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Astrophotography - Tripods vs Motorized Mounts

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posted on Feb, 15 2017 @ 12:27 PM
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So you got tired of reading about Trump on ATS and decided to take a look at my other thread on Astrophotography, the pretty pictures have given you an appetite for trying this out yourself. You've got a camera, and like that erik guy said: in today's world with digital cameras, I don't need to buy film, pay for it to be developed, wait days or weeks for it to be developed. I can see it right away!

Let's head on out and do it! CHAAAAARRRRGE!!!

Woah there Hoss. Yer gonna need to figure out a few things first.

First up is: weather. If it's cloudy, even partly cloudy out, you are going to have some issues.

Second up is: Moon. Is the Moon out tonight? If it is and you want to take pictures of it, you're almost good to go. If it is, but you wanted to take pictures of the stars......the light of the bright Moon is going to give you issues.

Third up is: Camera. What kind ya got? If it's a iPhone and you think you can just point it at the Big Dipper and you're good to go, you're going to be disappointed.

They do make devices that allow you to hook up your smart phone camera and other cameras like it to telescopes, and as long as you're looking at a very bright object in the telescope (Moon, planets like Venus, Jupiter, Saturn), you can get some excellent pictures, or take videos of them. Even some very bright nebulae like M42, Orion's Nebula.

But for wide angle lens photography of whole patches of the sky, you're going to need a camera like my DSLR that I have, because it allows you to adjust things like the f-Stop, the ISO and most importantly: how long the shutter stays open (exposure).

"But erik, I got a DSLR camera, so shut up already and let me run out there and buy up all the equipment I want!"

Again: Woah there!

Most of us that do this pretty much dream of having a set up like this:



When in reality, if you're dirt poor like me, this is what you have instead:



Basically a camera on a stick.

Okay, don't fret. This is how you should be starting off first anyways. You need to get comfortable with your camera, lenses and learning all the in's and out's. Especially if you've never done anything else, like actually owned a telescope, and used it to find things in the sky that your eyes can see!

Even so, you might already be comfortable with your camera and are ready to move on to the next step, which is mounting your camera in such a way so that you can "track" the object you're taking a picture of, but you do not have the money to spend on some of the expensive equipment for a motor mount. There is an answer for that too which I'll get to in a minute.

First: Static Mount vs. Tracking Mount.

When you're imaging the night sky, you have to keep in mind that you're going to take long exposures (measured in seconds and minutes). Bright objects like the Moon are so bright, you don't have to worry about that. You can take exposures as fast as 1/250 of a second, just like you're taking images during the day.
But those longer exposures we have a problem. It's called "The Earth Is Spinning At 1,000 Mph". The Earth's rotation causes the objects in the sky to appear to move.

If you set up your camera and open up the shutter, then walk away for about an hour, then come back and close the shutter, you'll end up with images like this:



These are called Star Trails, and can be very awesome and beautiful. If that's all you want to do, you can stop reading here as all it takes is a steady camera (a tripod) and opening up the shutter for very long periods. You just have to be aware of the weather (clouds) and light pollution. Some of these shots are the most beautiful I've ever seen:



Now, if you don't want star trails, but you only have a tripod, and don't have the money to blow on more expensive equipment, there are options.

If you just use a tripod, your option is limit how long you expose your frame for. How long is too long?

That's a hard question because it has a lot of "depends" on it. It depends on your lens (it's focal length), it depends on what you've set your ISO and f-stop to, and it also depends on what direction you have your camera facing.....which depends on where you live too.

I'm going to skip talking about ISO's and f-stops. Right now the most important thing is your focal length of your lens and what direction you're facing.

If you live in the northern hemisphere here on the Earth, objects in the sky when facing North will appear to move slower than objects in the sky when facing South. The opposite is true if you live in the southern hemisphere. Keep this in mind for the next part.

Focal Length: There is a rule called the Rule of 500. You take your focal length of your lens and divide it into 500. The answer is the amount of time in seconds you can open your shutter before the stars will move far enough to leave a trail.

