624 replies to this topic

[Lead_Weight]

Interesting to read this. I just assumed, even with poor mechanical quality, you still wanted to get everything lined up for perfect collimation. Looking forward to trying this one day on my Edge scopes. Are we getting closer to release now?

[FredOS]

I agree with Rockstarbill, this software is really excellent. Very easy to use with great results with CDK type of instruments where you only adjust the secondary. I guess the next tests will be with those requiring adjustment of both primary and secondary and how to use the software to optimise results.

[rockstarbill]

Here is a before and after view.

 

 

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[ChrisWhite]

Good stuff! 

 

I'm curious, if this can be used with a refractor to eliminate tilt that may arise from manufacturing tolerances in adapters, accessories, and sensor orthogonality.  I have been manually correcting for tilt and with a large chip and tiny pixels it is an iterative and challenging process.  With a Gerd CTU the adjustments are easy and precise, but evaluating and correcting for tilt is another matter. 

[rockstarbill]

I believe the full field version of SkyWave will be able to detect sensor tilt issues, along with off axis aberrations that can be corrected via collimation adjustments. This is the single star version which assists with collimation using a single defocused star.

[ChrisWhite]

I believe the full field version of SkyWave will be able to detect sensor tilt issues, along with off axis aberrations that can be corrected via collimation adjustments. This is the single star version which assists with collimation using a single defocused star.

Thanks Bill.  I just found this post from Gaston earlier in the thread: https://www.cloudyni...ion/?p=11255741

 

Looks like SKG Advanced will indeed be able to analyze starfield and take into account off-axis aberrations.  Would be extremely useful for tilt and spacing adjustments, especially for people who are masochistic enough to image with very fast optics. 

 

Any news on availability of these products for general consumption?

Edited by ChrisWhite, 14 August 2021 - 08:42 AM.

[rockstarbill]

Yeah I'm very impressed by this software and no doubt the full frame version will be even more powerful for solving issues like tilt. The literal bane of everyone's existence these days. I've always disliked trying to stare at a donut and make sense of whether or not the shadow is centered. Having a quantified method is wonderful, and it was interesting to see that the centered shadow isn't always correct for excellent collimation.

Now if we can get truly quantified visual feedback on sensor tilt adjustment, I think licenses for this software would fly off the proverbial shelves.

[ChrisWhite]

Yeah I'm very impressed by this software and no doubt the full frame version will be even more powerful for solving issues like tilt. The literal bane of everyone's existence these days. I've always disliked trying to stare at a donut and make sense of whether or not the shadow is centered. Having a quantified method is wonderful, and it was interesting to see that the centered shadow isn't always correct for excellent collimation.

Now if we can get truly quantified visual feedback on sensor tilt adjustment, I think licenses for this software would fly off the proverbial shelves.

I agree.  CCDI is an immensely useful tool however I find it difficult to translate results in "near real time" to quantitative adjustments in the field.  Having the ability to analyze data that is interpreted to show if spacing is short or long and I imagine that with AI learning ... by how much would be invaluable.  I'm getting really nice data with my gear, but it can certainly be improved up. I'll save additional comments about this for a future time, as I dont wish to pull this thread off-topic.

 

Looking forward to more from Gaston. 

[osbourne one-nil]

A gentle reminder that this area is for Vendor announcements, and questions relating directly to those announcements only. 

Regular users are to use the appropriate main forums to create threads concerning any questions/issues/reports.

 Thanks!

[Corsica]

I'll be more than happy to answer more questions related to SKW however in order to meet CN policy and request I would suggest that some of you should create a new thread for those, just let me know.

[KNak]

Is SkyWave any closer to release? 

[Corsica]

Is SkyWave any closer to release? 

Yes, SKW will be released by the end of November 2021, meanwhile we still accept beta testers.

Following beta tests and feedback we have/are implementing some useful suggestions and new features as well as two purchase options in order to give more choice and flexibility to users:

 

SKW Lite (the basic version for collimation) license key will be free. SKW includes a simulation mode for learning and training, as well as educational purpose which does not require any model.

 

SKW will also be available in standard with SKG.

