APT Live View stumbling block.

[paulbromley9]

Hi All,

First night out last night, I anticipated a huge number of idiots issues, but not to come to a halt where I did, I would appreciate being led by the nose as I can't get to grips with APT live view. If I can explain, I managed to get the gear polar aligned without issue mainly thanks to ioptron. My telescope is a WO Zenithstar 73 with flat and my camera is asi 533mc on heq5 pro. On opening live view I was confronted with the tiniest pinpricks of stars, almost invisible in size and few where there should have been more. I started with the "video" live view settings on auto and tried to use the zoom keys to get some increase in size, they appeared to have no effect. I then unticked the video live view and increased the bin to 4 x 4 and the loop exposure to 6 seconds which I had watched on you tube instructions , again that had no effect. I opened the histogram aid and noted three distinct peaks to the extreme left, stretch right had no effect and stretch left produced a bright grid pattern and nothing else.

If it seems from the above I have no clue what I am doing, you would be correct, and I apologise but none of this live view seems obvious.

The upshot was by the time I had read, played with stuff and got nowhere, I was frozen solid and the fog had rolled in, pretty much as I anticipated a lone beginners first night to be.

Could anybody lead me by the nose please and give me a clue  to how to use live view to be able to focus, I thought I understood that bit but couldn't get that far LOL! I have watched a huge number of you tube videos and read the apt instructions but clearly am missing something or not understanding.

If anyone can help I would be grateful and is there a way I could practice this in daylight before everything gets more difficult in the dark. If my explanations and questions make no sense I would not be surprised and apologise in advance. Perhaps the steepest learning curve of anything I have ever done !

Best wishes.

 

Paul.

 

 

[Jamgood]

I recently started with the 294mc and had a similar thing on my first night. Small stars, couldn't focus barely as Bahtinov mask image was a pin prick. 

My settings for live view were all default regarding gain and offset. I put it into Bulb mode with a 1 second loop binned 1x1. (Camera functuons down the bottom right)

Opened Histogram and stretched. Voila! I could see.

Hope this helps.

Edited April 2, 2021 by Jamgood

[PeterCPC]

There is also the magnifier which you can roll over the live view. In tools.

[david_taurus83]

Liveview isn't the best method for focusing. You should take an exposure of a few seconds at least to average out the seeing conditions. Try looping 5s exposures and you should have plenty of stars to focus on.

[bottletopburly]

As david says above , when funds allow get an autofocuser this locks focus so you will never be too far from focus and APT new multi  focus routine is excellent .

[paulbromley9]

Well I took your advice and have fitted a ZWO EAF focuser which seems very smooth and precise. However I would welcome some help in deciding what I do and don't need to do in APT. I'll try and explain.

The instructions for the focuser tell you when using the bracket as I am to define the end points, zero being fully retracted and the maximum presumably at the other end of the possible extension. I am familiar with stepper motors using cnc. I have entered the zero position without problem but in APT can't understand where you define the other end. I have a screenshot if someone could point me in the right direction. Thanks for bearing with a newbie and help very much appreciated.

 

[geordie85]

It sounds like you're very out of focus and the "pin prick stars" you're seeing are hot pixels.

 

[Paul M]

APT live view operates differently for DSLR and CCD/CMOS cameras.

I generaly don't check the "video live view" box which then causes live view to just loop exposures as set in the camera menu. I use 5 seconds or so at a gain of 200 and binned 2x2. I usually use histogram stretch too because other than the brightest stars won't show even if in focus.

My very first atempt to focus my ASI178 took ages. It only needs a few mm of travel on the  fucusser to go from so far inside to so far outside focus that nothing shows. I ended up putting an eyepiece in and getting a bright star in the center of the field before reverting back to the camera. Then starting with full inward travel, slowly wind out the focusser slightly between live view frames. Once stars star showing it becomes easier though getting exact focus is a skill I'm still honing!

The auto focusing routine in APT is a work in progress and there are some notes for it in the latest release (scroll down to the green text):

 https://aptforum.com/phpbb/viewtopic.php?f=16&t=4313

Edited April 8, 2021 by Paul M