What telescope would you recommend if I were only allowed one

[Northernlight]

Grumpy Martian,

'tell us your budget and your goals. Is it for visual, imaging or both ? Are you interested in wide, deep space or solar system ?

If it was me, I would have to go with a scope around the 900-1000mm F/L, short enough to use a reducer for wide field, and long enough to use a Barlow for planetary / DSO work, so a good quality refractor fits the bill.

dont have any experience of the Tak 100, but if it's a doublet, might be worth checking to make sure there aren't any colour aberrations when using visually and I'm certainly not qualified to discuss the merits of a fluorite doublet vs a triplet Apo.

Rich.

 

 

[Paul73]

Tricky question. 

The top end 100mmish frac would be lovely. But, I'd have to go for A light 10" Dob with gourmet optics. I'd miss the fuzzies too much.???

Paul

[Stu]

5 hours ago, Northernlight said:

dont have any experience of the Tak 100, but if it's a doublet, might be worth checking to make sure there aren't any colour aberrations when using visually and I'm certainly not qualified to discuss the merits of a fluorite doublet vs a triplet Apo.

Rich, for visual at least it doesn't have any visible CA, and the Fluorite gives you lovely contrast and low light scatter. I've seen be better in this respect than a Chinese triplet.

Of course a top end triplet, LZOS or Tak will likely show a purer image side by side, but I'm fairly sensitive to CA (more than other abberations such as pincushion distortion which doesn't bother me much) and the FC100 is quite acceptable as far as I'm concerned.

[Northernlight]

Hi Stu,

'not sure about the Tak, but I've read about other flourite doublets giving slightly red fringe to objects at higher magnifications, but on the plus side a good quality fluorite under most conditions will generally deliver a sharp image with slightly better contrast.

i do agree about the larger aperture being handy.

Rich

[Stu]

39 minutes ago, Northernlight said:

Hi Stu,

'not sure about the Tak, but I've read about other flourite doublets giving slightly red fringe to objects at higher magnifications, but on the plus side a good quality fluorite under most conditions will generally deliver a sharp image with slightly better contrast.

i do agree about the larger aperture being handy.

Rich

I've not noticed any red fringing at high power. It may be there but not something that that's an issue for me.

[John]

4 hours ago, Northernlight said:

Hi Stu,

'not sure about the Tak, but I've read about other flourite doublets giving slightly red fringe to objects at higher magnifications, but on the plus side a good quality fluorite under most conditions will generally deliver a sharp image with slightly better contrast.

i do agree about the larger aperture being handy.

Rich

The star images in my Tak F/9 fluorite are the purest I've ever seen in terms of colour and sharpness. I've no reason to think that the F/7.4 version is any different from the reports I've read.

The only scope I've used that matches the Tak doublet is my TMB / LZOS 130 F/9.2 which is a triplet which uses LZOS own glass types.

 

 

[festoon]

I have been considering a Borg 125SD as an OTA that fits many of the requirements mentioned here in this thread. From what I can find on the internet it seems to be lightweight, APO optics, reasonable 125mm aperture. I understand the Borg would be fantastic for imaging, but - For visual use, does anybody have any idea of how this compares to a Tak100? Would the Tak blow the borg out of the water? I'm always in 2 minds between weight and aperture with the contrast of set up time/awkwardness vs contrast and quality of view.

[jetstream]

One scope? the 15" dob, I wheel it out of the garage, use it then wheel it back in. This scope provides memorable views to say the least.

[Stu]

1 hour ago, John said:

The star images in my Tak F/9 fluorite are the purest I've ever seen in terms of colour and sharpness. I've no reason to think that the F/7.4 version is any different from the reports I've read.

The only scope I've used that matches the Tak doublet is my TMB / LZOS 130 F/9.2 which is a triplet which uses LZOS own glass types.

 

 

Interesting John, do you see any difference i.e. improvement with the LZOS over the Tak in terms of colour purity? I guess theoretically it should be there but I don't see any in the f7.4. Perhaps this should be taken to another thread....

[John]

10 minutes ago, Stu said:

Interesting John, do you see any difference i.e. improvement with the LZOS over the Tak in terms of colour purity? I guess theoretically it should be there but I don't see any in the f7.4. Perhaps this should be taken to another thread....

In brief, the TMB / LZOS shows stellar images that are nearly identical to the Tak but you get more resolution, as you would expect from the additional 30mm aperture. More weight, length and cool down time as well of course !

 

[Stu]

2 minutes ago, John said:

In brief, the TMB / LZOS shows stellar images that are nearly identical to the Tak but you get more resolution, as you would expect from the additional 30mm aperture. More weight, length and cool down time as well of course !

 

Thanks John, apologies to the OP.

