New to Astrophotography - Star Tracker?

Hi all,

I have been going through threads and trying to get an idea of what I need to get started at a basic level. Essentially, I want to be able to get nice long Milky Way shots and not just be limited to the 30 second rule because of the movement. I'm looking to set up my 5D III with my 16-35 2.8 III, and I'm not sure what I really need to use.

I was looking at the "SkyWatcher S20510 Star Adventurer Astro Package" which I guess just mounts on my tripod. Then I align it and I'm off? I can't seem to find a very clear path to this for some reason.

Thanks for any help!

Look through these and see if that helps some.
I don't know a thing about them myself.

https://www.youtube.co​m …+adventurer+ast​ro+package

JCseh wrote in post #18725002
Hi all,

I have been going through threads and trying to get an idea of what I need to get started at a basic level. Essentially, I want to be able to get nice long Milky Way shots and not just be limited to the 30 second rule because of the movement. I'm looking to set up my 5D III with my 16-35 2.8 III, and I'm not sure what I really need to use.

I was looking at the "SkyWatcher S20510 Star Adventurer Astro Package" which I guess just mounts on my tripod. Then I align it and I'm off? I can't seem to find a very clear path to this for some reason.

Thanks for any help!

Heya,

The Star Adventurer is a great way to start. There are alternatives, but they're all essentially going to do the same thing, but the Star Adventurer has a lot more potential "upgrade" paths as you get more into it. It's a great way to use cameras and telephotos to do astrophotography and stay light & portable. Good choice to start and finish!

These trackers are essentially right ascension driven worm gears setup in an equatorial fashion. So you point it North and adjust latitude so that the it's polar aligned, aligned with polaris. The better polar alignment you achieve, the longer exposures you can probably get without too much error. A rough alignment will still net you several minutes of exposure time with a wide angle lens. But yes, that's as simple as it is. Level the tripod/base. Point it North. Polar align it. And that's it, it will track at a specific slew rate to match the rotation of the Earth so you can essentially freeze the sky and take long exposures.

Lock up the mirror on your 5D3 so that the slap doesn't vibrate your exposure and introduces wobbly stars. Use an intervalometer so that you're not touching the camera setup for exposures. With your 16-35 F2.8, do not try to shoot that at F2.8. Stop down to F4 to decrease coma in the edges and increase overall performance. Shooting at low ISO provides zero benefit with this sensor, there are readings out there you can look up which will point you towards ISO 800 or ISO 1600 as the points you should probably be using (anything more or less is costing you dynamic range due to read/write noise, heat noise, and amplified noise). Exposure time is what you're gaining. For exposing the sky, you want to get a spike on your histogram at 1/3rd from the left. Exposing more than that and you're likely just getting amplified sky glow. Less than that, down to 1/4th from the left, will under-expose. Only use the histogram to judge exposure, don't try to see DSO's with the LCD. To gauge exposure, you can push to highest ISO and exposure for a few seconds to see where you are on the histogram. Then, count the stops and come down to ISO 1600 and see what the new exposure time needs to be. You'll have it ball parked after that for the future. At F4, ISO 1600, you could easily do 4 minutes give or take. Again, looking for that histogram spike at 1/3rd from the left.

You can frame the core of the galaxy at 24mm with a full frame by the way. But the milky way gets real interesting at 85mm~200mm with all the DSO's in there.

If you really get into this, you can use software like BackyardEOS and a laptop to setup better control. But you can start out with just an intervalometer.

Practice with single exposures at first. Noise is fine. You cannot escape noise.

In the future, you may want to get into stacking several exposures. Stacking exposures does two things: 1) reduces random noise, and 2) increases signal to noise ratio. This is not required. But again, it's something you're going to bump into as you read more into DSO astrophotography in general.

Very best,

Lots of information! Thank you so much! I'm looking a bit more into the actual foundation and setup. Maybe looking also at the iOptron SkyGuider Pro EQ on B&H. I have been practicing getting comfortable with my RS-80N3, as opposed to the previous little wireless thing I used for fireworks, etc.

