Want to try narrow band imaging but what scope to try?
Posted 26 January 2020 - 12:24 AM
Posted 26 January 2020 - 12:38 AM
So I live just out side chicago with heavy light pollution. Here is my confusion. I own two scopes. Celestron 9.25 HD edge with hyperstar. I also own Stellarvue 102t refractor with with .8 focal reducer. I own both color and mono cameras. I do not have a permanent observatory. I like features of SGP Software. So hyperstar defeats the use of filter wheel and only can use a slider tray. So is mono camera with slider tray at f/2 a better idea vs filter wheel with Stellarvue and SGP and slower f ratio. I thought about using color camera on hyperstar with dual band filter for galaxy’s and shoot mono on Stellarvue. Totally confused what I should try for narrowband.
Here's a plan to end the confusion. And make some nice images along the way.
Start with the 102, color camera, dual band filter. Get that working. Simple, gives you a baseline to measure other results against.
Next. 102, filter wheel, mono camera, just H alpha in black and white. Again simple. Gives surprisingly good results.
Now's the time to try Hyperstar. If you have the backfocus, Ha filter, mono camera. Otherwise filter slider.
That gives you a solid grounding and some experience with various equipment. At that point, you can decide for yourself where to go next.
Key thing. All this is for emission nebulae. The filters let that specific light through. For galaxies, they're borderline useless, the galaxies emit across the entire spectrum, so the filter blocks too much signal. That's devastating in light pollution. I'm just outside a city, Red Zone, Bortle 7, mag per arc sec squared low 18s. In that situation nothing works as well on galaxies as LRGB imaging with a mono camera. Samples on my astrobin.
Neither the 102 nor the Hyperstar is best for galaxies, and "galaxy season" is coming up fast. Best would be the 9.25 without Hyperstar.
Beware of experienced imagers here skipping steps and going right to something, based on what's "best", or preferred targets. First get your feet firmly planted. <smile> It's not about the images at first, it's about understanding the equipment, and how to use it.
Finally, learn to use gradient reduction in processing. It's a crucial step in light polluted skies. It's much better than the filters for imaging galaxies, since it sorts out light pollution with spatial analysis, not spectrum blocking.
Edited by bobzeq25, 26 January 2020 - 10:33 AM.
- schmeah, Oscar Szentirmai and DSOs4Me like this
Posted 26 January 2020 - 12:53 AM