So everything worked last night but the seeing was awful. It started like the previous night with total PHD2 guiding numbers around .8 then progressively got worse until I hit 1.9 (!!!) by 3 am.
Stars were consistently shimmering to the south and all of the bright stars of Sagittarius were twinkling. When watching PHD2, the guide star would sometimes move dramatically enough to see it move on the screen. I've seen much worse nights, but it was pretty awful.
I turned on PEC and I assume it helped? I dunno. I didn't have that weird issue from the previous session.
The focusing strategy worked pretty well and I only needed to focus once in the middle of the session. At the end, I could tell it was getting slightly out of focus so to hedge my bet, I added hand warmers around the lens cell. Partly I was doing it because it was getting noticeably humid, but I thought it might mitigate focal length change as well.
It's always something with astrophotography.
Friday, June 28, 2019
Thursday, June 27, 2019
PEC was a bust and a note on focusing
After recording the periodic error in the AP1200, I was very excited to try it out. Last night, I started my O3 imaging run of M16 and turned on PEC. (Called "PEM" in the settings.) It was a very odd result. There were these periodic large excursions in the DEC that only happened above the "zero line" in the PHD2 graph. The first two 20 min exposures were pretty decent -- except for vertically stretched stars! :(
The other thing to note is that when the large excursions DIDN'T happen, the guiding was really good. I'm guessing like .3 arc sec error in both DEC and RA.
So here's where my lack of methodical troubleshooting comes into play: the other time I've seen
this kind of error was when I was shooting my 135mm lens and had no way to lock down the lens and when the lens was "sideways", I had these oblong stars. My theory then was simply that there was "sideways" creep which corresponds to tiny slippage coincident with the DEC axis.
On a weird hunch, I tried moving the Dec axis by hand and it easily moved! So I tightened
down the knobs that hold the DEC in place. But to hedge my bet, I also turned off PEC. Well,
it went back to the old predictable behavior and the stars were basically round again. But my guiding was around .6 to .8 for both DEC and RA. The stars were noticeably shimmering.
The thing to note is that I did TWO things to address the issue and I'm sure only one of them actually fixed it. In my next session, I'd like to try PEC again but I need to make sure the DEC is tightly locked down.
Another thing I wanted to note was my focus behavior with the bahtinov mask. So, I always
start the imaging run with a bahtinov focus run which can take like 10-15 minutes because I have to use 30 sec exposures due to dimness of the O3 data. I put some tape down on the focuser tube so I can get pretty close. Because the focuser slips easily (ARGGGGGHHHHHHHH!!!!!), I have go through many more iterations of unlocking/relocking the focuser than I would with a decent focuser. About every 3 exposures (1 hour), I will focus the image.
So, my initial understanding is that as the temperature drops, the metal contracts, right? Right?!?!? This would imply that I would have to move the camera just a tiny bit further away, right? Well, for some reason, I have to do the opposite -- I have to move the camera CLOSER in toward the objective. This has been a curious mystery to me.
My only theory about this is that the spacing in the triplet lens does shrink which causes the focal point to move back. That sounds crazy to me but that may be what's happening.
Regardless, I've wondered if I can improve my focusing routine. So when I start an exposure after focusing, I'm "perfectly" in focus. So after time, it can only get worse. When using 20 min exposures and falling night temperatures, I'm probably slightly out of focus at the end of the 20 minutes. By letting SGP Pro do a second exposure, I'm pretty much guaranteeing that it will be slightly out of focus. So, I've thought about going slightly "closer in", then starting a run of 3 exposures so it "falls into" focus somewhere in the second exposure. It's very time consuming to focus so I feel like I need something to keep me from spending half the night focusing.
[Later: To do this, I have to look at the bahtinov pattern and figure out which "lobe" is smaller WHEN the focus tube is too far INSIDE -- meaning closer to the objective lens. Then settle on this slightly INSIDE focus so that as temperatures fall, it will become ideally focused. I don't know if this is a bad plan or what. I also would need to check temps to see how much of temperature drop requires a focus adjustment.]
The other thing to note is that when the large excursions DIDN'T happen, the guiding was really good. I'm guessing like .3 arc sec error in both DEC and RA.
So here's where my lack of methodical troubleshooting comes into play: the other time I've seen
this kind of error was when I was shooting my 135mm lens and had no way to lock down the lens and when the lens was "sideways", I had these oblong stars. My theory then was simply that there was "sideways" creep which corresponds to tiny slippage coincident with the DEC axis.
