756 replies to this topic

[asanmax]

Sounds about right, tonight will probably be clear *fingers crossed*, so will definitely take note of these tips

 

 

Thanks asanmax! It's really encouraging hearing from you as if you recalled earlier on, newfiestargazer and your images gave me a sense of direction I was aiming for. 

 

Plan on collecting Sii and Oiii tonight with succesful drift alignment. Oh and btw, how were you able to make minor adjustments to the azimuth? It was quite a challenge for me to do so and it made me PA even worse on PHD2 (i gave up and decided to redo a rough PA with decent results)

 

Cheers!
Ethan

Hi Ethan,

 

So I was imaging without proper polar alignment for quite some time. I set up the correct latitude angle on the mount and was just roughly pointing the counterweight shaft North with no Polaris visible of course.

The guiding was ok, but not as great as it is now. I was getting field rotation and it was quite noticeable, especially after comparing the first and the last images taken.

One night I decided that I needed to do proper polar alignment using PHD2 drift alignment. I should say I was excited to do that as I had never done drift alignment in PHD2 before.

 

So I just read some online articles and reviews on drift alignment feature of PHD2 and the same night spent about 40 minutes to align the mount properly.

It was a challenge because I had to unscrew the Az axis a bit and do some very slight adjustments to point the mount at the celestial pole.

I'm sure with the Az adapter I would have had more fun as it should clearly make the adjustments in Az axis waaaay easier.

 

From then, I have not adjusted the mount at all, and I have literally zero field rotation now. I don't have good viewing conditions ever! It is always average or below average. On an average night the total RMS is sitting around 1 arcsec, sometimes dropping to 0.7 for 10-15 minutes, and on a below average night it is usually around 1.3 arcsec.

 

I read somewhere on the forums that it's better to not have the guide scope to focus precisely. They recommended to get it into focus and then screw the camera in (not out) just a tiny bit so the star image becomes a little bigger. This way the edges of the star blob become sharper and it's easier for PHD2 to detect tiny movements. That's what I did and I have a feeling that the idea works very well.

[asanmax]

Witch's Broom nebula

Celestron C5

Canon T3i Ha modded

85x120sec at ISO 1600

Bortle 8

 

I feel like I really need a CLS-CCD filter as I just can't get the details of fainter parts of the objects I shoot.

 

Attached Thumbnails

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Edited by asanmax, 02 November 2019 - 12:25 AM.

[Jerry Hubbell]

Hi Ethan,

 

So I was imaging without proper polar alignment for quite some time. I set up the correct latitude angle on the mount and was just roughly pointing the counterweight shaft North with no Polaris visible of course.

The guiding was ok, but not as great as it is now. I was getting field rotation and it was quite noticeable, especially after comparing the first and the last images taken.

One night I decided that I needed to do proper polar alignment using PHD2 drift alignment. I should say I was excited to do that as I had never done drift alignment in PHD2 before.

 

So I just read some online articles and reviews on drift alignment feature of PHD2 and the same night spent about 40 minutes to align the mount properly.

It was a challenge because I had to unscrew the Az axis a bit and do some very slight adjustments to point the mount at the celestial pole.

I'm sure with the Az adapter I would have had more fun as it should clearly make the adjustments in Az axis waaaay easier.

 

From then, I have not adjusted the mount at all, and I have literally zero field rotation now. I don't have good viewing conditions ever! It is always average or below average. On an average night the total RMS is sitting around 1 arcsec, sometimes dropping to 0.7 for 10-15 minutes, and on a below average night it is usually around 1.3 arcsec.

 

I read somewhere on the forums that it's better to not have the guide scope to focus precisely. They recommended to get it into focus and then screw the camera in (not out) just a tiny bit so the star image becomes a little bigger. This way the edges of the star blob become sharper and it's easier for PHD2 to detect tiny movements. That's what I did and I have a feeling that the idea works very well.

Hi Asanmax,

 

As far as defocusing your guide scope, the reason to do this is to spread the light over more pixels so that the centroid calculation that PHD 2 is doing is more precise. That is one of the problems with using a very short focal length guide scope is because when it is focused well, the stars are would be very sharp and well under-sampled so that only a few pixels, probably < 6 have any signal at all that PHD2 can use to calculate a centroid.  Better to blob out the guide stars so that a very precise centroid can be calculated and the mount can be guided more precisely.

Edited by Jerry Hubbell, 02 November 2019 - 11:38 PM.

