and 150mm f/5 Newt would perform similar on a lot of objects. 

[petevasey]

Presumably you're wanting a fairly wide field view, because you haven't considered a 127 or 150 mm Maksutov which is extremely portable.  While the 150 mm reflector will probably outperform the 102 mm refractor for light grasp of faint fuzzies,  the refractor will travel better, not needing frequent collimation.  A possibility might be a larger refractor from the Skywatcher Startravel stable, they do relatively lightweight and inexpensive 120 and 150 mm offerings. Reasonable reviews optically although perhaps not the greatest mechanical quality.

Peter

[Skyline]

Buy the OO 6" 1/10th wave - I know you want to Grumpy !

or maybe a 100m F9 Doublet

[mikeDnight]

The refractor is really the better option if this is going to be a keeper. It will make a superb all round instrument offering spectacular, high contrast, rich field views while giving razor sharp high definition views of the Moon and planets. Perfect star images are still another visual delight!  

Triplets are completely unnecessary for visual only observing, as most modern ED refractors are essentially colour free. Some high end wide field eyepieces will add more false colour to an image that the ED's objective ever would!   Some years ago, Sky & Telescope printed a review of three 5" refractors and a 7" Mak newt'.   Over several nights from a dark site in the US, the two triplets and one doublet, along with the Mak, were pitted against eachother. Though slight, the doublet  was found to give brighter views of DSO's than either of the triplets, and all three refractors, surprisingly, offered brighter views of DSO's than the 7" Mak. 

The refractor will never need recolimating or recoating and will still be in perfect working order in a hundred years from now. They look good set up in the corner of a room too, and you can drool over it on those stormy winter nights, knowing it will thrill you again and again on those clear, transparent nights. And as many of our clear nights these days seem to be when the Moon is in the sky, the refractor has a powerful edge and will massively outperform the 150mm F5 Newtonian on lunar and planetary targets.

Parallaxer  (Jon) recently bought a beautiful 102ED with great optics mechanics, so may be have a chat with him and get some feed back.

[Moonshane]

What are you mounting it on Grumpy? And when you say transportable, do you mean in the car or on a 'plane?

[Guest]

9 minutes ago, Skyline said:

Buy the OO 6" 1/10th wave - I know you want to Grumpy !

or maybe a 100m F9 Doublet

I may end up totally grumpy if I didn't buy one skyline. Lol

[Guest]

1 minute ago, Moonshane said:

What are you mounting it on Grumpy? And when you say transportable, do you mean in the car or on a 'plane?

Hi Moonshane. The 120ed was a great scope. But it became a liitle too big and heavy to use and transport. Especially after my rib injuries. Looking to get a lighter tripod and AZ4 or similar. My area is ruined with light pollution. So transporting in my car to darker sky areas near to where I live. The slightly shorter and lighter refractor would suit my standing /observing position more. 

So would the 150mm Newtonian. 

[Zeta Reticulan]

I have a 102mm Altair Starwave, I think it's about 4kg. I can place it on a Vixen Porta II/SXG tripod combo. I recommend the Starwave.

[Moonshane]

In that case, I agree it's a tough choice. You cannot go far wrong with either but as Mike says, the frac would perhaps be a more robust and simpler design at as small cost of resolution vs the newt.

[Guest]

20 minutes ago, mikeDnight said:

The refractor is really the better option if this is going to be a keeper. It will make a superb all round instrument offering pectacular, high contrast, rich field views while giving razor sharp high definition views of the Moon and planets. Perfect star images are still another visual delight!  

Triplets are completely unnecessary for visual only observing, as most modern ED refractors are essentially colour free. Some high end wide field eyepieces will add more false colour to an image that the ED's objective ever would!   Some years ago, Sky & Telescope printed a review of three 5" refractors and a 7" Mak newt'.   Over several nights from a dark site in the US, the two triplets and one doublet, along with the Mak, were pitted against eachother. Though slight, the doublet  was found to give brighter views of DSO's than either of the triplets, and all three refractors, surprisingly, offered brighter views of DSO's than the 7" Mak. 

The refractor will never need recolimating or recoating and will still be in perfect working order in a hundred years from now. They look good set up in the corner of a room too, and you can drool over it on those stormy winter nights, knowing it will thrill you again and again on those clear, transparent nights. And as many of our clear nights these days seem to be when the Moon is in the sky, the refractor has a powerful edge and will massively outperform the 150mm F5 Newtonian on lunar and planetary targets.

Parallaxer  (Jon) recently bought a beautiful 102ED with great optics mechanics, so may be have a chat with him and get some feed back.

Excellent summation of where I'm at Mike. 

Thanks. 