Back on topic  

[mikeDnight]

3 hours ago, festoon said:

I have been considering a Borg 125SD as an OTA that fits many of the requirements mentioned here in this thread. From what I can find on the internet it seems to be lightweight, APO optics, reasonable 125mm aperture. I understand the Borg would be fantastic for imaging, but - For visual use, does anybody have any idea of how this compares to a Tak100? Would the Tak blow the borg out of the water? I'm always in 2 minds between weight and aperture with the contrast of set up time/awkwardness vs contrast and quality of view.

May be FLO can advise on the Borg 125. From what I understand, Borg get their lenses from Cannon the same as Tak, but they may well be of a slightly lower spec. Certainly the 125's greater aperture will make a noticeable difference on dso's. 

I'm not sure a Tak would "blow the Borg out of the water," just the same as I would never say a Tak would blow a SW ED out of the water. The Tak is simply a very good scope that seems to see through the seeing; don't ask me why! May be its more Kryptonite than fluorite? 

Mike

[paulastro]

Yes, this is just about the impossible question as there are as many different astronomical priorities and agendas as there are telescope owners.   I have had dozens of telescopes over the last 45 years plus, I'd be too embarrassed to say exactly how many even if I had time to check all my old observing books and diaries .

Of course, like many people my scopes have changed according to my changing observing priorities and varying disposable income throughout all these years.  However, I have now settled on two telescopes.  The first is an 80mm Equinox which gives almost fluorite like views and does so much well with no fuss and can be really taken anywhere on a Manfrotto 393 head and photographic tripod.  I use it as an all round astronomical scope, for wildlife, for white light solar viewing and photography with a wedge, and as a fine telephoto lens. A great much underrated scope in my view.  The other scope is a SW120ED which again is the next best thing to a fluorite doublet if you can't afford one. Also it is better for deep sky than the 80mm, at least on some objects, and gives me a little more light on the planets and moon when I need it with my aging eyes.

I must admit I'm also lucky in that I live close enough to MikeDnight who permits me to use his FC 100 and close enough to The Astronomy Centre nr Todmorden where I can use the fine range of telescopes assembled by Peter Drew including reflectors up to 30 inches and refractors up to 8.5 inches.  After all, the next best thing to owning a nice telescope of your own is having some good friends nearby who let you use their telescopes! 

[Highburymark]

I have a very bad back after a serious road accident over 30 years ago, so weight and ease of set up are critical for me. Hence why I bought the FC-100DC and Gitzo tripod, which together weigh around 5kg. Don't think there are too many lighter options on the market. Gitzos are very expensive if you buy a current model new, but mine was less than half price during a pre- Christmas sale - and it's capable of a 25kg payload, so robust for a 2.8kg ota. 

[Rick Towns]

I went through a similar situation recently. I went from a 10" Meade SCT down to an ED-102 APO as the 10" was becoming too much hassle to lug around and set up and tear down. I got a simple EQ-5 and put the ED-102 on it. I thought it was PERFECT! Not too heavy, I could even move the whole rig assembled around the yard without too much hassle. Looking at Sirius I was thrilled to see the "Pup" (Sirius-B) which is something I had never gotten around to bagging with my 10".

However, the fun wore off the first time I looked at M13. It was much dimmer and less resolved than in the 10". The APO glass simply couldn't overcome physics. Sure, the views of double stars and open clusters were beautiful and crisp - but anything faint wasn't better - it was a lot worse!

I used the ED-102 for 5 years, and I still think fondly about how easy it was to use, and the "snap" of the focus. But I wound up selling it and replacing it with a plain-jane Meade 2080 8" SCT. Mine has good optics, and the views through it are nice and sharp. Proper collimation and cooling are required to get the best views, which I don't mind. I made my own DIY version of a Lymax cooler, so cooldown times are around 15-20 minutes depending on how bad the temperature difference is and I am already quite adept at collimating it.

The views of M13 are much MUCH better! And at 12.5 lbs, the 8" SCT OTA really isn't that much bigger/heavier than the 4" APO OTA was. The effort to set it up and pack it up are pretty much equal.  What I gain at the eyepiece is simply so much more. Just food for thought (nom, nom, nom....).

[Highburymark]

That is the counter argument Rick- and an attractive option if you can achieve cool down so quickly. 8" otas are light and portable too - certainly grab and goable with a light alt az mount

[John]

12 hours ago, Rick Towns said:

I went through a similar situation recently. I went from a 10" Meade SCT down to an ED-102 APO as the 10" was becoming too much hassle to lug around and set up and tear down. I got a simple EQ-5 and put the ED-102 on it. I thought it was PERFECT! Not too heavy, I could even move the whole rig assembled around the yard without too much hassle. Looking at Sirius I was thrilled to see the "Pup" (Sirius-B) which is something I had never gotten around to bagging with my 10".

However, the fun wore off the first time I looked at M13. It was much dimmer and less resolved than in the 10". The APO glass simply couldn't overcome physics. Sure, the views of double stars and open clusters were beautiful and crisp - but anything faint wasn't better - it was a lot worse!

