This is the great orion nebula. 27 40s light images. 30 flats (with max pixel value at 22000 ADU) and 30 bias frames. I think the flats helped a great great deal!!! The lightbox works like a charm and is really easy to use. The LPS has made pollution gradients much more easy to handle, but there is still a local gradient visible. I think that for this target, given the trapezium, I needed to do a lot more light images (maybe 60 or 100) at 20 seconds each and that would have given the SNR that is desired. Also I am wondering if I should use a narrower LPS given the light pollution in my area. Pixinsight was used to do masked stretches and SCNR noise reduction (The image had a distinct green tinge after debayer). Stacking was done using DSS. All said and done, I am pretty pleased with the progress. Hopefully the next time I get a chance, I can correct some of these acquisition issues and come up with a much better image.
Friday, December 19, 2008
Post LPS and Light box
I got my IDAS LPS-P2, mounted it on the hyperstar and started shooting. I also now had the light box for flats. And here's the first attempt:
This is the great orion nebula. 27 40s light images. 30 flats (with max pixel value at 22000 ADU) and 30 bias frames. I think the flats helped a great great deal!!! The lightbox works like a charm and is really easy to use. The LPS has made pollution gradients much more easy to handle, but there is still a local gradient visible. I think that for this target, given the trapezium, I needed to do a lot more light images (maybe 60 or 100) at 20 seconds each and that would have given the SNR that is desired. Also I am wondering if I should use a narrower LPS given the light pollution in my area. Pixinsight was used to do masked stretches and SCNR noise reduction (The image had a distinct green tinge after debayer). Stacking was done using DSS. All said and done, I am pretty pleased with the progress. Hopefully the next time I get a chance, I can correct some of these acquisition issues and come up with a much better image.
This is the great orion nebula. 27 40s light images. 30 flats (with max pixel value at 22000 ADU) and 30 bias frames. I think the flats helped a great great deal!!! The lightbox works like a charm and is really easy to use. The LPS has made pollution gradients much more easy to handle, but there is still a local gradient visible. I think that for this target, given the trapezium, I needed to do a lot more light images (maybe 60 or 100) at 20 seconds each and that would have given the SNR that is desired. Also I am wondering if I should use a narrower LPS given the light pollution in my area. Pixinsight was used to do masked stretches and SCNR noise reduction (The image had a distinct green tinge after debayer). Stacking was done using DSS. All said and done, I am pretty pleased with the progress. Hopefully the next time I get a chance, I can correct some of these acquisition issues and come up with a much better image.
Wednesday, December 10, 2008
My Imaging setup
I finally have all the components I need for a decent imaging setup:
Everything mounted on my Atlas EQ-G. The main imaging scope is a Celestron C8 with Hyperstar and QHY8 and the guidescope is an Orion ShortTube 80 with Orion Starshoot Autoguider. The dew shield helps greatly! Especially since the camera projects outwards and upwards. It helps aids in mounting other things such as a light box, since there is no other easy way to do this with a hyperstar setup.
This setup is still much lighter than what I used before. I can getaway with two counterweights. With my XT10 setup I would have to use three 5 pound counterweights and they would be all the way at the bottom of the counterweight shaft.
The dew straps are mounted on both the short tube and the C8. On the C8 I am mounting it right behind the plastic endpiece holding the corrector. Contact with the metal should give better results overall.
All the cables have been split into two groups: Power, which is one bundle, and Control, which is another bundle. Show above is the power bundle and the control bundle. And below, both cable groups are secured by tieing them around the handle bar of the C8, with enough play so that the cables don't get taught when the scope moves around.
Focus control is through Robofocus. The new C8s have a curved back and as a result mounting the robofocus was a pain. Eventually I had to get the plastic wedge and the expansion bracket, seen here, from Technical Innovations. The expansion bracket can be extended in height and I collapse it all the way in when storing the scope. When on the mount, I extend it all the way which is just enough height for me to mate the robofocus to the fine focus knob of the FeatherTouch via a sprocket and a timing belt. I would much rather have the mating be done with the Coarse focus knob of the Feathertouch, but I don't have the right sprocket. I bought what was touted to be the right Sprocket from Technical innovations, but it does not fit and they have not sent me a replacement yet (4 weeks and waiting...). Maybe I will just trim the inner surface of the replacement Sprocket I got and use that on the coarse focus knob (the inner diameter of the replacement I got is just a tad short and hence does not go over the coarse focus knob). This should let me achieve faster focus since with the finefocus knob the step size has to be set too high for any resonable speed in focus.
Without the dew shield you can see the Hyperstar setup. I does look wicked cool!! All the cables around the tube are held losely using a welcro strip. Also I secure the power box for the QHY8 and the Robofocus control box on either side of the C8 using welcro. They stay pretty secure this way.