On a weird hunch, I tried moving the Dec axis by hand and it easily moved! So I tightened
down the knobs that hold the DEC in place. But to hedge my bet, I also turned off PEC. Well,
it went back to the old predictable behavior and the stars were basically round again. But my guiding was around .6 to .8 for both DEC and RA. The stars were noticeably shimmering.
The thing to note is that I did TWO things to address the issue and I'm sure only one of them actually fixed it. In my next session, I'd like to try PEC again but I need to make sure the DEC is tightly locked down.
Another thing I wanted to note was my focus behavior with the bahtinov mask. So, I always
start the imaging run with a bahtinov focus run which can take like 10-15 minutes because I have to use 30 sec exposures due to dimness of the O3 data. I put some tape down on the focuser tube so I can get pretty close. Because the focuser slips easily (ARGGGGGHHHHHHHH!!!!!), I have go through many more iterations of unlocking/relocking the focuser than I would with a decent focuser. About every 3 exposures (1 hour), I will focus the image.
So, my initial understanding is that as the temperature drops, the metal contracts, right? Right?!?!? This would imply that I would have to move the camera just a tiny bit further away, right? Well, for some reason, I have to do the opposite -- I have to move the camera CLOSER in toward the objective. This has been a curious mystery to me.
My only theory about this is that the spacing in the triplet lens does shrink which causes the focal point to move back. That sounds crazy to me but that may be what's happening.
Regardless, I've wondered if I can improve my focusing routine. So when I start an exposure after focusing, I'm "perfectly" in focus. So after time, it can only get worse. When using 20 min exposures and falling night temperatures, I'm probably slightly out of focus at the end of the 20 minutes. By letting SGP Pro do a second exposure, I'm pretty much guaranteeing that it will be slightly out of focus. So, I've thought about going slightly "closer in", then starting a run of 3 exposures so it "falls into" focus somewhere in the second exposure. It's very time consuming to focus so I feel like I need something to keep me from spending half the night focusing.
[Later: To do this, I have to look at the bahtinov pattern and figure out which "lobe" is smaller WHEN the focus tube is too far INSIDE -- meaning closer to the objective lens. Then settle on this slightly INSIDE focus so that as temperatures fall, it will become ideally focused. I don't know if this is a bad plan or what. I also would need to check temps to see how much of temperature drop requires a focus adjustment.]
Tuesday, June 25, 2019
More O3 Data, SkySafari and PEMPro
Decided to get out and try to collect more data last night and had the same problems with M16 being confusing for the mount. Earlier in the evening, I had figured out how to hook up SkySafari Pro via my cellphone.
Initially, I thought this would be my salvation. But whenever I opened SkySafari and connected
it to the mount, it thought I was pointing at the southern horizon. When I moved the scope via the arrow buttons and aligned it on a known object, the EAST button on the screen wouldn't work. AND the goto function wouldn't work. Also, the CP4 controller on the mount showed a yellow light which indicates an error in the controller. WTF.
This also means that I have to uplug everything to connect SkySafari again. And even then, SkySafari sometimes would throw up a connection error. The trick to resetting everything was to first disconnect the battery to the mount >sigh<, then forget the WIFI connection to the CP4 controller which means I have to type the password in again. Then I would be back to SQUARE ONE, which means I've wasted 15 minutes of my life... yet again.
After wasting two hours on this nonsense, I ended up just manually pointing the scope to M16. On a lark, I tried connecting SkySafari and it did align! And the GTO driver in windows showed the correct coordinates for M16. WTF. Anyways, I proceeded to collect about 4 x 20 min frames and the moon showed up at the beginning of the last frame.
At this point, I was poking around the driver settings and it was set to AP900 and CP3. >sigh<
I was really tired at this point and I don't know if I changed the driver settings to AP1200 and CP4 before my last attempt to connect to SkySafari or not. IF I did change it before my last attempt to connect to SkySafari that would suggest a "rational" explanation as to why SkySafari didn't work. But rational explanations sometimes seem a scarce commodity at midnight.
One thing that did happen was that when I hit goto on SkySafari it wanted to do a Meredian Flip which I let it do. Judging on the orientation of the scope, it seemed like it had another good hour before having to flip. I had to "sheppard" the cables as it flipped and it reminded me how far I was from having an "automated setup". I decided to collect one more frame even with the 50% illuminated moon just to see if the image was okay. It was okay.
