its been a long time but i am now looking to finishing up the setup for the 14" in the observatory. I now have the pyxis 2” rotator plus adaptors and tube extensions to use with the 0,62 reducer, but as per my stupidity the 14 is a very tight squeeze in the 2.3 Sirius dome. I will be using the cooled 40D to start with and if I like it will progress to a more specialised setup later with a mono camera. But here is the kicker – I know I need to use a off axis guider and I remember a few people saying to get the MOAG? Does anyone have a photo of their setup with their MOAG and guide camera? How do you set it up?
I was talking to Brett the other day, and I'm pretty sure he trash talked the MOAG, but then again, I was pretty wrecked and could have it back-asswards.
There are other solutions you may want to consider depending on the filter wheel you selection for the RGB work.
ATiK and Starlight can now supply almost "built-in" OAG's for their wheels...
The Ol' Lumicon GEG is also worth considering...
There are other solutions you may want to consider depending on the filter wheel you selection for the RGB work.
ATiK and Starlight can now supply almost "built-in" OAG's for their wheels...
The Ol' Lumicon GEG is also worth considering...
not quite up to the new oag camera yet but the thought has crossed my mind
No Dave, and unfortunately the 14" is not mounted at this stage. I have a Feather touch focuser out of the 14", then a 2" Meade flip mirror, next the OAG and last the Astro 40D. The set-up works well. Flip mirror helps for centring faint objects that are not visible through the camera.
I use a 25mm eyepiece to find a guide star in the OAG, and then replace it with the Orion starshoot auto guider that focuses at the same position.
An on axis guider (ONAG) allows to guide with the same field of view than your imager. Like an off axis guider (OAG) this solves differential flexure problems as well as the the guide scope room and extra load for the mount. However OAG are limited to a narrow donut's like shape field of view way off axis of the main ship. Also an OAG uses small prism to pick up the starlight leading to large F-numbers for the guider.
Most of the time it is challenging to find a guide star this way and most likely it will require to rotate the all camera body to reach the goal, which means you have to take new flat frames all over again each time you do so. An ONAG does not have those limitations.
Innovations Foresight (www.innovationsforesight.com) offers an ONAG, which is associated with an integrated X/Y stage, provides an easy access to your scope field of view by the guider camera. It can use on-axis as well as off axis guide stars, for a scope of 2m focal length the ONAG filed of view is in a range of 1.3 arc-degree.
The ONAG works by splitting the light between the visible range (<750nm) and the near infrared (NIR) range (>750nm). This is done with a dichroic beam splitter, known as a "cold mirror". The visible range is reflected for imaging, pretty much like a star diagonal would do, this insures perfect images, without any distortion, while the NIR light goes through toward the guider camera.
Monochrome, unfiltered CCD/CMOS camera are quite sensitive in NIR, this is why we need UV_NIR blocking filters for imaging with those.
I needed to use my guide-scope to read that tiny text
That is intriguing, so the visual part of the image goes through to the camera, and the near infra-red goes through to the guide camera?
I fing the onag interesting.... but too much backfocus for my setup. But it would probably work for your scope and imaging train.
You are going to struggle to get any aog to work well. You are using a pyxis le? It has a 42mm output, not 2 inch, which is too small to cover your 40d and a pickoff mirror for the guide chip. Unless you mount the oag in front of the rotator which kinda defeats the purpose.
The moag will not work in your situation houghy, the moag is designed to fit between a sbig camera and an sbig aol adaptive optics device. The mmoag however is designed to use adapters to facillitate use with other imaging trains, but you will have the same issues as mentioned above.
By the way, jJust a complement, to be clear.
When I wrote that the ONAG efficiency is 50% for class M stars, I mean from the guider point of view. The imager in any case will receive (by reflection) more than 95% of the visible light (from 370nm to 750nm).
I fing the onag interesting.... but too much backfocus for my setup. But it would probably work for your scope and imaging train.
