What else is new? Tried to go out and run Sequence Generator Pro with Autofocus and while I could get autofocus to function, it often shot past best focus and gave me out-of-focus stars. I tried for about an hour before I gave up. I can't figure out if it's some backlash issue or something else.
Overall, I felt I wasted time. But not really. I'll have to go out and try again.
I did have some success in getting better guiding in PHD2...that is, until I tried to Polar align
and had the scope bang against the pier really hard. WHAT THE HELL! Infuriating that
I didn't react quickly enough when I saw the scope heading towards the pier.
Up until that point, I was getting the best guiding I'd ever seen with RA aggressiveness set to .7 and Dec aggressiveness at .65. I was getting a total RMS in the .6 to.8 range consistently.
After banging the scope, I'm pretty sure I knocked polar alignment out of whack AND probably introduced some extra gear mesh issues. DAMN! I had spent about an hour getting that
polar alignment nailed. RA guiding went to crap and I had crazy oscillation numbers up to 1.1
in PHD2.
Next time, I need to really get the right angle polar alignment scope configured so I cut down on these 1-2 hour polar alignment routines.
I suspect I'll need to remesh RA and possibly DEC.
I want to have a go at the Angel Nebula (IFN) which is North of M81/82. Looking at my preliminary pics, I believe I need to center the image on NGC 3343 (or NGC 3348) using the 135mm lens and the Canon T3i. I believe I need to collect about 75 x 15 min exposures which will be a 5 night affair.
I think I can start exposing at 12:30. If I'm smart, I can start the evening shooting the Angelfish Nebula (Meissa) over those same nights.
As I don't have a provision for autofocusing that lens, I'll need to do this manually. Ugh.
Sunday, December 21, 2014
Thursday, December 18, 2014
M42... Required Image
So I've been taking pics of this nebula since I started astrophotgraphy sometime in the late 80's. Back then, I was using a 8 inch Meade Schmidt-Cassegrain that my mom bought for me. (Well, I asked and she okay'd it.) Astrophotography was done with film and there were many choices. Invariably, the results were blurry smears of red. Guiding was done through a finder scope with a reticle eyepiece. I shot many rolls of film, but nothing really came out to my satisfaction.
I didn't realize at the time that guiding a 2000mm focal length scope through a 60mm guidescope was never going to really work. I tried lots of combinations, but the end result was always disappointing.
Anyhow, fast forward 25 years and I got this image of M42, the Orion Nebula, and NGC 1977, the Running Man nebula.
I had to devote several nights to getting the exposures to make this image. This was shot on the nights of Nov 24, 25, 30, then Dec 14 and 15. I used 31 x 15 min exposures, 46 x 5 min exposures, 35 x 2 min exposures, 35 x 15 seconds, and 35 x 5 seconds. That's about 13 hours of exposure. I actually shot about 17 hours of total exposure, but I only used the best 80% of the shots to process the image. Scope: Takahashi TSA102S w/Televue .8x focal reducer/flattener. Mount: Used AP1200. Misc: Guided w/Orion 50mm guidescope and QHY5II-L autoguider.
It's kind of a mandatory shot for any astrophotographer, but I wanted to do it because I knew I would get something worthwhile as it's so bright.
There are issues with the image. The darker dust structures around the edges of the brightest parts are noisy. I got those structures from those longer 15 min subexposures, but I think I need like 3-4 times the number of 15 minute exposure which means another 3+ nights of imaging this object. Getting extra 15 minute shots would increase the signal-to-noise ratio which translates into less noise and more structure.
I was sorta lazy with using layer masks (a technique in Photoshop) and some of the stars are not the right brightness (too large) relative to other stars.
Sharpness is an issue. Overall, I think the image is a little blurry - except near the core of the Orion nebula where the Trapezium is located (the tiny grouping of 4 stars near the center). And that Trapezium is weirdly detailed with respect to everything else.
The overall color is little garish to me. I know this object gets overly saturated by most people and I ended up doing the same thing.
Also, there is some curvature in all the corners, but most obviously in the upper right and left respectively. I've known about this for awhile, but I haven't bothered to address it. *I think* it's focuser tilt as the curvature seems to be different depending on the orientation of the camera. I also picked up some spacers to place between the flattener and the camera. More crap to address.
If you look closely to the bottom edge, just to the right of the center you can see some artifacts from the constant parade of satellites I had to deal with. Actually the satellites aren't moving, there's a bunch of geostationary satellites that happen to be located in M42
Overall, to me, it's a "meh." But I'm glad I did it.
