First timer, focusing (?) problem

Discussions of Electronically Assisted Astronomy using the Live Stacking feature.
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turfpit
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Re: First timer, focusing (?) problem

Post by turfpit » Fri Nov 30, 2018 9:02 pm

Joe

Where you are now, is where I was at the end of 2016 viewtopic.php?f=16&t=596. The 2 years of elapsed time is because of so few nights to get out and image due to weather. Things do get better if you can stick at it. This was a recent clear night where everything went well viewtopic.php?f=16&t=1199.

The book you need - I am in the process of writing it, hoping to save others from all the stumbling around and wasted time that I went through. My big breakthrough was writing the SharpCap 2.9 docs, which was interesting as I had no background in photography or astronomy.

I think you have a Revolution camera. I started off with an AVS DSO-1 - which is similar technology. Based on my experience, that type of camera is hard to learn with as none of the controls are exposed to SharpCap, leaving the user to control the camera via a set of internal menus. Have a look round for a more conventional astro-imaging camera on somewhere like AstroBuySell.

Here are my own thoughts but YMMV and 10 people will arrive soon to disagree with me:
  • Understanding the histogram is key to progress.
  • Meticulous preparation is key to success - level mount, polar alignment, mount alignment, focusing.
  • Mono cameras are easier to start with as they remove the colour balance hassle.
  • Don't get drawn into guiding too soon - it is just another layer of complexity.
  • Don't get bogged down with darks and flats early on. They are just another level of complexity. As you evolve, then you will naturally want to learn about darks and flats in order to improve your images.
  • It looks like you are interested in the Live Stacking aspect of the hobby. When stacking, save all the frames so you can go away and learn about traditional methods of processing on those rare cloudy nights.
  • Getting involved with the NSN community will be a good help to you. When watching sessions, have a word processor open and capture screens (think settings) into the document for later reference.
  • You will always need to spend £100 on another gizmo which will make your images better :lol:
My stuff is here https://www.astrobin.com/users/turfpit/. A mix of SCT & refractor scopes; CMOS, CCD, DSLR & webcam cameras, 4 different capture programs running on Windows & Linux, several different programs for calibration, stacking & processing. I prefer to work in the more traditional ways of image capture, preferring to try to understand the underlying principles but that is a personal choice.

Have a look in the Gallery forum and you will find examples of some really good images which have been produced via the Live Stack process.

Astro-imaging is a tough hobby, both physically and mentally, but if you stick at it then it can be an extremely satisfying experience.

Good luck.

Dave

psy1280
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Re: First timer, focusing (?) problem

Post by psy1280 » Wed Sep 04, 2019 2:50 pm

After a year of trial-and-error frustration with my Celestron Evolution 8, Celestron graciously agreed to replace my mount. Now I'm finally back to working with SharpCap. I'll admit that I've forgotten most of what I learned a year ago, but last nigh--my first night using SharpCap--I was able to view the Andromeda Galaxy!!! Although I wasn't able to get LiveStack to add to the image, I was pleased to at lease be viewing a live image. Although I'm not sure why I couldn't get SharpCap to do live stacking (initially I got a message about a problem with alignment stars, after restarting I was able to see that images were indeed stacked, however nothing changed on the image. I will be doing more experimenting before asking for help, I'm sure I'll figure out some of this as I proceed, I just wanted to re-connect with Robin and the SharpCap community. This time I expect to progress.
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admin
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Re: First timer, focusing (?) problem

Post by admin » Wed Sep 04, 2019 8:58 pm

Hi,

Glad to hear that you are back in business. Remember that live stacking doesn't make the image grow brighter as more frames are added – instead it makes the noise level in the image gradually reduce as more and more frames are added to the stack. This can be harder to notice, but if you look carefully as the stack builds up you will see it happening.

Cheers, Robin

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Re: First timer, focusing (?) problem

Post by umasscrew39 » Tue Sep 10, 2019 12:35 pm

Welcome Joe

I just wanted to throw my 2 cents in to all of the great feedback you've already received. I have only been doing live viewing and some AP for a little over 3 years and it does have its rewards and challenges. I use a C11" which is not the easiest scope to learn on and I also had to return my to Celestron for a replacement some time ago. I decided to go with the new Celestron motor focuser and it works very well with SC via the ASCOM driver. This was mainly because my scope is over 12ft above the ground in an observatory but getting ti down the road might help. Regardless, once you get it focused in the ballpark, then the SC focus tool works very well. Like dave suggested, a Bahtinov mask is a simple, cheap, and effective solution to focusing on a SCT. As long as you are focused and your scope is collimated, then you are off and running.

We are all learning from each other....... and that is part of the enjoyment of doing this hobby.

