Daystar Quantum SE .7 Testing - Feedback Request

[Shawn_Quinn]

Greetings Everyone,

I’m relative newcomer to H-Alpha Solar Imaging and Observing. The information on SolarChat is incredible. I was recently loaned a DayStar Quantum SE 0.7. I believe it is one of the older versions as it has the screw for the potentiometer on the housing. I’ve been using it over the last couple of weeks and have recorded and processed serval images using the following configuration:

DayStar Front Mounted ERF -> Astro-Physics Stowaway -> Tele Vue Power Mate 4X -> Daystar Quauntum SE -> ASI174MM Camera.

Seeing conditions were reported by Clear Sky Chart to be average.

There’s been some discussion on this forum regarding the performance of the Quantum Filter. As I am new to Solar Observing, I do not know how judge the performance of the filter. I recorded several images via AutoStakkert!. JPEG versions of the results are shown below. There are a couple colorized ones too via IMPPG->Topaz AI->Photoshop. I am very interested in your feedback as to whether or not the filter performs as you would expect. Your thoughts will be most appreciated.

Thanks,

Shawn

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[Montana]

A very warm and sunny welcome Shawn what a stunning set of images, you can certainly produce a very fine set

As regards the filter performance, it is a 0.7A so will never have much contrast, it is not bad (fairly uniform), but perhaps not quite as on band as it could be, have you tried a few heating settings? I would try increments of half a degree or a degree each way over about +/- 3 degrees. Take an image at each of these settings using either an active region or filament (not a prominence). Line the images up after processing (don't use a flat) and use the same processing conditions. This way you will be able to judge at which point the filter is most on band (most contrast). This is the best way to judge. I did this with a Quark and a Solarspectrum to gauge where the best setting was. https://solarnutcase.livejournal.com/12257.html

Alexandra

[rigel123]

I agree with Alexandra, you are getting some good images and may be able to get a bit more contrast out of your filter by following her example. Welcome!

[marktownley]

Hi Shawn and welcome to the forum!

These are nice first shots. Like Alexandra says you are a tiny bit off band, and bracketing tuning will allow you to find that best contrast position.

Based on the images the filter appears to perform similarly to a decent Quark prominence model. Are you looking to buy a Ha filter?

Mark

[Shawn_Quinn]

Folks,

Thanks for the your comments and thoughts on next steps. I will try your suggestions changing the heating settings (thanks Alexandra!). Your feedback is most appreciated!

The sun is very 'cool' right now:)

Shawn

[DeepSolar64]

It should do decent on the disc but not as good as a 0.5A filter or doublestack setup but it should do really well on prominences. Your images resemble my 0.65A single stacked images but are more uniform than mine are.

James

[MAURITS]

Welcome Shawn, nice to see your images with a 0.7A Daystar.

I have about the same Ha filter but from SolarSpectrum, so in the end I have double stack it.

[Shawn_Quinn]

Hi Maurits,

I understand double stacking with pressure based etalons. Not sure I follow with a SolarSpectrum. How do you accomplish double stacking in a configuration with the SolarSpectrum filter (or Quantum)?

Thanks in advance.

Shawn

[MapleRidge]

Hi Shawn...

Welcome to the group !

The proms show quite well and the wider band-pass of this filter matches up pretty well with this, but I agree that some adjustment of the heater could improve the chromosphere contrast with this filter.

Even a 0.7A filter will be a great instrument, so I would suggest refining its use. The double stack idea will narrow the band-pass down to provide greater contrast on the chromosphereic filters, but that would be stage two. This will provide time to evaluate the ability of this filter and sort out options to double stack it should you choose to do so.

Brian

[MAURITS]

Hi Maurits,

I understand double stacking with pressure based etalons. Not sure I follow with a SolarSpectrum. How do you accomplish double stacking in a configuration with the SolarSpectrum filter (or Quantum)?

Thanks in advance.

Shawn

Hi Shawn,
To double stack the SolarSpectrum or Quantum ... I have used a SolarScope Etalon for double stack in a 2inch cell with T2 thread on both ends.
The etalon has an in-build tilt function for tuning.
I have place it just before my SolarSpectrum 0.7A Ha filter on the telescope side.

FRONT

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[Bob Yoesle]

Hi Shawn,

The mica etalon filters are the most difficult type of solar filter to optimize the performance. Given the circumstances, you seem to be getting what one would expect.

1. The Powermate Barlow is not a true telecentric lens system, and will not be able to deliver true telecentric lens performance.

Animation-Telezentrik.gif (176.57 KiB) Viewed 415 times

Baader Planetarium

Ideally, to get the best telecentric performance you'd use the Baader TZ4 and properly locate it in a fixed position. Per Baader, optimum telecentricity will occur when the instrumental prime focus of the objective lies exactly 93 mm behind the front of the TZ4:

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Baader Planetarium


You'd then place the etalon, and after that have a focuser for an eyepiece of camera. Unfortunately, DayStar provides no such optimization information for their filter systems, and there is no such information for using the TeleVue Powermates. But what applies for the Baader Solar Spectrum filter systems equally applies to the DayStar filter systems.


2, Review the work of Christian Viladrich on etalon performance. With the Stowaway's f6.65 focal ratio, with the TZ4 your EFR is ~27, and the very best FWHM of a true 0.7 A filter would be ~ 0.84 A. Compounded by the fact you're not using a optimized true telecentric, you're likely closer to FWHM of 0.9 A with the Powermate.

To get anywhere near a FWHM of 0.7 A you have to be closer to f50:

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Christian Viladrich


As noted previously, adjusting the etalon temperature will need to be played with to find your system configuration's optimal performance. The filter band-pass will widen per above and the filter will be shifted off-band into the blue wing a lesser f ratios, and fine tuning the temperature for these conditions will improve performance. Given the lower f ratio, you generally would need to adjust the temperature upward to shift the etalon CWL higher. Since the wavelength indicator (if present) is based on a temperature setting, it would need to be higher than the nominal 6562.8 A.

Etalon Mica EFR CWL shft.png (177.57 KiB) Viewed 415 times

Christian Viladrich (reordered)


Given that you have only borrowed the filter, I'm not sure how much you'd want to invest in all this, or a secondary filter to double stack with, which will significantly add to the complexity of the system...


Best wishes,


Bob

[Shawn_Quinn]

Folks,
I'd like to thank everyone for their very thoughtful and comprehensive technical responses! I'm still having fun with the borrowed filter and hope to one day have the necessary filters to use on my A-P Stowaway and A-P 130GTX. The sun is pretty amazing right now!
Shawn

[DeepSolar64]

WoW. You have two AP refractors. Awesome!!