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29561 Posts in 3543 Topics by 312 Members - Latest Member: Bob Gillette November 19, 2017, 07:18:10 PM
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East Coast Astro  |  The Imagers Lounge  |  Beginners Astrophotography  |  Vignetting with TOA 150
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Author Topic: Vignetting with TOA 150  (Read 506 times)

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Offline frainiea

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Vignetting with TOA 150
« on: March 04, 2017, 08:35:15 AM »
I recently aquired a TOA 150, an older model not the "B" and it seems to have a serious case of Vignetting as I am using it with a Optex TCF-S focuser.  Could it be a mechanical issue I am not aware of or just optics?  Post processing has been a challange.  I am curious if this is just a characteristic of the TOA refractors and how others have approached it.
Ed



Offline MikeM

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Re: Vignetting with TOA 150
« Reply #1 on: March 07, 2017, 09:00:53 AM »
What camera are you using and how is everything connected?
Mike
AT8RC-FSQ-106N
G11
Atik 383L+ & EFW2
IC 1XIOM 3X


Offline frainiea

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Re: Vignetting with TOA 150
« Reply #2 on: March 10, 2017, 08:05:09 AM »
My image train is:  OTA-optec TCF-S-FLI filter wheel-FLI 8300

The flats I was taking where an exposure of 0.03 sec, got some feedback that I was probably seeing shutter shadow and it was not Vignette effect after all.  So first chance I get to get back out to my dome I am going to retake some flats with at least 5 - 10 sec times and see how they look.

Ed

Offline MikeM

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Re: Vignetting with TOA 150
« Reply #3 on: March 10, 2017, 08:25:42 AM »
Hi Ed, yes that could be a problem with cameras with physical shutters. I use an Atik 383 and when taking my flats, I make sure that it is longer than 2 seconds to avoid shutter shadow.
I would be interested to hear your results.
Mike
AT8RC-FSQ-106N
G11
Atik 383L+ & EFW2
IC 1XIOM 3X


Offline frainiea

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Re: Vignetting with TOA 150
« Reply #4 on: April 02, 2017, 02:48:28 PM »
I do think you are spot on.  The root problem was my light source was to bright and I got twisted into shorting the exposure over and over and ended up less than a second long exposures.  Indeed it was the shutter shadow I was capturing.

Lesson learned the hard way.

Thanks for the feed back.

Ed

Offline Les (t_total123)

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Re: Vignetting with TOA 150
« Reply #5 on: April 17, 2017, 10:07:44 PM »
 I keep the flat exposure to no less than 5 secs with the Ml8300
I have used the TOA150 with the Ml 8300 great combo

Les
Lots of Nice Goodies to play with

IC 7XIOM 11X

Offline gquinzi

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Re: Vignetting with TOA 150
« Reply #6 on: April 27, 2017, 01:19:24 PM »
I was shooting M45 LRGB and the same thing happened to me when shooting my flats :(  My tablet setting was too bright and my shutter wasn't open long enough.
Tak FSQ-85ED
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Starlight Xpress H18 Mono/FW/OAG
EXview guide head
AstroDon 5nm Ha, SII, OIII, LRGB gen II
G11 w/Ovision & Gemini I
Several pieces of Televue glass

East Coast Astro  |  The Imagers Lounge  |  Beginners Astrophotography  |  Vignetting with TOA 150
 

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