Solar imaging with the TEC 140 f/7 Fluorite Apochromat

TEC APO 140 f/7 Fluorite Apochromat

TEC APO 140 f/7 Fluorite Apochromat (#1351005, € 8500,-)


On 2 June 2021, our customer Alan Jadanić sent us these amazing solar images taken with the TEC APO 140 f/7 Fluorite Apochromat (#1351005, € 8500,-) . He used our kam unser D-ERF Energy rejection filter 135mm, a Solar Spectrum H-alpha Filter and the Research Grade TZ-3 Telecentric System (3x focal length) (#2459257, € 395,-) . Thank you!

We would like to empahasise the multifunctional usability of the TEC APO 140 FL for DeepSky, visual observations and H-alpha. This optic can really be used day and night and is therefore a real all-rounder.


Dear Mr. Baader,

I have spent a few days with the TEC 140FL and a Solar Spectrum RG38 0,5Å filter and I must say that it is a very good filter both for visual observations and photography. The telescope for itself is an exceptional piece of astronomical equipment and with an excellent sharpness. With an ASTF 140 solar filter for white light, you can see the sunspots perfectly and even solar granulation is clearly visible. The FeatherTouch 3545 focuser is probably the best focuser you can find on the market and it comes as a standard with TEC 140FL

Solar Spectrum H-alpha Filter and Research Grade TZ-3 Telecentric System (3x focal length)As for the SolarSpectrum H-alpha filter, visually you can see details on the solar surface and the prominences at the same time. There is no big difference in brightness between those two. When the filter reaches the desired temperature (I have it at 45 degrees at the moment), the proms and surface details just pop out. If you are off that temperature you loose some details and proms, but this is not a bug, it is a feature of this filter. If you have steady weather you can easily see not only proms on the edge but you can see spiculae.

TZ3 works just fine and even at f/26 (I have variable diaphragm on) you can clearly see all the details. Closing down the aperture improves the contrast, but you loose some of the light entering your system. So if it is not necessary you don't have to be around f/30 or more. If you want the full solar disc you can use just a telescope with D-ERF and RG 38 but without TZ3. However, then you have to close down the diaphragm a lot if you want to get similar contrast. In that case you loose some of the details due to very small aperture. But it is a trade off for getting the whole solar disc.

Many people have seen proms directly through the telescope and they were amazed with some of the details that we saw even on a days with average seeing and some turbulence.

TEC 140FL and SS RG38 are a good combination for visual observing and solar imaging. I am sending you some photos made lately with Baader D-ERF + TEC 140FL +TZ3 + SS RG38 + ZWO ASI 174MM.

Best regards from Zagreb.

Alan Jadanić

Sonnenaufnahme mit TEC 140 FL









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