[asanmax]

Hi Asanmax,

 

As far as defocusing your guide scope, the reason to do this is to spread the light over more pixels so that the centroid calculation that PHD 2 is doing is more precise. That is one of the problems with using a very short focal ratio guide scope is because when it is focused well, the stars are would be very sharp and well under-sampled so that only a few pixels, probably < 6 have any signal at all that PHD2 can use to calculate a centroid.  Better to blob out the guide stars so that a very precise centroid can be calculated and the mount can be guided more precisely.

Thank you Jerry, that totally makes sense. And yeah, I use a 130mm guide scope

[wanthalf]

Hi Jerry,

what does it mean if the green LED does not turn on? Does it not boot? Am I able to fix such a problem myself?

Thanks.

[Jerry Hubbell]

Hi Jerry,

what does it mean if the green LED does not turn on? Does it not boot? Am I able to fix such a problem myself?

Thanks.

Hi,

 

When the PMC-Eight boots, the green light will come on when it starts and then go off after a few seconds. Once a connection is made and communications is active, then the green light will be on all the time. 

[burks]

I've had my mount for about 2 weeks now and the little I've used it, it has been a blast. Sorry, no photos as the mount is far more than my knowledge and skill are capable of at this point. What I am enjoying is having a solid platform that is easy to operate (movement wise and such). Even with my crap polar alignment, being able to slew "close" to objects has saved me a ton of time and effort. That alone has made the $400 so well worth it. Mount seems pretty sturdy too. Going to pour some footers this spring so I can place it on a more firm base that is already leveled.

 

Just for future reference, what is everyone using to connect to their laptop to use PHD2 for guiding? I get it's a ST4 port but any special cable? Hoping to have it autoguiding by end of year, starting out by using my webcam and a 50mm guide scope. Just need to figure out how to connect everything together and working.

Edited by burks, 12 November 2019 - 11:43 PM.

[asanmax]

Just for future reference, what is everyone using to connect to their laptop to use PHD2 for guiding? I get it's a ST4 port but any special cable? Hoping to have it autoguiding by end of year

Nope, it's not the ST4 port. It's the mini-USB port. You just need a mini-USB to USB-A cable. ST4 port is for the auto guider camera if you plan to use it. But with the ASCOM platform you can skip connecting to the ST4 port because the mount is controlled directly from computer via the USB cable.

I have a USB hub attached to the mount, so that the mount, the DSLR camera and the guiding camera are all connected to it. I only need to connect one USB cable from the hub to my laptop.

Edited by asanmax, 12 November 2019 - 11:45 PM.

[nwww66]

How do you connect via mini usb and still maintain wireless connection for the ‘goto’ Feature. 

[asanmax]

How do you connect via mini usb and still maintain wireless connection for the ‘goto’ Feature. 

You can only operate the mount via USB or WiFi. You can switch between the connection types in Configuration Manger.

I use Astrophotography Tool to slew to objects and then use plate solving in the same application so the object is precisely centered in the frame.

Works better than GoTo, you don't need to do the 2 or 3 star alignment.

Please visit https://espmc-eight....#iexos-100&ct=1

You'll find lots of information, including some tutorials from Jerry Hubbell on how to set up the mount and apps.

[asanmax]

Tonight I decided to test the Explore Scientific pair: iExos-100 mount and ES ED80 APO triplet.

I was blown away by performance of the two in my Bortle 8 backyard.

Guiding was exceptional as usual but unfortunately I was only able to shoot 17 frames before the fog from the ocean came in

Camera: Canon T3i Ha modified

Scope: ES ED80 APO

Mount: iExos-100

Guider scope: 37mm/130mm, AR0130 sensor

Filter: CLS clip-in filter

17 frames 120 sec each at ISO 1600

 

Attached Thumbnails

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[Ethanwyh]

The weather finally cleared up last night, managed to get some decent subs from 2am onwards. Hopefully, able to collect more data for Oiii and Sii to create a hubble palette image (just in time for Christmas too). Fingers Crossed!

 

28x 300s subs

guided on the iEXOS-100 mount

QHY183M + Optolong 7nm Ha filter

 

 

 

[Ethanwyh]

 

Hi Ethan,

 

So I was imaging without proper polar alignment for quite some time. I set up the correct latitude angle on the mount and was just roughly pointing the counterweight shaft North with no Polaris visible of course.

The guiding was ok, but not as great as it is now. I was getting field rotation and it was quite noticeable, especially after comparing the first and the last images taken.