I didn't realize at the time that guiding a 2000mm focal length scope through a 60mm guidescope was never going to really work. I tried lots of combinations, but the end result was always disappointing.
Anyhow, fast forward 25 years and I got this image of M42, the Orion Nebula, and NGC 1977, the Running Man nebula.
I had to devote several nights to getting the exposures to make this image. This was shot on the nights of Nov 24, 25, 30, then Dec 14 and 15. I used 31 x 15 min exposures, 46 x 5 min exposures, 35 x 2 min exposures, 35 x 15 seconds, and 35 x 5 seconds. That's about 13 hours of exposure. I actually shot about 17 hours of total exposure, but I only used the best 80% of the shots to process the image. Scope: Takahashi TSA102S w/Televue .8x focal reducer/flattener. Mount: Used AP1200. Misc: Guided w/Orion 50mm guidescope and QHY5II-L autoguider.
It's kind of a mandatory shot for any astrophotographer, but I wanted to do it because I knew I would get something worthwhile as it's so bright.
There are issues with the image. The darker dust structures around the edges of the brightest parts are noisy. I got those structures from those longer 15 min subexposures, but I think I need like 3-4 times the number of 15 minute exposure which means another 3+ nights of imaging this object. Getting extra 15 minute shots would increase the signal-to-noise ratio which translates into less noise and more structure.
I was sorta lazy with using layer masks (a technique in Photoshop) and some of the stars are not the right brightness (too large) relative to other stars.
Sharpness is an issue. Overall, I think the image is a little blurry - except near the core of the Orion nebula where the Trapezium is located (the tiny grouping of 4 stars near the center). And that Trapezium is weirdly detailed with respect to everything else.
The overall color is little garish to me. I know this object gets overly saturated by most people and I ended up doing the same thing.
Also, there is some curvature in all the corners, but most obviously in the upper right and left respectively. I've known about this for awhile, but I haven't bothered to address it. *I think* it's focuser tilt as the curvature seems to be different depending on the orientation of the camera. I also picked up some spacers to place between the flattener and the camera. More crap to address.
If you look closely to the bottom edge, just to the right of the center you can see some artifacts from the constant parade of satellites I had to deal with. Actually the satellites aren't moving, there's a bunch of geostationary satellites that happen to be located in M42
Overall, to me, it's a "meh." But I'm glad I did it.
Monday, December 15, 2014
Just another note to myself...
So, I've been collecting data on M42, the Orion Nebula. I got 3 days toward
the end of November. Got around 30-35 frames at 15 minutes, 30 frames at 5 minutes.
Tonight (night of 12/14) I got another 12 frames at 5 minutes with Orion in a
better part of the sky. Then got about 40 frames at 15 seconds, then 40 frames
at 2 minutes. I noticed that the 15 second frames were still blowing out the
Trapezium so I added 40 frames at 5 seconds. Lots of the 5 sec shots showed odd
shaped stars -- with slight elongation. But it was sorta random so I attribute it
to seeing.
I've been working on the used AP1200 mount and it seems less accurate than
the AP900. PHD2 does so many more corrections to keep the target in its sights.
I decided to try a different setting for Dec corrections. In PHD2's settings, I had set
the Dec correction to "Resist Switch" which in previous trips has resulted in
really crappy Dec corrections -- there are occasional elongated stars that I believe
are the result of crazy Dec movements.
So, I changed the settings to "Hysteresis" in the hopes of better Dec corrections.
Earlier I polar aligned and spent a lot more time getting the "east" or Dec alignment
solid with 250 second correction using the "iterative method".
And I spent some time re-seating the legs of the pier. I had brought out a level
and discovered that the legs were really out of kilter. I wondered if this was
responsible for the poor guiding.
Another new thing was going with a different connection between the autoguider and the mount.
Instead of using the standard ST-4 port connected to the autoguider camera, I went
through a USB-to-Serial interface, then to the RS-232 port of the mount. I dunno.
After doing some test autoguides, it might have been better. The RA guiding did
seem better, but the Dec guiding was still giving me some fits. Overall it might have
been better. It's hard to say. Except that I never lost the guide star.
In any event, guiding through the RS-232 connection worked and I'll probably stick with it.
I was done with the Orion shots around 1:30 AM when the moon made it's appearance.
I decided to try to image the Cone nebula using Dithering. Man, I just had problems.