All the power bricks sit currently on the eyepiece holder in the center of the tripod. This way there is no excess tension on the cables as the bricks are pretty heavy. But I need to figure out a better solution for this. Maybe a bag which hangs on one of the legs in which I can keep the bricks as they are plugged in. Yet to devise this
Everything mounted on my Atlas EQ-G. The main imaging scope is a Celestron C8 with Hyperstar and QHY8 and the guidescope is an Orion ShortTube 80 with Orion Starshoot Autoguider. The dew shield helps greatly! Especially since the camera projects outwards and upwards. It helps aids in mounting other things such as a light box, since there is no other easy way to do this with a hyperstar setup.
This setup is still much lighter than what I used before. I can getaway with two counterweights. With my XT10 setup I would have to use three 5 pound counterweights and they would be all the way at the bottom of the counterweight shaft.
The dew straps are mounted on both the short tube and the C8. On the C8 I am mounting it right behind the plastic endpiece holding the corrector. Contact with the metal should give better results overall.
All the cables have been split into two groups: Power, which is one bundle, and Control, which is another bundle. Show above is the power bundle and the control bundle. And below, both cable groups are secured by tieing them around the handle bar of the C8, with enough play so that the cables don't get taught when the scope moves around.
Focus control is through Robofocus. The new C8s have a curved back and as a result mounting the robofocus was a pain. Eventually I had to get the plastic wedge and the expansion bracket, seen here, from Technical Innovations. The expansion bracket can be extended in height and I collapse it all the way in when storing the scope. When on the mount, I extend it all the way which is just enough height for me to mate the robofocus to the fine focus knob of the FeatherTouch via a sprocket and a timing belt. I would much rather have the mating be done with the Coarse focus knob of the Feathertouch, but I don't have the right sprocket. I bought what was touted to be the right Sprocket from Technical innovations, but it does not fit and they have not sent me a replacement yet (4 weeks and waiting...). Maybe I will just trim the inner surface of the replacement Sprocket I got and use that on the coarse focus knob (the inner diameter of the replacement I got is just a tad short and hence does not go over the coarse focus knob). This should let me achieve faster focus since with the finefocus knob the step size has to be set too high for any resonable speed in focus.
Without the dew shield you can see the Hyperstar setup. I does look wicked cool!! All the cables around the tube are held losely using a welcro strip. Also I secure the power box for the QHY8 and the Robofocus control box on either side of the C8 using welcro. They stay pretty secure this way.
All the power bricks sit currently on the eyepiece holder in the center of the tripod. This way there is no excess tension on the cables as the bricks are pretty heavy. But I need to figure out a better solution for this. Maybe a bag which hangs on one of the legs in which I can keep the bricks as they are plugged in. Yet to devise this
Light Box
So I found out about these things called ElectroLuminescent Panels on the QHYCCD Yahoo forums and it provided for a convenient way for me to build a light box. Bought an A3 size EL panel from glowhut.com, which was shipped quick and courteously. Went to Michaels and bought two foam boards (16"x20") and made this:
I cut the foam board crudely, to be slightly bigger than the A3 EL Sheet. Cut a hole in one of the foam boards such that the dew shield fits through it snugly and then sandwiched the EL sheet in between the foam boards so the black side is outside and stuck the foam boards together with super glue. Voila! there's a light box!
It provides nice even illumination...
through the dew shield :)
The depth provided by the foam board with the hole is good enough to hold the board even when the dew shield is tilted and hence I should be able to mount this on the dew shield while the telescope is mounted on the mount. Just have to make sure that the telescope is pointing towards the zenith. I am excited to try this out. My primary problems so far have been light pollution gradients and bad flats. This should definitely solve the latter.
I cut the foam board crudely, to be slightly bigger than the A3 EL Sheet. Cut a hole in one of the foam boards such that the dew shield fits through it snugly and then sandwiched the EL sheet in between the foam boards so the black side is outside and stuck the foam boards together with super glue. Voila! there's a light box!
It provides nice even illumination...
through the dew shield :)
The depth provided by the foam board with the hole is good enough to hold the board even when the dew shield is tilted and hence I should be able to mount this on the dew shield while the telescope is mounted on the mount. Just have to make sure that the telescope is pointing towards the zenith. I am excited to try this out. My primary problems so far have been light pollution gradients and bad flats. This should definitely solve the latter.
Thursday, December 4, 2008
Light Pollution Filters
Trying to figure out what filters to get is like pulling teeth!! So many opinions on the net. And so much data as well. Mind numbing stuff. Anyways, after enough digging around I had sort of narrowed down to two: either the IDAS LPS P2 or the IDAS LPS V3. I eventually found this article on a spectrograph analysis of the various filters and also a live comparison on M42. Seems to indicate that the V3 is narrower than P2 (which is apparent from the product brochures) and might work better in situations where light pollutions contributors include high pressure sodium lamps. I live close to San Jose CA where, as you can see from the wikipedia entry, a conscious effort has been made to use only low pressure sodium vapor lamps, because of the proximity to Lick Observatory. As a result, at this point I am leaning towards the P2.