Since SKG does not use any star or related centroid but instead digital image correlation this offers the opportunity, on future SKG updates, to feature automatic re-centering of the defocused star(s) after collimation corrections.

 

1) Permanent model

 

SKW users could buy, for a given scope, a permanent model (all models are license and machine dependent). The model could be standard, for most scopes, or on demand customized for special needs. For instance high resolution models supporting higher order aberrations or high spatial resolution (for single or double pass modes), mainly in the context of the SKW professional version.

We will also provide models for testing optical surfaces, like mirrors at their centers of curvature.
A permanent model price would start around several $100 or more for custom once.

The model generation (AI training) can take up to a week of computing time, or more for some custom models, on the cloud. But once its done it takes less then one second to use the model in SKW. All the hard work has been down before hand.

With a permanent model one can check collimation as often as one wants, SKG/SKW will eventually also offers the option to monitor the scope collimation and related trend over time, for instance one can do an analyze each time before parking the scope, for predictive maintenance.

2) Pay per use (PPU) model

 

A SKW user could buy a pay per use (PPU) model, for a given scope, to be used with credits, the PPU model price will be then below $100 including the credits coming with it.

Each time a user loads and analyzes a NEW image in SKW one credit will be debited from his credit wallet. One can analyzes the same image as many time as one wants with the same credit though. It does not matter whether this is done inside a current SKW session, or later one in a new session after reloading the same image (shutting down the PC does not matter either).
SKW will remember images and related credits in order NOT to charge any credit twice for the same image.

When the initial credits coming with a PPU model will be depleted the user can buy new credits to be used with any PPU models he may already own, credits are not model dependent.
Also credit are used off-line, SKW does not require any Internet connection to be used with credit (or not), nor does it need to connect to any hardware (or drivers). SKW only processes monochrome FITS files (fixed or floating point formats) from any sources.
Credits are bought on-line and send in the form of a file such the transaction can be handled in any machine, if needed. The related credit file is then loaded to the machine running SKW, when applicable. SKW will then update the user credit wallet accordingly.

The more credit you buy the cheapest they will be, a credit will be around $1 or so.

 

In summary one can buy a permanent mode for life, or spend less and buy a PPU model with credits and only pay as needed. Credits can be used with any PPU models the user may already own.

 

PPU trial models and credits will be available for evaluation too.

For a given model, related to a given scope & SKW license, the user can freely change the imager pixel size and/or add a focal reducer/extender by setting a reduction (<1) or extension (>1) factor in the instrument form, at any time, related to this scope/model.
Changing those values DOT NOT require a new model, nor does changing the analysis wavelength or seeing value.
 

Edited by Corsica, 13 October 2021 - 07:59 AM.

[jsowens]

Hi Dr. Baudat

I'm considering a good investment into an SCT collimation tool.  Are you guys still on track for a release next month?

Thanks

[Corsica]

Hi Dr. Baudat

I'm considering a good investment into an SCT collimation tool.  Are you guys still on track for a release next month?

Thanks

Yes. If you want you can get the beta version already.

[rockstarbill]

Yes. If you want you can get the beta version already.

Highly recommend people check it out too. 

 

I have been showing it off to folks and most are reaching out to get on it. 

[ShitijB]

This is really interesting. I've only seen examples for cdk, does it work on a newt as well?

I have an epsilon 180 f2.8 so I'm wondering if I can further finetune collimation (both primary and secondary) using this over what I can achieve with catseye tools (which ultimately is subject to how accurately the center spot is pasted, registration issues, visual acuity at night, etc.). If I can get accurate feedback of my collimation quantitatively and end to end (since it uses a star) that would be game changing for me. I can finally be sure that my collimation is good.

[rms40]

ShitijB, Yes. From what I understand after Beta testing, any reflector or refractor can be modeled. See post #15 in this thread.

https://www.cloudyni...ion/?p=10911154

 

Randall

Edited by rms40, 23 October 2021 - 07:03 AM.

[Corsica]

This is really interesting. I've only seen examples for cdk, does it work on a newt as well?

I have an epsilon 180 f2.8 so I'm wondering if I can further finetune collimation (both primary and secondary) using this over what I can achieve with catseye tools (which ultimately is subject to how accurately the center spot is pasted, registration issues, visual acuity at night, etc.). If I can get accurate feedback of my collimation quantitatively and end to end (since it uses a star) that would be game changing for me. I can finally be sure that my collimation is good.

