Eye of God - testing Riccardi reducer - 26 hours of Ha
Hi all,
To date I only made a few brief attempts at using Riccardi reducer, as I found imaging with a short 4"refractor at f/4.5 more demanding than much more casual f/6.
Thanks to Glen's and Greg's clarifications on calculating correct spacing when accounting for thickness of filters in the imaging train, I corrected the spacing and star shapes have improved. Thank you Glen and Greg very much.
Humidity has gone up a bit so I may need to wait a bit for a few clear nights, nonetheless last night weather gods allowed me to collect initial 6 hours of 3nm Ha. I wish I had 5nm Ha to include nitrogen line.
I will most likely drizzle the data for the proper image.
Thank you Peter and Rick for your encouragement. Hopefully I will be able to put together a decent for my aperture image of the Helix - this is one of the targets that I really wanted to image for some time.
Your off to a good start Suavi, I'm sure when you add data from your other filters it will be an excellent image. I'm surprised by how bright the centre area is with the Ha filter as that area is mostly OIII.
Looks good to me. Looking forward to seeing the end result.
Steve
Glad you like it Steve. Skies are relatively clear but there is high humidity at the moment and fog forms quite easily. I am hoping for a drier and cooler breeze from SE
Quote:
Originally Posted by strongmanmike
Looks like quality data is being collected and a fine Helix is on the way Suavi...just needs more data
Mike
Glad you like it Mike. Doing what I can with my 105mm and foggy nights...
Quote:
Originally Posted by Placidus
To get the faint chevron at the far left under those conditions is amazing.
Thank you Mike and Trish. I hope there will be a bit more signal in the outer regions in OIII. I may need to invest in a 5nm Ha or perhaps in a narrowband nitrogen filter...wouldn't mind having a go at exploring planetary nebulae with my small refractor.
EDIT: Found this link to a website showing Ha and OIII. It looks like I need to add more Ha to highlight the outer bits a tad more...
Last night weather and equipment allowed to add a few more hours - 3nm Ha adds up to exactly 24hrs. It is my personal best/deepest for a single filter for any given dso.
Background noise of drizzled stack is at about 1.5 ADU (st.dev), and the faintest bits are just 1.4 ADU above the background in 15-minute subs, which at gain of 0.26 e/ADU equates to about 1 photon every 45 minutes, if my maths is correct.
Lookin' good Suavi! Looking forward to the final product.
You're doing some epic integrations these days... I usually manage about 2hrs a night in terms of actual data collected, takes me forever to get the kind of integrations you're cranking out in a few days.
I have been just lucky with the weather and our backyard is an enormous upgrade from all previous inner-city locations. Also, once I learnt to trust SGP to reliably run an overnight imaging session, I have been able to acquire much more data and much more easily. An obsy would be the next natural upgrade...one day.
Keeping fingers crossed for some more clear nights before the inevitable rise in humidity that spring attracts to North/Central QLD.
