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GavStar

Travel scope - Baader travel companion or AP Stowaway

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I think the 90-95mm refractor is a sweet spot for an airline travel setup. (Although my tv85 did a fine job in tenerife recently 👍)

If you had a choice between the following scopes which would you choose and why? (Assume price with rings etc is broadly the same). In many ways they are very similar...

https://www.baader-planetarium.com/en/baader-apo-95560-caf2-travel-companion.html

Or

http://www.astro-physics.com/index.htm?products/products

Edited by GavStar

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First, do you have a lead on a used Stowaway or have been on their waiting list for years already?

Second, the Baader seems to be in a similar situation.

Third, why would you want to take such an expensive scope on a trip and risk having it stolen from your hotel room while you're away at lunch or sightseeing?  You mention taking a TV85 in the past.  I took a $100 ST80 to Nebraska to view the eclipse and it worked fine for that job.  Roadside hotels are hotbeds for having cars broken into, and I didn't feel like bringing it into the room each night.

I'd probably get a Hubble Optics UP12 or similar for travel if I really wanted to bring along some telescope horsepower.  Of course, I generally travel by car or van rather than airplane.

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I was curious about who makes the lenses for the Baader refractor?

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im going to have to say it, crazzy money for a travel scope, a £500 ed scope would do the job just fine, is it made of gold or something, im sorry to be a neg but i was shocked to see the price and what its for. charl.

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1 minute ago, xtreemchaos said:

im going to have to say it, crazzy money for a travel scope, a £500 ed scope would do the job just fine, is it made of gold or something, im sorry to be a neg but i was shocked to see the price and what its for. charl.

Ok that’s a fair point!

I think better to say that it would be a main grab and go scope at home which could also be taken abroad as well as needed. At near 100mm these scopes should give very nice planetary views up to 200x and also show the brighter DSOs nicely together with big widefield views.

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38 minutes ago, Louis D said:

First, do you have a lead on a used Stowaway or have been on their waiting list for years already?

Second, the Baader seems to be in a similar situation.

Third, why would you want to take such an expensive scope on a trip and risk having it stolen from your hotel room while you're away at lunch or sightseeing?  You mention taking a TV85 in the past.  I took a $100 ST80 to Nebraska to view the eclipse and it worked fine for that job.  Roadside hotels are hotbeds for having cars broken into, and I didn't feel like bringing it into the room each night.

I'd probably get a Hubble Optics UP12 or similar for travel if I really wanted to bring along some telescope horsepower.  Of course, I generally travel by car or van rather than airplane.

Yes these scopes are very hard to get. However, after being on the Baader list for a while, i’m hoping I may get it this year. The recent launch of the Stowaway intrigued me so I was just interested in people’s thoughts regarding say differences in f-ratios, glass, oil vs air spaced etc...

Regarding taking the scopes abroad, I agree I wouldn’t be comfortable leaving it in the car so would take it into the hotel room (and make sure I had suitable insurance). Aeroplane portability is a critical factor for me which both these scopes do.

Edited by GavStar

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Difficult choice - which £3K plus 3.5 inch travel refractor with a long waiting list  :icon_scratch:

I'd probably go for the Astro Physics just because it's an AP.

Get them both Gavin - compare them, keep your favourite and get your money back (or more) when you sell the other. Simples !

I'm happy with my £200 TV Ranger for travel though. Don't usually do much astro when I'm away :rolleyes2:

 

 

 

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24 minutes ago, John said:

Difficult choice - which £3K plus 3.5 inch travel refractor with a long waiting list  :icon_scratch:

I'd probably go for the Astro Physics just because it's an AP.

Get them both Gavin - compare them, keep your favourite and get your money back (or more) when you sell the other. Simples !

I'm happy with my £200 TV Ranger for travel though. Don't usually do much astro when I'm away :rolleyes2:

 

 

 

Get them both John?? Interesting idea 😀😀

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Firstly I would say that I would be really happy with the TV85 as a travel scope never mind home use.

If I was giving a choice, like John, I would go with the Astro Physics simply because its going to be a classic.

Pity you can't bring all these fracs to the SGL star party - your location would have a very long queue 😁

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The Baader is slightly faster Gavin - with night vision in mind. Looks stunning, and beautifully engineered too. Think I'd go for that if I had the choice, though maybe doesn't have quite the brand cache of the AP.

