Re: Exos 2 PMC8 telescope size #EXOS2

kevin power

Thanks for your reply


I had excellent polar alignment according to Sharpcap and balance was as good as I could get due to guide scope being off center, maybe I could rotate more to balance out better?


I use the same guide scope as I do on the ED80 and have multi star guiding set up in PHD2.


I assumed that as I was using the same guide scope I wouldn’t need to change any settings in PHD2 but im guessing that is not the case? Would this be because of the positioning of the guide scope on the main telescope eg guide scope is now much further forward and would alter the signal to the mount?


Sounds like I need to do more research into PHD2 settings and hopefully can save more than one setup so to not have to recalibrate every usage.


The 2 times I have tried the 200PDS have been clear calm nights with no noticeable wind so I do not think this is the issue and have also seen videos of the EXOS2 handling large loads so felt safe getting this one.






Sent from Mail for Windows 10


From: jrichard333 <jrichard333@...>
Sent: 13 June 2021 01:43
Subject: Re: [ESPMC-Eight] Exos 2 PMC8 telescope size #EXOS2




Just so you know up front, I mostly do planetary imaging.  I’ve dabbled a

little into DSOs.


I don’t think it’s the mount.  The EXOS-2GT PMC8 can hold a lot of weight.

I’ve seen it handle over 80Ibs (36kg).  I have an iEXOS-100 with the  ST3

tripod legs and it can easily handle 20Ibs (9.1kg) and the rating for this mount

is a lot less.   Just make sure you are balanced and you should be fine once

you develop new settings for PHD2.


You will have to start over using PHD2 (settings, etc.); why, you are going from:

  1.  a small foot print (ED80) to a larger foot print (200dps) scope
  2.  a shorter focal length (480mm) to a longer focal length (1000mm)


Higher focal lengths make alignment a bit more critical and then you have to

consider wind causing the scope to move a bit which can results in errors as

well.  Don’t forget about seeing conditions as well.


a 50mm finderscope should be ok.  I will be using a 30mm guidescope on a

C90 after planetary season ends this year.


You might want to download the beta version of PHD2, which allows for multiple

guide stars.


I would make sure my stars are very sharp in my guidescope.



From: [] On Behalf Of kevin power
Sent: Saturday, June 12, 2021 5:31 PM
Subject: [ESPMC-Eight] Exos 2 PMC8 telescope size #EXOS2


Hi all i have had my mount just under a year now with no real issues. 

Generally use ED80 with ZWO 290mc camera and guide scope and can easily get 300 seconds and 600 second images after a decent polar alignment.

I now have a 200pds, 8 inch newtonion and can not use on this mount? Phd2 can not control the mount at all my total guiding is about 50 but goes higher.

I use the same 50mm guide scope could this be too small or is the mount just not capable of a telescope this size?

Is there anything I can try setting wise?

Thanks for any help


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