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Beginner EAA set up and ASIAIR calibration frame questions

EAA Explore Scientific Imaging
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#1 rlmxracer

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Posted 23 January 2025 - 11:31 AM

I am assembling my first EAA rig with my new ES ED80 FCD100 using ASI533MC pro, 32mm x 121mm guide scope with ASI120mm mini sitting on a modified belt driven Meade LX85 running with ASIAIR mini. 

I have been reading about the calibration frames but I am confused as to what is necessary for an EAA set up. I am also looking for advice on the easiest way to shoot and store the calibration frames with ASIAIR. What filters are you using for galaxies and which filters for nebulas? I have a UV/IR on order and currently have a Baader UHC-S and OIII filters. I currently live in a Bortle 7-8 zone. I plan to use guiding solely to see what my mount will do and to learn how to do it for the future. 

Thanks in advance, Rob. 


Edited by rlmxracer, 23 January 2025 - 12:00 PM.


#2 steveincolo

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Posted 23 January 2025 - 11:49 AM

Filters: for galaxies, try it without any filter.  For star clusters (globs and open) and maybe reflection nebulas, use your UV/IR cut.  For emission nebulas, consider getting a dual narrowband filter.  

 

With the 533MC pro, calibration frames are not necessary (smaller sensor, so less vignetting, and low thermal noise), but are good to use.  You can make them in Live view.  Look for the auto setting for exposure for flats.  You’ll need to make a bias master for your flat master.  Your dark exposure time and gain should match what you are planning for your light subs. 

 

You’ve got a nice scope for EAA, and the 533MC Pro is a great choice of camera.  Good luck!


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#3 GaryShaw

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Posted 23 January 2025 - 11:56 AM

Hi Rob

A couple points to get you started on your list:

- by tracking I assume you mean guiding. Guiding is unnecessary with Sharpcap but you can certainly do it to get the practice.

- filters for galaxies are really unnecessary as you start out. You want as much light from the target as possible so you can go unfiltered initially. I bought a uv/ir cut filter when I started EAA 6-7 years ago. I’ve never needed it or found it helpful for anything.

- you’ll probably want to use flats and darks given your sky brightness. Sharpcap can handle making both of these for you easily. Read the manual or watch some YouTube videos if you aren’t familiar with how to make them.

- for nebulae, you’ll really want a nice dual band filter such as Optolong L- enhance or the later version of that filter.

- you’ll also want a dark filter for making darks and flats. It goes in your filterwheel and will save you manually covering your scope’s aperture which is necessary for making darks and part of the time when making flats with Sharpcap. BTW, I’m assuming you’ll quickly discover the merits of setting up indoors to control the mount and scope outdoors via Wi-Fi using Remote Desktop or similar applications . You can figure that out and folks here can coach you on it when you’re ready.

- Don’t forget to check out the EAA for Dummies video series that’s located somewhere pinned near the top of the EAA forum.

good luck

Gary


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#4 rlmxracer

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Posted 23 January 2025 - 12:08 PM

Hi Rob

A couple points to get you started on your list:

- by tracking I assume you mean guiding. Guiding is unnecessary with Sharpcap but you can certainly do it to get the practice.

- filters for galaxies are really unnecessary as you start out. You want as much light from the target as possible so you can go unfiltered initially. I bought a uv/ir cut filter when I started EAA 6-7 years ago. I’ve never needed it or found it helpful for anything.

- you’ll probably want to use flats and darks given your sky brightness. Sharpcap can handle making both of these for you easily. Read the manual or watch some YouTube videos if you aren’t familiar with how to make them.

- for nebulae, you’ll really want a nice dual band filter such as Optolong L- enhance or the later version of that filter.

- you’ll also want a dark filter for making darks and flats. It goes in your filterwheel and will save you manually covering your scope’s aperture which is necessary for making darks and part of the time when making flats with Sharpcap. BTW, I’m assuming you’ll quickly discover the merits of setting up indoors to control the mount and scope outdoors via Wi-Fi using Remote Desktop or similar applications . You can figure that out and folks here can coach you on it when you’re ready.

- Don’t forget to check out the EAA for Dummies video series that’s located somewhere pinned near the top of the EAA forum.

good luck

Gary

Yes, I meant guiding (changed it in original post). I do not own a laptop currently so everything is being run on an iPad through ASIair app. I am looking for the actual process to do calibration frames with ASIair and can store internally or them on a thumb drive for now if needed. Thanks for the advise I will look up that post.  



#5 steveincolo

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Posted 23 January 2025 - 12:20 PM

Yes, I meant guiding (changed it in original post). I do not own a laptop currently so everything is being run on an iPad through ASIair app. I am looking for the actual process to do calibration frames with ASIair and can store internally or them on a thumb drive for now if needed. Thanks for the advise I will look up that post.  

The ASIAir makes it pretty easy to get started with guiding. It uses a simplified version of PhD2, the most used guiding software.  