Surprising there aren't more mainstream challengers in the travelscope market - I'm thinking a 90-95mm Synta ED doublet with sliding dew shield and case designed to meet aircraft cabin requirements. £750-ish?

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I emailed Baader about the lenses, lets see if they reply. Their add says made in Germany and if the lenses are...

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11 hours ago, Highburymark said:

Surprising there aren't more mainstream challengers in the travelscope market - I'm thinking a 90-95mm Synta ED doublet with sliding dew shield and case designed to meet aircraft cabin requirements. £750-ish?

I think a scope that fast needs to be a triplet to be good enough optically Mark. This is the ‘poor man’s’ version, still pricey though.

https://www.astronomics.com/astro-tech-at92-f55-triplet-apo-refractor-ota_p20545.aspx

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11 hours ago, jetstream said:

I emailed Baader about the lenses, lets see if they reply. Their add says made in Germany and if the lenses are...

Gerry,

Your question intrigues me. 😀

I just assumed that the fluorite was sourced from canon in Japan just like Takahashi. Are there other producers of fluorite for astronomy? Would a German made fluorite lens be any better?

Edited by GavStar
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4 hours ago, Stu said:

I think a scope that fast needs to be a triplet to be good enough optically Mark. This is the ‘poor man’s’ version, still pricey though.

https://www.astronomics.com/astro-tech-at92-f55-triplet-apo-refractor-ota_p20545.aspx

Good point Stu. Though my Equinox 80ED is a F6.25 doublet - focal length 500mm, and it performs very well as a visual scope

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4 minutes ago, Highburymark said:

Good point Stu. Though my Equinox 80ED is a F6.25 doublet - focal length 500mm, and it performs very well as a visual scope

I think it is the speed as much as the focal length, f5.5 is much more of a challenge to keep abberations at bay.

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I think I prefer the look of the Baader as to my eye the AP looks unfinished around the rear of the dew shade. I'm sure Baader will be absolutely top class optically and would bring a high resale price. I can see the appeal of the AP simply because its an AP, but its a bit of a spud compared to the Baader. In the field I doubt there'd be any real world difference in optical performance. I'm not sure where Baader source their optics but considering that virtually everything they produce is excellent, I'd have no worries about the scopes performance. Having said that, neither would give better planetary performance than a FC100, which could fit snugly up your trouser leg while passing through customs.

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4 hours ago, GavStar said:

Gerry,

Your question intrigues me. 😀

I just assumed that the fluorite was sourced from canon in Japan just like Takahashi. Are there other producers of fluorite for astronomy? Would a German made fluorite lens be any better?

I would think that the Canon fluorite is among the best available...no doubt. Baader has/had an association with Zeiss at one time and this is what intrigues me. There has to be superb glass in this scope from the reports read and the cost of the telescope IMHO.

If there is Canon or Zeiss lenses in this telescope it would be my pick, for sure. There may be other top notch German lenses out there too...

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I believe Baader hold a lot of the Zeiss optical designs and patents so its possible that the 95mm is using a Zeiss design executed, or partially executed, by Canon Optron ?

Could be a hybrid involving a Canon Optron CaF2 element between two German produced elements ?

Will we ever see a lens with a strehl of 1.0 I wonder ? :smiley:

 

 

 

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Here’s an example from the 10 test reports that Roland Christen has posted on the web. The different lens cells are testing very consistently...

 

730C10D8-4BF0-4070-8604-706FD4DE1C51.png

195A5422-458C-4C67-9DE8-86A13BE03FEB.png

And also tests at 4 different visual light wavelengths as follows

56306E57-D729-4784-9BD2-F64DAE7FC45E.thumb.png.d424ad7d6fdb091366d4455334e0baac.png

 

4A1E4C59-9105-4657-8925-3FCA24ADA3A4.png

Edited by GavStar
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1 hour ago, GavStar said:

Here’s an example from the 10 test reports that Roland Christen has posted on the web

Great stuff Gavin, I love these accurate test reports. What I really want to know if there is any difference visually on faint, diffuse, extended objects between scopes testing similarly.

Those color test fringe patterns are all taken of the lens assy I presume? a min .96 Strehl (red) is superb and more across the board.

