Focus on the Sun: Can the Baader SC-Triband replace a large refractor?

Our customer Mr. Karrer uses the 9.25" Triband-SCT - Schmidt-Cassegrain-based Multi-Purpose-Telescope, for Sun and Deep Sky (#2301003 , € 4810,-) . With his fantastic images Mr. Karrer proves that a SC telescope can keep up with the best refractors in solar photography. We are truely impressed – high-res images which compete with well-known professional observatories.

Read here the detailed field report of Mr. Michael Karrer about the Baader Triband SC 9.25":

I own the Baader 9.25 triband SC telescope now since august 2022, but I'm still not using it often enough. Last May, a calm weather phase was coming and I decided to to start working later in the morning than usual and take a look at the sun instead. Visually, there were no air turbulences visible in the small Lunt H-Alpha telescope, the image was "steady". Accordingly, I had high hopes for the camera view through the 9.25" Triband. For the first time I used the 3x Baader SunDancer telecentric system which I had just bought, which allows a quite short image train. Because everything had to go quickly, I saved myself the warm-up phase of the Solar Spectrum H-Alpha filter and used the etalon of a PST instead. The image on the monitor was the steadiest I have ever experienced! And that at around 7 m focal length! Not much later, I had the AVI data on the hard disk. "Autostakkert" selected the best zones as usual.

I compared my results with (the few) top solar photographers who work with refractors with up to 9" aperture: Details with the Triband-SC are at least on the same level, if not even better to recognise! A sensational result for me! A large refractor costs a lot, is heavy, is hardly transportable and requires a massive mount. With the "feather weight" of an SC, all this is no longer necessary.

Let these pictures be the prove that an SC telescope can keep up with or surpass the best refractors in solar photography (be sure to look at the photos in full resolution).

 And if you don't know it better, you sometimes do things which are "forbidden": I also used the Triband to take pictures in white light, together with the Baader Solar Continuum Filter. The image looked quite dull, but the details were good. The image processing was challenging. It was only afterwards that I discovered the now available Triband manual on Baader's website. The Triband-coating blocks the wavelength of the Solar Continuum Filter – hence the pale image! I should have used an OIII filter. Depending on the focal length extension, the sensitivity of the camera or even the transparency of the sky, a photographic Baader film or the Baader Herschel wedge may be necessary for further light attenuation.

How much of an issue is the obstruction of an SC compared to a refractor? It does reduce contrast, I can see that when I compare the image with that of my refractors. But image processing with dedicated contrast enhancement largely makes up for this disadvantage.

My conclusion:

Highest resolution, that's the goal. With the compact design of an SC, there is also the elegant option to observe at places with better chances for good seing seeing. Because only there can the optics unfold their true potential – and that is amazingly high! A refractor of the same size, on the other hand, will suerly stay at home...

Michael Karrer

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