AR 2786 on Nov 27 with the TOA 150 and double stack

[christian viladrich]

Hi,

Here are some images of this beautifull group visible on November 27.

These first two images were taken with a double stack combination (DayStar PE 0.6 A and Coronado SMN35 0.5 A) :





This one is taken with the Solar Spectrum 0.3 A. It shows the difference with the double stack combination. Lower layers are sampled in the chromosphere, more spots are visible :


Best regards
Christian

[ffellah]

Beautiful images and very nice comparison, Christian.

Franco

[Montana]

A superb comparison!! I would say the penumbra is most pronounced in the Solarspectrum image compared to the DS version. Wonderful images in both versions though

Alexandra

[pedro]

fantastic images Christian, well done

[DeepSolar64]

I don’t recall that particular Coronado filter. It’s pre-Meade, right?

[rsfoto]

Hi,

WOW, impressive details

[MalVeauX]

Super contrasty Christian!

Very best,

[marktownley]

Excellent images Christian. The difference between single and double stack is both subtle and dramatic at the same time. How do you find it affects exposure time between the two methods?

[christian viladrich]

Thanks to all !

The Coronado SMN35 was made in 2001. This was the time when David Lunt experimented various etalon configurations before converging to the front side air-spaced etalon we know now. This is a fused-silica etalon, themo-regulated and 0.5 A FWHM. Transmission is very high, which is of benefit for double stacking. It comes with a 2 A BF. I have to make a web page with some pictures of it one of these days.

Mark, the exposure time is about double with the double stack compared to the Solar Spectrum (if I used the same gain).

[christian viladrich]

Alexandra; I would say that the penumbra tends to vanish with the double stack. Probably because it is partly covered by the Ha canopy.

With the SS 0.3 A, there is a sort of brightening arround the penumbra of small spot on the right, which is not the case with the double stack.

[Astrophil]

Christian, those are exceptionally good images and the ss/ds comparison shows the difference nicely. I'm not sure which version I like the best.

Phil

[eroel]

Christian:
Super images.
Best regards.
Eric.

[jp-brahic]

Nice shots Christian

JP

[MAURITS]

Top Christian.