185 replies to this topic

[JimP]

How do you decide which to use on a given night? Do you always use the “best “one?

I understand owning a large Dobsonian and a smaller aperture refractor but many of us own multiple refractors all in a relatively narrow aperture range of about 3 to 6 inches.

If you own multiple refractors in the aperture range +/-above how do you decide which one to use on a given night?

Jim

[Kent10]

Hi Jim,

 

I was thinking about asking a similar question.  I have a Tec 180FL, Tec 160FL, TV-140, NP-101, Tak FC-100DL and a LOMO 80mm. 

 

I have fun comparing them when I take more than one scope out, but when I take only one or two out it is almost always the Tec 180FL and my larger Dob.

 

Yesterday I was busy into the evening and didn't have time to take the Tec 180 out early to cool and so I wondered if my views would be better with the Tak FC-100DL because it is a doublet and would cool fast.  When I don't cool the Tec, I notice the planets don't seem to be as sharp.  It is hard for me to know how much of this is due to seeing or the lack of cooling, but I can see the ripples of cooling in unfocused stars. 

 

So last night I took the Tak out and without any cooling started viewing.  The view of the planets was not very good but I think that was due to seeing because the out of focus star images had no rippling.  Yet, still, I missed the brightness and larger images of the Tec 180.  I did enjoy the relatively stable images of stars in the Tak, however.  The double cluster was really beautiful.

 

So while I use my Tec 180 the most by far, when I do take my other scopes out, I also enjoy them but maybe not as much.  The TV-140 also gives beautiful views that are brighter than the 100mm scopes and still wide but it also takes a while to cool down and the images do not look good until it has cooled.

 

I rarely use the Tec 160 but I have a friend coming over who will bring his Tec 140.  He wants to compare to see if he wants to "upgrade."  That should be a fun comparison.

 

Soon, maybe in Dec., I will be getting a Tec 200FL (you may recall our conversation), and I wonder if I will be using the Tec 180 anymore.  The 180 is so easy to set up though.  And the 200 on a GEM will not be so easy!  But I may keep it under a Telegizmos cover, in which case it will be ready to go.

[Kent10]

Also, I use the smaller aperture scopes more specifically for wider views, which they do very well.  I am not as concerned about portability as others may be since I do most of my viewing at home.  Even if I go to another site I might just take the 180.

[Richard O'Neill]

Whatever best fits the target. Available time and seeing conditions usually determine choice.   

[sg6]

Which ever one take my fancy on the night.

Usually it just comes to "I might try the ABC tonight".

 

None really gets more use then another, maybe better said as none get left unused. Smaller ones may get more use but the smaller ones suit the outreach use more. I suppose that could also be described as not my own specific use.

[junomike]

I use a simple algorithm comprised of:

 

Desired target (Moon, Planets, DSO's, Doubles, Etc)

Timeline (how long I'll be out)

Weather conditions (Clear, "ify", Etc)

Temperature (warm, cold, Freezing)

Physical and mental state (tired, cranky, Etc)

[CvBadengoth]

...when you do AP only its simple: its just another framing dimension. So you choose on what you want to show :-)))

[NEOhio]

I have a Celestron 102AZ, an ST80, and an Vixen A70LF, bought in that order with aperture running from 102 mm / 80 mm / 70 mm.Just got the A70LF last month so have had it out several times lately. My expectation going forward is to use the A70LF when I want super-lightweight and higher magnification due to its 900 mm focal length, and the ST80 if I want super-lightweight wider view/lower magnification with its 400 mm focal length. The A70LF also has no RACI and no way to mount one, so it is going to be mainly for quick views of planets and bright stuff I can find in my red zone backyard with just a Telrad.

 

The 102Az is the odd one out, it is heavy and awkward enough that if I am putting that much effort into going out I end up taking the 6SE/TWI setup instead, about the same weight and more compact/maneuverable. So the 102AZ is currently unmounted and stored in a closet. One of these days I may try to find a better home for it, either with me or more likely with someone else.

[CSG]

My largest *refractor* is an 88mm spotting scope so picking between it, the Pronto, or TV-85 is a matter of whatever I'm in the mood for.  Save for the spotting scope, I use the same eps on the other two.

[t.r.]