This is a very good question.

 

SKW can model any scope layouts, including refractors and reflectors, even scopes having a non circular aperture or offset mirrors in purpose, see below.

 

Today our modelization tool and scope library are focused on reflectors with CO since usually only those scopes can be collimated by the users. However this is not a limitation of SKW capability just a business priority, we will have refactor models (without any CO) available in few weeks too.

 

The mechanical CO offset leading to an asymmetric defocused star pattern (diffraction rings and CO shadow) is a common situation across all scope optical layouts, including SCT and Newtonian, for which this may be set by design to avoid vignetting.

The mechanical axis/center of a Newtonian 45 degree tilted flat secondary is not its optical axis, therefore some mechanical offset in the aperture is required to reach congruence (both optical axes fully superimposed) with the primary optical axis and avoid vignetting, specially for fast scopes (https://www.cloudyni...h/#entry9725749).
As a result the CO shadow and diffraction rings are always asymmetric in a Newtonian with an offset (in purpose) secondary mirror. SKW provides the offset values (X and Y) which then can be compared with the expected ones.
SKW is able to differentiate asymmetrical defocused star patterns due to mechanical offsets versus optical aberrations, such as coma.

 

Cassegrain scopes with secondary spherical mirrors, such as SCT, CDK, .., are much easier to collimate since any radius of a sphere is an optical axis, a simple tilt/tip of the secondary is enough to offset its optical axis for reaching congruence with the primary mirror.

For such scopes one needs only two degrees of freedom on the secondary for collimation (beside mirror spacing). Mechanical CO offsets of few percents (say 5% to 10% or so) relative to the scope aperture (diameter) have a negligible effect on the scope PSF and MTF (at critical focus), the Strehl ratio (SR) when compared to a centered CO one is essentially the same, not to mention that we are under seeing limited conditions anyway.

Usually too large offsets eventually lead to vignetting issues long before they have any practical impact on the scope PSF.

 

Since few percents of offset is usually not an issue there is no good reason for any scope manufacturer to spend too much time, energy and money for designing (and controlling/testing at production) a super accurate mechanic to center the CO and baffles, beside the vignetting limit, especially with spherical secondary mirrors

Most manufacturers those days use tools, such as wavefront sensors or similar, to test the scope actual optical performance at factory, regardless of any mechanical offsets, What matter at the end is the scope optical quantitative performance (such as its SR >80% for instance) not a nice symmetrical defocused star.

 

To place this in perceptive few percent of CO mechanical offset, say 1%, on a 10" (254mm aperture) scope is 2.54mm of offset. There are many SCTs with more than that when accounting for the Schmidt' plate and primary/secondary mount position tolerances. Tilt/tip of the secondary (when spherical) will take care of the scope optical alignment quite easily.

 

Below a defocused star from a SCT 10" well collimated (SR=96%) with a measured CO offset of 2.8mm, or about 1.1% of its aperture.

 

 

One clearly sees that the CO shadow and diffraction rings are not concentric, yet this scope is DL (SR>80%).

Only 1% of mechanical misalignment in this case was enough to show such a significant asymmetry during a star test already.

Calculations show that if one tilts the secondary mirror to make the defocused star perfectly symmetrical (including the diffraction rings) for this scope it adds about 0.1 wave rms of coma (55nm at 550nm) leading to a drop in SR down to 65%, the scope will not be DL anymore but the defocused star will look nice though.

Tilting the spherical secondary mirror is similar to an offset of its optical axis, doing so means that now both mirror optical axes are not congruent anymore, hence the drop in SR.

 

Having quantitative data in term of aberrations, SR, and other relevant figures of merit, is critical to know whether a scope is optically collimated indeed. Mechanical alignment is only a proxy good enough for coarse collimation in most scopes. With SKW the user has access to the same data than using an optical test bench and a wavefront sensor in the lab, but in this case using an actual star in the sky.

SKW will eventually provides field dependent aberration (on and off axis) at once when the frame under analysis features several stars. SKW already automatically locates them and by default uses the closest to the chip center for its analysis. The user can overwrite this and select any star in a FOV he may like instead.