So, for my EF-S 18mm to 55mm lens, if I have it set to 18mm, I'd divide 500 by 18 and the rounded answer is 27. So that means I should be able to do a 27 exposure and not get any star trails. If I set it to 55mm, the math says that I only have 9 seconds before I start to get star trails.

What about a 500mm telephoto lens? Do the math: 500/500 = 1

I can only expose the frame for 1 second. Which with stars and nebulae is not going to be enough time to capture anything in the frame.

Yet, if I attach a 6.5mm wide angle lens, I can expose the frame for a whopping 77 seconds before I get any trails!

Rule of thumb: The more you zoom in, the less time you have for an exposure if your camera is not tracking with the Earth's rotation.

Now, the Rule of 500 is not exact either. You will find that 27 seconds works perfect for the Big Dipper (pointed north), but if you do it with Orion (towards the south), you end up with a little bit of star trails. Just back off the exposure by a second or so.

I don't have the money to buy a motor mount!

Never fear! Human ingenuity is here!

All you need to do is go to the hardware store and by some cheap things:



Quit yer laughing! It WORKS. I built one myself back in the 1990s. You have to align the hinge of the device with Polaris (the North Star), Or the Southern Cross area for those of you downunder, and then slowly turn the screw (constantly) for a certain amount of time while you have the shutter on your camera open.

If you don't trust your hands, and have a little bit more money to spend, you can buy a stepping motor and it will do the same thing for you:



Astrophotography on a shoe string budget, and yes, you can get some amazing shots this way:





The bottom line is, if you want to take images of other galaxies, nebulae, globular clusters, you will need a mount that compensates for the Earth's rotation because their light is so faint, that you must make long term exposures.

I wouldn't complain though. In the old days with film......some shots you'd have to guide the camera with the shutter open for 45 minutes. Today's DSLR cameras can do it in 5 minutes.

(cont.)
edit on 2/15/2017 by eriktheawful because: (no reason given)




posted on Feb, 15 2017 @ 12:28 PM
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But let's say you have the money to spend.....or you finally emptied out your Swear Jar (ex-Navy....mine fills up fast):

Okay, well you can buy heavy duty motorized mounts like this:



This is what I'm going to be using again, mostly because I want to do some wide angle shots for a while with it, then I'll do more zoomed in shots.

Mounts like this have a couple of advantages: Most of them have what we call a Polar Alignment scope built into the mount. You adjust the mount so that the North Star is in the right spot on the alignment scope, and your mount is aligned enough to capture some great long exposure shots.

The other advantage of mounts like this is: if it's heavy enough, you can mount a telescope to it, and either piggy back your camera on the telescope, or attach it through the eye piece. If you want shots like this, that is what you will have to do:



Which of course means you'll need to learn how to use the telescope to find things in the sky. Much harder than it sounds, unless you use the "GoTo" telescope mounts, but most of those are not heavy duty enough for the added weight of camera gear attached to it.

Motorized mounts can be not too expensive. The one I'm getting costs about $180.00. But if you have the money to spend, they can start getting way, way up there in price.



posted on Feb, 15 2017 @ 12:40 PM
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Excellent. But you don't want a DSLR. The mirror causes vibration, which slightly blurs the image. You want a mirrorless. These days, you want a Sony a7rII or a7sII. The shutter can still cause a bit of vibrating, but not as much as the mirror. As well, the Sony a7s/ii has much better noise reduction in low light. Use the Zeiss or Rokinon with focus peaking and it's easier than ever before - even with a cheaper tripod and remote or smartphone.

Try it and you'll be impressed by how easy it is. The lightweight is remarkable, too. But the picture quality... Well, go to dxomark.



posted on Feb, 15 2017 @ 01:03 PM
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If you want Astro photography on the cheap buy a old Meade ETX 90 or similar and a used older model DSLR, get a camera mounting ring for the ETX scope tube and piggy back the Camera and away you go, a half decent tracking scope with a massive data base of objects and the capacity to piggy back, these units must be cheap now on the second hand market and no doubt will come with eye pieces filters etc??... Used DSLR cameras can be picked up for peanuts..