I choose which ever one is the right combination for the seeing, my enthusiasm and the mission for the night. And I have the gamut to choose from...
40, 60, 70, 80, 92, 100, 120, 130 and 140mm.

Edited by t.r., 07 September 2018 - 11:43 AM.

[Scott Beith]

Target, time allotted to observing, conditions, and amount of effort I am willing to put forth on any given night.

 

3", 4" and 5".   All have differing mounting requirements.

[bobhen]

My 100mm LUNT refractor is, of course, used exclusively for solar Ha observing.

 

My 102mm F5 achromat is used exclusively for wide field deep sky observing with a NVD Micro Image Intensifier.

 

My 102mm F9.8 achromat is used for solar while light observing and at my club’s public start parties for public viewing.

 

My Takahashi TSA 120 is used high power lunar/planetary observing and general deep sky observing with or without the intensifier.

 

Although all of my refractors fall between 100 and 120mm, they all serve different functions. More-or-less a right tool for the right job approach.

 

Bob

[rolo]

I'm greatly limited cause of diaylis so its pretty rare the big scopes come out.Most nights and for casual viewing from the rear deck a nice 4" APO on an alt-az mount. That would be the TV102/Gibraltar/SkyTour. Its enough aperture to enjoy deep space and planetary. For a bit more palnetary detail I'll roll out the FS128 out of the garage on a CGE Mount and enjopy some "go-to" viewing of the nights best objects. When planets are at opposition then AP180 f/9 is rolled out for the ultuimate planetary viewing experience. For a quick astro-snack I'll take out the Tak FC50 which does a great job on the planets for its small size.

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Edited by rolo, 07 September 2018 - 12:07 PM.

[hfjacinto]

Since I do mostly AP, I use a scope to frame the object. You generally pick a scope that matches the scale you want. As an example, this is with the 70MM, NGC 4565 is really to small for ~300MM Focal Length.

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[hfjacinto]

While at 900MM its a little better. 

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[Sketcher]

How do you decide which to use on a given night? Do you always use the “best “one?

Last question first:  No, I don't always use the "best" one.

 

Sometimes I like going out with my smallest and/or lowest quality refractors -- just to see what can be done with them.  For example, I've observed several galaxies, etc. using a 42mm singlet refractor -- yes, the objective is a single piece of cheap glass.  It's not even an achromat!

 

Sometimes I go out with my 50mm Galileoscope -- because I like to point out to others what can be accomplished with small apertures.  Hey, at least it's an achromat!

 

Sometimes it's my 60mm department-store 'trash' telescope that was literally someone else's garbage -- because it has 'near-perfect' optics, truly amazing optical quality.  I've used it to observe and sketch the moon, planets, double stars, DSOs . . . anything and everything.  People need to know that one needn't have the 'best' in order to do some quality observing.

 

One night I took out my ST-80 -- after having dedicated a few nights to using the previously mentioned singlet refractor.  I was amazed by the quality and light-grasp!  The Orion Nebula was so bright! so detailed!  I felt as if I were observing with an 8-inch or larger 'light bucket'.  Seriously!  That was my impression of what I was seeing!

 

I've been using a 6-inch f/6.5 (yes, it's colorful!) achromat for most of my 'major' observing lately -- mostly I enjoy seeing just how much one can see with such a 'beast'.  I've specifically spent a good deal of time using it for planetary observing -- largely because of the scope's reputation for not being a planetary telescope.  (It can be put to effective use for planetary observing!)

 

My least used telescope in recent times would be my 'best'.  I already know what it can do.  I could post observations using it; but people would just say: "Sure you can see all that -- I would be able to see all those things also if I had a 130mm Astro-Physics apochromat."

 

So one night I used my 'best' for some planetary observing -- but I used it with the stock eyepiece that came with the Galileoscope -- a truly cheap Plossl eyepiece consisting of four uncoated, plastic lenses.  Various barlows were incorporated in order to achieve 'decent' magnifications.  I was able to prove that one needn't use the 'best' eyepieces in order to get fantastic views!

 

Seriously, one can have a great deal of fun and see all kinds of amazing celestial sights without always going for the 'best' telescope, the 'best' eyepieces, etc.  So I use whatever I feel like using, whenever I feel like using it -- and I have an enjoyable time regardless of the equipment I choose to use.

