Strange appearance of Oiii MasterFlat
- XCalRocketMan
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Strange appearance of Oiii MasterFlat
Just wondering if anyone here can give me some guidance on a potential issue I might have with my Astrodon Oiii 3nm filter. All my masterflats look as I would expect them to look except for this Oiii. It has a darker oval surrounding the center of the FOV and light and dark bands emanating from the top left across the FOV . Has anyone ever seen something like this? Should I be concerned about it? I thought maybe the filter (31mm unmounted) is possibly being pinched because the 3 screws holding it in the filter wheel may be too tight.
Scopes Celestron EdgeHD-11; William Optics GT102; William Optics ZS61; Criterion Dynamax-8 SCT
Mounts AP1100GTO mount w/APCCpro; iOptron iEQ30 Pro; Criterion Dynamax-8 SCT
Lenses Hyperstar-III; Celestron 0.7x FR; WO Flat/Reducer 0.8x
Guiding Celestron OAG w/ASI174mm mini; WO 50mm; Orion ST80
Cameras and Filters ZWO2600mm Pro w/Optolong 3nm NB and RGB; ZWOASI1600mm Pro (ZWO LRGB and Astrodon Ha-5nm, Oiii-3nm, Sii-5nm), QHY10, Canon 50D; ASI174mm mini; ASI462MC; ASI120MC
Misc Moonlite focuser on Edge - Feather-Touch focuser on GT102; ZWO EAF on ZS61; ZWO 2" and 31mm FWs; Kendrick Dew System, Temp-est Fans
Software NINA; PHD; APT; BYE; PI; APP; PSP; Registax; FireCapture; SharpCap
Blog at: SkyAndRockets
Mounts AP1100GTO mount w/APCCpro; iOptron iEQ30 Pro; Criterion Dynamax-8 SCT
Lenses Hyperstar-III; Celestron 0.7x FR; WO Flat/Reducer 0.8x
Guiding Celestron OAG w/ASI174mm mini; WO 50mm; Orion ST80
Cameras and Filters ZWO2600mm Pro w/Optolong 3nm NB and RGB; ZWOASI1600mm Pro (ZWO LRGB and Astrodon Ha-5nm, Oiii-3nm, Sii-5nm), QHY10, Canon 50D; ASI174mm mini; ASI462MC; ASI120MC
Misc Moonlite focuser on Edge - Feather-Touch focuser on GT102; ZWO EAF on ZS61; ZWO 2" and 31mm FWs; Kendrick Dew System, Temp-est Fans
Software NINA; PHD; APT; BYE; PI; APP; PSP; Registax; FireCapture; SharpCap
Blog at: SkyAndRockets
- STEVE333
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Re: Strange appearance of Oiii MasterFlat
I have a 31mm unmounted Chroma 3nm Oiii filter. The unstretched MasterFlat looks very normal, but, the stretched version is very strange looking (stretched image below) and took my breath away. I thought for sure there was something wrong with the filter.
However, the MasterFlat for the Oiii data works fine and none of the MasterFlat "structure" appears in any of the calibrated images
Don't know if this helps you or not.
Steve
However, the MasterFlat for the Oiii data works fine and none of the MasterFlat "structure" appears in any of the calibrated images
Don't know if this helps you or not.