If you want a bit more tech involved then use a webcam and adaptor, the original model was the Toucam? from memory that was followed by a Philips SPC900 something something, just take off the OEM lense and screw in the eye piece adaptor.. Record the moon, Planets etc etc then run the file through Registax and it would select the best ones and stack them creating a image that can then be further enhanced as you wish..

RA



posted on Feb, 15 2017 @ 01:04 PM
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posted on Feb, 15 2017 @ 01:13 PM
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off-topic post removed to prevent thread-drift


 



posted on Feb, 15 2017 @ 01:15 PM
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a reply to: TarzanBeta

That would be certainly nice to have, however many people, like me, have already spent a very large chunk of money on the DSLR that we have.

The other good news: The vibration caused by the mirror flip is so small that it's stopped before the very dim light of the stars can been messed with. If you take a 1 second exposure at even ISO 1600, you will not capture much.

Case in point:



Big Dipper, 18mm focal, f5.6, ISO 800 exposure 5.0 seconds.....with a flip mirror camera.

Pretty much the majority of us old timers were stuck with flip mirror cameras back in the day of film SLR cameras and we were able to take shots just fine with the camera flip.

If you can afford something better, that's great. But not everyone can.

I'd kill to get my hands on a Canon 6D, which is considered one of the best modern day digital camera for astrophotography by even the pros. It has a flip mirror......it also has a $1,500 price tag. Way out of my range.

The camera you're suggesting, Sony a7rII, has a $2900.00 price tag.

That's obscene. Great if you have the money to blow. Most people are not going to have that kind of money.

That's the idea of these threads: being able to do this, and do it well, shouldn't cost anyone an arm and a leg.



posted on Feb, 15 2017 @ 01:17 PM
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originally posted by: TarzanBeta
Excellent. But you don't want a DSLR. The mirror causes vibration, which slightly blurs the image.

Most DSLR cameras have a mirror lock-up function. And even without it, this is not really an issue for long exposures, because the time during which the mirror vibrates is so short compared to the total exposure time that it won't visibly effect the image.

soulwaxer



posted on Feb, 15 2017 @ 01:20 PM
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a reply to: eriktheawful

One trick to reducing mirror slap is to set the camera into mirror lockup mode. Most SLRs have the ability to hold the mirror up for a period of time before opening the shutter, giving the mount a chance to stop vibrating before starting the exposure. Using a camera remote you engage the mirror lockup on the first press of the shutter button, and open the shutter itself after waiting a few seconds with a second press of the shutter button.

*Nevermind, soul beat me to the punch.
edit on 15-2-2017 by P2016J3 because: (no reason given)



posted on Feb, 15 2017 @ 01:22 PM
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originally posted by: eriktheawful
a reply to: TarzanBeta

That would be certainly nice to have, however many people, like me, have already spent a very large chunk of money on the DSLR that we have.

The other good news: The vibration caused by the mirror flip is so small that it's stopped before the very dim light of the stars can been messed with. If you take a 1 second exposure at even ISO 1600, you will not capture much.

Case in point:



Big Dipper, 18mm focal, f5.6, ISO 800 exposure 5.0 seconds.....with a flip mirror camera.

Pretty much the majority of us old timers were stuck with flip mirror cameras back in the day of film SLR cameras and we were able to take shots just fine with the camera flip.

If you can afford something better, that's great. But not everyone can.

I'd kill to get my hands on a Canon 6D, which is considered one of the best modern day digital camera for astrophotography by even the pros. It has a flip mirror......it also has a $1,500 price tag. Way out of my range.

The camera you're suggesting, Sony a7rII, has a $2900.00 price tag.

That's obscene. Great if you have the money to blow. Most people are not going to have that kind of money.

That's the idea of these threads: being able to do this, and do it well, shouldn't cost anyone an arm and a leg.



I shall let it be. Indeed sir.



posted on Feb, 15 2017 @ 01:33 PM
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a reply to: TarzanBeta

Don't get me wrong: it certainly would be nice.

But some times we just can't afford the good stuff.

But cheap isn't always bad either. Here's a shot I took with a $240.00 Sony Handycam of the moon. It actually captured the Earth Shine lighting up the dark side of the Moon.



And it's actually a single frame from a video I took of the moon, heh.

