Ideas for building a travelling telescope system (suitable to go in airline hand luggage)

[SiD the Turtle]

So I'm going to the southern hemisphere on holiday soon, to a bortle 4, (I live in a 5 in the UK) and I'm considering building a travel rig to take with me. However, whenever I price this up it get's pretty expensive, and I've got some questions on the parts, so interested to know people's experiences and ideas. Some background:

• Where possible I'd like to recycle parts from my existing rig, without making it super hard to put back together. This is a HEQ5 (too big and heavy to travel), William Optics ZS73 (not huge but probably a little too big to travel), ASI 1600MM-Pro camera, ASI-120MC and Skywatcher Evoguide for guiding, filter wheel, electronic focuser, Pegasus Power Box advance for power, a Celestron small power tank and a Raspberry Pi/EKOS/Indi for control.
• As travel is not frequent, the whole kit should be usable as a normal rig in the back garden.
• It should be robust enough to experience the usual bumps and knocks you'd expect going through security, in the back of a car etc. so maybe an APO over a Newtonian?

So here's my idea:

• Redcat 51 APO: it's a tiny scope, wide field, has a decent focuser and Bahtinov mask so I can dispense with needing the ZWO EAF, no need to buy a secondary field flattener etc.
• Replace the filter wheel with a filter drawer to slim down the size of the overall package, but I'd need to buy new filters as mine are unmounted, or just get a one shot colour camera instead.
• Camera: no idea, struggling to find a large frame sensor camera that works with the Redcat 51. I could take the DSLR but I've had much better results with dedicated astro cameras.
• A smaller guidescope like the one from William Optics or ZWO as the Evoguide is quite big, and recycle the ASI-120MC.
• ZWO AM3 (or AM5 if budget allows but is that overkill?)
• Take the Pegasus Power Box, dew heaters and Raspberry Pi from the main rig.
• Carbon fibre ZWO tripod can be chucked in the suitcase, and use whatever I can find around the hotel room as tripod weights.

[Elp]

You could use the evoguide as the main scope, it works well. Needs the flattener and other bits to setup.

If not, many camera lenses work well too, the Samyang 135mm F2 is one of the best imaging optics for astro and it's not even designed for it, beats most astro specific equipment due to it being small and supremely fast.

You'll still need a filter drawer, or can screw filters into the front of flatteners if using most astro cameras because many let all wavelengths of light through so you'll have to block the IR with a UV/IR cut or luminence filter otherwise you'll get star bloat.

If you've got the funds for it, a HD mount will be excellent, I've got a hem15, ever so slightly smaller than the am3.

How are you going to control it? An Asiair makes things simple via mobile phone control, Stellarmate on an rpi also has a phone app.

You can just use the 1600, but I assume you want short session quick results with OSC.

Edited January 30 by Elp

[PhilB61]

I take my full OSC imaging setup away on regular long trips to France and Spain but as we travel in a 6m campervan I don't really have to worry about size or weight, so can't really offer advice on that aspect. What I can say is whatever combination of gear you end up taking especially the imaging software/hardware make sure you have tested and used it for some imaging sessions before you go. It's a pain having to download and reinstall software, update firmware and generally trouble shoot when it's being done on your phone. Make a list of all your interconnect power and data cables so you don't leave anything behind, getting spares might be impossible if you are somewhere remote and just difficult anyway when not in your home country.

 

 

[900SL]

My response is bias driven and a result of my own purchasing decisions and  experience, so take it with a pinch of salt

My portable rig is a Nikon D5600 or 533MC Pro, filter drawer,  Redcat 51, AsiAir mini, Fornax LT2 tracker, ZWO EAF and Blackcat focuser. No guiding, no guide scope, no goto. I plate solve and adjust RA and Dec by hand to find targets. 

The Redcat is a great short focal length scope. ASI Air for PA, plate solving, focus, capture etc. Fornax LT2 tracks at 1" PE without guiding, so 3 min exposures at 250mm are spot on, no egg shaped stars 

Edited January 31 by 900SL

[SiD the Turtle]

Thanks all for the great input.

17 hours ago, Elp said:

You could use the evoguide as the main scope, it works well. Needs the flattener and other bits to setup.

If not, many camera lenses work well too, the Samyang 135mm F2 is one of the best imaging optics for astro and it's not even designed for it, beats most astro specific equipment due to it being small and supremely fast.

You'll still need a filter drawer, or can screw filters into the front of flatteners if using most astro cameras because many let all wavelengths of light through so you'll have to block the IR with a UV/IR cut or luminence filter otherwise you'll get star bloat.

