AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Light, portable 102 refractor for portamount
#5592984 - 12/28/12 05:18 PM
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Well right now I have a 100mm f/9 ED refractor with a moonlight 2.5" focuser on it. On the Vixen Starguy mount, it is a bit wobbley (it is long). Are there any 4" (or close to it) that would sit better on the portamount (starguy)? What about a used 102ED f/7 scope? Or what about just dropping down to 80mm? This is for grab and go, I stopped using the 100mm on the CG5 mount because I could set up faster with my C8.
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5593024 - 12/28/12 05:49 PM
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An 102mm f/7 worked for me, an 80mm f/7 apo is more stable, an NP-101 is less stable but acceptable.
Jon
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Denimsky
professor emeritus
Reged: 01/21/07
Loc: BC, Canada
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5593191 - 12/28/12 07:28 PM
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Abe, what is your budget limit?
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AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Re: Light, portable 102 refractor for portamount
[Re: Denimsky]
#5593212 - 12/28/12 07:39 PM
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I rather stay under $1000
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Larry Carlino
member
Reged: 06/05/06
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5593241 - 12/28/12 07:59 PM
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You might try the KSON ED1026 refractor OTA. It's a 102mm, f/6 ED doublet with a carbon fiber tube, available in either red or dark gray. Optical quality is excellent, and the scope is quite light. There is a bit of c.a. at higher powers as one might expect from a scope that uses FPL-51 equivalent glass, but the overall performance is very satisfying. It comes with tube rings, a red-dot finder and one very nice 20mm wide-angle eyepiece. I have mine mounted on a Vixen Portamount, and it's pretty steady - a perfect grab-and-go set-up. Current price (new) is $899.
Larry Carlino
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5593286 - 12/28/12 08:23 PM
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I noticed on my StarGuy while using my 102 F/9.8 achro when I would nudge the scope up and down that there was movement in the azimuth part of the mount. I took the mount apart and tightened the bolt on the the bottom. After tightening it was a lot better, not completely solid but satisfactory for me.
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5593802 - 12/29/12 04:57 AM
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A couple of thoughts...
The Lunt 102 ED is about $750 at Anacortes...
I would be willing to bet your money that the Portamount mated with the 2 inch SS legged CG-5 tripod would solidify things to the point where your 100mm f/9 was plenty stable. Since you have a CG-5, you could try it, it might take some simple fabrication...
Jon
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: Jon Isaacs]
#5593846 - 12/29/12 06:50 AM
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I would be willing to bet your money that the Portamount mated with the 2 inch SS legged CG-5 tripod would solidify things to the point where your 100mm f/9 was plenty stable. Since you have a CG-5, you could try it, it might take some simple fabrication...
Jon
He said he has the StarGuy so I would think the tripod (HAL130-SXG)would be sturdy enough.
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carlcat
sage
Reged: 11/26/07
Loc: Northern California
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5594318 - 12/29/12 12:28 PM
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I keep my 100ED on a cg4. I keep the scope mounted and can easily take the setup out with no problems. It's very steady as well.
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Kon Dealer
professor emeritus
Reged: 01/05/11
Loc: Cambridge UK
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Re: Light, portable 102 refractor for portamount
[Re: carlcat]
#5594678 - 12/29/12 04:14 PM
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+1 for the Kson. Really light, great focuser.
Much better than a Megrez90 that was my
Previous G&G
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AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Re: Light, portable 102 refractor for portamount
[Re: Kon Dealer]
#5594789 - 12/29/12 05:53 PM
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Where do you guys get one?
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5594972 - 12/29/12 07:29 PM
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Kson
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5595367 - 12/30/12 12:05 AM
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Quote:
He said he has the StarGuy soI would think thetripod (HAL130-SXG)would be sturdy enough
According to the original post, the mount is not stable enough. In my experience with the Portamount, that points to the tripod. I once mounted my Portamount head on my old Houston-Fearless tripod and it was rocksolid with my NP-101... My gut feeling is that the CG-5 tripod would be similar.
Jon
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Kon Dealer
professor emeritus
Reged: 01/05/11
Loc: Cambridge UK
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Re: Light, portable 102 refractor for portamount
[Re: Jon Isaacs]
#5595676 - 12/30/12 08:23 AM
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Kson OTA only weighs 5.6lbs and at f/6 is quite short.
