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Minor Phd2 guiding issue

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#1 chuckscap

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Posted 03 July 2020 - 11:24 AM

I've just started using PHD2.  My main scope is a TV-101, guide scope is a ZWO ASI224MC, and mount is an AP900GTO CP2.  Things seem to be working fine except the exposure scale in PHD2 seems off by an order of magnitude.  If I set it to 2 seconds, the screen goes totally white like I was trying to image during daytime not pointed at the sun.   0.2 secs is as high as I can go.  At 0.2 seconds the star stands out in black background and I'm getting about 60dB SNR.  PHD2 recognizes the mount and the camera as ASI (not the model).  I haven't run Guide Assistant yet.  I did do a successful calibration and RA and DEC values were both sub pixel (about 1.4 arc seconds).   I was about to assess my polar alignment using "Drift Align" but of course the clouds rolled in. Should I just be setting the camera's exposure, gain settings, etc. using the ASIStudio then run PHD2?  Before I can add a dark frame I need to understand the exposure issue.

 

Thanks!

 

Chuck



#2 Tapio

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Posted 03 July 2020 - 11:32 AM

What is your guide scope or are you using OAG ?

Are you using ASCOM driver or native driver ?

Check brain icon, Advanced setting - Camera - Gain (lower it if you can).


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#3 johnoelliott

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Posted 03 July 2020 - 11:34 AM

Very odd.

 

You do have Ascom and the correct ASI Ascom drivers installed?

 

PHD2 has no problem correctly identifying my ASI 120mm



#4 OldManSky

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Posted 03 July 2020 - 11:40 AM

You *choose* the mount in PHD2 -- it doesn't just "recognize" it automatically.  So in the "Connect" screen, drop down the mount chooser, and find the AP ASCOM driver listed.  Choose that.

For the guide camera, I would suggest using the ASI ASCOM driver instead of the "native" ASI driver -- that native driver in PHD2 recognizes and works with some ASI cameras, but not all.  Choose the ASI ASCOM selection, but before hitting the "Connect" button, hit the ASCOM settings button (the tool icon).  Make sure it's got your camera listed.  And while you're there, set the gain lower than it is, and that will probably take care of your white screen with normal exposures issue.  



#5 chuckscap

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Posted 03 July 2020 - 11:48 AM

Thanks for the quick responses.   My guide scope is an EVO 50ED.   I have the correct ASCOM driver for my mount loaded that all works great. I can move it using the ASCOM interface.  It reads out the RA/DEC.  I can set the various parameters like I do from the hand controller. I will try the ASI ASCOM selection that's probably my problem and set the gain lower too.

 

Thanks!



#6 Alex McConahay

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Posted 03 July 2020 - 11:58 AM

>>>>>the screen goes totally white like I was trying to image during daytime not pointed at the sun

 

The brightness of the display is controlled by a slider under the screen. Move it to one side to get all white, and the other to get black. Someplace in between, where you get white stars on black, is where you want to be.  

 

Have you played with that slider and still have the problem?

 

Alex


Edited by Alex McConahay, 03 July 2020 - 11:59 AM.

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#7 chuckscap

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Posted 03 July 2020 - 12:02 PM

I have played with the slider.  That is not the issue but thanks



#8 Alex McConahay

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Posted 03 July 2020 - 01:21 PM

How about the gain on the guide camera?

SOunds like it is boosting too much. 

 

Let's put this another way....PHD2 is so widely used, and has been so for such a long time with so many different pieces of equipment, that it is unlikely bad design, bad coding, or some kind of a bug. It pretty much has to be something with the configuration or exectution.

 

Alex



#9 chuckscap

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Posted 03 July 2020 - 02:08 PM

It was definitely caused by using the generic ASI driver.  I connected the camera to my laptop and brought Sharpcap up, the gain was set at 570!  I never use a gain higher than 100.   If it clears tonight I will verify everything is good. I'm creating darks at 1, 2, 4 and 8 secs at 0, 60 and 100 gain.  I'm sure that was my issue.

 

Thanks!

 

Chuck


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#10 chuckscap

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Posted 07 July 2020 - 09:04 AM

Issue resolved.  Thank you all!  It was, as you suggested,  using the generic ZWO driver and it pegging the gain settings on my ASI224MC.  Last night it finally cleared (mostly) by 11 PM and I got a good calibration, guiding, went through the drift align program (though I used Sharpcap to align) and the guiding assistant.   Polar alignment was sub arc min, RA and Dec were around .3 pixels.  Last thing I did was guide on a star and record PEM on my AP900.   If my new camera ever comes in (bought an ASI2600MC to replace my ASI183MC which is broken and at ZWO for warranty service) I can start imaging

 

Thanks again for all of your help,

 

Chuck




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