One night I decided that I needed to do proper polar alignment using PHD2 drift alignment. I should say I was excited to do that as I had never done drift alignment in PHD2 before.

 

So I just read some online articles and reviews on drift alignment feature of PHD2 and the same night spent about 40 minutes to align the mount properly.

It was a challenge because I had to unscrew the Az axis a bit and do some very slight adjustments to point the mount at the celestial pole.

I'm sure with the Az adapter I would have had more fun as it should clearly make the adjustments in Az axis waaaay easier.

 

From then, I have not adjusted the mount at all, and I have literally zero field rotation now. I don't have good viewing conditions ever! It is always average or below average. On an average night the total RMS is sitting around 1 arcsec, sometimes dropping to 0.7 for 10-15 minutes, and on a below average night it is usually around 1.3 arcsec.

 

I read somewhere on the forums that it's better to not have the guide scope to focus precisely. They recommended to get it into focus and then screw the camera in (not out) just a tiny bit so the star image becomes a little bigger. This way the edges of the star blob become sharper and it's easier for PHD2 to detect tiny movements. That's what I did and I have a feeling that the idea works very well.

Followed your advice on making permanent markings for ease of setting up, now i take less than 15 minutes transporting the mount to my balcony, plugging the wires and controlling everything from APT

 

 

Also, wished that cloud filters existed LOL

[asanmax]

 

Followed your advice on making permanent markings for ease of setting up, now i take less than 15 minutes transporting the mount to my balcony, plugging the wires and controlling everything from APT

 

 

Also, wished that cloud filters existed LOL

Cloud filters haha, good one! The first person who invents it will become a millionaire in no time.

Great shot in Ha by the way!

[Glenilacqua]

Hi All-

 

I just saw that this system went on sale at $350. That is a shockingly good price for the stated value proposition - if it works. However, I've read through almost all of this thread today and I'm having trouble appreciating the totality of all of this to inform my purchase decision. There have certainly been a number of difficulties described by new owners. But all products have compromises, quirks, etc. I have no idea the scale of the issues, and it's hard to  know how this compares to the frustrations of using any tracking mount.

 

I guess what I'm asking is whether this is a good, safe choice for a newbie wanting to dip his toe in the AP world?

 

Also, it appears that there was an upgrade in the tripod at some point? How do I know if the one at the retailer is pre or post that upgrade?

 

I have a Sky-Watcher Evostar 72 and a DSLR. I'd like to start with shooting the moon and build my skill toward larger deep sky objects. If purchased, I'd start with an iPad, but I have various laptops that I can employ if I decide to go that way. 

 

So if you have experience with this, is it recommendation for me, or not? 

 

I really appreciate all of the feedback. Fell free to PM me if that's better for you. Thanks!

Edited by Glenilacqua, 20 November 2019 - 04:24 PM.

[Ethanwyh]

Hi All-

 

I just saw that this system went on sale at $350. That is a shockingly good price for the stated value proposition - if it works. However, I've read through almost all of this thread today and I'm having trouble appreciating the totality of all of this to inform my purchase decision. There have certainly been a number of difficulties described by new owners. But all products have compromises, quirks, etc. I have no idea the scale of the issues, and it's hard to  know how this compares to the frustrations of using any tracking mount.

 

I guess what I'm asking is whether this is a good, safe choice for a newbie wanting to dip his toe in the AP world?

 

Also, it appears that there was an upgrade in the tripod at some point? How do I know if the one at the retailer is pre or post that upgrade?

 

I have a Sky-Watcher Evostar 72 and a DSLR. I'd like to start with shooting the moon and build my skill toward larger deep sky objects. If purchased, I'd start with an iPad, but I have various laptops that I can employ if I decide to go that way. 

 

So if you have experience with this, is it recommendation for me, or not? 

 

I really appreciate all of the feedback. Fell free to PM me if that's better for you. Thanks!

Just PMed you

[Ethanwyh]

Cloud filters haha, good one! The first person who invents it will become a millionaire in no time.

Great shot in Ha by the way!

Thanks! I'm lookin to gather data for S2 and O3 but so far, dismal details in my subs. Even at 5 mins. Maybe it's a 183 sensor limitation for the amount of aperture i'm using LOL

[asanmax]

First time doing 4 minute exposures with iExos-100 from my backyard.

Pretty satisfied with the results although atmospheric seeing was below average.

I have to admit, had I used the Explore Scientific ED80, I would've spent 50% less time imaging. It collects the light incredibly fast.