Fits on my Synscan AZ goto mount perfectly and is
Pretty stable.
Also fits on my SE mount and with an extension tube in
The diagonal, can reach zenith OK.
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AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Re: Light, portable 102 refractor for portamount
[Re: Kon Dealer]
#5596608 - 12/30/12 05:32 PM
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The issue I have is the overall length adds quite the moment arm and the moonlight 2.5" focuser adds some heft to it...
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Gary Riley
super member
Reged: 12/01/11
Loc: White Bluff, TN
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5597232 - 12/31/12 12:29 AM
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I have a 102mm f/9.8 achro on a CG-4 mount with the 1.75 inch dia. stainless steel legs and it carries it very well. If I have a fairly strong breeze blowing it will cause the OTA to shake at times slightly. Otherwise, it does very well.
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: Jon Isaacs]
#5597568 - 12/31/12 09:19 AM
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He said he has the StarGuy soI would think thetripod (HAL130-SXG)would be sturdy enough
According to the original post, the mount is not stable enough. In my experience with the Portamount, that points to the tripod. I once mounted my Portamount head on my old Houston-Fearless tripod and it was rocksolid with my NP-101... My gut feeling is that the CG-5 tripod would be similar.
Jon
The HAL 130 tripod is rated for 30 to 35 lbs. I tried my 102 F/9.8 with the "Mannys Bracket" and it was unusable. I took off the "Mannys Bbracket" and it was a lot better. I tightened the bolt on the azimuth stem and it was even better. In my opinion it is the mount itself and not the tripod. When I put my SLT mount on the HAL 130 with the 102mm F/9.8 scope it has less, much less vibrations than the porta mount on it with the same scope. My shorter scopes, ST120, C6-SCT amd C6-N which weigh more that the 102 F/9.8 are much more stable.
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AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5598708 - 12/31/12 08:28 PM
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What's the ST120 like on it?
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5598791 - 12/31/12 09:42 PM
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ST120 is pretty solid. Damping times are minimal, a second or so if I remember correctly.
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AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5599182 - 01/01/13 08:14 AM
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About how long is your ST120, I suppose if I get a refractor with similar dimensions, I would be set...
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Kon Dealer
professor emeritus
Reged: 01/05/11
Loc: Cambridge UK
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5599351 - 01/01/13 10:45 AM
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Had a ST120 and let it go for two reasons;
1 too much CA
2 too big for my SynscanAZ mount.
The CA has to be seen to be believed!!
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5599811 - 01/01/13 03:18 PM
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About how long is your ST120, I suppose if I get a refractor with similar dimensions, I would be set...
With the dew shield about 25" , without dew sheild about 19". This doesn't include diagonal.
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: Kon Dealer]
#5599838 - 01/01/13 03:34 PM
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Had a ST120 and let it go for two reasons;
1 too much CA
2 too big for my SynscanAZ mount.
The CA has to be seen to be believed!!
I fail to understand why people make these kind of statements. The stated purpose for it is for deep sky objects. It is not meant for planets, moon or bright stars. It is a wide field scope. If I buy an F/15 scope then complain that it is a terrible wide feild scope on here people would laugh at me. I don't mean to be harsh but it is what it is! Also, isn't the Synscan basically the same as the SLT? The SLT mount can handle quite a bit on a heavy duty tripod!
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Kon Dealer
professor emeritus
Reged: 01/05/11
Loc: Cambridge UK
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5600922 - 01/02/13 10:03 AM
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Had a ST120 and let it go for two reasons;
1 too much CA
2 too big for my SynscanAZ mount.
The CA has to be seen to be believed!!
I fail to understand why people make these kind of statements. The stated purpose for it is for deep sky objects. It is not meant for planets, moon or bright stars. It is a wide field scope. If I buy an F/15 scope then complain that it is a terrible wide feild scope on here people would laugh at me. I don't mean to be harsh but it is what it is! Also, isn't the Synscan basically the same as the SLT? The SLT mount can handle quite a bit on a heavy duty tripod!
This is because I had read a few reviews that said the CA in a ST120 was "overstated" and that if it did prove troublesome was "easily addressed" with a fringe-killer, or similar.
Well it wasn't- in both cases.
Also the mount struggled with it, particularly in altitude.
What I learnt from this is that telescopes and one's views of them (and through them) are very personal. What works for one may well be unacceptable to another.