I used the ED-102 for 5 years, and I still think fondly about how easy it was to use, and the "snap" of the focus. But I wound up selling it and replacing it with a plain-jane Meade 2080 8" SCT. Mine has good optics, and the views through it are nice and sharp. Proper collimation and cooling are required to get the best views, which I don't mind. I made my own DIY version of a Lymax cooler, so cooldown times are around 15-20 minutes depending on how bad the temperature difference is and I am already quite adept at collimating it.

The views of M13 are much MUCH better! And at 12.5 lbs, the 8" SCT OTA really isn't that much bigger/heavier than the 4" APO OTA was. The effort to set it up and pack it up are pretty much equal.  What I gain at the eyepiece is simply so much more. Just food for thought (nom, nom, nom....).

Globular clusters always seem to benefit from more aperture. It's more apparent with them than practically any other object type.

Threads like this always end up reminding me why I would not want to be restricted to a single scope. Just as well that its a hypothetical excercise !

 

[Helen]

15 hours ago, Highburymark said:

I have a very bad back after a serious road accident over 30 years ago, so weight and ease of set up are critical for me. Hence why I bought the FC-100DC and Gitzo tripod, which together weigh around 5kg. Don't think there are too many lighter options on the market. Gitzos are very expensive if you buy a current model new, but mine was less than half price during a pre- Christmas sale - and it's capable of a 25kg payload, so robust for a 2.8kg ota. 

Ah a sibling   What Gitzo model is that?

Thanks

Helen

[paulastro]

I agree with John that globulars are the most obvious indicators of increasing aperture, particularly at the more modest end.  This is one reason I have the 120ED in addition to the 80mm.  For me even a four inch won't quite hit the mark with globulars.

[StarryEyed]

Now fifty years old and observing for forty years. Same thought. Sold nearly everything for a Tak 100DF. I do still own an WO 80mm FD limited edition that I thought I would sell after getting the Tak and an eight inch dob which is with my uncle.

It is proving to have been the right thing to do but letting go of the 80FD is tuff I am more attached to it than I thought. Having a dob for reasons mentioned in the thread is just a case of being honest with ourselves.

[Highburymark]

5 hours ago, Helen said:

Ah a sibling   What Gitzo model is that?

Thanks

Helen

Helen - it's a systemic, if I remember correctly. I think the biggest have a 40kg payload (think Stu has one of these) but mine has 25kg. Incredibly light carbon fibre. 

[Cosmic Geoff]

I can only speak about the scope types I have actually tried.  If I had to slim my four scopes (five counting the vintage brass 70mm) down to one, I'd keep the Celestron C8 se. It has the aperture for DSO's and performs quite well on all kinds of objects, except very wide ones.  It has GoTo (indispensable to my mind) and is simple and convenient to use.  The eyepiece stays in a convenient position. With the Starsense, setup can be reduced to carrying the whole assemblage out of doors, putting it down, connecting battery and turning it on.  If money were no object I'd possibly have an 8" SCT with a better alt-az GoTo mount.

And why keep four scopes? The others fill various niches such as wide field or grab'n go.

[Skyline]

Buy yourself a Celestron 100ED f9 refractor, lens design probably by Vixen - Japan. If you can get one  

[Nyctimene]

I'll second estwing and John above. Aperture rules; and I've only once made the mistake to "downgrade" in aperture 40 years ago (from 9" to 6"). A very good  allround solution, if you don't do AP, could be a lightweight quality travel Dobsonian, as made by Sumerian Optics. A German stargazer reduced the weight of his 12"  Sumerian down to 13 kg (Carbon truss; primary mirror from nauris.de). I'm very happy with my 8" f/4 Traveldob from Hofheim Instruments; it's my "bigger" grab-and-go, and, with it's 8 kg total weight, I can take it out fully assembled and collimated in two minutes. Excellent build and quality optics; have a look at this: http://www.hofheiminstruments.com/   (only in German language; Dragan Nikin of Deep Sky Forum wrote a review of it 2013 in English, which is, at the moment, not accessible). They also build 12" and 16" traveldobs; not cheap, but worth every €. (No affiliation with them, of course).  If I was allowed to keep only one scope, it would be the 8".

Stephan

[JeremyS]

On 20/02/2017 at 12:41, festoon said:

I have been considering a Borg 125SD as an OTA that fits many of the requirements mentioned here in this thread. From what I can find on the internet it seems to be lightweight, APO optics, reasonable 125mm aperture. I understand the Borg would be fantastic for imaging, but - For visual use, does anybody have any idea of how this compares to a Tak100? Would the Tak blow the borg out of the water? I'm always in 2 minds between weight and aperture with the contrast of set up time/awkwardness vs contrast and quality of view.

I  owned a Borg 125 and a Tak FS 102 at the same time. Visually I found the Tak crisper and no colour worries, so kept that one in spite of smaller aperture.

This comparison was more than 10 years ago, mind you.

Jeremy