Reverse vignetting?
- metastable
- Pluto Ambassador
- Articles: 0
- Posts: 480
- Joined: Fri Dec 13, 2019 9:00 pm
- 4
- Location: California
- Status:
Offline
-
TSS Photo of the Day
- Larry 1969
- Milky Way Ambassador
- Articles: 0
- Posts: 1481
- Joined: Fri May 17, 2019 12:33 am
- 4
- Location: Pittsburgh PA USA
- Status:
Offline
-
TSS Photo of the Day
Re: Reverse vignetting?
My focuser sits 6 inches inside the tube and I have a dew shield that extends 8 inches past that. You think I need more?
Larry
For visual:
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
- metastable
- Pluto Ambassador
- Articles: 0
- Posts: 480
- Joined: Fri Dec 13, 2019 9:00 pm
- 4
- Location: California
- Status:
Offline
-
TSS Photo of the Day
Re: Reverse vignetting?
It depends… does any light from the moon (or other sources) illuminate the area of the main tube within the black cone of the diagram when you are using the current dew shield?
- Larry 1969
- Milky Way Ambassador
- Articles: 0
- Posts: 1481
- Joined: Fri May 17, 2019 12:33 am
- 4
- Location: Pittsburgh PA USA
- Status:
Offline
-
TSS Photo of the Day
Re: Reverse vignetting?
You're referring to this area, correct? I just want to be sure I understand.
I'll have to check next time I set up and that doesn't look like anytime soon...
Thanks!
Larry
I'll have to check next time I set up and that doesn't look like anytime soon...
Thanks!
Larry
- Attachments
-
- Stray-Light-Control_html_m1d4bfa9a.jpg (10.35 KiB) Viewed 2653 times
For visual:
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
- yobbo89
- Moderator
- Articles: 0
- Posts: 2593
- Joined: Sat May 11, 2019 7:44 pm
- 4
- Location: australia qld brisbane
- Status:
Online
-
TSS Photo of the Day
Re: Reverse vignetting?
you can get an lop sided vignetting by having the secondary not properly alighned to your focuser ie depth dimension /the center bolt adjustment .
scopes :gso/bintel f4 12"truss tube, bresser messier ar127s /skywatcher 10'' dob,meade 12'' f10 lx200 sct
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
- Larry 1969
- Milky Way Ambassador
- Articles: 0
- Posts: 1481
- Joined: Fri May 17, 2019 12:33 am
- 4
- Location: Pittsburgh PA USA
- Status:
Offline
-
TSS Photo of the Day
Re: Reverse vignetting?
I bought a tool for that. It's basically a Cheshire eyepiece with a clear filter attached that has concentric circles. Maybe I misused it???
For visual:
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
- yobbo89
- Moderator
- Articles: 0
- Posts: 2593
- Joined: Sat May 11, 2019 7:44 pm
- 4
- Location: australia qld brisbane
- Status:
Online
-
TSS Photo of the Day
Re: Reverse vignetting?
if you have any error with the light cone illuminating center on theLarry 1969 wrote: ↑Mon Dec 06, 2021 5:03 pmI bought a tool for that. It's basically a Cheshire eyepiece with a clear filter attached that has concentric circles. Maybe I misused it???
i rack my focuser out somewhere near to the same focus postion as my camera and then look through the cheshire , you might want to try different focus position just to generaly get the
if it isn't comming out in your flats then really the problem is most likely not with the scope but an outside source ,moon ectt, street light .
scopes :gso/bintel f4 12"truss tube, bresser messier ar127s /skywatcher 10'' dob,meade 12'' f10 lx200 sct
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
- SkyHiker
- Local Group Ambassador
- Articles: 0
- Posts: 2293
- Joined: Sat May 11, 2019 8:40 pm
- 4
- Location: Santa Barbara, CA
- Status:
Online
-
TSS Photo of the Day
TSS Awards Badges
Re: Reverse vignetting?
I had some bad gradients with my DSLR when imaging the horsehead no matter how I rotated it. Eventually I switched to an astro camera and the problem is gone. I attribute that one to Alnitak hitting a shiny part of the camera.
I also had reverse vignetting when I started using an astro camera using just flats and no biases. TheDSS forum straightened me out that I really need biases in order for the stacking math to work. This never was a problem with my DSLR . I suppose this is not your issue since it happens with uncalibrated lights as well.
