Re: Reflections in Images
At that point then maybe I should reconsider the Astro Don filters although I have both the LRGB and NB sets.
Steve
Sent: Wednesday, February 03, 2016 12:27 PM
To: ap-gto@...
Subject: Re: [ap-gto] Reflections in Images
Steve
Yes, at five years they would be the newer versions.
Kent
-----Original Message-----
From: 'Steven Reilly' sreilly24590@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Wed, Feb 3, 2016 11:24 am
Subject: RE: [ap-gto] Reflections in Images
Kent,
Both filters and camera are about 5 years old. I think these are the newer series.
Steve
From: ap-gto@... [mailto:ap-gto@...]
Sent: Wednesday, February 03, 2016 11:16 AM
To: ap-gto@...
Subject: Re: [ap-gto] Reflections in Images
Steve:
How old are your filters?
Astro imaging filters have gone through two evolutions, hence in the case of Astrodon filters, Series 1 and Series 2. I believe Baader filters have also done this. The later series have much better anti reflection coatings and on both sides. Your reflections appear to be of your mirror and secondary....much like what you'd see with an eyepiece and an out of focus position. If your filters are before the improved coatings I would suspect them.
Kent Kirkley
-----Original Message-----
From: 'Steven Reilly' sreilly24590@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Wed, Feb 3, 2016 9:26 am
Subject: RE: [ap-gto] Reflections in Images
At this point there is no OAG in place. I had one when I had the flattener in place though but removed and tried with the same results. I guess I could remove the filter carousel and see if that makes a difference. I’m using Baader 50mm unmounted filters in my FW8.
Thanks,
Steve
From: ap-gto@... [mailto:ap-gto@...]
Sent: Wednesday, February 03, 2016 10:13 AM
To: ap-gto@...
Subject: Re: [ap-gto] Reflections in Images
Steve, the reflection could be from inside your filter wheel or adapters for connecting it. Or from an OAG. I recall years ago that some people complained of flaring and odd artifacts that were traced to the fact that their filters' uncoated, unblackened edges were exposed and the solution was to take a thick sharpie and colour in the sides of the glass filters.
Stuart
On Wed, Feb 3, 2016 at 10:09 AM, 'Steven Reilly' sreilly24590@... [ap-gto] <ap-gto@...> wrote:
Joel,
The ota tube is carbon fiber and a dull black interior. There are two small dovetail bars mounted near the end of the ota for additional counter weights if needed. I guess I could remove them and see if that makes a difference. Other than that there is just the spider vane holding the secondary and its stepper motor. It is baffled well. I’ll try this and see if that make a difference. I have a 3-pound weight that I can find another way to attach for balance.
Thanks,
Steve
From: ap-gto@... [mailto:ap-gto@...]
Sent: Tuesday, February 02, 2016 11:49 PM
To: ap-gto@...
Subject: Re: [ap-gto] Reflections in Images
Steve,
I've seen this kind of reflection caused by a bright object just off the field of view. If your date is correct then NGC3521 was very close to Jupiter and Sh2-263 was rather close to Bellatrix. The reason the reflection seems to change is because as time goes on the relative position of your camera orientation and slight differences in the camera sky position can change how intense the reflection is. I've had cases where I moved the scope just a tiny distance away from the bright star or object and the reflection went away. Yours is pretty extreme though. I don't know if I've seen one quite that bright.
But that may only be half the problem. I suspect your scope may have something shiny in it that is reflecting. Is there any silver metal somewhere in the tube? Is it baffled well? Is it painted black?
joel
On Tue, Feb 2, 2016 at 10:12 PM, 'Steven Reilly' sreilly24590@... [ap-gto] <ap-gto@...> wrote:
Back a few months ago I posted a webpage with some reflections I was getting in some images. The link to that page is http://www.astral-imaging.com/reflection.html Since then I have removed the flattener lens from the RC and am again seeing some reflections I had thought were from the lens. The latest images to show this strongly are of NGC3521 and seen here http://www.astral-imaging.com/reflections.html Any ideas how to track down the source of these reflections would be great. The telescope is a OGS 12.5” RC with a Pyxis 3” rotator, STL-11002M w/fw8.
Thanks,
Steve
--
Stuart Heggie