The procedure of getting dithering going involves turning on the server in PHD2,
shutting PHD2 down, then restarting PHD2 and going about calibrating as usual.
What I found was that PHD2 would often just hang after connecting to the camera
and mount. What gives? I would have to CTRL-ALT-DEL to shut down the program
and the Astro-Physics driver which controls the mount.
I tried multiple different approaches. At one point, the QHY5L-II guider wasn't
even showing a red light. I'd have to unplug it and replug it in. Sometimes that would
allow the camera to show up, but other times, the camera just wasn't cooperating.
Troubleshooting this crap with 20 degree temps and freezing hands is a pain in the ass.
Turned off and on the computer. Same problems.
At one point, my computer decided to hang.
Was it the 18 degree weather?
So, I began to be methodical and stumbled upon one instance of success.
After restarting the computer (yet again), I opened PHD2 and made sure I only connected
the camera so I could see an image. *I think* I stopped the camera, then selected a star
on the image, then I connected the mount, restarted the 2 sec images. Then I stopped,
disconnected, enabled the server, then shut down. *I think* I opened PHD2 again, then
started JUST THE CAMERA to see if I could get an image. Then hit stop, then connected
the mount (a slight delay occurs), then restarted the 2 sec images with SUCCESS. I was
then able to calibrate and begin guiding. IT WAS ONLY THEN that I started Backyard EOS.
And after loading a profile of 60 sec shots, it worked!
Earlier, I had been connecting both the camera and mount at the same time when starting PHD2.
And this leads to a hang.
Also, I had been trying PHD2 with Backyard EOS loaded in the background. I think this causes problems because PHD2 wants BYE wants to communicate with PHD2 before it's ready.
I'm not sure if I found a way to make it work OR the system just randomly decided to work one time.
It seems like if PHD2 hangs, then I need to restart the computer which is a pain.
We'll see next time. I want to try to exclusively use Dithering.
So, I've been collecting data on M42, the Orion Nebula. I got 3 days toward
the end of November. Got around 30-35 frames at 15 minutes, 30 frames at 5 minutes.
Tonight (night of 12/14) I got another 12 frames at 5 minutes with Orion in a
better part of the sky. Then got about 40 frames at 15 seconds, then 40 frames
at 2 minutes. I noticed that the 15 second frames were still blowing out the
Trapezium so I added 40 frames at 5 seconds. Lots of the 5 sec shots showed odd
shaped stars -- with slight elongation. But it was sorta random so I attribute it
to seeing.
I've been working on the used AP1200 mount and it seems less accurate than
the AP900. PHD2 does so many more corrections to keep the target in its sights.
I decided to try a different setting for Dec corrections. In PHD2's settings, I had set
the Dec correction to "Resist Switch" which in previous trips has resulted in
really crappy Dec corrections -- there are occasional elongated stars that I believe
are the result of crazy Dec movements.
So, I changed the settings to "Hysteresis" in the hopes of better Dec corrections.
Earlier I polar aligned and spent a lot more time getting the "east" or Dec alignment
solid with 250 second correction using the "iterative method".
And I spent some time re-seating the legs of the pier. I had brought out a level
and discovered that the legs were really out of kilter. I wondered if this was
responsible for the poor guiding.
Another new thing was going with a different connection between the autoguider and the mount.
Instead of using the standard ST-4 port connected to the autoguider camera, I went
through a USB-to-Serial interface, then to the RS-232 port of the mount. I dunno.
After doing some test autoguides, it might have been better. The RA guiding did
seem better, but the Dec guiding was still giving me some fits. Overall it might have
been better. It's hard to say. Except that I never lost the guide star.
In any event, guiding through the RS-232 connection worked and I'll probably stick with it.
I was done with the Orion shots around 1:30 AM when the moon made it's appearance.
I decided to try to image the Cone nebula using Dithering. Man, I just had problems.
The procedure of getting dithering going involves turning on the server in PHD2,
shutting PHD2 down, then restarting PHD2 and going about calibrating as usual.
What I found was that PHD2 would often just hang after connecting to the camera
and mount. What gives? I would have to CTRL-ALT-DEL to shut down the program
and the Astro-Physics driver which controls the mount.
I tried multiple different approaches. At one point, the QHY5L-II guider wasn't
even showing a red light. I'd have to unplug it and replug it in. Sometimes that would
allow the camera to show up, but other times, the camera just wasn't cooperating.
