Telescopes

Starting in Astro Photography

Starting in Astro Photography
by Zoltan Trenovszki, 365Astronomy

I’ve written this article in response to a question from one of our kind customers, Gareth T.
My reply email has grown into such a size that I’ve decided to publish it for the benefit of the public. Customer’s original question used by his kind permission.

Question:
I’ve taken an interest in astro photography but just using a tripod, DSLR and good lens only gets you so far. I would like to be able to take amazing
photos of the Milky Way but also try to get some good shots of M83. Of course I have a budget of up to around £400, but don’t particularly know
what to get. I would be interested in a motorized scope, too. Could you advise me on my best options?

Answer:
There are many different options for you and you don’t even necessary have to buy a telescope, but for some objects like planets and deep sky objects a telescope is helpful to have.

1. Mobile Tracking Devices
You could start astrophotography with your existing camera and lens kit by adding a mobile tracking device like an Astrotrac, Baader Nano Tracker, Vixen Polarie or Fornax 10 mount, so lets star with these devices first and then we’ll discuss appropriate telescope kits further down the page as well.

These are quite different from all the rest that will follow in a way that these are really mobile solutions that can be taken with you on the airplane in a backpack, although some can be boosted to a significant but still very mobile size, read further and you’ll see…
I should also mention that these mounts are practically precise motorised single-axis equatorial mounts. There is no built-in GOTO functionality (cannot be with just one axis), so the desired objects for photography will have to be found by yourself.

Astrotrac Travel System - NEW!

Astrotrac Travel System – NEW!

AstroTrac System – Payload 3-4kg that can be increased to max 15kg
One of the most popular and the first that came around, Astrotrac Mobile Tracking mount offers a solution for those who want a very lightweight solution for a simple camera + lens setup with a photo tripod, geared head and a ball head or their system can be upgraded to be able to carry an APO refractor telescope up to 15 kg overall payload capacity. All in amazingly beautiful and clever design and you can start with just the Astrotrac mount for just above £400 if you already have a tripod, a ball head and probably a geared head. Far not as comfortable, but instead of the geared head, you may use a simpler video/photo head on your tripod.

I should mention that their polarscope is a warmly recommended extra as to achieve really great astrophotos you’d  really need a very precise polar alignment that can be done with the help of the polarscope.

FORNAX 10 LighTrack Mobile Tracking SET with Wedge, Ball Head & Tripod

FORNAX 10 LighTrack Mobile Tracking SET with Wedge, Ball Head & Tripod

Then if you eventually get there that you want to further improve your results or use a bigger camera lens then you may simply add their finely adjustable wedge and if you would want to use it with even a small refractor telescope, there is also an Astrotrac Head deal that contains a counterweight system that makes it possible to use heavier equipment safely. If you travel a lot, all these can be completed by a pier and a pier bag. By the time you have got all these described above you’ll reach £1500 expenses, but the good thing is that you can simply stop at the first stage and buy only the mount, polar scope and battery pack that is just slightly above £500. Most of our customers would stop at that stage and only those traveling around the world a lot would buy the complete kit, called Astrotrac Travel System.

Fornax Tracking System – Fornax 10 LighTrack – Payload 3-5kg that can be increased to max 6-7kg

An exciting product from Hungary that even resulted in better tracking than the Astrotrac, according to Steve Richard’s review, published in the Sky at Night Magazine in April 2012. One of the faults was about the less attractive design that Fornax has improved  since then. Now it comes with an added ball bearing on the drive shaft, safety rail around the drive surface and the black plastic cover containing the electronics has been replaced by a much nicer and stronger aluminium housing. Similarly to the Astrotrac it could be used on a geared head, if you’ve got one already, or a wedge is a comparatively inexpensive addition, so we would strongly recommend to buy it with the wedge. To be honest, there is a Fornax 10 kit that contains the mount, a ball head, a wedge, a tripod that can carry much more than the similarly complete iOptron Skytracker, so if you are thinking of the Astrotrac Travel System, but it’s way out of  your budget, this is the cheapest complete kit that would replace it, and now even a counterweight system will be available from us soon. Without the counterweight system you are limited to 3-5 kg payload depending on whether you use your gear in on-axis or  off-axis position, but with the addition of the counterweight system it can be further increased by few kilograms. The counterweight system is expected to be available from Feb-March 2014.

UPDATE (Apr 2015): the new Fornax 10 LighTrack II is coming soon. Beautiful, modern design and even further improved performance!

Vixen Polarie Star Tracker – Payload 2kg

This is again a very nice looking device that is coming from the famous Japanese telescope manufacturer Vixen. It has the lowest carrying capacity of 2kg and so it will manage a DSLR camera with an average, but not large telephoto camera lens, but don’t try to use it with a small APO. Otherwise, this is nearly a pocket sized device, so really easy to carry on an airplane. It comes with usual high-quality feel that characterises many Japanese products and the optional accessories (polarscope and compass) are also very well made and practical, but this is not the cheapest product in compare to what it does. So, it’s a beautiful, very high quality product and certainly fills the gap for those looking for an extremely compact device, just bear in mind the limited payload.