So, I was sitting there at 3:15-ish am thinking I should pack up. But earlier I had noticed my PEMPro shortcut on the desktop and I thought I should give it a shot. Though exhausted, I fired it up and saw a message about my trial being expired! I paid for PEMPro like a year ago and when it asked me if I wanted to download the latest version, I expected nothing to work.
Well, it did work. But of course there were issues. The default configuration seems to want to connect to PHD2 and use the guide camera. Well, I encountered a whole host of errors and troubleshooting took another 30 minutes. I had tried this a year ago and I had to download a special version of PHD2 that was compatible with PEMPro. Well... it seemed like PEMPro was trying to connect with my regular version of PHD2 and I couldn't figure out how to point it to the special version. >more sighs<
Eventually, I switched the camera from PHD2 to the main ATIK camera and everything basically worked from there. I wish I had made a screenshot, but I was able to record a 10 arc sec periodic error (from peak to peak). Then I was able to program the correction into the CP4 mount controller.
Now, I get to finally use "PEM" in the GTO drivers the next time I fire up the mount! I'm pretty sure the PEC will get the error down to 4 arc seconds which is just a guess based on online accounts of how much PEC can help. :)
Initially, I thought this would be my salvation. But whenever I opened SkySafari and connected
it to the mount, it thought I was pointing at the southern horizon. When I moved the scope via the arrow buttons and aligned it on a known object, the EAST button on the screen wouldn't work. AND the goto function wouldn't work. Also, the CP4 controller on the mount showed a yellow light which indicates an error in the controller. WTF.
This also means that I have to uplug everything to connect SkySafari again. And even then, SkySafari sometimes would throw up a connection error. The trick to resetting everything was to first disconnect the battery to the mount >sigh<, then forget the WIFI connection to the CP4 controller which means I have to type the password in again. Then I would be back to SQUARE ONE, which means I've wasted 15 minutes of my life... yet again.
After wasting two hours on this nonsense, I ended up just manually pointing the scope to M16. On a lark, I tried connecting SkySafari and it did align! And the GTO driver in windows showed the correct coordinates for M16. WTF. Anyways, I proceeded to collect about 4 x 20 min frames and the moon showed up at the beginning of the last frame.
At this point, I was poking around the driver settings and it was set to AP900 and CP3. >sigh<
I was really tired at this point and I don't know if I changed the driver settings to AP1200 and CP4 before my last attempt to connect to SkySafari or not. IF I did change it before my last attempt to connect to SkySafari that would suggest a "rational" explanation as to why SkySafari didn't work. But rational explanations sometimes seem a scarce commodity at midnight.
One thing that did happen was that when I hit goto on SkySafari it wanted to do a Meredian Flip which I let it do. Judging on the orientation of the scope, it seemed like it had another good hour before having to flip. I had to "sheppard" the cables as it flipped and it reminded me how far I was from having an "automated setup". I decided to collect one more frame even with the 50% illuminated moon just to see if the image was okay. It was okay.
So, I was sitting there at 3:15-ish am thinking I should pack up. But earlier I had noticed my PEMPro shortcut on the desktop and I thought I should give it a shot. Though exhausted, I fired it up and saw a message about my trial being expired! I paid for PEMPro like a year ago and when it asked me if I wanted to download the latest version, I expected nothing to work.
Well, it did work. But of course there were issues. The default configuration seems to want to connect to PHD2 and use the guide camera. Well, I encountered a whole host of errors and troubleshooting took another 30 minutes. I had tried this a year ago and I had to download a special version of PHD2 that was compatible with PEMPro. Well... it seemed like PEMPro was trying to connect with my regular version of PHD2 and I couldn't figure out how to point it to the special version. >more sighs<
Eventually, I switched the camera from PHD2 to the main ATIK camera and everything basically worked from there. I wish I had made a screenshot, but I was able to record a 10 arc sec periodic error (from peak to peak). Then I was able to program the correction into the CP4 mount controller.
Now, I get to finally use "PEM" in the GTO drivers the next time I fire up the mount! I'm pretty sure the PEC will get the error down to 4 arc seconds which is just a guess based on online accounts of how much PEC can help. :)
More Weird Problems with the Mount and Scope
So, I was writing an email to Charles where I was trying to figure
out my recent goto problems. I decided not to bore him with my
imaging travails so I'm simply cutting from the email and pasting it
here:
Speaking of 75% confidence in astrophotography (my number is like 50%), I've been having this crazy problem with the AP900 and goto. For the last 4-5 times I've used
the mount, the goto's will be fine. But for a few objects like M16 (Eagle), I'll get an error "-45 below horizon". I keep thinking that the mount got confused as to where it is.