If you've got the funds for it, a HD mount will be excellent, I've got a hem15, ever so slightly smaller than the am3.

How are you going to control it? An Asiair makes things simple via mobile phone control, Stellarmate on an rpi also has a phone app.

You can just use the 1600, but I assume you want short session quick results with OSC.

Good shout on needing an LP filter, and wonderful idea using the guide scope, never thought about that! I see some complaints about backfocus with it, so I'll do some more research. I'm using an Rpi and the free version of Stellarmate + laptop which work

15 hours ago, PhilB61 said:

I take my full OSC imaging setup away on regular long trips to France and Spain but as we travel in a 6m campervan I don't really have to worry about size or weight, so can't really offer advice on that aspect. What I can say is whatever combination of gear you end up taking especially the imaging software/hardware make sure you have tested and used it for some imaging sessions before you go. It's a pain having to download and reinstall software, update firmware and generally trouble shoot when it's being done on your phone. Make a list of all your interconnect power and data cables so you don't leave anything behind, getting spares might be impossible if you are somewhere remote and just difficult anyway when not in your home country.

Very good shout. I'm a checklist weirdo just for remembering to pack enough underwear, so will be adding an astro section!

18 minutes ago, 900SL said:

My response is bias driven and a result of my own purchasing decisions and  experience, so take it with a pinch of salt

My portable rig is a Nikon D5600 or 533MC Pro, filter drawer,  Redcat 51, AsiAir mini, Fornax LT2 tracker, ZWO EAF and Blackcat focuser. No guiding, no guide scope, no goto. I plate solve and adjust RA and Dec by hand to find targets. 

The Redcat is a great short focal length scope. ASI Air for PA, plate solving, focus, capture etc. Fornax LT2 tracks at 1" PE without guiding, so 3 min exposures at 250mm are spot on, no egg shaped stars 

Lovely, I was wondering for such short usage, OSC, no very long narrowband exposures plus a decent mount I could probably get away without a guide scope. Star trackers scare me though, before I had a go-to I was rubbish at centring targets so computerised go-to and plate-solving saved the day!

[900SL]

14 minutes ago, SiD the Turtle said:

Thanks all for the great input.

Good shout on needing an LP filter, and wonderful idea using the guide scope, never thought about that! I see some complaints about backfocus with it, so I'll do some more research. I'm using an Rpi and the free version of Stellarmate + laptop which work

Very good shout. I'm a checklist weirdo just for remembering to pack enough underwear, so will be adding an astro section!

Lovely, I was wondering for such short usage, OSC, no very long narrowband exposures plus a decent mount I could probably get away without a guide scope. Star trackers scare me though, before I had a go-to I was rubbish at centring targets so computerised go-to and plate-solving saved the day!

I would prefer goto in a portable rig, also dithering capability, but at darker sites the Fornax does pretty good. Plus I like a challenge 😎 

Fornax, unguided, broadband Andromeda and dual narrowband ET:

 

Edited January 31 by 900SL

[michael.h.f.wilkinson]

I am travelling to Texas for the eclipse, and my current rig is:

iOptron HEM15 mount plus tripod (5kg check-in luggage)

APM 80mm F/6 triplet imaging scope (2.5kg hand luggage)

Lunt Ca-K module (haven't weighed it yet, hand luggage)

Carl Zeiss 500 mm F/8 mirror lens (1 kg, hand luggage)

ASI183MC for white light ASI178MM for Ca-K imaging (120g each, check in luggage)

Lightweight laptop for imaging/data acquisition (1.2kg, hand luggage)

 

If you replace the Zeiss telephoto with a guide scope, and my non-cooled ASI183MC with a cooled camera, this would work for DSOs. The Samyang 135mm is brilliant for this kind of work, and it combines neatly with the HEM15. It works even without guiding, as this shot shows (120s subs, just tracking on the HEM15)

 

 

[900SL]

My two caveats with the Samyang 135mm are based on my own experience, and are (1) image scale (2) Check any purchase carefully. My copy has very bad off center issues with one or more decentered lens elements. Even at f4 part of the field is a flurry of coma, elongation and CA. Unfortunately only became apparent outside return and after starting astro

[Elp]

Mine have tilt issues (more to do with the mounting), and they don't like o3 filters much either which exasperates the issue. But the speed is amazing, I use them more than my refractors.