A future binoscope project is watching this thread closely...

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17 hours ago, jetstream said:

Great stuff Gavin, I love these accurate test reports. What I really want to know if there is any difference visually on faint, diffuse, extended objects between scopes testing similarly.

Those color test fringe patterns are all taken of the lens assy I presume? a min .96 Strehl (red) is superb and more across the board.

A future binoscope project is watching this thread closely...

Probably not as aperture is the biggest differentiator on faint fuzzies.  Where these highly accurate figures come into their own is on low contrast planetary details and breaking up globular clusters to the core at crazy high powers where it is very important there is no stray light not being focused exactly where it should be focused.  This is where I've found the EdgeHD SCTs outperform regular SCTs as well.  If you're only interested in teasing out faint fuzzies, a 3 or 4 inch travel APO refractor is not the right tool compared to a 16" Dob for similar money.  If you are traveling and need faint fuzzy capturing abilities, an 8" or 10" suitcase Dob would be a much better option.

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49 minutes ago, Louis D said:

Probably not as aperture is the biggest differentiator on faint fuzzies.  Where these highly accurate figures come into their own is on low contrast planetary details and breaking up globular clusters to the core at crazy high powers where it is very important there is no stray light not being focused exactly where it should be focused.  This is where I've found the EdgeHD SCTs outperform regular SCTs as well.  If you're only interested in teasing out faint fuzzies, a 3 or 4 inch travel APO refractor is not the right tool compared to a 16" Dob for similar money.  If you are traveling and need faint fuzzy capturing abilities, an 8" or 10" suitcase Dob would be a much better option.

Well...it depends on the object and size of the object that is being viewed ie large faint nebula.

Louis, can you explain to me why there are differences in what I see on these faint objects between quality telescopes?

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3 hours ago, jetstream said:

Louis, can you explain to me why there are differences in what I see on these faint objects between quality telescopes?

I'm not sure I understand your question, but faint objects don't typically have much in the way of fine detail.  Sometimes there are tendrils as in the Veil nebula which could be helped by telescopes having a higher MTF.  MTF is what is being enhanced in high end telescopes.  Modulation transfer function (MTF) is a measure of how well the image's details are resolved and at what contrast level.  Poorer scopes will tend to blur fine details together that better scopes resolve.  As I said earlier, if all of the wavelengths of light are not focused at the same point, there will be loss of detail and contrast.  If the figure of the scope is not super even across its surface, light rays from different entering light ray bundles will not all be brought to focus at the same point, again causing loss of detail and contrast.

If on the other hand, all you want to do is detect a faint fuzzy and not resolve it, aperture generally rules except for very large objects where either a short, fast scope or night vision works best.  It doesn't really matter if all of the light is focused where it should be focused because fuzzy is still fuzzy and unresolved in smaller scopes.  That's simply a function of aperture and the Rayleigh criterion.  An example might be a large globular cluster.  A 100mm f/5 achromat will be able to detect it as a faint smudge, but probably not resolve it even at high power due to poor figure and massive amounts of false color.  A finely figured 100mm APO will also detect it and just might be able to resolve it as well at very high powers.

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Increased aperture brings the potential to see more fine detail on planets etc and optical quality determines how much of it gets "through".

In terms of seeing extended objects it is the optimum exit pupil at the mag needed to see them, and this in part is a function of aperture, that determines how we see them. Rayleigh criterion etc does not apply to extended objects such as the ones I mention as they are not "point source" objects to resolve.

I have no idea why some refractors are better than others on these faint nebulae. There is a difference to my eyes, under my conditions and it is noticeable.

My question is why?

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23 minutes ago, jetstream said:

Rayleigh criterion etc does not apply to extended objects such as the ones I mention as they are not "point source" objects to resolve.

I was thinking in terms of globular clusters where in smaller apertures they appear to be unresolveable extended objects; but in larger apertures, they will resolve into individual stars.  Galaxies are the same way if you can just go big enough and have steady enough seeing (as with the Hubble Space Telescope).  Truly extended objects like nebula never resolve and the Rayleigh criterion never applies.  I surmise that is what you were referring to.  For them, quality of figure doesn't matter all that much.  It's much more effective to take the extra money and go the night vision route to tease out dimmer or larger extended objects visually.

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