[scngc7317]

I don't have to decide, it never rains in SoCal anymore so I use them all !!  

 

[jeremiah2229]

It greatly depends on the targets for the night but I have a habit of rotation, each one gets used. And if I go out solo and it's nice with good transparency I'm very likely to grab another and dual mount. Sometimes the dual mount idea ends up in more comparing and less relaxed observing though so when I set up initially and it's one of those "perfect" nights I won't bother at all grabbing other scopes because you never know when "perfect" will end and I refuse to take my eye out of the eyepiece on those nights.

 

 

Peace...

[John Huntley]

Which ever one take my fancy on the night.

Usually it just comes to "I might try the ABC tonight".

 

None really gets more use then another, maybe better said as none get left unused. Smaller ones may get more use but the smaller ones suit the outreach use more. I suppose that could also be described as not my own specific use.

That pretty much sums up my approach as well

 

My 12" dob also get it's turn although it's likely to get more of it's share of the limelight as the evenings get dater earlier here.

[Codbear]

Hi Jim,

 

I was thinking about asking a similar question.  I have a Tec 180FL, Tec 160FL, TV-140, NP-101, Tak FC-100DL and a LOMO 80mm. 

 

I have fun comparing them when I take more than one scope out, but when I take only one or two out it is almost always the Tec 180FL and my larger Dob.

 

Yesterday I was busy into the evening and didn't have time to take the Tec 180 out early to cool and so I wondered if my views would be better with the Tak FC-100DL because it is a doublet and would cool fast.  When I don't cool the Tec, I notice the planets don't seem to be as sharp.  It is hard for me to know how much of this is due to seeing or the lack of cooling, but I can see the ripples of cooling in unfocused stars. 

 

So last night I took the Tak out and without any cooling started viewing.  The view of the planets was not very good but I think that was due to seeing because the out of focus star images had no rippling.  Yet, still, I missed the brightness and larger images of the Tec 180.  I did enjoy the relatively stable images of stars in the Tak, however.  The double cluster was really beautiful.

 

So while I use my Tec 180 the most by far, when I do take my other scopes out, I also enjoy them but maybe not as much.  The TV-140 also gives beautiful views that are brighter than the 100mm scopes and still wide but it also takes a while to cool down and the images do not look good until it has cooled.

 

I rarely use the Tec 160 but I have a friend coming over who will bring his Tec 140.  He wants to compare to see if he wants to "upgrade."  That should be a fun comparison.

 

Soon, maybe in Dec., I will be getting a Tec 200FL (you may recall our conversation), and I wonder if I will be using the Tec 180 anymore.  The 180 is so easy to set up though.  And the 200 on a GEM will not be so easy!  But I may keep it under a Telegizmos cover, in which case it will be ready to go.

 

Please be sure to let us know and/or PM me about your thoughts on the TEC200 vs the 180. I'm very curious what you find the 200 will do better than the 180. The extra focal length will of course give higher mag views and allow for less barlow use at times.

 

I have my 180 on JMIs with a 365Telegizmo and it works great. If I were to get the 200, I'd put it on my same AP1100 on an ATS permanent pier in the back yard. Unfortunately, I don't believe there is a 365 that will cover the 200 unless they make a custom cover.

 

I thought that there might be nights that seeing wouldn't allow my 180 great views so I'd go down to the TV127, but the 180 never fails to impress. 

 

When i want a 3* field of view, I bust out the 127, which has the same pinpoint star images as the 180...both better than my AP130 I sold. The 127 will most likely end up atop my C14HD as a nice offset to the 14's 1/2* FOV.

 

P.S. Once you get the 200, do you think you'll have any desire to pick up the 140 for a nice set of 4 Yuri's...or go for the 250?!?

 

Sam

[Codbear]

I'm greatly limited cause of diaylis so its pretty rare the big scopes come out.Most nights and for casual viewing from the rear deck a nice 4" APO on an alt-az mount. That would be the TV102/Gibraltar/SkyTour. Its enough aperture to enjoy deep space and planetary. For a bit more palnetary detail I'll roll out the FS128 out of the garage on a CGE Mount and enjopy some "go-to" viewing of the nights best objects. When planets are at opposition then AP180 f/9 is rolled out for the ultuimate planetary viewing experience. For a quick astro-snack I'll take out the Tak FC50 which does a great job on the planets for its small size.