 

Just to be clear, my advice above regarding calibration masters was intended for the ASIAir.  To make a dark master, the simplest and cheapest approach will be to wait until dark and cap your scope.  

 

While Gary mentioned filterwheels, you do not necessarily need to use one.  The cheapest but least convenient approach is to screw 1.25" filters directly into your camera.  ZWO includes an adapter for this.  Another approach is to use filter drawers, but I believe these are designed for 2" filters, which are more expensive.  You could also consider a manual or electronic filter wheel, which you can buy sized for particular filter sizes.  1.25" filters are fine with the 533 sensor size.

 

UV/IR cut filters help with star bloat and colors, so they are useful for star clusters.  


Edited by steveincolo, 23 January 2025 - 12:21 PM.

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#6 rlmxracer

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Posted 23 January 2025 - 12:27 PM

The ASIAir makes it pretty easy to get started with guiding. It uses a simplified version of PhD2, the most used guiding software.  

 

Just to be clear, my advice above regarding calibration masters was intended for the ASIAir.  To make a dark master, the simplest and cheapest approach will be to wait until dark and cap your scope.  

 

While Gary mentioned filterwheels, you do not necessarily need to use one.  The cheapest but least convenient approach is to screw 1.25" filters directly into your camera.  ZWO includes an adapter for this.  Another approach is to use filter drawers, but I believe these are designed for 2" filters, which are more expensive.  You could also consider a manual or electronic filter wheel, which you can buy sized for particular filter sizes.  1.25" filters are fine with the 533 sensor size.

 

UV/IR cut filters help with star bloat and colors, so they are useful for star clusters.  

I will likely get a filter drawer in the near future to make switching filters easier. 


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#7 kgrier

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Posted 23 January 2025 - 01:37 PM

I have a similar optical train - was SW80ED, now SharpStar 94EDPH - ASI533MC Pro, ASI174MM Guide Camera, ASIAIR (mini, now plus). I started briefly with SharpCap and laptop but found it overkill / overly complex for EAA and my "AP Lite" goals. I'm assuming that the ASIAIR can control your LX85 as I have no experience with that mount. I've used SW AZ-GTI, SW StarAdventurer GTi, SW Wave 150i and now ZWO AM5N with the ASIAIR. Here's what I have found. I am in Bortle 6 skies.

 

I take 120 seconds subs with default gain of 100, typically 1 hour's worth using LIVE mode, displaying on an Android tablet. Most DSO's resolve well for eyeball viewing the image in the ASIAIR UX in under 15 minutes. More than that is rarely necessary but since I dabble with post-processing I will let it run unless there is another target I want to jump to right away. I have ASIAIR save the subs to an external flash drive. If you want to save the final ASIAIR stacked image, you need to do that manually with the "save" button on the display.

 

I typically use a UV/IR filter with a SVBony 2" filter drawer that comes with an adapter for 1.25" filters. The 533MC Pro does not have a UV/IR filter integrated and reportedly "IR leakage messes with the color and micro-lens artifacts." I have several filters (too many). The most useful are the Optolong UV/IR, L-eNhance and SVBony SV220.

 

I sometimes take calibration frames which are useful in post processing, chiefly for removing the occasional dust mote, or vignetting that happens with the APEX ED-L. For real time EAA viewing calibration frames are unnecessary. For flats I picked up one of those inexpensive USB powered light panels artists use. Then a piece of translucent white plexiglas. That allows me to take all the calibration frames at the same time, rather than waiting for the right lighting for the t-shirt method for flats. 

 

I've stepped up to guiding with the AM5N. It was unnecessary with the AZ-GTi and StarAdventurer GTI. I've read that others don't guide with the AM5's for EAA but that has not been my experience, at least if I want to post process. The ASIAIR makes guiding easy, and it works well most of the time with the default settings. A week ago, I lost guiding 30 minutes in on my two sessions.  Last night, (3) 1 hour sessions with guiding of .75" or better. Go figure. 

 

Last night I had good viewing on M81 and M82 with a hint of NGC 3077, probably my best so far. I could see a dust mote on the ASIAIR display. So I decided to take flats, darks, bias at the end of the session so I could post process the image. 

 

- Kirk 


Edited by kgrier, 23 January 2025 - 01:38 PM.

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#8 rlmxracer

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Posted 23 January 2025 - 01:47 PM

I have a similar optical train - was SW80ED, now SharpStar 94EDPH - ASI533MC Pro, ASI174MM Guide Camera, ASIAIR (mini, now plus). I started briefly with SharpCap and laptop but found it overkill / overly complex for EAA and my "AP Lite" goals. I'm assuming that the ASIAIR can control your LX85 as I have no experience with that mount. I've used SW AZ-GTI, SW StarAdventurer GTi, SW Wave 150i and now ZWO AM5N with the ASIAIR. Here's what I have found. I am in Bortle 6 skies.

