Which UHC did you pull the trigger on?

Dave

 

The Baader UHC-S is a broadband filter. I don't think it's technically an ultra high contrast filter in the strict sense of the term.



I have a few filters. The latest being a 2" Baader UHC-S. I have the 1.25" version already.

Lumicon invented the UHC filter and the term 'UHC' has been used for a variety of filters by other manufacturers. Contrast filters basically fall into the 'narrowband' and 'broadband' categories. Broadband filters are better for emission nebulae than traditional narrowband filters. There are also OIII and Swan filters. The Astronomik UHC-E is unusual in being a wide narrowband filter intended for apertures under 150mm, it also passes a couple of the Swan bands for viewing gaseous comet tails.

 

I'm going to have to break down and buy a Baader filter.

 

I'm not sure of the efficacy of this filter with a slow 60mm aperture.

https://www.firstlightoptics.com/all-filters/baader-uhc-s-filter.html

I'd aim for a 3mm exit pupil at the bare minimum. I have successfully used the UHC-S on emission nebulae with a 102mm f/12.7 Mak, with a 40mm Plossl for 32.5x, giving a 3.1mm exit pupil and about one arc degree, seventeen minutes of true field of view.


One arc degree is about two Full Moons. With a refractor you need not worry about seeing the obstruction, so as low a magnification as you can go helps. M45 & M42 look great even at 10x or 20x.

 

You sent me a PM saying a Svbony UHC? Ever heard of these, Mak? Seems to be on eBay. Here's a CN thread:

https://www.cloudynights.com/topic/582965-svbony-uhc-flter/

Dave

 

I've heard of Svbony, my guess is it's a distributor name importing from a Chinese OEM. Could be a similarity to Solomark. As far as I can determine Solomark is a trademark of Yuyao Qihang Optical Instrument Co., Ltd. Yuyao City, Zhejiang Province, China.

I don't know much about their 'UHC', by the looks of it it's a broadband, probably not dissimilar to the Baader UHC-S.

 

Some places that I think would be interesting to experience close up would be:
1. The view from a planet in the Albireo system as it would be cool to see two different colored suns in the sky.
2. The view from a planet around any star nearer the center of the M80 globular cluster as it is one of the most dense globulars so would be interesting to see a night time sky tightly packed with so very many stars.
3. The view from a planet around a star that is about 15 LY from M76. M76, the Little Dumbbell Nebula, while dim for us is one of the brightest surface brightness Messiers. As such it might be naked eye visible in the sky if close enough. So 15 LY from it would make M76 appear about the size of 10 Moons across in the sky!
4. The view from the Trapezium in Orion. While the view might be cool from here, the massive radiation from all the new forming stars in this region would probably make it much too dangerous to visit.

Of the 4 places above, I think #2 would be the coolest for me.

 

Ah but how could you visit a constellation? They're just groups of stars as seen from earth and generally the stars making them up are not near to each other although the Ursa major moving cluster is one exception to this.never seen the little dumbbell but I regularly look at m27 the great dumbbell.