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Can anyone make heads or tails re my AVX PHd logs?

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#26 Ballyhoo

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Posted 13 February 2019 - 11:39 AM

 It is time to move past this stumbling block and invest in a 60mm guide scope and camera. We have all gone through this in our own learning curve. Guiding is something you can not do without. I chose a ZWO guide scope and a ZWO120 camera. The return was no more guiding issues and fast and easy setup. You will also be able to use Sharpcap PA and away you go.

 There are no shortcuts in learning this hobby. It is time and patience.   

I do not need  a guide-scop per say bc I have the same ST 50mm finderscope which ST uses as a guidescop and I invested in the guidefocuser. so the only think I might need is the new camera. 



#27 Night shift

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Posted 13 February 2019 - 11:51 AM

Well that is good news. You are halfway to getting it set up. Get it done and be happy. It will reduce your learning curve substantially 

I do not need  a guide-scop per say bc I have the same ST 50mm finderscope which ST uses as a guidescop and I invested in the guidefocuser. so the only think I might need is the new camera. 



#28 Stelios

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Posted 13 February 2019 - 01:31 PM

I am not sure how to do that, Phd provides a link.

Do you have Dropbox? You could move the file there and post the link (right-click, then "Copy Dropbox Link")



#29 WadeH237

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Posted 13 February 2019 - 01:42 PM

This may sound crazy but how about if I barlow the DSI 1 guide scope?

It's not crazy, but it would likely limit your guide star choices to really bright stars.

 

Consider that a 2x barlow will require 4x longer guide exposures.

 

I think that the ASI120mm Mini at $149 seems like a reasonable next step.  I'm actually thinking about picking one up to use as the guider for my "entry level imaging rig" that I'm putting together.  It's been so long since I lived with an entry level system, that I want to play with it with modern software.  I also want to have it for star parties, so that I can share it with people that are interested in trying out astrophotography for themselves.



#30 Stelios

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Posted 13 February 2019 - 01:53 PM

This may sound crazy but how about if I barlow the DSI 1 guide scope?

 

Look, this is all about improvement and getting to a great place in the hobby.  But if the results are not currently satisfactory, what about POst #4 & 11?

 

I am not wanting to argue w anyone. I Would like to divide the "must have/must gets" on the left and on the right a "wish list."  Is a new guide camera a must or a wish?  I ask bc I know that many have, or are, guiding with the DSI 1.  

I am just looking at all sides. I can also see that I have a $1700 refactor, $1700 mount, $1000 camera, perhaps, well, is there an expression for saving money on a cheap piece of equipment when you have an otherwise valuable set-up?  "Penny wise, ... pound foolish?"

 

I do not want to rush out and get something unless I have to. But hey, if $150 will make my guiding noticeably easier, then yea

 

Regarding the cable I need: perhaps I could look at connecting the HC to the main camera, but the IEQ45 seems fickle like that.

 

Great thread,  great feedback, IMHO. Thank you all!

Yes, it's crazy. Try to avoid flights of fancy (= wasted time) in this hobby.

 

I couldn't find the specs for DSI-1 camera. Can you post them? I don't really see that the guide camera was your problem (although I'm sure the ASI120MM-mini is better). However, if the DSI-1 has no ASCOM drivers, then you should get rid of it for sure. 

 

The image in post 4 is not bad. The Orion nebula (a popular, but *extremely* tough object to do right) is both over-exposed and under-exposed. The stars look fairly decent, good eccentricity.

 

I really can't comment more till I see the log. 

 

In a previous thread I showed you how to download PhDLogView.exe which lets you create an image of your log such as:

 

ExamplePhd2logview.JPG

 

In the immortal words of Jerry McGuire: Help *us* help *you*.



#31 Ballyhoo

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Posted 13 February 2019 - 02:11 PM

Yes, it's crazy. Try to avoid flights of fancy (= wasted time) in this hobby.

 

I couldn't find the specs for DSI-1 camera. Can you post them? I don't really see that the guide camera was your problem (although I'm sure the ASI120MM-mini is better). However, if the DSI-1 has no ASCOM drivers, then you should get rid of it for sure. 

 

The image in post 4 is not bad. The Orion nebula (a popular, but *extremely* tough object to do right) is both over-exposed and under-exposed. The stars look fairly decent, good eccentricity.

 

I really can't comment more till I see the log. 

 

In a previous thread I showed you how to download PhDLogView.exe which lets you create an image of your log such as:

 

attachicon.gif ExamplePhd2logview.JPG

 

In the immortal words of Jerry McGuire: Help *us* help *you*.

https://www.dropbox....171652.txt?dl=0

 

 

https://www.dropbox....231942.txt?dl=0

 

 

EDIT:  AND HERE IS A LINK RE THE DS1

 

http://www.astronomy...5_meade_dsi.pdf

Attached Thumbnails

  • phd guidelog.gif

Edited by Ballyhoo, 13 February 2019 - 02:49 PM.


#32 Ballyhoo

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Posted 13 February 2019 - 07:36 PM

so am I golden?



#33 Stelios

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Posted 13 February 2019 - 08:41 PM

Not quite--you posted the log in such a way that I can't download it, because you didn't put it in the Public folder (my fault, I should have told you that). So I could only download (cut and paste) part of it.

 

Still, it was good enough to get an idea. (The first log is useless BTW, just a failed calibration. The second log starts with a failed followed by a perfect calibration).

 

I snipped out the bad regions to get an idea of the true performance when you are *not* losing the star and causing disasters. 

 

I was able to see the full first section and about 45 mins of the second.

 

On the first section you had about a 2.39" RMS (poor, and mainly due to two *additional* spikes--walking near the mount? touching something?).