Troubleshooting this crap with 20 degree temps and freezing hands is a pain in the ass.
Turned off and on the computer. Same problems.
At one point, my computer decided to hang.
Was it the 18 degree weather?
So, I began to be methodical and stumbled upon one instance of success.
After restarting the computer (yet again), I opened PHD2 and made sure I only connected
the camera so I could see an image. *I think* I stopped the camera, then selected a star
on the image, then I connected the mount, restarted the 2 sec images. Then I stopped,
disconnected, enabled the server, then shut down. *I think* I opened PHD2 again, then
started JUST THE CAMERA to see if I could get an image. Then hit stop, then connected
the mount (a slight delay occurs), then restarted the 2 sec images with SUCCESS. I was
then able to calibrate and begin guiding. IT WAS ONLY THEN that I started Backyard EOS.
And after loading a profile of 60 sec shots, it worked!
Earlier, I had been connecting both the camera and mount at the same time when starting PHD2.
And this leads to a hang.
Also, I had been trying PHD2 with Backyard EOS loaded in the background. I think this causes problems because PHD2 wants BYE wants to communicate with PHD2 before it's ready.
I'm not sure if I found a way to make it work OR the system just randomly decided to work one time.
It seems like if PHD2 hangs, then I need to restart the computer which is a pain.
We'll see next time. I want to try to exclusively use Dithering.
Saturday, December 13, 2014
Just a reminder to myself to align the guider camera so the X and Y-axis are lined up with
the arrows on the keypad.
https://groups.yahoo.com/neo/groups/ap-ug/conversations/topics/58067
https://groups.yahoo.com/neo/groups/ap-gto/conversations/messages/33545
Notes on gear mesh tightening: https://groups.yahoo.com/neo/groups/ap-ug/conversations/topics/56741
the arrows on the keypad.
https://groups.yahoo.com/neo/groups/ap-ug/conversations/topics/58067
https://groups.yahoo.com/neo/groups/ap-gto/conversations/messages/33545
Notes on gear mesh tightening: https://groups.yahoo.com/neo/groups/ap-ug/conversations/topics/56741
Sunday, November 30, 2014
Notes about Ground Loop (boring entry)
I want to describe a problem I had with the mount and computer setup and a problematic "buzzing" sound. I wanted to post this to remind myself of my trouble-shooting and to give folks a sense of the
technical problems that seem to regularly plague astro-photographers.
About a week ago, I connected the "big" AP mount to a 13.8 volt power supply, then connected the computer and dew heater to a 12 volt AGM battery via the 600 watt PowerBright inverter. I instantly heard a buzzing sound from the hand controller. It's not a sound I had ever heard before.
It wasn't especially loud, but it was loud enough to hear from about 2 feet away.
I re-seated the connection to the power supply a few times with no change. I slewed the
the mount around and everything seemed fine. So, I proceeded to set up for a night of
imaging.
One thing I noticed immediately was that the trackpad on the laptop was working erratically.
I couldn't move the mouse cursor anywhere but up and down. This is a problem I had
on the second night of our recent Van Vleck trip. My solution was to simply plug in a mouse.
(Need to order a rugged mouse.)
On this particular night, temps were in the mid-20's F. And I had to battle a 5-30 mph wind
so it felt much colder. I wondered if temps were affecting electronics -- though at Van Vleck,
the temps rarely were generally higher in the mid-30's and there was little wind. Why would
I see this problem at both VV and home under different conditions?
I finally had polar alignment and started to do a test track using the Tak102 and the Orion 50mm guider. The first test guiding session with PHD2 was perfect. I guess since I was having so
many little issues I wanted to make sure things were fine. Feeling confident, I centered the target
in Focus/Framing mode in Backyard EOS and started to re-calibrate the guide.
Normally, PHD2 goes through this routine where it does a bunch of North and South "steps"
to calibrate itself in one axis, then moves to the East-West "steps" to calibrate the other axis.
A good calibration generally takes about 15-20 steps in one direction before returning by going back the way it came. There can be problems when the calibration takes 40+ steps or too few steps.
PHD2 guided the mount 2 steps North, then returned. Then it guided 2-3 steps West before it finished calibration. The whole process normally take 2-5 minutes. It finished in 5-10 seconds.
Uh... What? In addition, I kept hearing "clicking sounds" from the mount. Not good.
So, my first course of action was to stop or "quit" PHD2 on the computer. Waiting, waiting,
waiting... I ctrl-alt-del'ed... Waiting. I finally "Task End"ed twice before it shut down.