[Alfian]

I have had both the SW 150p f5 reflector and the SW ED100 f9 refractor and it looks like you are aiming a little higher on the optical/build quality with regard to both but for what its worth I'll give an opinion. The 150p was a nice scope and on paper should have been a good all rounder and in many ways it was but it never quite grabbed me. "Jack of all trades - master of none" springs to mind but that is perhaps a tad harsh. The ED100 likewise ticked all the boxes apart from "only" being 4" aperture. Howevet it was the ED100 that gave the wow factor at the eyepiece. I never thought I would part with it  - but its funny how it goes. Circumstance and ideas change. Incidentally both scopes worked well on  an AZ4. One thing that surprised me was having seen an ED120  it did not seem that much bigger than the ED100 though of course they are both 900mm. This is all pushing towards a nice 4" ED refractor which will be easy to manage mount wise but significantly perhaps because its bought for a special occasion,it will undoubtedly feel much more special than an f5 reflector even if it does have hand finished mirrors.

[John]

This one is F/6.5 but thats near enough !. I've had a good session with a 150mm F/5 newt on the AZ-4 as well but I think I'd go for the 100mm ED refractor for all round ability and portability.

 

[wookie1965]

I loved my Skywatcher 6" only scope I have seen the E and F stars in the Trapezium with. I bought a big plastic box put sponge in it and carried it that way only needed tweak the primary.

I have a Tal 100rs and a Meade 5" Refractor now I have not had the 5" out for a good session yet due to health, mount problems (now fixed) and weather.

if the 5" performs well I will be fine if not I will be looking out for a 6" reflector myself.

 

[Ullomat]

Hi,

I vote for the refractor and later on a bigger Newton in combination.

cs,

Uli

[petevasey]

Hi, Grumpy,

Looking back at the answers, particularly the mount (AZ4) you are considering, I guess the 102ED is as good an option as any - ok weight wise and particularly if you go for the FPL53 model a beautifully crisp contrasty image.  I have an older good quality 4" refractor, admittedly a triplet, but although I don't do much visual these days, always enjoy it on those rare occasions.

Maybe you are a purist, but I see there is a wi-fi GOTO version of the AZ4.  To be fair, you  may not have a smart phone (I'm still a dinosaur!) but if you do, that looks like a good price.  And if you've never used GOTO you'd be amazed at how much time it saves.  Indeed when I first went GOTO I was living in a light polluted environment, but I was then able to observe targets which previously I'd had great difficulty in finding due to the lack of easily visible finder stars.  And of course observing with a tracking mount is much more relaxing - no more nudging to keep the target in view, particularly if using high magnification.  In the case of the mount I mention, the 'Freedom Find' encoder technology means you can rapidly move the scope to another part of the sky without waiting for the drives to do the job.

Sorry to see you have had rib damage.  Hope it's not too bad - I've been there, twice, four broken the second time!  But they do usually fully heal after a few months.

Cheers,

Peter

[petevasey]

While on the subject of mounts, the AZ GTi might be worth a look - with the extension pillar, (need to check dimensions) it might easily reach the zenith with the 102ED.  With the pillar and tripod still a bit cheaper than the one above, and also has 'Freedom Find'.  Well reviewed.

Cheers,

Peter

[Skyline]

Just to add another piece to this good topic, I must admit I can remember using my C100ED on Jupiter one night with a 9mm Orthoscopic eyepiece, the belts were very defined with not even a hint of colour, even so better then my OMNI XLT150 Reflector I would hasten to add.

If I had to choose a keeper for my birthday - I don't think you could go wrong with a 4" ED Refractor,  no collimation needed, low cooldown time and very transportable.

There's something nostalgic about refractors which can't be found in reflectors.

[Guest]

2 hours ago, Skyline said:

Just to add another piece to this good topic, I must admit I can remember using my C100ED on Jupiter one night with a 9mm Orthoscopic eyepiece, the belts were very defined with not even a hint of colour, even so better then my OMNI XLT150 Reflector I would hasten to add.

If I had to choose a keeper for my birthday - I don't think you could go wrong with a 4" ED Refractor,  no collimation needed, low cooldown time and very transportable.

There's something nostalgic about refractors which can't be found in reflectors.

Hi Skyline. I have an eight inch OO UK f4. 5 Newtonian which I keep in Dorset. I do put it in a car and travel with it occasionally. But it mostly gets used in the in laws garden. So whilst I like the idea of the six inch version. I will probably go for the refractor. The 100 mm F9 ED is a great scope indeed. But I have always hankered  after a shorter focal length version. So it looks like the Williams Optics 103 Zenithstar could be the one. Although primarily an imaging scope, I'm sure it will serve as a great visual scope as well. 

[Guest]

15 hours ago, petevasey said:

Hi, Grumpy,

Looking back at the answers, particularly the mount (AZ4) you are considering, I guess the 102ED is as good an option as any - ok weight wise and particularly if you go for the FPL53 model a beautifully crisp contrasty image.  I have an older good quality 4" refractor, admittedly a triplet, but although I don't do much visual these days, always enjoy it on those rare occasions.

