First Light with C8 ERF (Timelapse flare added on 13Mar17)

[yltansg]

Finally I settled down to do some testing of a C8 Energy Rejection Filter (ERF) that I got recently. It is also a 3-band filter, permitting imaging in HA, CAK and 430nm (Fe-based) imaging of the Sun.

The setup was: ERF C8 SCT with Baader Herschel wedge + 1.25" H-A filter + x2.5 televue barlow + ASI174 mono camera.



The exposure was set to 0.291 msec to freeze the seeing condition. Here is the first light result:

[Airconvent]

Nice! Do post some prominences too if there are any at the moment.
But curious as to using a C8 to view the sun. Is it an overkill? What additional features can the bigger aperture offer?

[yltansg]

[But curious as to using a C8 to view the sun. Is it an overkill? What additional features can the bigger aperture offer?[/quote]

Hi Airconvent,

My eventual goal is to do high-resolution H-Alpha (will use an PST with this C8) and Fe-based solar imaging (using a 430nm filter) with the C8. Need the large aperture for this type of high resolution imaging. Didn't do proms imaging.

Here is another image of that sunspot taken yesterday

[yltansg]

With the same ERF, I added a 25mm Edmund Optics 430/10nm filter and got this G-Band granulations.

[yltansg]

The G-band images were obtained at the same time as the following 3-band images of the Sun in H-Alpha, CAK and whitelight bandwidths. It was a spotless Sun

[superiorstream]

Hi Alfred
Congratulations to your success. Did you use com. software to achieve the result.Did something similar years ago and find that largest aperture for continuous observations is around 100mm.Anything larger also gather too much atmospheric turbulence in the form of wavy images and made image worse off. In fact largest aperture tried was 150mm. with negative results.

[yltansg]

Hi Mr Chia,

Thanks for your kind words. Here is my response to your questions/comments:

a. Did you use com. software to achieve the result? Yes, I make use of AS!2 for alignment & stacking and IMPPG for deconvolution and sharpening.

b. I find that largest aperture for continuous observations is around 100mm.Anything larger also gather too much atmospheric turbulence in the form of wavy images and made image worse off. Yes, I have arrived at the same conclusion too. However, I seldom do visual observation. Most of my work is concentrated on imaging. I have gotten around this limitation with the use of an appropriate energy rejection filter (ERF) to block out most of the IR energy and prevent the build up of tube current. Then there is the atmosphere turbulence pick up by high image-scale recording. For this I use very low exposure setting (less than 0.5msec) to freeze the image. With these 2 combined techniques I have gotten around the 150mm aperture limitation. Presently I have 2 ERFs, one for 150mm refractor and another one for C8 SCT. Both have worked beautifully to produce high definition zoom-in images. At present I am working on adapting a PST etalon (Stage 2 Mod) to work with the C8 ERF on a C8 for HD H-Alpha imaging. I will be going for C14 next.

Here are some images taken with my Celestron 150mm XLT refractor fitted with a front-end ERF:


Celestron 150mm XLT refractor fitted with an ERF


The strongest flare in 2016 taken on 23Jul16


Zoom-in on a sunspot and filament (eye and brow) on 16 June 16


Heart-shaped sunspot imaged on 16Apr16

[Airconvent]

Those are awesome images! Especially the one with the prominence!

[yltansg]

Those are awesome images! Especially the one with the prominence!

Hi Airconvent,

That image was one of 50 that I captured on 23 Jul 16 and made into a time-lapse movie

[youtube]https://www.youtube.com/watch?v=rwoz7FxYJ7g[/youtube]

Enjoy