I've had random weird stuff happen via PHD2 before and usually quitting and starting back
up has fixed the issue. But this time, PHD2 wouldn't even connect to the camera -- PHD2 was
stuck. So, I ctrl-alt-del'ed. Closed all programs ....waiting....Backyard EOS is not closing either.
I decided to power down the camera, unplug the usb cables, then shut everything down, then
turned off the computer. Is this a problem with temps?
For good measure, I unplugged/reseated the power. And I tried a different socket on the 600 watt inverter. Just to be sure, I disconnected any connection between the mount and the computer. The buzzing sound continued to present itself without any connection to the computer.
Reconnected. Fired everthing back up. Same behavior. During calibration, I watched the calibration (N-S, etc), and I noticed that the calibration steps were quite excessive -- so excessive at times that PHD2 would lose the guide star. I also noticed that I would occasionally lose
the camera -- it would disconnect whenever the slightest touch was applied to the cables. What
the heck!!!
After reconnecting all the cables, closing and restarting again. I fired up PHD2, completely reset the configuration, then tried a different calibration step, then tried to calibrate. I could hear the clicking
as I had heard at each previous attempt at calibration. It only took 2-3 steps and started tracking. When the mount tracks, it shows some data every time it makes an adjustment to the mount.
Normally with my setup, you see something like ".2 pixel, N 90 ms" or ".3 pixels, E 60 ms".
Now, it was showing bizarre numbers like "2 pixels, N .33 ms". ??? But it seemed like it was guiding. Though I could see the guide star move more noticeably. It seemed like this was just a bizarre settings issue.
Though I had setup around 8:30, I wasn't able to start an imaging run until 12:30 -- which meant I had easily wasted 2 hours of imaging time! I let the setup run until around 2:00, then
checked my results in BackyardEOS. It wasn't perfect, the first 15 min subexposure had trailing
stars, and another had elongated stars, but a few of them looked "acceptable" so I let it run
until 4 AM. The winds had died down to maybe 4-5 mph coming from the N to NE. And
every so often, a 15-20 mph gust would whip up so I assumed between the suspicious guiding and the random gust, I was losing good data. Out of the 13 subs, it looked like I only had maybe 6-7 good ones.
What are the possible causes for the problems?
Cold temps?
(causing the AP control box to have problems?)
(causing the computer to malfunction?)
Ground loop problem (buzzing is a symptom)?
Bad connections?
Bad power supply?
Snagged USB cable(s)?
This configuration (power supply to the mount) was new to me. I normally attach the mount to an Optima 12 volt battery. Then I either plug in the computer/camera AC adapter to an extension cord that runs to the shop OR I plug everything to a 12 v battery and 600 watt inverter. The reason for the change was that I thought the power supply might be a better source of higher voltage in colder temps. I never bothered to test either the power supply or the voltage from the inverter. It's quite possible that the cold temps (low 20's) were affecting the inverter or the power supply to the mount.
The following night I completely reverted back to connecting the mount to the 12 volt Optima battery and the computer/camera battery to the outlet. Temps were 10-12 deg warmer. Everything acted and worked normally. I even added a USB hub to prevent USB cables from having to run at 90 degrees out of the computer.
technical problems that seem to regularly plague astro-photographers.
About a week ago, I connected the "big" AP mount to a 13.8 volt power supply, then connected the computer and dew heater to a 12 volt AGM battery via the 600 watt PowerBright inverter. I instantly heard a buzzing sound from the hand controller. It's not a sound I had ever heard before.
It wasn't especially loud, but it was loud enough to hear from about 2 feet away.
I re-seated the connection to the power supply a few times with no change. I slewed the
the mount around and everything seemed fine. So, I proceeded to set up for a night of
imaging.
One thing I noticed immediately was that the trackpad on the laptop was working erratically.
I couldn't move the mouse cursor anywhere but up and down. This is a problem I had
on the second night of our recent Van Vleck trip. My solution was to simply plug in a mouse.
(Need to order a rugged mouse.)
On this particular night, temps were in the mid-20's F. And I had to battle a 5-30 mph wind
so it felt much colder. I wondered if temps were affecting electronics -- though at Van Vleck,
the temps rarely were generally higher in the mid-30's and there was little wind. Why would
I see this problem at both VV and home under different conditions?
