169 replies to this topic

[Astrojensen]

How does the 102 F-11 from China compare with the 102 F-10 from Japan

??? Which 102 f/10 from Japan?

 

 

Clear skies!
Thomas, Denmark

[KevH]

??? Which 102 f/10 from Japan?

 

 

Clear skies!
Thomas, Denmark

https://www.vixenopt...ope-p/26071.htm

 

This one is close....

[Astrojensen]

https://www.vixenopt...ope-p/26071.htm

 

This one is close....

Compared to the 102mm f/11 achromat, the Vixen is probably quite close, but the ED version is going to be far superior. The images in my 4" f/11 ED really are shockingly clear and sharp, far better than an achromat. 

 

 

Clear skies!
Thomas, Denmark

Edited by Astrojensen, 26 March 2020 - 03:53 PM.

[dusty99]

Thomas:  I have no clue how dark it is on your island in the Baltic Sea, but my one concern is the decrease in light to the eye with an f/11.  How does it compare to an f/6 or f/8 scope?

Paul

 

 

Compared to the 102mm f/11 achromat, the Vixen is probably quite close, but the ED version is going to be far superior. The images in my 4" f/11 ED really are shockingly clear and sharp, far better than an achromat. 

 

 

Clear skies!
Thomas, Denmark

[Astrojensen]

Thomas:  I have no clue how dark it is on your island in the Baltic Sea, but my one concern is the decrease in light to the eye with an f/11.  How does it compare to an f/6 or f/8 scope?

Paul

f/number is irrelevant for a visual scope, as far as brightness is concerned. The image at 100x at any given aperture in a f/6, f/8 and f/11 or f/whatever is equally bright. A slow f/ number only limits your true field of view, not how faint you can go. 

 

The f/ number does play a key role in eyepiece selection, though. 

 

 

Clear skies!
Thomas, Denmark

[dusty99]

Mark:  I didn’t feel like my Meade R5 (1000mm f/8.3 - just a little heavier and about the same length as the 102 f/11) was steady enough on my LX-70 (my SW120ED is almost 9” shorter (about the same weight) and does better).  How is your long 102 working out on the LX70?  How much wiggle do you get when fine-adjusting and focusing?

 
EDIT: The OP may not have seen my question, but I’d appreciate anyone’s input.  It looks like Thomas’ Zeiss mount is pretty beefy, but Terra’s and Bob’s may be closer to my LX70’s 20lb capacity.  Any thoughts about the scope’s 48” length and resulting moment/torque?

 

The Sky Rover just sits on the Twilight Mount when not in use.

I put it on the Meade LX70 when I observe with it !

 Mark

Edited by dusty99, 31 March 2020 - 08:38 AM.

[dusty99]

I'll move my edit here, to show the addition:

 

EDIT: The OP may not have seen my question, but I’d appreciate anyone’s input.  It looks like Thomas’ Zeiss mount is pretty beefy, but Terra’s and Bob’s may be closer to my LX70’s 20lb capacity.  Any thoughts about the scope’s 48” length and resulting moment/torque?

[Don Taylor]

I use the Altair 102F11 ED on a Celestron ASGT, a Vixen GP2+HAL130, or a Meade LX70 and it works well on all of them. The ASGT is slightly more stable and is fitted with a TPI spreader. Do use Viscoelastic pads under the tripod when on hard surfaces. Sufficiently stable for visual high power Lunar, planetary, double stars etc. - typically ~1 second damping after focusing .

 

Here's a photo I've posted previously - showing the 102F11  on the LX70. I've changed the accessories a bit since the photo was taken - using a Baader Vario Finder now vs the SV shown here. Click on the photo for a larger view.

 

Edited by Don Taylor, 31 March 2020 - 03:10 PM.

[photoracer18]

I used to work for Gary at HOO. Surprisingly I never bought one of those 102 Planet Killers although I used them now and then. Views were very nice. Maybe not as nice as my custom built Japanese Carton 100mm F13 but very nice.

[drd715]

Couldn't resist  $525 shipped.  Probably didn't need it, but always wanted one of these for general visual quick use.

The F-11 arrived in 5 days from TS to Florida!, no duty.  Added the long blue padded carry bag for $50 more.  Looks sharp. Haven't set it up yet, trying to find my spreader plate from my portable tripod. It's here somewhere. Overall it seems small compared to the 152ed, but that is perfect for a portable hour view or to show a guest the night sky without the major fanfare of setting up the CGEM and pa/alignement. Can always stick it on the spare CGEM for a dedicated night or two.  Hope to give it a test run this week.

[drd715]

I noticed Altair astro doesn't list the F-11 ED on their website product list anymore? 

[coopman]

Even Takahashi America is now listing it as having a 4 week wait.

[daquad]

Even Takahashi America is now listing it as having a 4 week wait.

Looks like people can't get enough of them.  Quite understandable.

 

Dom Q.

[jag767]

Last night I had a small comparison of my f11ed to a 127 mak I just ended up with. I had considered keeping the mak, but decided to see exactly how redundant it would be. It didnt take me very long the realize how redundant it really is, and has to go. 102 was sharper, cooled faster, and wider fov. On dsos the mak seemed to bring out a touch more, but almost fell into the negligible category. That all being said, it got me thinking. I ended up with a .63 sct reducer, going to try it on the f11ed and see what happens. I've seen this attempted with other refractors, generally with good results. Being it's starting at F11, I see this having great potential.

