14 replies to this topic

[Astral Ace]

I guys so I was planning to buy a mount for doing AP and well I came across three mounts and I'm super confused as what to pick, need inputs from people having experience with any of these mounts to answer the question.
So here's the thing I'll be doing unguided astrophotography at 300mm FL and I want round star for at least 2 minutes of exposure per shot, so I don't know what to buy, I checked out the goto mounts well because of the ease of finding targets and also since I wouldn't be able to see the polar star I was planning to use it for TPPA through NINA.
Now here's the thing I can't find any details if the SH or the iexos-100 will hold up at 2 minutes of exposure for rounded stars at 300mm and that worries me, also for skyguider I found like few images that did show 2 minutes unguided shots with round stars. Can anyone with first hand experience with any of these mounts help me out?
I'm very much on a budget that's why I get get guiding setup either.
Payload : 1.9KG / 2.2 lbs

Focal length: 300mm

[martz]

Hello,

I use the iEXOS-100, but guided and only up to a 135mm lens on a Nikon APS-C sensor camera, so much more forgiving, although with heavier gear than your setup for sure. The mount and its software have many quirks; a source of frustration for many users until you learn how to deal with it. TPPA works fine. I would encourage you to go to the Explore Scientific forum for the mount before buying. Some users end up giving up on it due to the learning curve involved in using the mount.

Good luck.

[Astral Ace]

Hello,

I use the iEXOS-100, but guided and only up to a 135mm lens on a Nikon APS-C sensor camera, so much more forgiving, although with heavier gear than your setup for sure. The mount and its software have many quirks; a source of frustration for many users until you learn how to deal with it. TPPA works fine. I would encourage you to go to the Explore Scientific forum for the mount before buying. Some users end up giving up on it due to the learning curve involved in using the mount.

Good luck.

I mean I can cope up with the learning curve that's not an issue, the only problem I'm facing is approximating it's tracking accuracy, I seriously need to ask someone who has done unguided on it and well it seems no one has ever done unguided on this idk why.

[martz]

This forum does not have many users of that mount. The place to ask about tracking accuracy is the forum I referenced.

[Devonshire]

Ace,

 

Here's a link to the PMC8 support forum:   https://espmc-eight.groups.io/g/MAIN

 

There are lots of iExos-100 owners over there, so you can ask the people who actually have one and use it for Astrophotography.  

We do have some over here on CN, but not many by comparison.

 

I understand that you want to do AP unguided, and you will find that some have made that work for whatever exposure length, but the thing about working unguided is that all it takes to create a discarded image, is a puff of wind, a bit of ground vibration, a minor mechanical imperfection, or a less-than-perfect polar alignment...   For most of us,  unguided AP is not worth the trouble.

 

Anyway, here's the forum link - do check it out. 

Edited by Devonshire, 22 April 2025 - 11:05 AM.

[hughesthompson]

I have had both the iExos-100 and SkyGuider Pro.  Even though I replaced the iExos-100 with a harmonic drive mount a couple of years ago I think it's still the best mount in its price range.  Tripod is flimsy and needs a weight bag to stabilize it a bit.  Otherwise it's capable of much higher capacities than advertised.  Always used it guided with an ASIair and scopes ranging from 180mm to 1300mm.  I would not go over 60 seconds unguided.  About half of the images on my AstroBin page were taken with this mount.  https://app.astrobin...hompson#gallery
 

As for the SkyGuider Pro it's a great tracker but no substitute for a goto mount.  You can waste a lot of time finding targets and it can only guide in RA.  You will quickly run into its weight limitations.  I still use it as a lightweight portable setup and for visual with small scopes.  I wanted to upgrade to a SkyHunter for goto but checking here on Cloudy Nights it has had terrible reviews.  Hope this helps.

[ZigZagZebraz]

I have the iexos-100-2. Gave up on it due to several issues and got a Skywatcher strain wave mount.

 

May be add skywatcher az-gti tracker in your prospective list. I have seen pinpoint stars in images taken using it, in astrobin.

[Astral Ace]

Ace,

 

Here's a link to the PMC8 support forum:   https://espmc-eight.groups.io/g/MAIN

 

There are lots of iExos-100 owners over there, so you can ask the people who actually have one and use it for Astrophotography.  

We do have some over here on CN, but not many by comparison.

 

I understand that you want to do AP unguided, and you will find that some have made that work for whatever exposure length, but the thing about working unguided is that all it takes to create a discarded image, is a puff of wind, a bit of ground vibration, a minor mechanical imperfection, or a less-than-perfect polar alignment...   For most of us,  unguided AP is not worth the trouble.