I finally had polar alignment and started to do a test track using the Tak102 and the Orion 50mm guider. The first test guiding session with PHD2 was perfect. I guess since I was having so
many little issues I wanted to make sure things were fine. Feeling confident, I centered the target
in Focus/Framing mode in Backyard EOS and started to re-calibrate the guide.
Normally, PHD2 goes through this routine where it does a bunch of North and South "steps"
to calibrate itself in one axis, then moves to the East-West "steps" to calibrate the other axis.
A good calibration generally takes about 15-20 steps in one direction before returning by going back the way it came. There can be problems when the calibration takes 40+ steps or too few steps.
PHD2 guided the mount 2 steps North, then returned. Then it guided 2-3 steps West before it finished calibration. The whole process normally take 2-5 minutes. It finished in 5-10 seconds.
Uh... What? In addition, I kept hearing "clicking sounds" from the mount. Not good.
So, my first course of action was to stop or "quit" PHD2 on the computer. Waiting, waiting,
waiting... I ctrl-alt-del'ed... Waiting. I finally "Task End"ed twice before it shut down.
I've had random weird stuff happen via PHD2 before and usually quitting and starting back
up has fixed the issue. But this time, PHD2 wouldn't even connect to the camera -- PHD2 was
stuck. So, I ctrl-alt-del'ed. Closed all programs ....waiting....Backyard EOS is not closing either.
I decided to power down the camera, unplug the usb cables, then shut everything down, then
turned off the computer. Is this a problem with temps?
For good measure, I unplugged/reseated the power. And I tried a different socket on the 600 watt inverter. Just to be sure, I disconnected any connection between the mount and the computer. The buzzing sound continued to present itself without any connection to the computer.
Reconnected. Fired everthing back up. Same behavior. During calibration, I watched the calibration (N-S, etc), and I noticed that the calibration steps were quite excessive -- so excessive at times that PHD2 would lose the guide star. I also noticed that I would occasionally lose
the camera -- it would disconnect whenever the slightest touch was applied to the cables. What
the heck!!!
After reconnecting all the cables, closing and restarting again. I fired up PHD2, completely reset the configuration, then tried a different calibration step, then tried to calibrate. I could hear the clicking
as I had heard at each previous attempt at calibration. It only took 2-3 steps and started tracking. When the mount tracks, it shows some data every time it makes an adjustment to the mount.
Normally with my setup, you see something like ".2 pixel, N 90 ms" or ".3 pixels, E 60 ms".
Now, it was showing bizarre numbers like "2 pixels, N .33 ms". ??? But it seemed like it was guiding. Though I could see the guide star move more noticeably. It seemed like this was just a bizarre settings issue.
Though I had setup around 8:30, I wasn't able to start an imaging run until 12:30 -- which meant I had easily wasted 2 hours of imaging time! I let the setup run until around 2:00, then
checked my results in BackyardEOS. It wasn't perfect, the first 15 min subexposure had trailing
stars, and another had elongated stars, but a few of them looked "acceptable" so I let it run
until 4 AM. The winds had died down to maybe 4-5 mph coming from the N to NE. And
every so often, a 15-20 mph gust would whip up so I assumed between the suspicious guiding and the random gust, I was losing good data. Out of the 13 subs, it looked like I only had maybe 6-7 good ones.
What are the possible causes for the problems?
Cold temps?
(causing the AP control box to have problems?)
(causing the computer to malfunction?)
Ground loop problem (buzzing is a symptom)?
Bad connections?
Bad power supply?
Snagged USB cable(s)?
This configuration (power supply to the mount) was new to me. I normally attach the mount to an Optima 12 volt battery. Then I either plug in the computer/camera AC adapter to an extension cord that runs to the shop OR I plug everything to a 12 v battery and 600 watt inverter. The reason for the change was that I thought the power supply might be a better source of higher voltage in colder temps. I never bothered to test either the power supply or the voltage from the inverter. It's quite possible that the cold temps (low 20's) were affecting the inverter or the power supply to the mount.
The following night I completely reverted back to connecting the mount to the 12 volt Optima battery and the computer/camera battery to the outlet. Temps were 10-12 deg warmer. Everything acted and worked normally. I even added a USB hub to prevent USB cables from having to run at 90 degrees out of the computer.
Thursday, October 9, 2014
NGC 925 REDO
So I guess I was right about the bad data ruining my NGC 925 shot. Well, "ruining" may be too strong of a verb. I re-stacked the frames only taking exposures that were 21 degrees and cooler. As an experiment, I did a stack without BIAS frames and a stack with BIAS frames, but no dark frames. Both resulted in a cleaner image with noticeably less noise which meant I could push the image further in terms of pulling out small detail in the galaxy's arms.