But when I look at the mount's coordinates, it's all accurate. And I can slew to things around M16 which seems crazy because then when I type in M16, it gives the error again.
SO, I manually pointed the scope/mount at M16 and hit "sync". When I look at the coordinates, it thinks the object is at -45 declination! It's actually at around -19. So,
my working theory is that the database in the hand controller has been corrupted for some targets. When my laptop is connected to the mount, it looks like the hand controller information
trumps everything else so when I try to slew to M16 via my imaging software, I get all kinds of weird errors. So, my plan is to replace the battery for the hand controller and
update the handcontroller firmware.
Fun times with telescopes...
Speaking of 75% confidence in astrophotography (my number is like 50%), I've been having this crazy problem with the AP900 and goto. For the last 4-5 times I've used
the mount, the goto's will be fine. But for a few objects like M16 (Eagle), I'll get an error "-45 below horizon". I keep thinking that the mount got confused as to where it is.
But when I look at the mount's coordinates, it's all accurate. And I can slew to things around M16 which seems crazy because then when I type in M16, it gives the error again.
SO, I manually pointed the scope/mount at M16 and hit "sync". When I look at the coordinates, it thinks the object is at -45 declination! It's actually at around -19. So,
my working theory is that the database in the hand controller has been corrupted for some targets. When my laptop is connected to the mount, it looks like the hand controller information
trumps everything else so when I try to slew to M16 via my imaging software, I get all kinds of weird errors. So, my plan is to replace the battery for the hand controller and
update the handcontroller firmware.
Fun times with telescopes...
Friday, June 7, 2019
Notes on Sequence Generator Pro and Atik One CCD camera
This is just another "note to self" entry as I'm working out some bugs in using SGP with the Atik One. There seems to be a problem with the drivers getting confused with two ATIK cameras.
I'm shooting with the ATIK One CCD, but the guide camera on the OAG is a ATIK GP camera.
For some stupid reason, when SGP automates the sequence, there is some kind of driver conflict with the GP guide camera.
Either the guide camera doesn't show images in PHD2 (which results in the warning that it's been over 15 seconds) or it throws up an error message about temperature control. The latter is ridiculous because the GP camera is NOT a cooled camera. I had this problem years ago and apparently, ATIK hasn't fixed it.
So, my solution has been to start PHD2 first, getting the loop from the images going, THEN firing up SGP. This seems to be a viable, but stupid work-around. This work-around creates a weird situation where I have to go back and forth with the plate solve and sync.
Oh, the other inane issue I've been having is that when SGP is trying to slew to the target (M16), it starts to move the scope so it points to the ground; or the mount tries to head for a collision with the pier. What a crock. The problem seems to be correlated with having BOTH the keypad and SGP connected to the mount at the same time.
In a related vein, I was having a weird newbie problem of not being to sync the mount AFTER
a plate solve. By the way, I'm getting better at plate solving with the Planewave software as well the the easier Astrometry.net solve. I was desperately searching, "How to sync in SGP with Astro-Physics mount," to no avail. It's in one of the control panel menus for the mount/telescope.
Right now, I'm running a 20 min. test on M16 with O3 filters. Who knows if it will work out.
Later... Need to replace the focuser. There's so much focus creep with the ES80 scope.
I probably spent two hours tonight just getting focus to be decent -- only to have it
go out when I accidentally touch the camera. :/
Later, later... Also, there's problems with the Televue reducer which keeps partially slipping out of the focuser because the focuser tightening ring can't quite grasp the grooves in the reducer.
Also, looking at the first 20 min O3 exposures, I'm disappointed as the stars are very large.
I added a space between the OAG and the reducer which adds about 8-10 mm of distance.
I did this because the specs on the reducer called for about 56mm. Now, I'm not sure what
spacers (if any) I used at Kentucky camp. I wonder if I should try it to remove the spacer
and compare the stars. Hm...
Later, later, later... Just realized my spacer takes up too much distance. I need like 5 mm which is about 3/16 of an inch. I currently have something like a 3/8 of an inch. >sigh< This is the reason the stars are goofy.
[Next day...]