The exposure and histogram tracking sounds like it's going to take a bit to get the hang of, but should be interesting to get into. I wasn't really shooting for DSO's off the bat, more like a broad Milky Way shot, across the night sky. Currently I'm just doing simple single exposures on the moon here and there at like 1/100 @ 400mm, and at this point, I'd like something a bit more interesting. If I can get tracking down, and exposure, etc, I might be more interested in opening it up with large zooms and stacking as mentioned.

Thank you for that wealth of information. I have a lot to review and thins to test!

JCseh wrote in post #18725595
Lots of information! Thank you so much! I'm looking a bit more into the actual foundation and setup. Maybe looking also at the iOptron SkyGuider Pro EQ on B&H. I have been practicing getting comfortable with my RS-80N3, as opposed to the previous little wireless thing I used for fireworks, etc.

The exposure and histogram tracking sounds like it's going to take a bit to get the hang of, but should be interesting to get into. I wasn't really shooting for DSO's off the bat, more like a broad Milky Way shot, across the night sky. Currently I'm just doing simple single exposures on the moon here and there at like 1/100 @ 400mm, and at this point, I'd like something a bit more interesting. If I can get tracking down, and exposure, etc, I might be more interested in opening it up with large zooms and stacking as mentioned.

Thank you for that wealth of information. I have a lot to review and thins to test!

All of the major trackers are good and will do the job. They're all similar in price too. You can't go wrong with the SkyGuider PRO or the Star Adventurer. The more capacity they can take, the better, and the more accessories like wedge and counter weight options, the better. And if they have guiding options, even better, for the long run. Overall, you cannot beat the cost of a $500 or less tracker for astrophotography compared to buying a "fast prime" and all that, that people try to do. There's a ton of youtube videos to show how to set them up, they're quite easy at this scale. Put more effort into getting a good polar alignment until it's muscle memory, and you'll do great.

Depending where you are, go to the darkest skies you have access to.

Beware zooms, they often produce seagull shaped stars due to the elements and lens design. Primes are ideal for simplicity and best coma performance. Stopping down is preferred, you wouldn't want to do this at F1.4 because fast optics produce larger more pronounced amounts of coma, so if you stop down a bit, you get a much better field and star shapes, such as at F4 to F5.6 with a lens designed to be F2.8 (stopping down 1 or 2 stops). Depends on the lens, each is different for this purpose (if it has excellent coma wide open, by all means, shoot wide open).

Lastly, a huge piece of advice, you need dew control. The easiest way is to get a little heater wrap for your lens and a lithium battery. As long as you keep your optics warmer than ambient temperature, dew cannot form on it.

I use these on my lenses and some of my telescopes and eyepieces. It has a built in regulator to allow you to choose hot and hotter basically (to avoid having to buy a temp controller unit). It has velcro and just wrap it around the front element of your lens. You can use the smaller one for camera lenses, up to 3 inches in diameter (80mm basically and smaller):

https://www.amazon.com …RMZ9?_encoding=​UTF8&psc=1

Simply plug it directly into a decent lithium battery pack and you're set for all night, or several nights. I use TalentCell batteries. They're inexpensive and perform great. A standard male to male 5.5 x 2.1 DC cable will connect the two.

https://www.amazon.com …ywords=talentce​ll+battery

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I miss the days of putting on storm boots, lighting my pipe, taking some coffee in a thermos, and hiking out into a dark field in a green zone (very little light pollution) and just seeing what was up in the sky with a tracker and all that. So simple and satisfying!

I had an iOptron Skytracker Pro back when I started getting into astrophotography a little more seriously. It opened doors. I later went nuts, but I still miss the simple days!

This was one of my first setups... the SkyTracker Pro and a ball head with an APS-C with LCD (T4i) and various inexpensive prims, with a tripod low to the ground, an intervalometer and a pipe with some cavendish!

IMAGE LINK: https://flic.kr/p/nrWd​9W

IMAGE LINK: https://flic.kr/p/nzCy​TM

IMAGE LINK: https://flic.kr/p/kPpD​Si

This thread needs to be a sticky, amazing information for newcomers!

Good hell! That's a lot of info and I appreciate the product specifics. So far the info I've gotten all over is something like:

Solid tripod and head. It seems like lower center of gravity and counter weights will help keep things stable.
I was originally looking at the SkyWatcher S20510 Star Adventurer, but also started looking at the iOptron SkyGuider Pro EQ setup.