While I was getting more exposures in my original stack, I was basically ADDING UNNECESSARY NOISE with all those exposures between 22-29 degrees celsius. I immediately started researching ways to non-invasively cool the Canon T3i. About a year ago, I bought some aluminum sheet and a cooler to make one of Gary Honis's DSLR coolers. But I wonder if I would get the same result by simply attaching the peltier/heatsink/fan combo to the back of the camera using the tripod socket? Hm... I'm going to have to figure something out since every time it dips above 45 degrees F my camera has heat stroke.
Anyways, here's the processed shot of NGC 925 using better data:
So get this... this is 61 x 600 sec light frames, NO DARK FRAMES, 20 flat frames, and 44 bias frames!!! Brought into Lightroom and Photoshop. This is about a 70% crop of the original image.
This image is ever-so slightly less noisy than the version with dark frames and no bias frames.
Weird.
Anyways, here's an even tighter crop:
While I was getting more exposures in my original stack, I was basically ADDING UNNECESSARY NOISE with all those exposures between 22-29 degrees celsius. I immediately started researching ways to non-invasively cool the Canon T3i. About a year ago, I bought some aluminum sheet and a cooler to make one of Gary Honis's DSLR coolers. But I wonder if I would get the same result by simply attaching the peltier/heatsink/fan combo to the back of the camera using the tripod socket? Hm... I'm going to have to figure something out since every time it dips above 45 degrees F my camera has heat stroke.
Anyways, here's the processed shot of NGC 925 using better data:
So get this... this is 61 x 600 sec light frames, NO DARK FRAMES, 20 flat frames, and 44 bias frames!!! Brought into Lightroom and Photoshop. This is about a 70% crop of the original image.
This image is ever-so slightly less noisy than the version with dark frames and no bias frames.
Weird.
Anyways, here's an even tighter crop:
It's cool to pick out all the little galaxies in the background. I can make out about 25 in this close-up crop.
Wednesday, October 8, 2014
Trying to Push Forward... M33, IC 405 (Flaming Star Nebula), and NGC 925
I've been trying to ride the momentum of the Van Vleck trip by taking a few shots back home. I upped the ante by going for multiple nights on 3 targets. I also switched scopes -- going back to the Tak 102 with the Televue .8x Focal Reducer/Flattener. One of the things I immediately noticed was that the flattener tends to enlarge the size of the stars in the image. I noticed this when I did a test shot of M45 (Pleiades) and the stars were gigantic. But I figured I would just move forward and see what I could I get.
My first target was M33 -- the big galaxy in Triangulum:
This is one of the largest galaxies in the sky -- next to M31 (Andromeda) and the Large and Small Magellanic Clouds. It's about 2.7 million light years away so the image you're seeing is what it looked like 2.7 million years ago! All things considered, it's actually right next door compared to most of the small galaxies you can view through a telescope.
The shot is 64 x 5 minute images at 1600 ISO through the Takahashi 102 @ F/6.4 (w/.8x Focal Reducer/Flattener - part #RFL-4087). I collected the data over three nights - around 360 minutes total. But I let Deep Sky Stacker take the best 64 frames (5 hours, 20 minutes). Everything is riding on the AP900 and the QHY 5II-L is guiding through the Orion Miniguider mounted to the scope.
It took me several attempts (maybe 8-9 hours) of processing to get this version which I'm OK with. I'm happy that the H-a regions (red areas) in the arms came out pretty well. The brightest H-a region (NGC 604) located in the lower right of the image is obviously blown out. A more fastidious imager would reshoot about 40 - 1 minute shots. :/ There are several globular clusters visible -- but they appear as stars. Also, there are a couple of interesting blue nebulae visible -- most noticeable is IC 132 in the lower middle part of the image.
My approach during the 6 days of imaging was to try to shoot one target for a few hours in the early evening (9:30 to midnight) and then another target for later (1 AM - 4:30 AM). For M33, this meant about 2-3 hours early in the evening for three nights. Unfortunately, after the first night, I got hit by an intestinal bug and I had to bow out for 2 nights to recover. However, the first night I did collect data on M33 and IC 405.