Okay, so I tried to connect the 3mm spacer, but the threaded "neck" coming out of the TV reducer is so long that it always maintains about 7 mm of space regardless. So I was trying to reconstruct what I was using at Kentucky camp and I think it was this spacing. I found a Baader 7.5mm spacer that had written on it something like 'To connect Atik One to reducer'. When I put on the 7.5mm spacer, it took up the same amount of space as the 3mm spacer! So there is not really an easy way to create the 56mm ideal spacing between the reducer and the sensor. The threaed "neck" looks like it takes up 5mm by itself. What I would need is basically an adapter which would look like a 6-6.5mm tube and then a male-female adapter for t-thread. That's too complicated.
Basically I need a different reducer OR a custom-made ($$$$) OAG which takes up less space.
A different reducer is much cheaper.
I'm going to push through the O3 data tonight and see if it's worth continuing. The data looks disappointing in general. That's ANOTHER thing: I'm shooting 20 min subs at -15 deg. Since it's so warm outside, the camera is having a hard time maintaining that temp. But the subs look sorta noisy and not so sharp even the though the guiding has been fine.
I'm shooting with the ATIK One CCD, but the guide camera on the OAG is a ATIK GP camera.
For some stupid reason, when SGP automates the sequence, there is some kind of driver conflict with the GP guide camera.
Either the guide camera doesn't show images in PHD2 (which results in the warning that it's been over 15 seconds) or it throws up an error message about temperature control. The latter is ridiculous because the GP camera is NOT a cooled camera. I had this problem years ago and apparently, ATIK hasn't fixed it.
So, my solution has been to start PHD2 first, getting the loop from the images going, THEN firing up SGP. This seems to be a viable, but stupid work-around. This work-around creates a weird situation where I have to go back and forth with the plate solve and sync.
Oh, the other inane issue I've been having is that when SGP is trying to slew to the target (M16), it starts to move the scope so it points to the ground; or the mount tries to head for a collision with the pier. What a crock. The problem seems to be correlated with having BOTH the keypad and SGP connected to the mount at the same time.
In a related vein, I was having a weird newbie problem of not being to sync the mount AFTER
a plate solve. By the way, I'm getting better at plate solving with the Planewave software as well the the easier Astrometry.net solve. I was desperately searching, "How to sync in SGP with Astro-Physics mount," to no avail. It's in one of the control panel menus for the mount/telescope.
Right now, I'm running a 20 min. test on M16 with O3 filters. Who knows if it will work out.
Later... Need to replace the focuser. There's so much focus creep with the ES80 scope.
I probably spent two hours tonight just getting focus to be decent -- only to have it
go out when I accidentally touch the camera. :/
Later, later... Also, there's problems with the Televue reducer which keeps partially slipping out of the focuser because the focuser tightening ring can't quite grasp the grooves in the reducer.
Also, looking at the first 20 min O3 exposures, I'm disappointed as the stars are very large.
I added a space between the OAG and the reducer which adds about 8-10 mm of distance.
I did this because the specs on the reducer called for about 56mm. Now, I'm not sure what
spacers (if any) I used at Kentucky camp. I wonder if I should try it to remove the spacer
and compare the stars. Hm...
Later, later, later... Just realized my spacer takes up too much distance. I need like 5 mm which is about 3/16 of an inch. I currently have something like a 3/8 of an inch. >sigh< This is the reason the stars are goofy.
[Next day...]
Okay, so I tried to connect the 3mm spacer, but the threaded "neck" coming out of the TV reducer is so long that it always maintains about 7 mm of space regardless. So I was trying to reconstruct what I was using at Kentucky camp and I think it was this spacing. I found a Baader 7.5mm spacer that had written on it something like 'To connect Atik One to reducer'. When I put on the 7.5mm spacer, it took up the same amount of space as the 3mm spacer! So there is not really an easy way to create the 56mm ideal spacing between the reducer and the sensor. The threaed "neck" looks like it takes up 5mm by itself. What I would need is basically an adapter which would look like a 6-6.5mm tube and then a male-female adapter for t-thread. That's too complicated.
Basically I need a different reducer OR a custom-made ($$$$) OAG which takes up less space.
A different reducer is much cheaper.
I'm going to push through the O3 data tonight and see if it's worth continuing. The data looks disappointing in general. That's ANOTHER thing: I'm shooting 20 min subs at -15 deg. Since it's so warm outside, the camera is having a hard time maintaining that temp. But the subs look sorta noisy and not so sharp even the though the guiding has been fine.
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