Tuesday, December 2, 2008
New look, new setup...
I know, I know! It's been a while. Too many other things happening in life and I got a little busy and distracted ;) Anyways, now I am back, once again, and have a completely new setup!! You might remember that initially I used to use the following:
1) Atlas EQ-G Go-to mount controlled via EQDIR and EQMOD
2) Orion XT-10 telescope tube with Feathertouch focuser and Robofocus
3) Starlight Xpress MX7C single shot color for both imaging and guiding (in interlaced mode)
I upgraded a bit :) The mount is the same, but the rest changed:
1) Celestron C8 with Hyperstar modification, Feathertouch Micro SCT focuser and Robofocus
2) Hyperstar
3) QHY8
4) Guiding with Orion Short Tube 80 and Orion Starshoot Autoguider
I will upload some setup pictures soon. I feel that I have a much cleaner setup at this point (even though it's more components). All the cables are neatly tied up etc. As far as software goes, only one additionl piece of software: PHD Guiding. But of course the laptop setup is completely new. The old one blew up, and I don't have a windows machine anymore. So now I am running everything on a copy of Windows running inside Parallels on my Mac Book Pro. It works just fine! In fact in some ways it's better!
Initially I had some problems getting the QHY8 to work. I kept thinking I could not focus, but turns out the QHY8 was not capturing at all. After some emails and web searches, I figured out that the 4-pin DIN (S-Video) connector supplying power to the camera electronics and CCD was not seating in properly (QHY8 has to power supply cables coming from the adapter to the camera. One for the cooler and the other supplying power to the camera electronics and CCD). After some cable swapping and jacket-trimming (Shaved the plastic jacket on the power cable and now it seats properly), it started capturing. Set it up that night but took some time, reestablishing parameters for robofocus, Maxim DL etc. The data I acquired was too noisy and I didn't have flats. So abandoned them. The next night I set it up again and images a few other targets:
M33. Leaves much to be desired in many areas. 52x30s. Flats, Bias and Dark were used but flats were not too good. Also after calibration I used the "Auto Flatten Background" Filter in Maxim DL and it messed it up a little more...
This is the Pleiades star cluster. Also called the seven sisters. The cool thing about this is that the solar winds are blowing back the gases and you can actually see the ripples in the gases around these stars!! Really cool...The image was 49x30s. Flats, Bias and Dark were used but flats were not too good.
The processing is a little hasty and also I need a better mechanism to take flats. With the big chip and the fast system, there is some severe vignetting. I might even benefit with a Light Pollution filter in the optical train. The next time I image, I need to have better flats. Hopefully I will get some more time this week.
1) Atlas EQ-G Go-to mount controlled via EQDIR and EQMOD
2) Orion XT-10 telescope tube with Feathertouch focuser and Robofocus
3) Starlight Xpress MX7C single shot color for both imaging and guiding (in interlaced mode)
I upgraded a bit :) The mount is the same, but the rest changed:
1) Celestron C8 with Hyperstar modification, Feathertouch Micro SCT focuser and Robofocus
2) Hyperstar
3) QHY8
4) Guiding with Orion Short Tube 80 and Orion Starshoot Autoguider
I will upload some setup pictures soon. I feel that I have a much cleaner setup at this point (even though it's more components). All the cables are neatly tied up etc. As far as software goes, only one additionl piece of software: PHD Guiding. But of course the laptop setup is completely new. The old one blew up, and I don't have a windows machine anymore. So now I am running everything on a copy of Windows running inside Parallels on my Mac Book Pro. It works just fine! In fact in some ways it's better!
Initially I had some problems getting the QHY8 to work. I kept thinking I could not focus, but turns out the QHY8 was not capturing at all. After some emails and web searches, I figured out that the 4-pin DIN (S-Video) connector supplying power to the camera electronics and CCD was not seating in properly (QHY8 has to power supply cables coming from the adapter to the camera. One for the cooler and the other supplying power to the camera electronics and CCD). After some cable swapping and jacket-trimming (Shaved the plastic jacket on the power cable and now it seats properly), it started capturing. Set it up that night but took some time, reestablishing parameters for robofocus, Maxim DL etc. The data I acquired was too noisy and I didn't have flats. So abandoned them. The next night I set it up again and images a few other targets:
M33. Leaves much to be desired in many areas. 52x30s. Flats, Bias and Dark were used but flats were not too good. Also after calibration I used the "Auto Flatten Background" Filter in Maxim DL and it messed it up a little more...
This is the Pleiades star cluster. Also called the seven sisters. The cool thing about this is that the solar winds are blowing back the gases and you can actually see the ripples in the gases around these stars!! Really cool...The image was 49x30s. Flats, Bias and Dark were used but flats were not too good.
The processing is a little hasty and also I need a better mechanism to take flats. With the big chip and the fast system, there is some severe vignetting. I might even benefit with a Light Pollution filter in the optical train. The next time I image, I need to have better flats. Hopefully I will get some more time this week.
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