Baader NANO Tracker

Baader NANO Tracker

Baader NANO Tracker

This is the latest and lightest mobile tracking device available on the market and probably in the whole universe (we cannot prove it…)

Made in Japan, the incredibly small Baader Nano Tracker weighs a mere 350g. It is so small and light, you might even think that you forgot it at home. Despite of its tiny dimensions it’ll safely carry a 2kg payload.

 

2. Non-motorised, equatorial mount that can be upgraded later

Another approach (to keep you within your budget for now…) is to buy an equatorial mount with a telescope and add a single or dual axis motor or even full GOTO later:

SkyWatcher SKYMAX-127 EQ3-2 Maksutov-Cassegrain

The advantage of going for an equatorial mount is that these are more usable for longer exposure astro photography, but only if you have it at least motorised. These are certainly better for deep sky astro photography than an Alt-Azimuth mount and could be made even better by the addition of a guiding system, however it would probably be over its limit to add guiding to an EQ3-2 mount, although these days you can buy very compact guiding systems like the MGEN from Lacerta or LVI from Baader that work very well, but those are not cheap at all.

3. Increase your budget and jump for a GOTO now

Above telescope would cost over your budget if you buy it with GOTO installed (but somewhat cheaper than the overall cost if the GOTO added later):

SkyWatcher SKYMAX-127 EQ3 PRO SynScan GOTO Maksutov-Cassegrain

Under paragraph 2. it has been explained why it is good to have a motorised or GOTO equatorial telescope.

4. O.K., lets stay within budget, lets go for a compromise with an AZ GOTO

buy an alt azimuth mounted telescope with full GOTO out of the box but this will be not as good for astro photography, you might still take images of planets and not too long exposure images of deep sky, but you’ll have to find comparatively bright deep sky objects, like galaxies, double stars, clusters.

SkyWatcher SKYMAX-127 SynScan AZ GOTO Maksutov-Cassegrain

The above 127mm Maksutov is good for illustration of price differences, as the OTA is the same (OTA=optical tube assembly) and also because it’s a very popular tube as it provides comparatively sharp images even at high magnifications if the seeing is otherwise good. So whilst it’s very good for planets, it’s not so good for faint deep sky objects as it is an f/11.8 instrument. Just like in photography, the focal ratio of f/12 means it’s far not as bright as a f/8 or f/6 optical system would be, but with an f/6 instrument of the same aperture planets would appear much smaller than in the f/12 system with the same eyepiece or camera.

Newtonians usually come with focal ratios somewhere between f/5 and f/7, so these are better for fainter deep sky objects, but Newtonians frequently have a problem with back focus, unless specially designed for astro photography, like the Skywatcher Explorer-130PDS.

SkyWatcher Explorer-130PDS Parabolic Dual-Speed Newtonian Reflector OTA

Sometimes these come with even lower focal ratio: f/4 or long tubed Newtonians with focal ratio up to f/9 -f/10, but again there are not so many of these.

Celestron NexStar 4 SE Maksutov-Cassegrain Telescope

Celestron NexStar 4 SE Maksutov-Cassegrain Telescope

 

5. Just a little above budget, a very good compromise

If you may increase your budget to around £440 then there is also a good alternative to the Skymax-127 AZ GOTO from Celestron, the Nexstar 4 SE. The Nexstar 4 SE and the much more expensive Nexstar 5 SE are similarly sized, the 4 SE is a Maksutov like the Skymax-127 and the 5 SE is a Schmidt-Cassegrain. The latter one has got the exact same aperture as the Skymax-127: 5 inches, but whilst SCTs (abbreviation for Schmidt-Cassegrain Telescopes) are not as sharp as Maksutovs, those are still a very good compromise for an all-rounder. Another benefit of having an SCT is that these would cool down to ambient temperature quicker than Maksutovs.

On the other hand the dual-purpose mount of the Celestron Nexstar 4 SE and 5 SE can be converted into an equatorial mount thanks to the built-in wedge, that makes it comfortable to use them for slightly longer exposure than it is possible with a simpler alt-azimuth mount.

Celestron NexStar 4 SE Maksutov-Cassegrain Telescope

 

Celestron NexStar 5 SE Schmidt-Cassegrain Reflector Telescope

 

I should mention that there is a very special autumn promotion that we’ve just started for the Celestron SE series at 365Astronomy…

Article by Zoltan Trenovszki, www.365Astronomy.com

Please note, above content has not yet been fully completed. We’ll have to read it through and will probably add more info and images…

 

 

 

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Posted on October 17th, 2013.