When I finally got out again, the weather turned out to be unstable after midnight for two nights in a row. So I only ended up collecting 50 five minute frames of IC 405 (Flaming Star Nebula) which is located in Auriga. Of the 50 frames, I only stacked 42 frames (210 minutes) which is really not enough.
This shot also consisted of 24 darks, 22 flats, and 20 bias frames. It's also a 75 percent crop of the original image. The right side of the nebula is noisy and was only barely visible on the single frames that I was collecting. Everything else equipment wise is the same as the M33 shot.
The nice thing about 5 minute exposures is that I have a lot of darks and bias frames from previous outings. That means I can get to processing immediately after I take my flat images.
So after looking at these two images and thinking about a comment someone made on Cloudynights about shooting at least 6 hours on a target, I decided to really collect a lot of data on a fainter galaxy. My target was NGC 925 which is located in Triangulum, the same constellation that contains M33.
As the galaxy is relatively small, I opted to forgo the focal reducer and shoot at the native F/8 of the Tak 102.
My first target was M33 -- the big galaxy in Triangulum:
This is one of the largest galaxies in the sky -- next to M31 (Andromeda) and the Large and Small Magellanic Clouds. It's about 2.7 million light years away so the image you're seeing is what it looked like 2.7 million years ago! All things considered, it's actually right next door compared to most of the small galaxies you can view through a telescope.
The shot is 64 x 5 minute images at 1600 ISO through the Takahashi 102 @ F/6.4 (w/.8x Focal Reducer/Flattener - part #RFL-4087). I collected the data over three nights - around 360 minutes total. But I let Deep Sky Stacker take the best 64 frames (5 hours, 20 minutes). Everything is riding on the AP900 and the QHY 5II-L is guiding through the Orion Miniguider mounted to the scope.
It took me several attempts (maybe 8-9 hours) of processing to get this version which I'm OK with. I'm happy that the H-a regions (red areas) in the arms came out pretty well. The brightest H-a region (NGC 604) located in the lower right of the image is obviously blown out. A more fastidious imager would reshoot about 40 - 1 minute shots. :/ There are several globular clusters visible -- but they appear as stars. Also, there are a couple of interesting blue nebulae visible -- most noticeable is IC 132 in the lower middle part of the image.
My approach during the 6 days of imaging was to try to shoot one target for a few hours in the early evening (9:30 to midnight) and then another target for later (1 AM - 4:30 AM). For M33, this meant about 2-3 hours early in the evening for three nights. Unfortunately, after the first night, I got hit by an intestinal bug and I had to bow out for 2 nights to recover. However, the first night I did collect data on M33 and IC 405.
When I finally got out again, the weather turned out to be unstable after midnight for two nights in a row. So I only ended up collecting 50 five minute frames of IC 405 (Flaming Star Nebula) which is located in Auriga. Of the 50 frames, I only stacked 42 frames (210 minutes) which is really not enough.
The nice thing about 5 minute exposures is that I have a lot of darks and bias frames from previous outings. That means I can get to processing immediately after I take my flat images.
So after looking at these two images and thinking about a comment someone made on Cloudynights about shooting at least 6 hours on a target, I decided to really collect a lot of data on a fainter galaxy. My target was NGC 925 which is located in Triangulum, the same constellation that contains M33.
As the galaxy is relatively small, I opted to forgo the focal reducer and shoot at the native F/8 of the Tak 102.
Shooting at F/8 presents its set of challenges. Being used to F/5.6 on the 80mm scope and F/6.4 on the Tak, I had to shoot longer exposures. I opted for 10 minute shots. Over the course of 4 nights, I collected 80 shots and Deep Sky Stacker culled the best 72 minutes. I also used 160 darks, 40 flats, and 120 bias frames. It took me 3 days to get those darks!
As the single frames were coming in, I thought it looked promising:
But honestly, I thought the final stacked image had A LOT of noise considering the 720 minutes (12 hours) of data! In a way, I consider the NGC 925 shot a failure. Where is all the detail? I know part of the issue is that about 1/2 of the frames came in at 22-29 degrees celsius. I had one warm night (in the low 50's) that seemed to wreak havoc on the sensor. I suppose I should try re-stacking only the cooler frames (below 20 deg c) and see if I get anything better.
The other issue here might simply be scale. On Cloudynights, there was a guy recently who shot this same target with his 8" F/8 Ritchey-Chretien scope. Although he only shot around 5 hours, he got tons more detail in the arms of the galaxy. So, that makes me think that I was just shooting the wrong focal length.
"We're gonna need a bigger boat."
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