You are going to struggle to get any aog to work well. You are using a pyxis le? It has a 42mm output, not 2 inch, which is too small to cover your 40d and a pickoff mirror for the guide chip. Unless you mount the oag in front of the rotator which kinda defeats the purpose.
The moag will not work in your situation houghy, the moag is designed to fit between a sbig camera and an sbig aol adaptive optics device. The mmoag however is designed to use adapters to facillitate use with other imaging trains, but you will have the same issues as mentioned above.
Brett
Brett i upgraded the pyxis LE to the 2" pyxis. I am beginning to wonder what i will do. This system seems like i will have to sacrifice the pyxis in the train in order to use a OAG or the on axis version.
i also have the leupus 0.62 reducer to put in place. i really need to find out more about this on axis version.
An on axis guider (ONAG) allows to guide with the same field of view than your imager. Like an off axis guider (OAG) this solves differential flexure problems as well as the the guide scope room and extra load for the mount. However OAG are limited to a narrow donut's like shape field of view way off axis of the main ship. Also an OAG uses small prism to pick up the starlight leading to large F-numbers for the guider.
Most of the time it is challenging to find a guide star this way and most likely it will require to rotate the all camera body to reach the goal, which means you have to take new flat frames all over again each time you do so. An ONAG does not have those limitations.
Innovations Foresight (www.innovationsforesight.com) offers an ONAG, which is associated with an integrated X/Y stage, provides an easy access to your scope field of view by the guider camera. It can use on-axis as well as off axis guide stars, for a scope of 2m focal length the ONAG filed of view is in a range of 1.3 arc-degree.
The ONAG works by splitting the light between the visible range (<750nm) and the near infrared (NIR) range (>750nm). This is done with a dichroic beam splitter, known as a "cold mirror". The visible range is reflected for imaging, pretty much like a star diagonal would do, this insures perfect images, without any distortion, while the NIR light goes through toward the guider camera.
Monochrome, unfiltered CCD/CMOS camera are quite sensitive in NIR, this is why we need UV_NIR blocking filters for imaging with those.
Clear skies!
Happy new year 2012
Gaston, i see you are involved with the company, so in that respect you would know your product. in my case i have a TCF-S focuser with a leupus 0.62 reducer and wanting to use a cooled Canon 40D on a meade 14". how would your product fit in the image train? would i get focus with the camera and how would the guider work ( DMK 21).
More to the point do you have some more examples of use with a DSLR. And what is the cost?
Attached the FR in front of the ONAG (SP), this way imager and guider cameras will see the FR.
In this configuration you would place the imager focal plane (IFP) at a distance (q) from the FR flange in the order of FR back focus (DFR) nominal distance.
A FR can work at a different back focus distance (q ) than the nominal one q=DFR. Doing so will change the reduction factor (h) though.
There is simple relationship here:
h=1-q/f, where f is the FR focal length, about 276mm for the OPTEC 0.62x.
However if the FR is also a corrector, you have to keep q close to the DFR nominal value. For instance the Celestron/Meade 0.63x FR-corrector (field flattener) will work fine if you stay in a range of q= DFR +/- 25mm (1”).
The Optec Lepus 0.62x is designed for corrected scopes, such as the SCT (ACF, EdgeHD), it acts as a simple FR, not a corrector. It is very forgiving on spacing, as we should expect.
Canon DSLR cameras have 44m back focus, and most T-thread to DSLR adapters will add an extra 8mm or so to the back focus, leading to 52mm of back focus.
The ONAG has a 66mm back focus. You will also need an custom adapter to connect the OPTEC FR to the ONAG SP (T-thread). We can make one for you, its expected back focus will 11mm.
Therefore the total back focus from the FR flange to the IF) will be 52+66+11=129mm, or 129-105=25mm, about one each more than the FR DFR (105mm).
This would result in a new reduction factor of h=1-129/276=0.53x, or 14% more reduction.