 

On the second section you (after removing the bad region) had a 1.38" RMS (probably a bit better as it *still* included a spike that I didn't bother to remove).

 

The second result is about what I was getting on my CG-5 and can produce round (if a bit bloated) stars. You can improve on it a bit more when it's not windy, seeing is good, etc. But it doesn't appear to be due to any major mount or guiding disasters (except the spikes, probably due to clouds). I think your parameters will let you average around 1.1" guiding which is less shabby than it may sound. 

 

Some comments on your parameters:

 

Exposure: You have 1ms. If you record and enable PEC, you should be able to increase that to 2 or 3". This will make you less dependent on seeing. You can also try (instead of recording/enabling PEC) to use the PPEC instead of the hysteresis algorithm. I would experiment with the following 4 combinations:

Hysteresis at 1", Hysteresis at 2", PPEC at 1", PPEC at 2", PEC (mount) at 2". However the improvements won't be drastic--you may get it down to 0.9-1" this way though.

 

RA: see above re algorithm. I assume the MinMo is from guiding assistant (seems reasonable). Hysteresis % seems reasonable and aggression as well--maybe raise to 0.8 or 0.9 because it looks like your RA doesn't quite catch up. 

 

DEC: Consider guiding in one direction (North or South, not Auto) since you've disabled backlash compensation. The logic is that you're never *perfectly* polar aligned, so you only correct in the direction of drift away from the pole--if you overshoot, you'll eventually drift back on your own. You may want to lower aggression to 90%, for smoother adjustments.

 

Play with the things I suggested *one* at a time. However, I don't think you have major guiding issues at this point. You *do* need to be careful with PA *every* time, and it would help if you used Sharpcap. Another thing you can eventually try is to measure and enable backlash compensation. Not sure it'll work well with the AVX, but it might with the iEQ45.

 

At this point you need to work on your calibration frames. And don't image when there are clouds, unless you are stuck babying the mount. 


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#34 Ballyhoo

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Posted 13 February 2019 - 09:08 PM

I am just not sure how to enable pec. does that involve much more than a checkboxconfused1.gif ?



#35 Ballyhoo

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Posted 13 February 2019 - 09:53 PM

Not quite--you posted the log in such a way that I can't download it, because you didn't put it in the Public folder (my fault, I should have told you that). So I could only download (cut and paste) part of it.

 

Still, it was good enough to get an idea. (The first log is useless BTW, just a failed calibration. The second log starts with a failed followed by a perfect calibration).

 

I snipped out the bad regions to get an idea of the true performance when you are *not* losing the star and causing disasters. 

 

I was able to see the full first section and about 45 mins of the second.

 

On the first section you had about a 2.39" RMS (poor, and mainly due to two *additional* spikes--walking near the mount? touching something?).

 

On the second section you (after removing the bad region) had a 1.38" RMS (probably a bit better as it *still* included a spike that I didn't bother to remove).

 

The second result is about what I was getting on my CG-5 and can produce round (if a bit bloated) stars. You can improve on it a bit more when it's not windy, seeing is good, etc. But it doesn't appear to be due to any major mount or guiding disasters (except the spikes, probably due to clouds). I think your parameters will let you average around 1.1" guiding which is less shabby than it may sound. 

 

Some comments on your parameters:

 

Exposure: You have 1ms. If you record and enable PEC, you should be able to increase that to 2 or 3". This will make you less dependent on seeing. You can also try (instead of recording/enabling PEC) to use the PPEC instead of the hysteresis algorithm. I would experiment with the following 4 combinations:

Hysteresis at 1", Hysteresis at 2", PPEC at 1", PPEC at 2", PEC (mount) at 2". However the improvements won't be drastic--you may get it down to 0.9-1" this way though.

 

RA: see above re algorithm. I assume the MinMo is from guiding assistant (seems reasonable). Hysteresis % seems reasonable and aggression as well--maybe raise to 0.8 or 0.9 because it looks like your RA doesn't quite catch up. 

 

DEC: Consider guiding in one direction (North or South, not Auto) since you've disabled backlash compensation. The logic is that you're never *perfectly* polar aligned, so you only correct in the direction of drift away from the pole--if you overshoot, you'll eventually drift back on your own. You may want to lower aggression to 90%, for smoother adjustments.

 

Play with the things I suggested *one* at a time. However, I don't think you have major guiding issues at this point. You *do* need to be careful with PA *every* time, and it would help if you used Sharpcap. Another thing you can eventually try is to measure and enable backlash compensation. Not sure it'll work well with the AVX, but it might with the iEQ45.

 

At this point you need to work on your calibration frames. And don't image when there are clouds, unless you are stuck babying the mount. 

do you observe at Mt Pinos?



#36 Stelios

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Posted 14 February 2019 - 02:47 AM

do you observe at Mt Pinos?

I have in the past, but I almost always observe at the LAAS dark site nowadays (a private site for members only in Lockwood Valley, about 8 miles south of Mt. Pinos at around 6,000 ft). 

 

I am just not sure how to enable pec. does that involve much more than a checkbox confused1.gif

 

Unfortunately, PEC is a bit of a bother. See the AVX Manual pages 31 and 32. 

 

The PITA part is the recording, which only has to be done every year or so. Once you've recorded as per the instructions in that manual, enabling playback *is* as simple as a checkmark (rather selecting a menu option) but it has to be done every time (you can't default to it). 

 

Even with PEC guiding is necessary, but the mount has smaller intensity corrections it needs to make. 

 

As noted, selecting (from the PhD2 "brain" icon) PPEC rather than Hysteresis as the RA guiding algorithm simulates PEC (it's a learning process for the software, so the guiding will keep improving during the night). 

 

I *have* used PEC and results were somewhat better with it. I have *not* used the PPEC algorithm--by the time it came out I already had my Mach1.




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