Maybe you are a purist, but I see there is a wi-fi GOTO version of the AZ4.  To be fair, you  may not have a smart phone (I'm still a dinosaur!) but if you do, that looks like a good price.  And if you've never used GOTO you'd be amazed at how much time it saves.  Indeed when I first went GOTO I was living in a light polluted environment, but I was then able to observe targets which previously I'd had great difficulty in finding due to the lack of easily visible finder stars.  And of course observing with a tracking mount is much more relaxing - no more nudging to keep the target in view, particularly if using high magnification.  In the case of the mount I mention, the 'Freedom Find' encoder technology means you can rapidly move the scope to another part of the sky without waiting for the drives to do the job.

Sorry to see you have had rib damage.  Hope it's not too bad - I've been there, twice, four broken the second time!  But they do usually fully heal after a few months.

Cheers,

Peter

Hi Peter. I have wondered about the star discovery mount. It would suit a smaller refractor. But specifies a payload weight of 5 kg. The refractor, 30mm Eyepiece and two inch diagonal would come in at just under 6.5 kg. Visual only. Not sure if it would suit the mount. 

[petevasey]

1 hour ago, Grumpy Martian said:

Hi Peter. I have wondered about the star discovery mount. It would suit a smaller refractor. But specifies a payload weight of 5 kg. The refractor, 30mm Eyepiece and two inch diagonal would come in at just under 6.5 kg. Visual only. Not sure if it would suit the mount. 

Hmm.   Perhaps you are being a bit pessimistic about the weight.  Altair quote 4Kg for a 102 ED.  I've weighed my 2" diagonal and 30mm eyepiece and they come in at 911 grams.  Add a good quality red dot finder and bracket another 200 grams.  My 40mm finder and bracket weigh 320 grams, but a 30mm one would probably be nearer 250.  You don't really need anything bigger than a red dot at your focal length when using GOTO. The field of view with a wide angle 30mm eyepiece will be around 3 degrees - plenty big enough to get an alignment star in the fov using a red dot finder.  So if you went for a red dot, your all up weight would be slightly over 5.1 Kg. 

Cheers,

Peter

[Alkaid]

I personally feel that Orion Optics scopes are a little overpriced.   I had one with 1/10 wave optics and it was very nice, but it was the 6" f8 version which I used for planetary, purchased 2nd hand from a forum member here at a good price.   I wouldn't buy one brand new, the pricing is just too far out for what you're getting.

If it's the F5 version you want, which would be better for DSO's & wide field at low power - do you really need the high grade mirror?   I have a standard Celestron model and I doubt I would see any difference between that and the 1/10 wave OO equivalent at low to medium power.

My other scope, a 100mm achromatic refractor, delivers a superior view on Lunar / planets than my F5 newt.  It is just...sharper...

On deep sky, the Newt does pull ahead, but it is not a 'night and day' difference.  There is more contrast in the refractor, which fools the brain into thinking that the object is a little brighter. 

Spend your pennies on the refractor.  Best of both worlds, and more portable.

[petevasey]

I've been away for a few days, and see from my emails that someone complained about the advert for a mount and 127Mak for £300.  The reason I posted it in this thread was because it would have given 'Grumpy' the opportunity to purchase a virtually new GOTO mount complete with handset and a travel scope suitable for planetary and Lunar observing for little more than the cost of the GOTO mounts suggested above.  Then add the 102ED which the mount would probably carry ok, and all set.  So, 'Grumpy' if you are interested, let me know and I'll see if the kit is still available.

Cheers,

Peter.

[F15Rules]

Hi Martin,

You said..

" The 100 mm F9 ED is a great scope indeed. But I have always hankered  after a shorter focal length version. So it looks like the Williams Optics 103 Zenithstar could be the one."

Have you considered the lightweight F7.7 Vixen ED103s? The bare tube is only 3.6kg☺..

photos show my first one on a Porta II mount - a wonderful, portable setup with top class optics (a notch up from the excellent ED100 IMHO).

Dave 

[JG777]

Martin already knows this story but I sold him my 100 ED semi apo SW and replaced it with a 150 F5 OO 1/10 reflector. The reflector out performed the refractor on DSO thanks to the extra mm and for wide field viewing as well my OO sample delivers beautiful crisp views and very close to the edge. It is collimated within 1 minute and with practically zero focus slop. Cooldown is 15 minutes with the fan. It also travels extremely well and mechanically no issues. My 100 EDs focusser on the other hand expired after 16 months of light use so didn't seem very robust to me. On planets the refractor put a more contrasty and sharper  view but the reflector pulls in more detail. I guess you take your pick there. Ultimately I think the 6 inch reflector is the better all rounder and was no harder to transport than the refractor. I wouldn't swap back based on experience of both. 

I do like refractors though, they are a great choice for smaller scopes I have 2 myself, but the 150 mirror is the choice for a mid sized scope and all round versatility.