ASIAir Pro and SGPro - A deeper dive and alternate use case

[jimjam11]

The ASI Air Pro is an amazing device and it is rapidly evolving. However, having used it for a few months it does have some limitations which have led me to use it slightly differently.

Pros:

• I have a Polemaster and Sharcap, but for polar alignment the ASIAir is in a different league. You click go and it takes an image which is plate-solved. You click go again and it moves the mount, plate-solves and then tells you what correction to make. Polar alignment takes me <2mins with my average time approx 70s. I can PA with the Polemaster in approx 3mins, but if I need to do the rotation calibration it is more like 6mins. Sharpcap is good when it works, but I have found it very hit/miss. The £280 polemaster is redundant.
• Platesolving is like witchcraft. It is based on the raspberry pi but it platesolves faster than my i7 laptop running SGPro/ASTAP. 
• Custom objects - It has an extensive built in catalog but you can save your own objects by specifying the ra/dec.
• Power distribution - It has 4 12V sockets including PWM control so no need for a dew heater controller. The £260 pegasus powerbox is redundant.
• Autofocus - As of the current beta (Sep 2020) it can do autofocus and it appears to work well.
• Speed - It is blindingly fast at saving an image and moving onto the next sub. This delay can be very significant with short cmos subs and something like SGPro.
• Rate of evolution - ZWO are developing the software rapidly. They listen to users and it is becoming more and more capable.
• Fewer cables - The HEQ5 doesnt have any cable management but with the ASIAir you only need to supply it with 12v power. The only other cable coming off the OTA (assuming on-OTA mounting) is the cable to the mount.
• 12v power - It runs on 12v power so you can run the entire setup easily on battery using a single 12v feed up to the ASIAir.

 

Cons:

• Wifi connectivity - it doesnt work so save yourself the hassle and buy the TL-WR902AC.
• Platesolving - It solves using the jnow epoch rather than the more standard j2000. This means you cannot plan images with something like telescopius. 
• Mosaics - It has no mosaic capability although this is possible using telescopius and custom objects if you remember to convert the telescopius ra/dec for each panel into jnow. Also remember each goto needs to  be manually invoked.
• Platesolving - The solve returns the rotation angle, but it is not part of the goto. You therefore need to manually ensure your rotation angle is correct.
• An imaging sequence is still manual; once Pa is completed you need to goto your object (it will platesolve to an accurate location), turn on the cooler, configure guiding, run autofocus and finally start autorun. Once complete it can park the mount.
• Gain is manually set. I typically image at gain 76 for RGB and 200 for NB. Autorun cannot currently do this so you need to autorun for RGB and then rerun for NB after changing the gain.
• Autofocus - I believe this is based on a single star as opposed to the entire frame.

 

This combination of pro/con has led me to an interesting place. SGPro has way more features and is completely automated, but it is slow and cannot do PA. I bought a cheap mini-pc from amazon which runs windows/sgpro and now I use the ASIAir for power distribution + polar alignment before switching to the mini pc if I am looking to do something the ASIAir cannot currently do (such as mosaics). My concerns with this approach are:

1. SGPro switching to a subscription model.
2. The horrible performance of SGPro made worse by the underpowered mini-pc. This leads to significant interframe wastage which I measured this by taking 20x1s exposures. SGPro needed 4 minutes(!) to complete this take. By comparison Nina only needed 47s with an average interframe delay of 1.3s which is completely acceptable (and insignificant) once subs are >60s. 

 

Hopefully there is some useful information in here for people considering the ASIAir.

[SmokeyJoe]

I love my Asiair Pro, complete game changer, it has its problems (the WiFi range is terrible, TL-WR902AC is on the shopping list).  I'm using it without guiding and with a refurbished Canon 450D at the moment (roll on Christmas). Couldn't be happier, PA is a dream, getting 2-3 minute subs every night.  The only niggles  I have are the aforementioned wifi range, and that it restricts you to ZWO equipment, but I suppose that means there are no communication problems. Now I want a dedicated astro cam, auto focuser, filter wheel........  

I'm on a really restricted budget at the moment, bought the wrong scope 8 years ago and it has taken me till now to get the beginning of an AP rig.  The Asiair Pro is the best £300 odd quid I've spent on astronomy would highly recommend it.  (It works with sky safari as well).