So my best guess is some sort of reflection. I hope you find the cause.
I also had reverse vignetting when I started using an astro camera using just flats and no biases. The
So my best guess is some sort of reflection. I hope you find the cause.
... Henk. Telescopes: GSO 12" Astrograph, "Comet Hunter" MN152, ES ED127CF, ES ED80, WO Redcat51, Z12, AT6RC, Celestron Skymaster 20x80, Mounts and tripod: Losmandy G11S with OnStep, AVX, Tiltall, Cameras: ASI2600MC, ASI2600MM, ASI120 mini, Fuji X-a1, Canon XSi, T6, ELPH 100HS, DIY: OnStep controller, Pi4b/power rig, Afocal adapter, Foldable Dob base, Az/Alt Dob setting circles, Accessories: ZWO 36 mm filter wheel, TV Paracorr 2, Baader MPCC Mk III, ES FF, SSAG, QHY OAG-M, EAF electronic focuser, Plossls, Barlows, Telrad, Laser collimators (Seben LK1, Z12, Howie Glatter), Cheshire, 2 Orion RACIs 8x50, Software: KStars-Ekos, DSS, PHD2, Nebulosity, Photo Gallery, Gimp, CHDK, Computers:Pi4b, 2x running KStars/Ekos, Toshiba Satellite 17", Website:Henk's astro images
- Larry 1969
- Milky Way Ambassador
- Articles: 0
- Posts: 1481
- Joined: Fri May 17, 2019 12:33 am
- 4
- Location: Pittsburgh PA USA
- Status:
Offline
-
TSS Photo of the Day
Re: Reverse vignetting?
Thanks for all the replies and suggestions. I get so few clear nights to test anything out. I was able to get out for a few hours this past weekend and I spent it on NGC 1333. It was low in the east and I think there was some terrible sky glow in that area so the image is crap, but I took new flats at 32,000 ADU and the vignetting seems solved. I couldn't deal with the noise in this but I didn't notice any vignetting to speak of.
Larry
For visual:
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
10" Skywatcher collapsible goto dob, various EP's and a Celestron StarSense auto align.
For imaging:
Orion 8" astrograph 800mm @ F3.9
Eq6-R Pro controlled by APT via EQmod with an OTA mounted mini PC
Tele Vue Paracorr Type 2 coma corrector
Altair Hypercam 26C
- yobbo89
- Moderator
- Articles: 0
- Posts: 2593
- Joined: Sat May 11, 2019 7:44 pm
- 4
- Location: australia qld brisbane
- Status:
Online
-
TSS Photo of the Day
Re: Reverse vignetting?
it's actualy some pretty reasonable detail and sharpness in the center , it looks like longer exposer time will seatle out the noise in the outer regions,but you do face skyglow comming in doing so ..Larry 1969 wrote: ↑Wed Dec 08, 2021 10:59 pm Thanks for all the replies and suggestions. I get so few clear nights to test anything out. I was able to get out for a few hours this past weekend and I spent it on NGC 1333. It was low in the east and I think there was some terrible sky glow in that area so the image is crap, but I took new flats at 32,000 ADU and the vignetting seems solved. I couldn't deal with the noise in this but I didn't notice any vignetting to speak of.
Larry
scopes :gso/bintel f4 12"truss tube, bresser messier ar127s /skywatcher 10'' dob,meade 12'' f10 lx200 sct
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
cameras : asi 1600mm-c/asi1600mm-c,asi120mc,prostar lp guidecam, nikkon d60, sony a7,asi 290 mm
mounts : eq6 pro/eq8/mesu 200 v2
filters : 2'' astronomik lp/badder lrgb h-a,sII,oIII,h-b,Baader Solar Continuum, chroma 3nm ha,sii,oiii,nii,rgb,lowglow,uv/ir,Thousand Oaks Solar Filter,1.25'' #47 violet,pro planet 742 ir,pro planet 807 ir,pro planet 642 bp ir.
extras : skywatcher f4 aplanatic cc, Baader MPCC MKIII Coma Corrector,Orion Field Flattener,zwo 1.25''adc.starlight maxi 2" 9x filter wheel,tele vue 2x barlow .
Create an account or sign in to join the discussion
You need to be a member in order to post a reply
Create an account
Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute