Lightweight Imaging mount

[festoon]

I'm pretty sure this has been discussed before. I'm looking for advice on which mount and tripod suits my needs most for DSO widefield imaging.

For me portability is key. I'm looking to put together a system which I can leave fully assembled and be able to easily carry. I already have my main imaging rig a HEQ5 and ED80, but more often than not, with me having a full time job and kids I find it takes too long to set up and its not getting the use it should. I also have a AZ-EQ5 which is a bit lighter than the HEQ5 but still its a beast to carry if I leave everything fully assembled.  What I'm looking to achieve is a lightweight grab and go widefield imaging set up ASCOM/EQMOD controlled setup that I can leave fully assembled. For this purpose I've started assemblling a widefield low weight rig including a lightweight lens and camera (Atik 414EX and Samyang 135mm F2 lens). If I can leave everything fully assembled and easily carry it into the garden on a clear night, then I think I'd be getter much more data to process

So the question is which mount?

Requirements:

1) EQ mount

2) Weight - including counterweights - fully assembled

3) Able to cope with Focal length 135mm and maybe 30-60 second unguided subs

4) ASCOM/INDI controllable

In the grand scheme of things I'd be happy to spend more money to achieve the most time out imaging, but budget wise probably around £1000. For instance if it eeks a few kg off the weight I'd be happy to substitiute a standard tripod for a carbon fibre one.

I've a list of options in my head e.g. EQ3-2 Pro with a carbon fibre tripod, CEM25P, Explore Scientific iEXOS-100 but I'd really like to hear other opinions...oh and in my dreams https://www.firstlightoptics.com/rainbow-astro-mounts/rainbow-astro-rst-135-mount.html

[vlaiv]

How about simple tracker like SW adventurer?

Or perhaps, something similar to your ideal mount - just a bit less precision and less carry capacity

https://www.firstlightoptics.com/skywatcher-mounts/sky-watcher-az-gti-wifi-alt-az-mount-tripod.html

You can use that mount both in AZ and EQ mode, but EQ mode requires a bit of fiddling and few more pennies spent.

You'll need EQ wedge, Counterweight bar and counter weight and flashing firmware to version that supports EQ operation.

I have that mount and have used it AZ mode so far. I think I'll tune it since there is quite a bit of backlash (there is tutorial on how to open and adjust this mount). It can be guided and I think it's supported by EQMod (with custom settings).

You can place it on photo tripod of your choice - so you can find a very light weight one ...

[festoon]

Thanks @vlaiv

Can you use ASCOM with a SW adventurer?

Really good point about the AZGTi. I think its a good option. The only issue is I'm not a particularly good DIY'er and I'd hate the thought of bricking £250! Now if someone was prepared to buy and set up the AZGTi mount for me in EQ mode I'd happily pay for their help!

[vlaiv]

1 hour ago, festoon said:

Can you use ASCOM with a SW adventurer?

SW star adventurer is simple star tracker - it's like a "clock" device - it does not move in DEC and has no goto capability. It also can't be guided. You do good polar align, let it track and shoot exposures. If your working resolution is low and polar alignment is good - you should keep most of your frames (there will still be some periodic error in that mount).

AZ GTi is really easy to setup in EQ mode. You need three items:

1. Wedge. There are couple of them available:

https://www.firstlightoptics.com/skywatcher-star-adventurer/skywatcher-star-adventurer-equatorial-wedge-white.html

https://www.firstlightoptics.com/william-optics-mounts/william-optics-wedge-and-extension-bar-for-skywatcher-star-adventurer-and-ioptron-skyguider-pro.html

https://www.teleskop-express.de/shop/product_info.php/info/p7929_TS-Optics-ATC-Wedge---Mini-Equatorial-Wedge-for-Giro--AstroTrac--photo-tripods.html

https://www.teleskop-express.de/shop/product_info.php/info/p11485_iOptron-Polar-Wedge---base-for-SkyTracker-Pro-and-for-many-tracking-mounts.html

There is not much to it. AZGti has photo thread at the base and so does every one of these wedges - so you just screw it on and you are ready to go.

2. Suitable CW bar and counter weight. Most people adapt this one:

https://www.firstlightoptics.com/skywatcher-star-adventurer/skywatcher-star-adventurer-counterweight-kit.html

There is a problem with particular CW bar - it has M8 thread (I believe) and AZGti expect M10 or M12, so you need to purchase suitable male to male adapter.

see here for details:

https://www.cloudynights.com/topic/631581-sky-watcher-az-gti-mount-counterweight/

Or here (it also says you can use EQ1 counterweight bar and counter weight and there is offering from TS as well):

3. You need to flash your firmware to latest version. This is rally really simple to do - it took me something like 10 minutes to do it. It is also useful in AZ mode if you observe with your left eye as it changes scope orientation from mount on right to mount on left.

http://skywatcher.com/download/software/motor-control-firmware/

You need firmware loader (one that uses wifi)

and AZ/EQ firmware for AZGti "Firmware: AZGTi Mount, Right Arm, AZ/EQ Dual Mode, Version 3.20"

I used my laptop - just powered the mount, connected with laptop to access point it created, started loader and loaded the firmware.

