IMAGING MOUNT

[Pennyless]

I've always had an interest in astronomy and have owned a few scopes in years past.  I built a 2 Cookbook Cameras when they where available, still have them somewhere, but at the time I did not have a mount capable of tracking accurately enough for photography.  I couldn't even place any objects in the sensors field of view with the equipment I had.  I had one lucky shot of M13 that I could never duplicate.  My wife recently bought me a Celestron 130 slt and and a ZWO ASI120 MM-S.  She knows my interest in astronomy and wanted to surprise me.  Her heart was in the right place and I will always love any gifts from her, we have been married for over 35 years, but we all know this is far from a useful beginning setup.  Anyway, the first item I think I need to upgrade is the mount.  I can probably spend about $2000.00 without having to hide anything from my wife. I've looked at the AVX, SW EQ35, and the iOptron 25EC, I'm leaning toward the iOptron, it is supposed to be capable of longer unguided shots than any other mount in it's price class.  I see that most people here seem to like SW.  What is the difference between the various Sky Watcher Mounts I see here the HEQ5 Pro, EQ6R, EQ5 ect…  I am interested in DSO

[vlaiv]

This is not easy topic, and in fact, many will point out (me included) that mount is the most important piece of kit when it comes to imaging.

In budget category, and all the mounts you've listed are budget category mounts, we can roughly say there are two important things that you need to pay attention to:

- weight capacity

- accuracy of tracking

Btw, I said budget mounts - but that does not mean all of these are poor mounts - a lot can be accomplished with such mounts - I have Heq5 for example and it serves me very well within its limits.

Weight capacity - you need to have at least 50% of head room with respect of all your imaging gear to be placed on the mount (this is just a recommendation - more stuff you put on the mount - greater chance something will not work as it should - mount will not track properly, wind will be more of an issue, something will not work as expected). My Heq5 is rated at 15-18kg (depending on the source) and I've put as much as 15kg on it for imaging and it worked, but I did not feel comfortable with that much weight on it. Nowadays, I limit weight on the mount to about 10-11kg (maybe 12kg, but no more), so keeping about 50% of headroom is very sound advice.

Accuracy of tracking - most of these budget mounts will have issues unguided. Most suffer from periodic error and greatly benefit from guiding. Longer the focal length (or to be more specific - higher sampling rate you use) - shorter your exposures will need to be to avoid star trailing.

Exception to above are mounts with encoders, and in this price range, as far as I know, only iOptron offers encoders. Encoders are really expensive and it is much cheaper to get guiding kit. Guiding solves some other issues that encoders can't (at least not without very sophisticated software and building of sky model - something that is done in permanent setups as it is time consuming to be done on each session).

Eq3 / Eq35 are really very basic mounts that can hold camera + lens and very small scopes. You will be very limited in exposure length with those mounts and will benefit greatly from guiding.

Eq5 is step up from above two in terms of weight capacity and performance, but same holds - smaller / lighter scopes (up to say 6-7kg of total weight, btw when I say total weight - that does not include counter weights, it just means scope and camera and any other gear attached to it) and if possible - guide it.

I would personally avoid AVX mount as I've read that it suffers from some issues that make it less than desirable imaging platform. Take this with grain of salt as I've never even seen one live, let alone used one.

iOptron mounts are said to be good, and I've read many excellent reports on their performance. I would personally probably go for iOptron with encoders (EC model) if I don't plan to guide. Since you are in Texas, you'll probably get better prices on iOptron then we get here in Europe, so that is a plus.

If you can - get iOptron CEM40EC, it is over your budget at about $3000 - but it is Heq5 class mount with 18kg payload and it has encoders, and is lighter weight.

CEM25EC is EQ5 class mount - so keep weight up to 8-9kg on it (it has 13kg load capacity) and again it has encoders - which you want if you don't want to guide.

That is about mounts, now about scopes and camera.

ASI120mc is very good planetary camera and very good guide camera. You can use it for EAA/EEVA with 130slt, but that is about it. You can try imaging with it - I've done it and even managed some decent images, but that sensor is very small.

If you are serious about imaging - you will need better imaging gear. Look into Skywatcher ED80 + flattener / reducer or Skywatcher 130PDS newtonian and coma correcotr and Canon DSLR. Something like used Canon 450 or similar will be very good option.

