Lightweight scope for astrophotography?

[Alaness]

So if there's anything I've learned in the past year of owning a telescope, it's that portability is a pain in the Bottom! Especially as I don't own a car. Is there any 'scope + mount out there that is lightweight enough to be packed in a hiking bag and good enough for exposures of about 5 - 10 minutes?

Cheers,

Alan

[E621Keith]

How much are you willing to spend.

A Borg 71FL weights 1.2kg. Probably the lightest astrograph on the market. The cheaper 77ED weights 1.6kg, still less than half of other small Apos.

Couple one of those with an Astrotrac (1kg), 2 heads and a decent tripod (3-4kg) and you will be looking at a portable AP system with a total weight around 6-7kg.

[rowan46]

the other mount you may consider is a fornax lighttrack not as strong a load or as light a mount but it is a little cheaper

[ronin]

No small light weight mount will allow 5-10 minute exposures without the use of a guide scope and camera system. I would doubt that even an HEQ5/EQ6 would enable exposures of that duration without guidance.

Usually it is reckoned that around 30 seconds in the max unguided.

Smallest "sensible" scope would be something like the WO 71mm or a 66mm if you can locate one.

[rowan46]

according to reports the astrotrac will give 5-10 min subs providing it is correctly aligned the fornax in tests was even more accurate some thing like an equinox 60 should be doable on these mounts although you will be better off with camera lenses. both systems are however expensive by the time you factor in tripod, mount heads etc

[Catweazel]

I can recommend the Megrez72 if youcan pick up a 2nd hand one. 5 - 10 minute exposures would be tricky on a lightweight mount though

[ollypenrice]

Why not use a camera lens? The Canon EF200L is a stunner.

The optics aren't the problem, of course, in portabuility. It's the portable mount that's the issue.

The length of unguided exposure is dominated by the focal length. Short FLs are very tolerant indeed, long ones the opposite.

A very short FL camera lens can do 5 minutes reliably on an EQ2/3, for instance.

I'd go for an Astrotrac and a good prime lens. However, without at least a netbook focus is going to be very difficult.

Olly

[VigdisVZ]

The optics aren't the problem, of course, in portabuility. It's the portable mount that's the issue.

The length of unguided exposure is dominated by the focal length. Short FLs are very tolerant indeed, long ones the opposite.

A very short FL camera lens can do 5 minutes reliably on an EQ2/3, for instance.

I'd go for an Astrotrac and a good prime lens. However, without at least a netbook focus is going to be very difficult.

Olly

This man speaks the truth.

[RikM]

I agree with Olly as well.

I have had presentable 3min subs off an EQ3-2 with a 300mm lens. (or would have been presentable, if I hadn't botched the focus )

Something like an Astrotrak or Vixen Polarie would likely do even better.

[ollypenrice]

Yup, focus is a big issue. You can use software focusing if using a Canon camera. Peter (Psychobilly) also discovered that if you focus with a star on one of the one third line intersections an EF200L will give clean stars at F2.8. Now that is fast.

Olly

[themos]

My DIY solution was to convert an EQ1 to autoguiding in RA. http://www.astrobin.com/19257/

[Catweazel]

This probably sounds lika a bonkers question, but isn't it much harder to find stuff using a camera lens than with a scope?

[RikM]

I have a hot-shoe mounted red dot finder on my 1000D to get in the general area, then take 10-30 second shots to frame the object.

[themos]

This probably sounds lika a bonkers question, but isn't it much harder to find stuff using a camera lens than with a scope?

It's a great question! yes, it can be hard. One solution is a RDF on the camera. Another is described in this thread and it amounts to taking a picture and "solving" it, which lets you know which bit of sky you are pointing at. You can then move the camera to the right direction.

[Capricorn]

Lyra Optics do a 66mm ED for £299, fraction over 4lbs.

[roarke80]

I agree with Olly as well.

I have had presentable 3min subs off an EQ3-2 with a 300mm lens. (or would have been presentable, if I hadn't botched the focus )

Something like an Astrotrak or Vixen Polarie would likely do even better.

Oh wow that's beautiful! I assume this was done with only tracking of the mount? I'm wondering what I can get out of my EQ3-2 too without any guiding.....