[cl300stick]

The F-11 arrived in 5 days from TS to Florida!, no duty.  Added the long blue padded carry bag for $50 more.  Looks sharp. Haven't set it up yet, trying to find my spreader plate from my portable tripod. It's here somewhere. Overall it seems small compared to the 152ed, but that is perfect for a portable hour view or to show a guest the night sky without the major fanfare of setting up the CGEM and pa/alignement. Can always stick it on the spare CGEM for a dedicated night or two.  Hope to give it a test run this week.

 

I'm curious what blue padded bag? I'm looking at their site to order the ED and would like to add the bag.... Thanks!

 

Andrew

[kmparsons]

jag767,

 

I once heard refractor aficionados called "drooling refractor geeks." Guilty as charged! But our love of these instruments is not irrational. Even a modestly-priced achromat can beat the view of a larger (even subtracting the central obstruction) reflector. When the Kunming 102mm f/11 was reviewed in Astronomy Technology Today a few years back, the reviewer said that a friend observing with an 8" Dobsonian was wowed by the view of the Orion Nebula in the refractor. Of course, a bigger aperture brings in fainter objects, but for pinpoint stars and a flat field a well-made, longer-focus refractor really delivers. 

[drd715]

I'm curious what blue padded bag? I'm looking at their site to order the ED and would like to add the bag.... Thanks!

 

Andrew

On the TS website  locate the 102mm ED F-11  page. Scroll down to the list of accessories  at the bottom of the page and the blue bag is there. 49+ euro⁶  

[jag767]

Last night I had a small comparison of my f11ed to a 127 mak I just ended up with. I had considered keeping the mak, but decided to see exactly how redundant it would be. It didnt take me very long the realize how redundant it really is, and has to go. 102 was sharper, cooled faster, and wider fov. On dsos the mak seemed to bring out a touch more, but almost fell into the negligible category. That all being said, it got me thinking. I ended up with a .63 sct reducer, going to try it on the f11ed and see what happens. I've seen this attempted with other refractors, generally with good results. Being it's starting at F11, I see this having great potential.

For anyone interested, epic fail. Needs more in travel than even removing the tube section yields.

[Terra Nova]

Gary's 'brand' was Astro Telescopes.   I actually owned the one that was used in that Planet Killer  Review, but sold it when we moved out to Western Massachusetts.  Even when near Boston,  the views were incredible.  Not sure, but I always thought that Kunming had a hand in it.

They really were wonderful scopes. Heavy but very well made. I bought mine from HOO back in 2010 and used it a lot. It was a great solar scope too! I sold mine a few years ago after I acquired a couple of 4” F15s. Later, I went to shorter, lighter apos so those went too. I enjoyed it very much while I had it. It gave wonderful, very sharp, high contrast images- pinpoint diamond stars cast against black velvet.

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Edited by Terra Nova, 22 April 2020 - 04:06 PM.

[dscarpa]

 Nice scope! I wouldn't leave it on the Twilight I even for storage however. My Voyager I's az axis came apart with my 20lbs  with accessories WO ZS110 F7   triplet on it. If I hadn't been standing next to it it would have taken a death dive to my patio .   It's now over mounted on a Twilight II which works great. It was also very stable on one of my three Unistars. David

Edited by dscarpa, 22 April 2020 - 03:59 PM.

[GOLGO13]

For anyone interested, epic fail. Needs more in travel than even removing the tube section yields.

Quite possible a less aggressive reducer would work.  A website for one of these says this: The optics are compatible with the Lightwave 0.8x field flattener / reducer

 

Could be worth a try, but not sure how that affects visual performance. I know in general these are used for imaging. 

[Galicapernistein]

I’ve been thinking of getting one of these F11’s, but I don’t know if there’s enough of a performance difference between that and my F9 Skywatcher 100ED. Although from what I’ve read, the TS 100 is better mechanically.

[zombie1210]

The TV Gibraltar 5 with Berlebach tripod will handle it nicely:

 

5.jpg

My heart just sank. I had to sell my Gibraltar with the same tripod during my divorce ten years ago.  Ugh!

[daquad]

They really were wonderful scopes. Heavy but very well made. I bought mine from HOO back in 2010 and used it a lot. It was a great solar scope too! I sold mine a few years ago after I acquired a couple of 4” F15s. Later, I went to shorter, lighter apos so those went too. I enjoyed it very much while I had it. It gave wonderful, very sharp, high contrast images- pinpoint diamond stars cast against black velvet.

I too had one from HOO.  I loved the 2-speed R&P focuser, very robust and smooth.  If the f-ratio had been a bit higher, 12 or 13, I would have kept it.  But I sold it and stayed with my old Jaegers 4" f/15.5.  Used it on my Losmandy GM100.

 

Dom Q.

 

[Binofrac]

Here's mine badged Lyra Optic. It is a beautiful thing to look through and at. I've done a number of one man outreach evenings with it. This scope easily fulfills the requirement to attract interested people to stop and talk about astronomy and look through the eyepiece. It's my only scope as I researched a fair bit to get the right one and this is definitely it. It sits on a Skywatcher eq5 which is fine for my purely visual use. I've just ordered a BST (Arcturus) binoviewer to use on the sun, moon and planets. It will be interesting to see how this works out.

 

I was very interested in the ED version that appeared. The only reasons I held off were because the new one didn't have a rotating focuser, and I didn't want to spend that much money without looking through one first. Mine is very good and it was hard to see how one that was twice the price could produce views that were twice as good (to me). If I had bought one then I would've swapped the focusers over. I'll keep an eye out on the used market.

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