Btw - you need to take into account disclaimer given by Skywatcher:

Quote

This firmware is for mounting a telescope on the right side of the AZ-GTi(or AZ-GTe) mounts when the telescope is pointing forwards. Warning: Please note that the AZ-GTi ( or Az-GTe) mount is not intended for astrophotography. In this firmware version, we enable the option to operate the mount in equatorial mode for experienced customers who want to explore the full potential of the AZ-GTi (or AZ-GTe) mounts and have fun. Performance for astrophotography is not guaranteed and average customer might experience challenges in obtaining the result that they expected.

If you are experienced, want to explore and have fun - then go for it

Given the above - chances of bricking the mount are very slim. Only serious DIY that comes to mind would be tuning the mount for backlash and such. Here is some info on that - just so you put things into perspective as some people complained about serious periodic error and backlash. My mount has quite a bit of backlash and I intend to do this before I start fiddling with EQ mode (I've done the firmware update but am yet to get wedge and CWs myself).

https://www.cloudynights.com/topic/668785-adjusting-backlash-on-skywatcher-az-gti-mount/

 

Edited August 11, 2020 by vlaiv
typos or spelling or something else ....

[fireballxl5]

+1 for the AZ-GTi as a light weight travel mount, though I do use the ASIair Pro now for alignment,  control and guiding. Works well for me using focal lengths ranging up to 650mm with my 60mm travel refractor. 

There are a couple of related threads already on SGL, such as 

 

[festoon]

For anyone who has adapted their AZGTI into EQ mode...what is the weight of the mount with a light counter weight attached (enough to balance a photocamera lens and Atik CCD)? And does anyone know how that compares to the weight an EQ3-2 Pro mount or a CEM25P mount?

[DaveS]

Just a note: the SA has a guiding port for ST4, but it only guides in RA, so your PA still has to be pretty good.

[festoon]

One other option which I have come across is the EQM-35 Pro. Seems quite lightwight at 4.38kg. How would you expect this to perform against an eq modified GTi?

[vlaiv]

17 minutes ago, festoon said:

One other option which I have come across is the EQM-35 Pro. Seems quite lightwight at 4.38kg. How would you expect this to perform against an eq modified GTi?

You'd think that it would be light weight but it is not.

Well, it depends on what you compare it to - it is certainly light weight compared to HEQ5 or EQ6 class mount, but let's be realistic.

Can you move it assembled in one hand?

Head is approx 4.4kg, tripod is 5.7kg, it has 2x3.4kg of counter weights - let's assume you are using only one so 3.4kg.

Let's also assume that your imaging rig has something like 1.5kg max. That totals to 15Kg. I know that I can lift a compact object weighing at 15Kg and carry it needed distance but I'm not sure how I would feel about bulky sensitive object of that weight.

AzGTI with tripod weighs about 4kg (3.9kg). Add counter weight of 1kg and add another 0.5kg for wedge and 1.5kg of imaging kit and it totals to something like 6kg?

EQM-35 Pro will certainly have less issues like backlash / PEC / tracking and goto precision and it can carry more. It is higher class mount / step up AzGTI, and that shows both in weight of the rig and carry capacity (both almost double).

 

[festoon]

Makes perfect sense @vlaiv

The GTi rig will be half the weight in the end. Could probably get the EQ35 down to 12kg if you used a carbon tripod, but even still 6kg is a much more attractive option

 

[jiberjaber]

If the aim is a quick setup in the garden, why not just add a todmorden pier and leave the mount installed and covered.  It's just concrete blocks that can easily be dismantled if you are worried about moving house for example and with a coat of paint or a bit of wood cladding can blend in well.  Probably looking at less than £100 inc painting and a cover.

From my experience, it's not so much the assembly that takes time, it's the PA etc.  With my current setup I just head out, take the cover off the mount (HEQ5Pro) and attach the scope (ED80) and connect three cables (power, ethernet and mount control) (Pi running EKOS, Dew Controller, focuser all mounted on the scope)

Of course I don't want to get in the way of teh business case for new toys either   You certainly need a small rig to play with, I've got the iOptron Sky Guider Pro for that but that isn't ASCOM controlled.

[Guest]

I would be slightly warey of the EQM-35 just based on my personal experience. It has been a very good mount for me whilst also being very bad! Let me quantify...

I purchased this mount a few months ago as my first astrophotography mount and to start with it behaved its self very well indeed. I have taken many PHD2 guided 600 subs with the setup with no issues whatsoever but even early on I would have unexplained dec issues. We aren't just taking mild backlash issues but seismic issues. You can adjust the worm gear tension etc but the mount overall has been used with hugely variable success rates and if you search the internet enough you can hear other comments realting to inherant dec issues.

The mount is also not that mobile and quite heavy for portable use though it does have the advatage of having a mode whereby the dec motor can be removed and it can be used in a ra only way like the Star Adventurer.

I have just taken delivery of an EQ6-R Pro as my main mount - I purchased this earlier than I had anticipated because of the issues I was suffering. Moving forward I suspect I will replace EQM-35 with a AZ-GTi for dark site imaging.

I am not saying do not purchase one as at times mine was nothing short of exceptional but be aware that there are potential issues and the weight barely qualifies it as mobile as marketting would suggest.

[R26 oldtimer]

I also had an azeq5. Recently I got myself a second hand azgti as a travel mount, in very good condition from Stu, and found that it can easily be guided below 2 arcsec with a flimsy photo tripod. Now sold the azeq5 and got an eq6 replacement