 

Anyway, here's the forum link - do check it out. 

I mean coming from untracked even a star tracker is a huge thing for me and well I would love to go guided but it very out of budget for me RN.
Thank you so much for the link tho, really helped me out.

Edited by Astral Ace, 22 April 2025 - 01:32 PM.

[Astral Ace]

I have had both the iExos-100 and SkyGuider Pro.  Even though I replaced the iExos-100 with a harmonic drive mount a couple of years ago I think it's still the best mount in its price range.  Tripod is flimsy and needs a weight bag to stabilize it a bit.  Otherwise it's capable of much higher capacities than advertised.  Always used it guided with an ASIair and scopes ranging from 180mm to 1300mm.  I would not go over 60 seconds unguided.  About half of the images on my AstroBin page were taken with this mount.  https://app.astrobin...hompson#gallery
 

As for the SkyGuider Pro it's a great tracker but no substitute for a goto mount.  You can waste a lot of time finding targets and it can only guide in RA.  You will quickly run into its weight limitations.  I still use it as a lightweight portable setup and for visual with small scopes.  I wanted to upgrade to a SkyHunter for goto but checking here on Cloudy Nights it has had terrible reviews.  Hope this helps.

I checked your astrobin and it's just wow, I mean even one minute is good but some people go like we get trails after 30 seconds and stuff and that's well weird. Secondly since you've on-hand experience I'll take it from you but since I'm spending on this I was really looking forward to like 2 or 3 minutes lol, it would've been amazing. I mean I'm willing to waste my time finding targets as long as the skyguider pro offers me a higher exposure time, I'll gladly sacrifice the GOTO over it. So please let me know if the skyguider pro can actually pull it more.

[hughesthompson]

I checked your astrobin and it's just wow, I mean even one minute is good but some people go like we get trails after 30 seconds and stuff and that's well weird. Secondly since you've on-hand experience I'll take it from you but since I'm spending on this I was really looking forward to like 2 or 3 minutes lol, it would've been amazing. I mean I'm willing to waste my time finding targets as long as the skyguider pro offers me a higher exposure time, I'll gladly sacrifice the GOTO over it. So please let me know if the skyguider pro can actually pull Is youe

At 300mm and 2.2 lbs a SkyGuider Pro will work fine but add the cost of a good tripod.  Just plan on multiple 60 second exposures and stack them with free software.  With a fast lens you don't need to go longer than that unguided.

 

A simple guide scope and camera is about $200 used and well worth it. Only very expensive mounts with encoders can do long unguided exposures.

Edited by hughesthompson, 22 April 2025 - 06:30 PM.

[Astral Ace]

At 300mm and 2.2 lbs a SkyGuider Pro will work fine but add the cost of a good tripod.  Just plan on multiple 60 second exposures and stack them with free software.  With a fast lens you don't need to go longer than that unguided.

 

A simple guide scope and camera is about $200 used and well worth it. Only very expensive mounts with encoders can do long unguided exposures.

Thank you so much that was helpful and well I do own a f/2.8 lens so that's also there and the tripod I currently own is a very sturdy one I did invest in it well when I brought it back never thought it would come this handy. From where I come there's like very few astrophotographer so there is 0 chance to find anything on the second hand market forcing me to buy everything a new.

[hughesthompson]

Peter Zelinka on YouTube has some good videos on using a SkyGuider Pro with a camera and lens.

[gna72]

I owned an iexos-100, the periodic error of my mount was about 600 seconds,

here is a 900 sec long exposure to show it, the focal length was about 500 mm and the camera was a Canon T1i/500d

Attached Thumbnails

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Edited by gna72, 28 April 2025 - 04:40 AM.

[Devonshire]

I owned an iexos-100, the periodic error of my mount was about 600 seconds,

here is a 900 sec long exposure to show it, the focal length was about 500 mm and the camera was a Canon T1i/500d

Yes, that 600s periodic error is expected, a product of the gearing.  Not a flaw.  

Correcting periodic error is one of the reasons why people guide.  :-)

 

Those sine waves look reasonably clean (ie: not jagged), so it should have guided well.

 

I spent a LOT of time going over the periodic error of my EXOS2 PMC8 with PECprep, getting it to the point where its' PE was a nice smooth sine wave that's easy to guide around.

Edited by Devonshire, 28 April 2025 - 10:01 AM.

[Astral Ace]

I owned an iexos-100, the periodic error of my mount was about 600 seconds,

here is a 900 sec long exposure to show it, the focal length was about 500 mm and the camera was a Canon T1i/500d

I have no idea if that's good or bad Y_Y