 

I take 120 seconds subs with default gain of 100, typically 1 hour's worth using LIVE mode, displaying on an Android tablet. Most DSO's resolve well for eyeball viewing the image in the ASIAIR UX in under 15 minutes. More than that is rarely necessary but since I dabble with post-processing I will let it run unless there is another target I want to jump to right away. I have ASIAIR save the subs to an external flash drive. If you want to save the final ASIAIR stacked image, you need to do that manually with the "save" button on the display.

 

I typically use a UV/IR filter with a SVBony 2" filter drawer that comes with an adapter for 1.25" filters. The 533MC Pro does not have a UV/IR filter integrated and reportedly "IR leakage messes with the color and micro-lens artifacts." I have several filters (too many). The most useful are the Optolong UV/IR, L-eNhance and SVBony SV220.

 

I sometimes take calibration frames which are useful in post processing, chiefly for removing the occasional dust mote, or vignetting that happens with the APEX ED-L. For real time EAA viewing calibration frames are unnecessary. For flats I picked up one of those inexpensive USB powered light panels artists use. Then a piece of translucent white plexiglas. That allows me to take all the calibration frames at the same time, rather than waiting for the right lighting for the t-shirt method for flats. 

 

I've stepped up to guiding with the AM5N. It was unnecessary with the AZ-GTi and StarAdventurer GTI. I've read that others don't guide with the AM5's for EAA but that has not been my experience, at least if I want to post process. The ASIAIR makes guiding easy, and it works well most of the time with the default settings. A week ago, I lost guiding 30 minutes in on my two sessions.  Last night, (3) 1 hour sessions with guiding of .75" or better. Go figure. 

 

Last night I had good viewing on M81 and M82 with a hint of NGC 3077, probably my best so far. I could see a dust mote on the ASIAIR display. So I decided to take flats, darks, bias at the end of the session so I could post process the image. 

 

- Kirk 

Thanks for the tips Kirk. 
I have done a ton of research on how to get my mounts (I have 2 LX85s) to work with ASIAIR. I was able to get it to do PA and view a few objects using my guide scope and camera. I’m pretty sure I have the guiding sorted but I had to wait my scope arrived. I will be guiding using the ST4 cable. The modifications I made besides the belts should get this mount to a decent level of tracking accuracy. Eventually I will get a strainwave mount. 


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#9 rlmxracer

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Posted 25 January 2025 - 01:59 PM

Here’s my set up all mocked up on the mount. I have custom cables on order and just waiting on clear skies.

I also need to order a few short button head screws to fill the mounting holes for the original dovetail and finder mount. For now I have the ES finder mount on backwards so it will clear the rings but I have lost the ability to rotate the focuser temporarily. 

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Edited by rlmxracer, 25 January 2025 - 03:48 PM.

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#10 rlmxracer

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Posted 26 January 2025 - 03:31 PM

Making my first dark frame library. Wish me luck. 


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#11 rlmxracer

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Posted 26 January 2025 - 05:59 PM

Ok so I shot several series of darks at various exposures. What do I do with the files now that they are stored on the air hard drive? I was hoping to use them for EAA but I don’t have a computer for processing if that’s what is needed. 


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#12 steveincolo

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Posted 27 January 2025 - 05:38 PM

Ok so I shot several series of darks at various exposures. What do I do with the files now that they are stored on the air hard drive? I was hoping to use them for EAA but I don’t have a computer for processing if that’s what is needed. 

In Live view, you can select the dark master to use to calibrate the light subs.  No separate computer needed for processing.  


Edited by steveincolo, 27 January 2025 - 05:38 PM.

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#13 rlmxracer

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Posted 01 February 2025 - 01:30 PM

Once you complete your dark frame stack are there things you look for in the image? I’m not really sure how they are supposed to look ie how much noise is in the image. Thanksgiving 



#14 steveincolo

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Posted 01 February 2025 - 08:21 PM

Once you complete your dark frame stack are there things you look for in the image? I’m not really sure how they are supposed to look ie how much noise is in the image. Thanksgiving 

It depends on the camera.  Some show “amp glow,” a distinctive pattern at one edge. Your 533MC Pro has very little amp glow, so it’s not easy to see.  More generally, cameras have “thermal noise,” which increases with gain, temperature, and exposure time.  If your dark master matches the lights, it will correct for these flaws.  Darks will also correct hot pixels (pixels that give much brighter values than they should).

 

I use the free tool FITS Liberator to look at FITS files.  It gives you various statistics, a histogram, a lot of different stretches, and the ability to look at FITS headers (name-value pairs that describe the FITS).  

 

In EAA and AP, the data is always stretched so that we can see the objects. Without a stretch, you’ll usually just see a few stars (exception: M42).  Stretches also emphasize imperfections like amp glow, light gradients, dust particles in the optics, and vignetting.  Flats help with the last two. 


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