This is the best my much more expensive EOS camera can do:




posted on Feb, 15 2017 @ 01:35 PM
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originally posted by: eriktheawful
a reply to: TarzanBeta

Don't get me wrong: it certainly would be nice.

But some times we just can't afford the good stuff.

But cheap isn't always bad either. Here's a shot I took with a $240.00 Sony Handycam of the moon. It actually captured the Earth Shine lighting up the dark side of the Moon.



And it's actually a single frame from a video I took of the moon, heh.

This is the best my much more expensive EOS camera can do:





Great stuff.

I'm not financially mature. I'm just obsessive about doing the best. Ask my wife who dislikes me. Lol.



posted on Feb, 15 2017 @ 01:51 PM
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a reply to: eriktheawful

Well written!
You can ( and should),start out with some of the cheaper innovative ways that you described (I did), but my thirst for better, longer, (exposures), faster....led me to the pics below....and YOU CAN use DSLR camera's. for optimal performance, they should be "modified" (IR). I have tried some of the lesser expensive CCD cams....they are OK, but I still prefer my DSLR for the time being. What was not covered here is the art of post processing, which has a STEEP learning curve for bringing out the best of your images....It can be absolutely amazing how much detail you can bring out of what looks like a "pretty good" capture.

Current setup


First "real" image M13 (4 yrs ago) Unprocessed


Second "real" image Orion (4yrs ago) Unprocessed



posted on Feb, 15 2017 @ 01:57 PM
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Great point about the image processing learning curve. One very important thing when doing astrophotography with an SLR is to make sure to save the images in a raw format, NOT just a low bit depth compressed JPG format. As long as you have the raw files, you can always start over on the processing. Some of the software for processing astrophotography is quite expensive as well. PixInsight runs what, about 230 euros these days? It can get crazy just buying software for astronomy, but there are some great free tools out there as well. I use Deep Sky Stacker along with PixInsight LE (a formerly available free version) and occasionally IRIS. IRIS has some powerful tools for handling raw FITS files as well as some SLR raw formats, but it's not terribly user friendly. Still, if you go the free route you may find that you need some of its tools.
pixinsight.com...
www.astrosurf.com...
deepskystacker.free.fr...



posted on Feb, 15 2017 @ 02:28 PM
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Great shots and advice all.

But do us a favor: stick to talking about mounts, that's pretty much what this thread is for.

Going into image processing, stacking and post processing images would be better as a dedicated thread.

And I most certainly would not mind someone here that has much more years of experience and has used many different software packages to make their own thread about it.



posted on Feb, 15 2017 @ 02:42 PM
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Good thread, I found it engrossing.

My request:
Please post pics of Saturn or Jupiter + moons (or Neptune - Uranus if possible?).
Any other planets are good too. Thanks!!!
(Curious to see what cheap equipment can do these days)

Great pics, look forward to seeing more!
edit on 2/15/2017 by muzzleflash because: (no reason given)



posted on Feb, 15 2017 @ 02:59 PM
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a reply to: muzzleflash

Here's an image I took of Saturn, many years ago with a telescope, not exactly the best:



I hope to get some better ones of both it and Jupiter down the road.

I'm betting some of the others most likely have some good planetary shots they can share though.



posted on Feb, 15 2017 @ 03:37 PM
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a reply to: eriktheawful

Thanks for following up on this--I'm a big fan of making my own stuff, so those homemade mounts should be a fun thing to do (and maybe I can get my 13-year-old son out there to help out).



posted on Feb, 15 2017 @ 04:48 PM
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Great thread.... I've always wanted to get into astrophotography, but just never got around to it. I would need to save up on a good DSLR camera and dobson scope, as I haven't bought a camera in years since iphone came out.

I wonder what I can do with a cheap Canon PowerShot SX170, I think mine has ISO and f-Stop, I bet not a very good one. I also have one of those cheap telescopes Celestron PowerSeeker 60AZ sitting in the garage... Maybe I might tinker with it, though I doubt the pictures will be pretty.



posted on Feb, 15 2017 @ 05:25 PM
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Another great thread for any budding photographer and loving the idea of a DIY motor mount I'll have to give it a go at some point

S+F Erik!




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