 

As stated before SKW Lite for collimation will be released by the end of November 2021, below is a screenshot of its simplified GUI designed to be used without any special knowledge in optics for providing the best possible user experience in the context of collimation.
Under the hood it is still the same engine, an actual wavefront analyzer, but detailed data such as Zernike coefficients and related aberrations are not displayed.

 

 

The SKW pro. version will be release during Q1 2022.

P.S: Since this thread is about product announcement I would suggest to discuss/ask more detailed questions about SKW itself either by creating a new thread (I cannot do that as a vendor, but any CN member can, just let me know) or using the following one for instance:

https://www.cloudyni.../#entry11442351

 

This should make CN moderators happy :-)

 

Clear skies!

 

Edited by Corsica, 23 October 2021 - 09:29 AM.

[Ruediger]

Hello Corsica,

 

I am also very strongly interested to participate in beta test and also purchasing the SW, I own a PWI CDK 14 and I have some serious issues with its collimation. I am fighting now for a couple of weeks with it, because my secondary holder became lose and had to recenter it. Though it is a spherical, the results a far a away from its best performance.

Currently I am also experimenting with the new OCAL optical Collimator. But the results so far are not satisfying, I consider this  as another proof of evidence, that a pure concentric allignemnt is not sufficient for a perfect wavefront. 

 

The only way to get a reasonable result was to adjust the secondary based on a focused star and its remaining coma and astigmatism. Since the seeing in my location is decent to bad, this is a very coarse adjustment, since it is heavily seeing limited for sure. 
 

Please let me know to whom to drop a mail to participate as beta tester or purchase the product. 
 

Many thanks in advance!

Rüdiger

 

PS: I came about this thread because Randall had posted his great results on AstroBin with the same scope. It looks like a very good match. 

Edited by Ruediger, 24 October 2021 - 04:29 AM.

[Corsica]

Dear Rudiger,

Send me an email at gaston@innovationsforesight.com, I'll be able to provide you with the SKW beta version then.

[carballada]

Dear Rudiger,

Send me an email at gaston@innovationsforesight.com, I'll be able to provide you with the SKW beta version then.

 

 

Dear Dr.Baudat, sorry but after reading all that information I am also so interested, any plans to do an open Beta of this software any time in the near future?

[Corsica]

 

Dear Dr.Baudat, sorry but after reading all that information I am also so interested, any plans to do an open Beta of this software any time in the near future?

 

Feel free to send me an email at gaston@innovationsforesight.com
 

[Corsica]

Here is a link to a SKW introduction video which should help current beta testers and everybody who may be interested by SKW:

https://youtu.be/AwdGdD1YAQg

SKW will be available for sale by the first week of December.

[Ruediger]

Hello Gaston,

 

many thanks for the good video. Very clear and understandable. Only one question: in collimation view, what is open color ring indicating?

Looking forward to purchasing SKW. Any update on release date and pricing?

 

CS

Rüdiger

 

Edited by Ruediger, 04 December 2021 - 08:08 AM.

[Ruediger]

Hello all,

 

I want to give a short feedback on my experience with my Planewave CDK 14 and Beta-Version.

Setup: Planewave CDK 14, ASI6200, 10 Micron GM 2000 HPS II, used Ha 3,5nm filter for collimating.

 

I did a rough collimation with the new OCAL collimator also discussed in a parallel thread. This gave me a fair result in the yellow ring. After approx. 10 minutes and a few refinements I ended up almost in the center. I have crosschecked the result in a final single exposure. Please find results below.

 

Conclusion:

Aside some minor bugs (still Beta phase) the result is overwhelming. I had not achieved a good collimation, since I always tried to get perfect concentric circles of the Airy disk. But as pointed out from Gaston, very often this is not the perfect collimation in respect to the wavefront. I can confirm that for my CDK. In my opinion a must have for anyone who want s to get the best out of his optics.

 

CS

Rüdiger

 

1. Airy Disk

2. Single exposure 600s of M33 unguided. Randomly picked a star at 600% magnification

3. Result of SKW

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Edited by Ruediger, 09 December 2021 - 05:27 PM.