4 replies to this topic

[astroflak88]

Did another run of imaging. Stacked only 4 scans since it was windy. Happy Monday

 

 

[rigel123]

Nice disk!

[minhlead]

Nice shots!

How do you find the optical performance of the SHG 700 and the SolEx that you used before? (I'm purely curious about the optical side, mechanically, the SHG 700 is far superior than any 3D printed kit, that's without question).

[astroflak88]

Optical performance i believe is more superior than the solex because the quartz slit allows you to get more light entry into the spectroheliograph w/o using a uv/ir filter or an nd filter or wedge. With a solex you have to use it with an nd filter or a wedge to protect the slit glass (since its not made from quartz) from solar damage, so your getting less light in as a result. Less light in is less details. The body of an shg 700 (metal) is 100x more solid than a solex (PETG plastic). This is why I think shg 700 more superior. If you look at my astrobin you can see my shg 700 and solex images, both being done using the same technique and equipment and shg 700 images comes out looking better

Edited by astroflak88, 24 June 2025 - 09:19 AM.

[thesmiths]

How do you find the optical performance of the SHG 700 and the SolEx that you used before? (I'm purely curious about the optical side, mechanically, the SHG 700 is far superior than any 3D printed kit, that's without question).

I think the custom lenses in the MLAstro are likely superior to the essentially stock Thorlabs lenses that are standard with the Solex. My personal opinion is the 1:1 ratio of collimator to imaging lens in the MLAstro is also better than the 80:125 ratio of the Solex (which tends to result in oversampling).

 

One thing that certainly improves optical quality is the elimination of the photographic ND filter. These filters are nowhere near as good as astronomical filters and significantly degrade the whole optical system. Using a slit that can withstand the heat without using an ND filter (or alternatively using a Herschel wedge) by itself will improve image quality. I would still recommend using a high-quality UV/IR filter in front of a quartz or borosilicate slit as it will significantly increase the life of the chrome layer, particularly for larger telescope apertures.

Edited by thesmiths, 24 June 2025 - 09:57 AM.