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ATX/STX rumor (1 Viewer)

Auch, down here summer ends........today:-C:-C

Jan

Fortunately we still have summer today.
The 115 looks very head-heavy.
The optic is fantanstic, esp. the CA control is noticeably better than 95mm, a wonder for a 115mm F4.8 objective. Report has it that it can easy support 200x and the optic is better than any right angle telescope(except the ones eqiupped with Matsumoto EMS) in this world. I bet they use multiple ed glasses.
 
ok I just found it in the specs as the 95mm and the new 115mm are both the same length at 11.6 inches..USA websites saying they will be shipping these out to customers in 7-10 days..hmmm
 
These 115mm objectives will vary from one sample to another.

So if one wants a good one it would have to star and resolution tested.

I presume that the extender/multiplier is a matched modified Barlow, which changes the f/4.8 ratio to about f/8.

The fact that one tested sample can easily take 200x does not mean every sample can.

But a good sample might be very interesting.

B.
 
Anyone else heard the rumor of a 115mm objective lens for the ATX/STX?

Congrats for being right here, JT.

I laughed out loud thinking about this posting when I saw this 115mm advertised at Europtic, thought of you thinking about deleting your 'rumor.'
Nailed it.
 
These 115mm objectives will vary from one sample to another.

So if one wants a good one it would have to star and resolution tested.

I presume that the extender/multiplier is a matched modified Barlow, which changes the f/4.8 ratio to about f/8.

The fact that one tested sample can easily take 200x does not mean every sample can.

But a good sample might be very interesting.

B.

Based on your experience, how wide would you expect the sample variation to be?
Does variation increase with the increased size of the optics?
Clearly we are getting into telescope territory here and it would be very helpful to have a sense of what to watch out for.
 
Based on your experience, how wide would you expect the sample variation to be?
Does variation increase with the increased size of the optics?
Clearly we are getting into telescope territory here and it would be very helpful to have a sense of what to watch out for.

Hi,

faster focal ratio optics tends to show more minute aberrations, so hopefully QC is going to be upped a bit. Like actually putting each 3k objective on an interferometer and making sure that it's at least diffraction limited.

Quite frankly, astro refractors faster than f6 are rare (and usually multiplet designs with 4 or more elements).

Joachim
 
As the zoom range and closest focus are the same with the 115mm and the 95mm direct comparisons will be interesting. In the meantime what advantages is such a large objective likely to show?

Better performance in low light situations = brighter?
Increased fov
Better resolution
What about depth of field?
Useable at higher magnifications (air conditions allowing)
Anything else?

Cons would include increased weight and cost - but is a larger objective inherently more difficult to “ get right” are there downsides or is bigger always better?
 
As the zoom range and closest focus are the same with the 115mm and the 95mm direct comparisons will be interesting. In the meantime what advantages is such a large objective likely to show?

Better performance in low light situations = brighter?
Increased fov
Better resolution
What about depth of field?
Useable at higher magnifications (air conditions allowing)
Anything else?

Cons would include increased weight and cost - but is a larger objective inherently more difficult to “ get right” are there downsides or is bigger always better?

More light and less CA are specially welcomed by those, like me, that frequently use the 1.7x extender!... B :)
 
Hi Edudiant, post 48.

115mm is small for an astro refractor, so the quality should not be a problem for skilled opticians.
But a good f/4.8 115mm needs a lot of care to get it right if one expects 200x plus performance.

10 inch or 250mm refractors begin to have problems getting perfect blanks.

A 600mm f/4 top quality camera lens or say an 800mm f/5.6 are much more expensive and probably just as difficult or more difficult to make well.

The extender or two extenders will not be perfect themselves, so may contribute to errors.

If quality control is good, hopefully these 115mm will all be a pleasure to use.

Regards,
B.
 
I wonder how big a demand there will be for this new awesome 115MM objective..? I have the 95MM ATX Kit and thought it was the bomb and now comes this beauty... I would think this may be easier to get from the get go then the 10-12 X 42 NL Pure..?
 
I expect the 110mm clear aperture is accurate for the BTX. I'm surprised there isn't more vignetting, including with the ATX and STX.

This thing will be hard to pull off properly. They'll certainly need to up their game for color correction. The ED glass will have to one of the types with an Abbe # around 95 and the mating glasses will have to be just right, etc.

Edit: Just saw David's post. I assumed the smaller objective modules were already using the usual fixed triplet and focusing doublet. If they want to keep the same level of spherical correction in the 115 as the 95mm that may need an upgrade, whatever that might mean.

Hi Henry,

You are right about the 110mm for the BTX.
The response of Swarovski is as follows:

The effectiveness of the lens diameter is limited in the 115 by the BTX eyepiece module, as the prims used in the BTX were ‘designed’ for a 30-70x95 system. The 115mm has a larger aperture ratio and the prism system is therefore too small for the beam in the center of the image. With the smaller lens modules (65mm, 85mm, 95mm) the BTX prisms can take up the entire beam. ATX and STX can completely get the bundles of rays with all lens modules, which is the reason for why the lens diameter is not reduced here.
Larger prisms would have the disadvantage for the 95/85/65 models, they would be too big and too heavy. The 110mm for the BTX is therefore a little “trade-off” due to our modular system.

Here goes my "wet dream" for a 150mm BTX........

Jan
 
Jan,

With a slow 150mm module you might be able to have your dream.
But it would be a long telescope.

In fact the binocular module could probably be attached to any existing 150mm, 200mm or bigger telescope.

I am not sure if the binocular module is matched to Swarovski objective modules, or whether any normal long focus refractor can be used.

Regards,
B.
 
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