Rolo,

 

That's a nice setup for your AP180. It is a very similar setup to my TEC180, but I am curious...what pier is that you are using and did you modify it to take the wheels and the bolt levelers or did they come with it?

 

My only worry about my setup is the 5 inch wheels on my large JMI put it a bit higher than I'd like.

[JimP]

Sam, yes Telegizmos makes custom 365 covers.

[rolo]

Rolo,

 

That's a nice setup for your AP180. It is a very similar setup to my TEC180, but I am curious...what pier is that you are using and did you modify it to take the wheels and the bolt levelers or did they come with it?

 

My only worry about my setup is the 5 inch wheels on my large JMI put it a bit higher than I'd like.

That's the original AP800 mount and 8" diameter AP pier that it came with. I installed the wheels but the leveling screws were installed before I got it.  It was refigured,reoiled and recoated last year. It's an optical masterpiece.

Edited by rolo, 07 September 2018 - 08:48 PM.

[Nippon]

I have three, SV102T, SV80ST and Vixen ED103S. which one gets used on any given night depends on what mount I choose. The SV102 has a Losmandy D dovetail so it gets used if I use my Losmandy GM8 or my SV M2C alt/az. The SV80 and the Vixen 103 have Vixen style dovetails so the 103 pretty much lives on a Vixen Sphinx SXW and the SV80 on a DSV1 alt/az. So when I want goto it's the Vixen, If I want to find stuff myself it's the SV102 and quick looks and white light solar go to the SV80.

[Kent10]

Please be sure to let us know and/or PM me about your thoughts on the TEC200 vs the 180. I'm very curious what you find the 200 will do better than the 180. The extra focal length will of course give higher mag views and allow for less barlow use at times.

 

I have my 180 on JMIs with a 365Telegizmo and it works great. If I were to get the 200, I'd put it on my same AP1100 on an ATS permanent pier in the back yard. Unfortunately, I don't believe there is a 365 that will cover the 200 unless they make a custom cover.

 

I thought that there might be nights that seeing wouldn't allow my 180 great views so I'd go down to the TV127, but the 180 never fails to impress. 

 

When i want a 3* field of view, I bust out the 127, which has the same pinpoint star images as the 180...both better than my AP130 I sold. The 127 will most likely end up atop my C14HD as a nice offset to the 14's 1/2* FOV.

 

P.S. Once you get the 200, do you think you'll have any desire to pick up the 140 for a nice set of 4 Yuri's...or go for the 250?!?

 

Sam

Hi Sam,

 

Yes, I will make a report.  I think I can guess what it will be like.  Everything will be just a little brighter and with just a little more resolution on planets and the moon.  I have talked with several who have a 180 and 200 not necessarily Tec and they see an obvious difference.  That may be an important difference for some and not for others, especially for the amount of money spent.  I think I will appreciate the difference and knowing that I have reached the limit of what I can afford and manage.  It is something I needed to do or possibly regret.  I am excited.  I would be happy with the 180 for the rest of my life but knowing how much I appreciated getting the 180 over the 160, I had to try the 200 as well.

 

I really like the Tec 140, the little I have viewed through my friends.  He is not local so I have only used it a few times.  The 140 was going to be was lifetime scope but then a 160 appeared on AM 1st.  I have the TV-140 so it covers the 140 aperture even though the Tec might be better in some ways.  I don't think I will get the Tec 140. Then there is the Tec 110 too!

 

The Tec 200 was to be my last scope.  I told my wife "probably" my last.  But my name is in for the new AP Stowaway.

 

The Tec 250 is certainly a bargain for its size, but I could never manage it on my own and I don't have a permanent setup.  But I also wondered about the air spacing and if it could keep up with the falling temperature here at night.  I am thinking the 200 might be the best compromise for my seeing conditions and cooling.  My dob often doesn't look as good as the 180.  While that could be the cooling and boundary layer etc, I also think the 16.5" doesn't do well in my seeing most of the time.  I have had some astounding views but they are rare compared to the 180 and usually don't last long right at sunset.

 

Sorry for the brief excursion off topic.  I hope Jim doesn't mind.