Imaging is rather serious business if you want to do it right and there are many aspects of it, and best thing you can do is do a lot of research before you commit to particular gear. Book - "Making every photon count" is said to be very good book for anyone planning to get into astro imaging. Of course, SGL is place where you can read a lot about all topics that interest you and ask questions, and hopefully get decent answers.

 

[MarkAR]

Also take note of the weight of the mount, how easy it would be for you to move it around.

[FMA]

Vlaiv, your answer are always poor gold for beginners.......

 

What do you think about this one? its the one im in love with

 

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-az-eq5-gt-geq-alt-az-mount.html

 

 

[vlaiv]

9 minutes ago, FMA said:

Vlaiv, your answer are always poor gold for beginners.......

 

What do you think about this one? its the one im in love with

 

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-az-eq5-gt-geq-alt-az-mount.html

 

 

Don't have much info on that mount. Most of info on mounts that I have, comes from reading about the specs and more important - first hand experience. I don't remember reading any first hand experience with that mount from people doing AP. It does not mean that it is not good mount.

I know people owning older brother of that mount - AZEQ6 who are perfectly happy with their mounts. AZEQ6 performance is similar to the performance of EQ6 - maybe a bit better than old EQ6 and in line with EQ-6R because both AZEQ6 and EQ6-R have belt drive.

AZEQ5 also has belt drive, so that is a plus.

I've read once that someone found that lead that connects RA and DEC axis to be awkward. This one:

Fact that this mount has both AZ and EQ operation does mean it is preferable in rather specific situation - where you want to use it as both Imaging and Visual mount (I'll address this point later with some additional info).

As for imaging performance, I can only sort of guess what it will be like based on numbers. On this page, we have information on internals of this mount:

http://eq-mod.sourceforge.net/prerequisites.html

One thing that I'm slightly concerned is 0.25" stepper resolution - it is less than Heq5 class mount by almost double, and just a bit more precise than Eq5 class mount. With stepper motors this limits how well guided this mount can be. I think that realistically you can expect about 1" RMS guiding with it, maybe down to 0.8" RMS on a good night - which again means that max resolution that you can go with such mount is 1.5"/px - 2.0"/px - which is ok, that is sort of smaller scope - up to 700mm focal length with sensibly sized pixels (or some sort of binning to get you to that resolution).

It looks like this mount has PPEC, and this is good. My Heq5 does not have this feature and I use VS-PEC in EQMod - which means that I can't really use my mount for AP and visual, because I would like to be able to use mount for visual without dragging laptop outside - with only hand controller. But that messes up my periodic error correction since it is not permanent and I need to park to exact position each time I finish using my mount otherwise PEC will go out of sync (no encoders on the mount).

AZEQ5 has encoders and PPEC so it is well suited to be used in both roles at the same time (well not at the same exact time - but you know what I mean - you don't to do anything special if you image one night and observe the other in AZ configuration).

If you want better precision in imaging then go with either Heq5 or EQ6-R or AZEQ6 - all of which are heavier mounts but offer better precision for AP. Mind you - stock HEQ5 / EQ6 is going to have vary greatly sample to sample in their performance and only once you tune it and mod it - it will be able to deliver best performance.

I stripped my Heq5 and changed all the bearings, I did belt mod on it, replaced saddle plate and changed tripod and now it guides at 0.5" RMS, so if you are going to keep things stock - not sure if price premium (of EQ6 class) and weight are worth it if you have your heart set on AZEQ5.

Hope this helps

 

[johnturley]

1 hour ago, vlaiv said:

 

I've read once that someone found that lead that connects RA and DEC axis to be awkward. This one:

 

 

I'm currently awaiting a replacement lead from Skywatcher via Rother Valley Optics, the original one was slightly frayed, and I now suspect that was the reason as to why to low voltage flashing light was coming on after less than one hour of use. 

I have used the mount for visual use several times since without the above lead attached, and it will now run for several hours before the light comes on, only snag with this is that you have no dec slow motion.