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Locoman
professor emeritus
Reged: 03/09/09
Loc: Abilene, Kansas
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Re: Light, portable 102 refractor for portamount
[Re: Kon Dealer]
#5600968 - 01/02/13 10:33 AM
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I guess my ST120 may a good one because the other night Jupiter looked very good. I don't usually look at planets, moon and brighter objects with it but I wanted to try it on my SLT and it was a full moon night. Still, it is a great grab n go scope for the $ and if one sticks with dso's for which it was intended then CA is not an issue.
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Mr Onions
Two Time International Photographical Competition Winner
Reged: 04/14/07
Loc: Newcastle upon Tyne.
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5600974 - 01/02/13 10:36 AM
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William Optics has a new 102mm coming out soon.
You might want to consider it.
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AlienRatDog
Carpal Tunnel
Reged: 07/15/05
Loc: Ann Arbor
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Re: Light, portable 102 refractor for portamount
[Re: Mr Onions]
#5601842 - 01/02/13 07:52 PM
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Where can I read up on it?
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Mr Onions
Two Time International Photographical Competition Winner
Reged: 04/14/07
Loc: Newcastle upon Tyne.
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5602339 - 01/03/13 04:18 AM
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Was on their Facebook page.
In red trim like the 81GT
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Light, portable 102 refractor for portamount
[Re: Locoman]
#5602798 - 01/03/13 11:37 AM
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I guess my ST120 may a good one because the other night Jupiter looked very good.
I suspect it has more to do with the observer and the conditions, the bright moon in particular, than having a good one. In my experience, achromats are very consistent in their color correction, I have owned several ST-80, all are about the same, I have owned several 80mm F/11s of varying ages and qualities and yet, are have been very similar. Color correcting an Crown-Flint achromat has been well understood for nearly 200 years.
I have owned two 100mm F/6s, both are very similar and the chromatic aberration definitely hinders the view of Jupiter and brighter objects. As you stated previously, an 120mm F/5 achromat is a low power, wide field scope. Based on the fact that it will have significantly more false color than a 100mm F/6, I think that is a fair accessment.
So, when Kon Dealer points out that the false color is excessive, you can either agree that it is and say that it is a low power widefield scope or you can say that Jupiter looked very good.
But if you say Jupiter looked very good, then Kon needs to state that there is an excessive amount of false color and he had been mislead into thinking it might provide "very good" views of Jupiter.
I happened to be viewing Jupiter last night with my 100mm F/6 achromat. The view was "adequate" though Jupiter was surrounded and covered with purple haze. I switched to my 80mm F/7 apo and saw a clear and significantly more detailed view even though the aperture was reduced...
Jon
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SteveG
Post Laureate
Reged: 09/27/06
Loc: Seattle, WA
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Re: Light, portable 102 refractor for portamount
[Re: AlienRatDog]
#5603077 - 01/03/13 02:02 PM
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Where can I read up on it?
Unfortunately, nothing to read yet as the 4" version isn't on the market. I'm looking forward to hearing how well this 5 element refractor is for both visual and imaging. The 4" might be good competition for the NP101 line from TV.
I'd love to hear from anyone who has the 3", 5-element version.
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Kon Dealer
professor emeritus
Reged: 01/05/11
Loc: Cambridge UK
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Re: Light, portable 102 refractor for portamount
[Re: SteveG]
#5603420 - 01/03/13 05:47 PM
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Well stated Jon 
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Jon Isaacs
Postmaster
Reged: 06/16/04
Loc: San Diego and Boulevard, CA
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Re: Light, portable 102 refractor for portamount
[Re: Kon Dealer]
#5604213 - 01/04/13 08:11 AM
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Just to get back to the original topic.. sort of..
If ARD (AlienRatDob) wants a shorter focal length 4 inch refractor, there are a number of choices but unless he spends a substantial amount of money, the only gain visually will be the wider field of view. The mid power and high power views should be better with his current scope, the ED-100.
It seems to me that if the only problem is the stability of the Portamount, then that can be addressed either by improving the Portamount or with a different mount that is more stable.
Jon
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Scott Beith
SRF
Reged: 11/26/03
Loc: Frederick, MD
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Re: Light, portable 102 refractor for portamount
[Re: Jon Isaacs]
#5604869 - 01/04/13 02:00 PM
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A used AT102ED or SV102ED would get my vote.
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