Researching these led me to the Equatorial Wedge for easier polar alignment and a counterweight kit, mostly for larger camera setups. Also, it seems like there's essentially a rail that mounts to the hotshoe where you can attache a reflex site, or red dot, for easier alignment.

I can see this all adding up a bit, but sourcing just parts spot checking, it doesn't seem too too crazy. It might be a bit more than I was looking at up front. I think I'll start putting pieces together, and hopefully after my trip to Maine, I'll have a good list to start working on! If I can get decent results, I'll happily throw this all into the thread if it helps, along with the information above!

Thanks for the help!

To follow up on my last response, to make it super easy, it looks like the iOptron SkyGuider Pro package comes with with a wedge base and counter weight included. As I read more, the app pairing makes alignment very easy. With a solid tripod and ballhead, it seems like all I'd need to get started. I might look at the wrap for dew, but I don't know that I'll be out for that long starting out. Plus, I can put my huge Anker battery to work for this setup!

http://a.co/d/blc3YTY
$430 seems like a pretty reasonable price for an all-in-package that I can kick start my star gazing with! Maybe less than a month or so, and hopefully I can be adding my own photos in this Genre.

I found this one thru Google. I "tried" finding it at the iOptron website to get more data on it, but I did not find it there.

There are a few videos on youtube.

Good luck on your search.

Mike wrote in post #18725976
This thread needs to be a sticky, amazing information for newcomers!

Agree!

If you haven't gotten it yet ( Skyguider Pro) I picked one up earlier and this is what I've found. I'm also a noob in astro photography.
Bought at BH
I thought the controller would work to find objects, it's only good for polar alignment. You need a real mount for it to have goto capabilities.
Using a 5div, manfrotto hyrdrostatic and a 300/4 is really pushing it but works as below. (single shot 31 seconds 1250 iso)
I tried using my 100-400L but it was too heavy I think.
Even with the counterweight, I had to add some more to get it reasonable. Anytime you swing the lens around it throws the balance off and I have to hope I have the clutch tight enough.
I'm using a manfrotto 055cxpro4 and I think it picks up vibrations if there is anything more than a very slight breeze.

Have your tripod on concrete. Polar aligning can be tough depending on your vision as you are focusing both on the grid and Polaris.
I think I'll just bite the bullet and get a real goto mount since the camera and lens are so heavy.

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Great info in this thread. The tracker I use is no longer made... the Sky Watcher and iOptron models (they each make two different models... with a lesser model that claims to handle 2.5Kg load and a higher model that claims to handle 5Kg load) are what dominate the market today.

The camera's auto-focus won't work on stars... their just too tiny and not really bright enough. You'll need to focus manually and... this naturally provides an opportunity to screw things up.

When I started, I'd find a bright star (and it really should be a star ... not a planet), crank the ISO to max, crank the shutter duration to 30 secs (because the Canon does "exposure simulation" in live-view ... so doing this makes the stars brighter) to focus... focus in to make the points of light as small as possible. In live-view you can zoom the view to 10x and that'll help you get closer when refining stars to the tiniest point possible.

Return the camera exposure settings to something reasonable (you wont want 30 secs at max iso ... that was just to help you see the live-view screen while focusing). Take some test shots. INSPECT the test shots.

The first time I did this... I rushed it, thought the images look pretty good (everything looks great on a 3" screen). On my 27" computer monitor... not so much (they were all a bit mushy).

Next time out I was a little more careful ... but not enough. I still had slightly mushy stars. I find you really need to take your time and if you can unload the images and inspect them on a bigger screen... that would be much better.

Ultimately I bought a Bahtinov focusing mask. Lonely Speck makes one (they call it the "Sharp Star 2"). You can also make your own. It's a series of slots or grooves that cause points of light to throw diffraction spikes... specifically three diffraction spikes that are in different directions. When out of focus, they wont have a common central intersection. But when IN focus... they all converge at the same point. It makes it much easier to know if you really nailed the focus.

Good luck and hope for clear moonless skies!