John

Edited February 19, 2020 by johnturley

[johninderby]

The AZ-EQ5 GT has the same max load capacity as the HEQ5, 15kg in EQ mode but can handle a 15kg load on each side in ALT Az mode. I think of it more as an ALT AZ mount that can also be used in EQ mode. Ideal if you are mainly visual and just doing a bit of imaging. If it’s mostly imaging  then the HEQ5 with belt mode would be more suited.

Would fit a decent saddle though. The Primaluce saddle and puck are very good. Really liked my AZ EQ5 and would like to get another one someday. 

[vlaiv]

@FMA - there is interesting thread with AZEQ5 tuning and touch - up that might be interesting to you:

 

[FMA]

I didn't understand all, but I assume in your opinion is less accurate than this...

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-heq5-pro-synscan.html

And is 230 pounds less.......

Am being stupid to think that having an equatorial and az in the same tripod is something desirable?

 

 

 

[johninderby]

This is the HEQ5 version with the belt mod that you should be comparing it too. The AZ EQ5 already has drive belts.

https://www.firstlightoptics.com/skywatcher-mounts/sky-watcher-heq5-pro-with-rowan-belt-mod-upgrade.html

Edited February 19, 2020 by johninderby

[vlaiv]

57 minutes ago, FMA said:

I didn't understand all, but I assume in your opinion is less accurate than this...

https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-heq5-pro-synscan.html

And is 230 pounds less.......

Am being stupid to think that having an equatorial and az in the same tripod is something desirable?

 

I'm not sure who you are referring to, but if that response was directed towards me, I was saying following:

If you want a mount that you will be using for both visual in alt-az mode and imaging in eq mode and that is equally important to you, and you want to have something more lightweight and you have limited budget - then it is a good choice.

If you don't have limited budget and you don't mind the weight - AZEQ6 is better mount for both imaging and observing - well, primarily for imaging.

If you are limited with your budget and imaging is very important to you, but visual not so much - then look at Heq5, and understand that stock version is not going to perform to best of its ability, but once you tune it and mod it - it will perform better than AZEQ5 mount for imaging.

From what I gathered, I think you will be happy with AZEQ5 as you want to both observe and do some casual imaging - this is why I linked that thread where AZEQ5 mount has been tuned a bit. I also asked on that thread if owner could confirm what sort of guiding results could be expected from AZEQ5 - and yes, I was right about that - about 1" RMS or a bit less. This is in range of stock Heq5 mount, so guide performance for casual imaging will be quite good (although that also means that you will need to tweak your mount as most SkyWatcher owners do at some point when imaging to bring the best out of their mounts).

[FMA]

tHANKS VERY MUCH VLAIV

[SamAndrew]

The AZ-EQ5 is very light and easy to use. If you use a small refactor you don't have to dismantle anything, as the whole setup including counter weights can be picked up fully assembled which means you can be imaging in minutes. I had one, and it typically guided at about 0.75" total RMS, but depending on where you were pointing in the sky it would sometimes be under 0.5"

The EQ6 is very heavy in comparison and not a mount I'd use for a mobile setup in a changeable climate like the UK where the clear spells can be very short. You'll find you won't bother setting up if the gap in the clouds is only forecast to be a couple of hours. 

 

[2STAR]

On 19/02/2020 at 11:43, johnturley said:

I'm currently awaiting a replacement lead from Skywatcher via Rother Valley Optics, the original one was slightly frayed, and I now suspect that was the reason as to why to low voltage flashing light was coming on after less than one hour of use. 

I have used the mount for visual use several times since without the above lead attached, and it will now run for several hours before the light comes on, only snag with this is that you have no dec slow motion.

John

The power lead in this above diagram is not correct, the power lead is attached first, then the dec lead, thus avoiding them becoming 'tangled', there is no problem during operation with either lead if attached like stated.

The AZ/EQ 5 gt also has dual encoders incorporateed. The tracking is smooth and good in both eq or alt/az.

regrds

eric

[2STAR]

On 19/02/2020 at 11:43, johnturley said:

I'm currently awaiting a replacement lead from Skywatcher via Rother Valley Optics, the original one was slightly frayed, and I now suspect that was the reason as to why to low voltage flashing light was coming on after less than one hour of use. 

I have used the mount for visual use several times since without the above lead attached, and it will now run for several hours before the light comes on, only snag with this is that you have no dec slow motion.

John

Leads not correctly placed on ths diagram