[SiD the Turtle]

Thanks again all for the input. I have gone a little off-piste in then end, with an eye on super-portability. Here's what I'm planning once all the parts are in stock, critical opinions welcome:

• ZWO AM3
• Redcat 51
• ZWO ASI2600MC-DUO
• Optolong L-pro LP filter
• Pegasus power box advance for power/USB hub (already owned)
• Raspberry pi for control (already owned)
• Dew heater on the 51 (already owned)

My rationale is that makes the setup super light- just the scope and the ZWO OSC that has a built in guide cam, so no need for separate guide cam, scope etc. so I won't need the capacity of the AM5 or similar as the total payload should be around 3kg.

Downsides is that this option is super expensive, that camera isn't cheap nor is the Redcat, and there the risk of under-sampling. Though after much reading here and elsewhere, it seems there's a lot of successful people undersampling but then using dither/drizzle to solve.

[Elp]

Seems decent. You can do without the Lpro, it's a waste of time. Better to learn how to background extract in Siril or equivalent instead. If you want a filter that actually makes a difference (for emission nebula rich in ha and o3 only) get a narrowband OSC like Lenhance/extreme/ultimate, Antlia ALPT or equivalent, there's now also S2/o3 filters too so you can better achieve the Hubble pallette look (you need the S2), if you're not too concerned about Hubble pallette the ha/o3 ones work fine for better separating emission from background sky.

[LoveFromGallifrey]

So I took my Zenithstar 73II, asiair pro, and Canon 700D plus accessories (filters, dew heaters, chargers, guidescome and guide cam etc) in a plain old camera backpack as hand luggage when flying from the UK to Australia for a year. I even managed, miraculously, to get away with it as my "small purse" (I'm a woman) and took a cabin suitcase as well 🤣 it weighed slightly over 10kg but nobody ever checked, fortunately. 

It definitely pushed the limits.

In the future, I'll be looking for either a Redcat or something similar, or a decent camera lens.

The main issue I had was the mount and power supply. I already had a full suitcase because I was going out for a year; I could hardly pack up an EQM-35 and a heavy battery pack as well. The lightweight HEM/AM5 mounts had not yet been released, and all the lightweight star trackers wouldn't take thebweight of my rig. I ended up buying a 2nd battery and a CEM26 while I was over there. 

But with a Redcat/camera lens, I'd be able to use it with a star tracker, like a sky guider pro with a lighter tripod. The battery pack would be easier to accommodate then. 

Failing that, I'll be trading the CEM 26 in for a lovely HEM mount instead 😄

Edited February 17 by LoveFromGallifrey

[GTom]

11 hours ago, LoveFromGallifrey said:

So I took my Zenithstar 73II, asiair pro, and Canon 700D plus accessories (filters, dew heaters, chargers, guidescome and guide cam etc) in a plain old camera backpack as hand luggage when flying from the UK to Australia for a year. I even managed, miraculously, to get away with it as my "small purse" (I'm a woman) and took a cabin suitcase as well 🤣 it weighed slightly over 10kg but nobody ever checked, fortunately. 

It definitely pushed the limits.

In the future, I'll be looking for either a Redcat or something similar, or a decent camera lens.

The main issue I had was the mount and power supply. I already had a full suitcase because I was going out for a year; I could hardly pack up an EQM-35 and a heavy battery pack as well. The lightweight HEM/AM5 mounts had not yet been released, and all the lightweight star trackers wouldn't take thebweight of my rig. I ended up buying a 2nd battery and a CEM26 while I was over there. 

But with a Redcat/camera lens, I'd be able to use it with a star tracker, like a sky guider pro with a lighter tripod. The battery pack would be easier to accommodate then. 

Failing that, I'll be trading the CEM 26 in for a lovely HEM mount instead 😄

I made a pocket power supply from 10 AA-size eneloops. OK for small, well balanced mounts (afraid harmonic drives will need more power). I wonder if the Fornax LT2 could handle the z73+flattener+DSLR. Not the lightest tracker but still smaller footprint than any reasonably priced EQ mount I know. I have an EQ3-2 for home use, bringing it to the Canaries would definitely mean a second check-in luggage with all the hassle.

So far my gear is:

Canon 6D with 2 spare batteries
Canon 2.8/200L
Fornax LT2 with Fornax wedge and polar finder
Cheap aliexpress ball head
Cheap plastic mini tripod that I boost up with rocks
DIY 10x eneloop battery pack

I am looking for a better but still small tripod (important: it should work near the Equator!) and the maximum size scope the LT2 can handle without counterweight. Maybe a better head/dec unit would be useful too.
 

 

Edited February 17 by GTom