Steve
Steve King: Light Pollution (Bortle 5)
Telescope + Mount + Guiding: W.O. Star71-ii + iOptron CEM40 EC + Orion Magnificent Mini AutoGuider
Camera: ASI 1600MM Pro + EFW Filter Wheel + Chroma 3nm Siii, Ha, Oiii + ZWO LRGB Filters
Software: PHD2; APT; PixInsight ***** My AP website: www.steveking.pictures
Telescope + Mount + Guiding: W.O. Star71-ii + iOptron CEM40 EC + Orion Magnificent Mini AutoGuider
Camera: ASI 1600MM Pro + EFW Filter Wheel + Chroma 3nm Siii, Ha, Oiii + ZWO LRGB Filters
Software: PHD2; APT; PixInsight ***** My AP website: www.steveking.pictures
- XCalRocketMan
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Re: Strange appearance of Oiii MasterFlat
Yeah, the calibrated images look fine. I was just a bit taken aback at what the flat looked like. I guess it's not really a problem (at least it's nice to see someone else has a similar looking stretched Oiii Master Flat :Think: )STEVE333 wrote: ↑Tue Sep 22, 2020 6:22 pm I have a 31mm unmounted Chroma 3nm Oiii filter. The unstretched MasterFlat looks very normal, but, the stretched version is very strange looking (stretched image below) and took my breath away. I thought for sure there was something wrong with the filter.
However, the MasterFlat for the Oiii data works fine and none of the MasterFlat "structure" appears in any of the calibrated images
Don't know if this helps you or not.
Steve
Scopes Celestron EdgeHD-11; William Optics GT102; William Optics ZS61; Criterion Dynamax-8 SCT
Mounts AP1100GTO mount w/APCCpro; iOptron iEQ30 Pro; Criterion Dynamax-8 SCT
Lenses Hyperstar-III; Celestron 0.7x FR; WO Flat/Reducer 0.8x
Guiding Celestron OAG w/ASI174mm mini; WO 50mm; Orion ST80
Cameras and Filters ZWO2600mm Pro w/Optolong 3nm NB and RGB; ZWOASI1600mm Pro (ZWO LRGB and Astrodon Ha-5nm, Oiii-3nm, Sii-5nm), QHY10, Canon 50D; ASI174mm mini; ASI462MC; ASI120MC
Misc Moonlite focuser on Edge - Feather-Touch focuser on GT102; ZWO EAF on ZS61; ZWO 2" and 31mm FWs; Kendrick Dew System, Temp-est Fans
Software NINA; PHD; APT; BYE; PI; APP; PSP; Registax; FireCapture; SharpCap
Blog at: SkyAndRockets
Mounts AP1100GTO mount w/APCCpro; iOptron iEQ30 Pro; Criterion Dynamax-8 SCT
Lenses Hyperstar-III; Celestron 0.7x FR; WO Flat/Reducer 0.8x
Guiding Celestron OAG w/ASI174mm mini; WO 50mm; Orion ST80
Cameras and Filters ZWO2600mm Pro w/Optolong 3nm NB and RGB; ZWOASI1600mm Pro (ZWO LRGB and Astrodon Ha-5nm, Oiii-3nm, Sii-5nm), QHY10, Canon 50D; ASI174mm mini; ASI462MC; ASI120MC
Misc Moonlite focuser on Edge - Feather-Touch focuser on GT102; ZWO EAF on ZS61; ZWO 2" and 31mm FWs; Kendrick Dew System, Temp-est Fans
Software NINA; PHD; APT; BYE; PI; APP; PSP; Registax; FireCapture; SharpCap
Blog at: SkyAndRockets
- Stuart
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Re: Strange appearance of Oiii MasterFlat
My guess is that it just be an artifact of the autostretch, because it's trying to stretch minor differences in the data.
Personal equipment: TEC 140 F7 on Astro-Physics Mach 1 mount. Camera QSI 683ws7. Guide with Vario guiding scope
Shared equipment through Star Shadows Remote Observatory through PROMPT/ CTIO/Chile 16" RCOS 16803 chip
Shared equipment through San Diego Astronomy Society 14" RC with 16803 chip on a paramount
Software (for my stuff) PemPRO, SGP, PHD, Focus Boss, ASCOM, and Pixinsight on the other end.
Shared equipment through Star Shadows Remote Observatory through PROMPT/ CTIO/Chile 16" RCOS 16803 chip
Shared equipment through San Diego Astronomy Society 14" RC with 16803 chip on a paramount
Software (for my stuff) PemPRO, SGP, PHD, Focus Boss, ASCOM, and Pixinsight on the other end.
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