Recently Browsing 0 members
No registered users viewing this page.
Hi all, my second attempt at imaging over multiple nights, captured 60 mins Ha and a couple of 5 mins on Oiii and Sii on Christmas evening, then added more Oii and Sii on the 30th
Total of 60 mins Ha 25 mins Sii and 30 mins Oiii
Hubble mapped - SII,Ha,OIII = R,G,B. The Oiii data was very noisy but I'm fairly happy overall, also the ZWO Oiii filter caused a massive ring around Alnitak when stretched !
Comments welcome, I know it needs more data and I will need to learn to be more patient but the year is running out 🙂
Thanks for looking and have a good 2020.
I went to my family house in the countryside and was able to take some pictures during xmas eve.
Total exposure: 6h
H_Alpha: ~3h (730x15s) --> R, G
Oxigen III: ~3h (710x15s) --> B, G
I didn't have a view on Polaris and could not spend too much time drift aligning (it was xmas eve after all :D) hence the short exposures. Moreover I dont have the proper connection rings to put my flattener on my mono camera so all stars off center are a mess :_(.
Selling my full narrowband set up for multiple reasons: I could do with the money and mono just isn't really doing it for me.
Altair Astro 183m Tec
Baader Narrowband filters (Ha, OIII, SII and Clear)
ZWO Electronic Mini Filter Wheel
All associated cables/plugs
T2 extensions to reach 55mm back focus for use with reducers
Boxes and cases
There is a scratch on the T2-T2 adaptor for the filter wheel and a couple of the labels on the filter boxes have been torn. But otherwise the important parts work perfectly well.
Collection or postage via DPD.
Buyer to pay postage and PayPal fees.
No offers currently accepted, and I would rather not split
Time for yet another cry for help when it comes to choosing diagonal. I have read the many similar threads and gathered some knowledge (too many to start linking). I have come some way in my process and now that it is coming to final decisions I would like to hear from the experts. Not many of threads I have read end with the OP returning to deliver some review/verdict of his/her final decision. While I wait for response on some thread where I asked about the result, the eagerness in me forces me to write my own thread. Perhaps some of the people asking these questions before can now answer in my thread as experts!
I have the Nexstar Evolution 9.25 and am currently using the stock diagonal. My eyepieces are the Baader 8-24 mm zoom and the stock 40 mm Plössl. I would also like to upgrade EPs and there I'm looking at something better in 24 mm range, as well some nice low power for more FOV. I'm following threads about EPs and SCTs with great interest for this (on CN). Can say that I'm currently leaning towards the 1.25" 24 mm ES 68° and 2" 36 mm Hyperion aspheric (if going 2" route).
I'm thinking 2 alternatives (including a budget alternative for one of them). I'm looking at Baader mainly for ClickLock (and expect good optics):
Baader T2 Zeiss prism with a 1.25" ClickLock EP (T2 part #08) -OR- the 2" prism with 2" ClickLock (splurging that is). The budget alternative would be to get the non-Zeiss T2 prism instead for the 1.25". Worth noting that I would like to get the Celestron f/6.3 Reducer/Corrector. This would be for future purposes of delving into EAA but of course I would use it visually as well (especially if choosing the T2 route). The reasoning for my alternatives:
Go for the 2" Zeiss prism to theoretically get the best of the best in visual terms. I would make better use of the 46 mm baffle tube opening. Theoretically possible to combine with the R/C thanks to relative short light path (although not necessarily needed with 2" EPs). Downside of going to 2" accessories would be the cost, EPs, filters etc., on top of diagonal. Would not be able to spend all these costs at once. Cheaper route with T2 prism (especially the non-Zeiss), not only diagonal but also the other accessories. Cost of the R/C would be comparable to e.g. the 36 mm aspheric and give similar power and FOV with the 24 mm ES, i.e. the 24 mm would act as both. Extra plus is the ClickLock clamp for 1.25" with built in fine focusing not involving the mirror. Downside of knowing that not all light coming out of baffle tube is used. To get the wide FOV (24 mm + R/C) I'm adding glass to the optical train (theoretically not a good thing). I'm leaning towards the T2 as it would be a cheaper diagonal and for EPs I would only need the 24 mm and then the reducer instead of a 30-40 mm, so saving the expense of one EP. Then I would already have the reducer for continuing into EAA. The questions I hope the experts here can help with:
The old reducer vs 2" diagonal question. With R/C and the 24 mm I can get roughly the same mag and FOV as e.g. the 36 mm Hyperion (technically 38 mm vs 36 mm and 68° vs 72°). Also reading good things about the ES 68° and with R/C the EP should behave the same. Am I missing something here? The logics say that the I would lose some contrast with the R/C (not using full opening + adding elements), correct? Possibly flatter fields though (not important now, hopefully the EP threads might tell soon enough). The Zeiss vs non-Zeiss T2? Big differences? I have read a few posts on this so most to get some updated views here (have read that Baader has changed some things over the years). Using the R/C (f/6.3) with these prisms. I know f/7 is mentioned as "the limit" but also remember BillP's test where he was happy down to f/6 with the prisms (in 2014 at least). Perhaps most important: have I missed some other obvious alternative here? Maybe I have forgotten some question here but perhaps for the best as I assume those who have gotten this far are tired of reading now. Thanks for getting here though!
I scrapped all the Oiii and Sii data I previously took during a full moon (about 15 hours worth) and retook it all when the moon was a bit smaller at 76%. Ha was taken during 98% and 67% moon. All the lights were taken on the following nights: 12th, 19th and 20th September 2019.
Integration times, all in 600s subs unbinned:
Ha = 28.33 hours
Oiii= = 5.67 hours
Sii = 5.67 hours
The Ha data is really nice, and unsurprisingly the Oiii and Sii is not as strong (or nice).
I'm missing that (vital) step in my processing routine of getting the Sii and Oiii properly stretched to match the Ha, before combining. I dont really know how to deal with the weaker data properly. Any pointers would be appreciated.
What I do currently:
All the data is loaded into APP into separate channels/sessions.
The data is stacked and registered against the best Ha sub
This produces individual stacks of Ha, Sii and Oiii that are all registered
Each channel is processed with DPP in APP and then saved as a 16bit TIFF
Each is opened in PS
Stars removed with AA and any remnants removed and tidied up
I then open a blank RGB document in PS
I paste Ha into Green, Sii into Red and Oiii into Blue
Adjust the selective colour settings to get 'Hubble palette'
Adjust levels, curves, saturation until looks ok
All the Ha Sii Oiii data is then combined together in a single 'super' stack in APP using quality weighted algorithm to create a 'luminance'
That luminance layer is adjusted using levels, curves, and NC tools such as local contrast enhancement and deep space noise reduction (using masks to apply as required)
The luminance is pasted onto the above colour layer, and incrementally added using gaussian blur
Cropped and saved.
Here it is anyway I haven't intended on any more exposure time for this one, but will consider it, if the expert opinion dictates otherwise!