Tracking was near perfect sitting at around 1 to 1.2 arcsec of total RMS, sometimes dropping below 1 arcsec.

33x240sec @ ISO1600

Lens: 3M-5CA, 500mm F8

Canon T3i modded

CLS filter

Bortle 8

Edit: cannot appreciate enough how it is easy to use the mount in combination with PHD2 and APT, setting the mount up, plate solving, framing - all works amazingly fine.

Attached Thumbnails

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Edited by asanmax, 23 November 2019 - 12:46 AM.

[Jerry Hubbell]

First time doing 4 minute exposures with iExos-100 from my backyard.

Pretty satisfied with the results although atmospheric seeing was below average.

I have to admit, had I used the Explore Scientific ED80, I would've spent 50% less time imaging. It collects the light incredibly fast.

Tracking was near perfect sitting at around 1 to 1.2 arcsec of total RMS, sometimes dropping below 1 arcsec.

33x240sec @ ISO1600

Lens: 3M-5CA, 500mm F8

Canon T3i modded

CLS filter

Bortle 8

Edit: cannot appreciate enough how it is easy to use the mount in combination with PHD2 and APT, setting the mount up, plate solving, framing - all works amazingly fine.T

Thanks so much asanmax for the updated report on your latest imaging. This is an awesome shot and it very gratifying to see your results. I will forward your message to our team in Arkansas.

 

Great work!

[Ethanwyh]

First time doing 4 minute exposures with iExos-100 from my backyard.

Pretty satisfied with the results although atmospheric seeing was below average.

I have to admit, had I used the Explore Scientific ED80, I would've spent 50% less time imaging. It collects the light incredibly fast.

Tracking was near perfect sitting at around 1 to 1.2 arcsec of total RMS, sometimes dropping below 1 arcsec.

33x240sec @ ISO1600

Lens: 3M-5CA, 500mm F8

Canon T3i modded

CLS filter

Bortle 8

Edit: cannot appreciate enough how it is easy to use the mount in combination with PHD2 and APT, setting the mount up, plate solving, framing - all works amazinglyThi

This is an amazing shot!

[asanmax]

Thank you both Jerry and Ethan. I hope I'll be able to get out of the city to a Bortle 4 site next week if the sky is clear.

[asanmax]

Cocoon nebula

95x90sec @ ISO3200

Explore Scientific ED80

Canon T3i

I think this is as much as I can do from my backyard, I don't think I'll be able to pull out more details even if I acquire more frames.

 

Attached Thumbnails

• 

[John59]

Hello everyone!

I have been watching this thread for a while and the mount certainly seems to be very capable for AP with small aperture telescopes.

I have been using an iOptron Skyguider Pro with iPolar and my SW Evostar 80ED.

This mount looks like a logical next step up.

However there is only a "peephole" to polar align.

I see that folks are using drift alignment but to me this simply takes too long.

My question, what is the longest capture time without trailing stars that anyone has achieved using only the provided "peephole"?

[Devonshire]

John,

 

You may find some AP'ers using the peephole for alignment, but I think the more usual case is a mix of Sharpcap (leveraging the guidescope for PA), ASAir/Stellarmate capabilities similar to Sharpcap, and various phone apps. These tend to be fast, convenient, and much easier on the knees.

 

You're asking about this for unguided use?  The PMC8 mounts in general are positioned for unguided visual use, and guided AP - where they really can punch above their price point. A few folks on the PMC8 support forum have posted experiments with unguided iExos-100 shots and done better than one would expect, but the reliability of guiding is really hard to beat. 

 

- Bob

[asanmax]

I totally agree with Devonshire.

 

I tried using the mount unguided a couple of times when I was just starting using it. But then I realized that I wanted to use all the capabilities of the mount, goto, 2-axis guiding, ASCOM compatibility etc.

The mount is a gem if you follow the instructions and enjoy learning new stuff.

I did not do polar alignment for the first one or two months of using the mount because the Polaris is not visible from my backyard. I just pointed the mount to the North roughly and then just did the imaging with auto-guiding. Of course I was getting some field rotation over the course of the imaging session, but it was nothing to worry about if I kept the exposure time below 180sec.

You will also improve your image quality because you will be able to dither.

 

Then one day I decided to do the drift alignment and spent some 40 minutes on it (first time doing it). After that I just marked the tripod leg positions on the ground. And since then, I haven't had to do any corrections at all, I just bring the whole thing out, let it cool for a bit and start imaging.

 

So if you're planning to do guiding then you will benefit big time upgrading.