Second:
Place the FR at the ONAG IP, in front of the imager, this way you can use the standard adapter for the Lepus FR with your DSLR and be at q=DFR. You will need our AFR reducer for the guider port, because the guide does not see the Optec focal reducer in this context. You will also need a T-thread to 2” female adapter to attach the Lepus at the ONAG IP, like you do with your TCS-S.
I use this option in some configuration, I also have a TCS-S focuser, very handy. You can see an example on the website www.innovationsforesight.com main page (C11+TCS-S+AO-8+ONAG+Celestron 0.63x FR).
Since the Lepus is not correcting for the SCT field curvature I would recommend the first option.
For further information you may want to visit the website, I would also suggest you download the ONAG’s user manual (ver. 3.0) from:
Attached the FR in front of the ONAG (SP), this way imager and guider cameras will see the FR.
In this configuration you would place the imager focal plane (IFP) at a distance (q) from the FR flange in the order of FR back focus (DFR) nominal distance.
A FR can work at a different back focus distance (q ) than the nominal one q=DFR. Doing so will change the reduction factor (h) though.
There is simple relationship here:
h=1-q/f, where f is the FR focal length, about 276mm for the OPTEC 0.62x.
However if the FR is also a corrector, you have to keep q close to the DFR nominal value. For instance the Celestron/Meade 0.63x FR-corrector (field flattener) will work fine if you stay in a range of q= DFR +/- 25mm (1”).
The Optec Lepus 0.62x is designed for corrected scopes, such as the SCT (ACF, EdgeHD), it acts as a simple FR, not a corrector. It is very forgiving on spacing, as we should expect.
Canon DSLR cameras have 44m back focus, and most T-thread to DSLR adapters will add an extra 8mm or so to the back focus, leading to 52mm of back focus.
The ONAG has a 66mm back focus. You will also need an custom adapter to connect the OPTEC FR to the ONAG SP (T-thread). We can make one for you, its expected back focus will 11mm.
Therefore the total back focus from the FR flange to the IF) will be 52+66+11=129mm, or 129-105=25mm, about one each more than the FR DFR (105mm).
This would result in a new reduction factor of h=1-129/276=0.53x, or 14% more reduction.
Second:
Place the FR at the ONAG IP, in front of the imager, this way you can use the standard adapter for the Lepus FR with your DSLR and be at q=DFR. You will need our AFR reducer for the guider port, because the guide does not see the Optec focal reducer in this context. You will also need a T-thread to 2” female adapter to attach the Lepus at the ONAG IP, like you do with your TCS-S.
I use this option in some configuration, I also have a TCS-S focuser, very handy. You can see an example on the website www.innovationsforesight.com main page (C11+TCS-S+AO-8+ONAG+Celestron 0.63x FR).
Since the Lepus is not correcting for the SCT field curvature I would recommend the first option.
For further information you may want to visit the website, I would also suggest you download the ONAG’s user manual (ver. 3.0) from:
There was a solid write up about ONAG in cloudy nights; I think its a product I will buy into once (when) I become cashed up again. The price I gather for base set-up is around $1,000.
The only question I had was how easy is it to precisely focus the guide camera to the primary camera?
My challenge precision focusing the guide camera to the primary camera using an Lumicon OAG - required focusing the primary using a Bhatinov mask - primary using Rigel, guider using Jupiter! Only Jupiter was big and bright enough to let me see the diffraction pattern! Precision focusing the guider wasn't fun at all because the OAG didn't had a threaded tube mechanism to allow the guide camera to be adjusted by fractions of a mm at a time.
I think anyone designing ONAG or OAG should correct this by allowing a micro focus arrangement for at least one of the cameras attached to their rig! All it needed was a threaded sliding inner tube!
but the thought has crossed my mind
Onag
. This system seems like i will have to sacrifice the pyxis in the train in order to use a OAG or the on axis version.
