Re: #iEXOS-100 #iEXOS-100

Ian Morison

Dear Parag - a few pointers.  

'I have been getting started in AP with my DSLR.  So far I have been doing landscape (Milky Way) on a tripod without tracking by using image stacking approach.  I would now like to start imaging closer DSO (M31 etc) using my DSLR and 18-300 mm lens.  I have seen YouTube videos showing how that can be done without tracking, but I don't want to go about processing 600-1000 images for single object.  I'm interested in acquiring a low entry point tracker specifically iExos-100.  Can the community help me with a few questions to help me narrow down my choice?'


1) I see a lot of posts on challenges with polar alignment on this model.  Does a rough polar alignment followed by three star alignment a good way to get long exposures without investing in additional hardware at this time?

I would not try to use long exposures - there are problems apart from tracking - for example, if imaging the Orion nebula exposures of longer than about 15 seconds will 'blow out' the central region of the nebula. The same is true for the centre of the Andromeda Galaxy.  Image attached is of the Sword of Orion taken with 50, 15 second exposures.   I think 30 second or 1 minute exposures would be fine.  Only 60 frames needed at 1 minute for a 1 hour exposure.  Sequator will align and stack these quite quickly.  (See article in Digest mentioned below.)

2) With the above mentioned alignment, what are some realistic exposure times on an APS-C DSLR and 300mm zoom?

I had no problem  with 30 second exposures without star alignment having aligned on the NCP reasonably accurately.   It is good for the image to move across the sensor during the period of the exposure to remove the effects of hot pixels and 'Color Mottling'.  Just keep the exposures short enough so that star trailing is not a problem. 

3) The description says Open source software, but I'm unclear on exactly what portion of software is truly open source.  Is there an IDE and source code available to "tweak" the software?

Out of my league - though I have taught computer programming at University!

4) Is it possible to do planetary photography with long exposures?

No, long exposures are not needed.  BUT, if you have a Canon camera, you can use the free 'EOS Movie Record' program to use it as a webcam and do 'lucky imaging'  to greatly remove the effects of the atmosphere.  See the article in my Astronomy Digest ( - note a single 'r')  on imaging the Moon   -  'Using Deconvolution Sharpening on Lunar images captured with a Canon DSLR and EOS Movie Record'  

5) Is it possible to do time lapses?

I do  not see why not.  I think that you will need an intervalometer  ~ $20 on Amazon to automatically take the frames.  But I wonder what objects. ?   

6) Does Explore Scientific offer discounts for first time buyers?

Not that I know of.

I have put up a first 'review' of the  iExos-100  in the digest  which will be added to as I am able to use it more - only a couple of clear nights since I acquired it.  I had no real need to buy one but felt it 'deserved' to be bought as I really liked the concept and engineering.  It is really for use for astrophotography with a couple of short focal length refractors  but, given additional counter weights can support, for example, a Celestron C6 Schmidt-Cassegrain.

There are many other articles in the Digest that could help you on your way.  Let's hope the  iExos-100 is available again soon.

I do hope that this might help.



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