All the best,
Bruce

psy1280
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Re: First timer, focusing (?) problem

Post by psy1280 » Wed Sep 18, 2019 2:33 pm

Thank you Robin and Bruce,
Last night I had a taste of this exciting hobby (just a taste). I'd like to think that my frustrations aren't that unusual, although sitting here this morning I'm wondering if I'm just not intuitive enough to master (or at least manage) all the intricacies involved. I only hope that I continue to find good--and patient--people to point me in the right direction. All that said, last night I was able to image the moon without much of a problem. Prior to moon-rise, I tried to image the Andromeda galaxy (this is the second attempt, with the same results as before). I'm posting the image I got and the settings in the hope that I might get a few suggestions for bringing out more of the galaxy.

Thank you,
Joe
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Re: First timer, focusing (?) problem

Post by admin » Thu Sep 19, 2019 6:23 pm

Hi,

Looking at that image I can see that your stars are quite an odd shape with a sort of wing pattern coming out from each of them. That's usually the sign of some sort of optical aberration or misalignment and you could expect things to perhaps work better (and give you sharper images) if you can get that sorted and get pinpoint stars.

Cheers, Robin

psy1280
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Re: First timer, focusing (?) problem

Post by psy1280 » Fri Sep 20, 2019 3:14 pm

Much thanks Robin,
I will definitely use my Bhatinov mask next time. Even though this image isn't crisp, if it were better focused, would that allow LiveStack to bring out the galaxy? I tried to do this, but obviously failed.

Thank you in advance for your feedback,
Joe

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turfpit
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Re: First timer, focusing (?) problem

Post by turfpit » Mon Sep 23, 2019 9:52 am

Joe

Some ideas you might want to try that work for me.
  • During daylight, use an eyepiece to focus on a land based object about a mile away, something like a tower block, mobile mast, power pylon, TV mast.
  • Swap the eyepiece for the camera, run up Sharpcap, turn on the reticule and re-focus. This focus will be very near for a celestial object.
  • When dark (leaving focus as above) align the mount using whatever process is required.
  • Choose a star which is near to the object of interest (don't try to focus on a deep sky object). For example, if I was imaging M31 then I would use a medium brightness star such as Alpheratz. Avoid bright stars like Vega for focusing.
  • Using just the Bahtinov Mask (not the focusing tool in SharpCap as this just puts in another layer of complexity) adjust focus to achieve the correct pattern . I consider the diffraction pattern image in here to be good focus viewtopic.php?f=16&t=1940. Some hints here viewtopic.php?f=18&t=1151
  • At this point, slew to the object of interest.
If using Live Stack and adjustments have been made to settings, then it may be prudent to reset all Live Stack settings to the installation defaults (which are pretty good). In Live Stack, on the Log tab, there is a button Reset All Settings - click this. Note also the logging window gives informational messages about what SharpCap is seeing/doing.

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To find out which stars SharpCap can actually see (rather than what the imager thinks is there), select the Alignment tab and check Highlight Detected Stars. Stars 'seen' by SharpCap will have yellow boxes drawn around them.


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I note from the camera settings and image you are running at 640x480 (probably using a CCTV type camera). With this type of setup, I found the use of a 0.5x reducer was helpful as it increases the field of view.
I'm wondering if I'm just not intuitive enough to master (or at least manage) all the intricacies involved
None of this is intuitive - to achieve results will require hard work, discipline, attention to detail and patience.

Dave

psy1280
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Re: First timer, focusing (?) problem

Post by psy1280 » Thu Oct 10, 2019 8:56 pm

Robin,
Thank you so much for your ongoing patience and assistance. I was able to get a clear sky recently and used my Bahtinov Mask. Using Folder Monitor Camera, I was able to stack 811 frames of the Andromeda Galaxy. The results were, well, I'll let you be the judge. I'm not sure if the "halo" around the galaxy's bright core is actually part of the galaxy or an artifact of my efforts. If it happens to actually be part of the galaxy (which would be very exciting to hear) what would be the next step in bringing out more detail, i.e., more frames, etc.

Thank you for all your help,
Joe
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chongo228
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Re: First timer, focusing (?) problem

Post by chongo228 » Thu Oct 10, 2019 9:38 pm

I think that is part of the galaxy.

Have you played with the live stack histogram? You can pull out some pretty good detail with it. Let a decent number of frames (10 or so) stack before you start adjusting it or it will change too fast. Once you get it dialed in play with the features to sharpen the image (if you have SC pro).


I was playing with some backfocus spacing the other night and used 30 second exposures at 139 gain on my 80mm and was pulling out the first two dust lanes once I pulled the histo. Try increasing the exposure a bit if you are auto guiding. If you're not auto guiding go as long as you can until you see long stars or it can't align frames. I would guess around 15-30 seconds until you ran into problems depending on polar alignment.


I think most people can only get the first two dust lanes to stand out in live stack....you're half way there.

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