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 ULTIMATE Astrophotography Resource Thread 
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Post ULTIMATE Astrophotography Resource Thread
Astrophotography Resource Thread

So i started into astrophotography last fall. It has been a very steep learning curve for sure. Tracked vs non tracked, stacking, lights, darks, flats, biased, its a bunch to take in at once and it was a bit difficult piecing this stuff all together. I have two other astrophotography threads on other forum boards, there seems to be a lot of people into AP on here, or at least interested in learning about it so i figured i would start a Q/A resource thread to try to de-mystify it a bit.

We have all seen these timelapses with the outer band of the milkyway streaking across the sky, very very awesome to see the movement of such a thing, not that long ago to do that was nearly impossible. It was actually one of those videos that started me onto timelapse. So to many, timelapse and astrophotography will be going hand in hand, this place seems to have timelapse covered very well, but is lacking to a degree on astrophotgraphy. So hope



Here is the image i took last fall that got me hooked. No tracking, no stacking, just a single image. This is the image that started me down the dark path of Astrophotography> I dont like this image, i know i can do much much better now that i know more about AP.

Shot with Nikon D90, 12-24 f/4 Tokina
3200 ISO, 30 seconds, 12mm.
Shot RAW, all NR turned off. Exposure delay mode active, triggered with ML-13 wireless remote.
Manfrotto 190xprob tripod with manfrotto ball head.
70 miles east of denver
Noise reduction and WB adjustment in Camera RAW in CS5.

Image

Image

NON TRACKED ASTROPHOTOGRAPHY

So the earth moves, and that sucks for people who want to take long exposures of the stars. The longer you expose the longer you risk getting images of pill shaped stars or star trails. Star trails can make for interesting pictures, but they are not much of a challange so whats the fun there? ;)

Here is some guidlines for Non Tracked Focal length vs shutter speed to retain dot shaped stars.

(on DX, for FX do the crop factor equation for the focal length, ie: 12 becomes 18, 24 becomes 35, 50 becomes 60-75,

Crop Sensor
12 mm good for < 30 seconds.
24 mm good for < 15 seconds
50 mm good for < 7-8 seconds
100mm good for < 3-4 seconds
200mm good for < 1-2 seconds.

FX
12 mm Good for < 45 seconds
24 mm good for 22 seconds
50 mm good for 11 seconds

so on and so forth, every time you double the focal length you cut the time you can expose non-tracked in half.


Non Tracked camera settings

ISO - go high or go home, the image above was done at 3200 ISO for 30 seconds. Even then i had to boost it a bit in photoshop.

Shut off noise reduction if you plan to stack images! If you are going for a single image without stacking, you may want to use LONG EXPOSURE NOISE REDUCTION, but do NOT use HIGH ISO NR. I will cover stacking more later.

WB set to 5000-5500k


TRACKED ASTROPHOTOGRAPHY

Now this is the shit. BUT, you have to have a system that si capable of tracking. One method is to buy an expencive ass rig. Like a big ol tracking telescope system and you can piggyback your DSLR with your choice of lens, or use an adapter to turn the telescope itself into a big lens. This is not my method of choice, because this seems like cheating to me, which is a stupid way to look at it because results count right? But really, where are we? on a timelapse forumboard with very few out-of-the-box timelapse systems, many fo us are DIY folks so that what im going to cover, besides, i dont know anything about telescopes.

The only non-telescope out-of-the-box solution i know if is AstroTrac. It is about $600 for the tracker, another $150 for the polar alignment scope (yes you need it), then you have to have a Sturdy tripod, and an adjustable system for levling it (Manfrotto 410 geared head) $250, and a tripod head to mount ON the AstroTrac.

The astrotrac, quite simple put, is badass. Ive seen images where people shot 500mm reflex lenses for 8 minute periods with NO star drift. As ive worked on my DIY tracker i have learned to appreciate how hard that is to achieve. I purchased an AstroTrac in january, however it was a malfunction unit, and the place i got it was out of stock, so i sent it back and got my 24-70 2.8 lens and decided to keep working on my own tracker.

Here is a shot of the AstroTrac i purchased, It looked so nice i had to do some product shots before i returned it.

Image


BUILD YOUR OWN TRACKER

SO, You want Astrotrac performance for way less? Good luck! It can be done, but it is not so simple.

First off, what does a tracker do?... In a nutshell the goal is VERY simple.

You need 2 pieces of wood hinged together that open up at a precise rate of 15 degrees per hour to compensate for the rotation of the earth.

Simple right?.. maybe not so much. I am now on my THIRD iteration of my design, and im finally feeling confidant, last night i worked out a few more bugs that were causing the stars to wave back and forth. There are some brilliant fabbers and DIY'ers on this site that will no doubt do MUCH better than i have done. I walked into this with NO experience on this sort of stuff at ALL. So ive had a bit of a learning curve that others may have already gone past.

My design is largely based off of the platform on Gary Seroniks site.
http://www.garyseronik.com/?q=node/52

I had problems with the control circuit, the voltage was not stead and continually dropped as the battery depleated so i had to constantly tweak the speed. Also, if i went from a light lens to a heavy lens i had to recalibrate the speed. The small gear was to move at 4rpm causing the big hear to move at 1rpm, which would open the mount at exactly 15 degrees per hour to compensate for the rotation of the earth.

I had a mixed bag of results, the longest track i got with pill shaped stars was 5 minutes at 50mm. That was the best i ever did, and i have not been able to recreate that untill now. That was mostly just luck.

I am now on the third version, and what i have learned on the design im using is that the threaded rod MUST NOT wobble back and forth or it will really screw things up, it must move in a perfect arc, if there is ANY front-back-side-side play it will screw up the final results. I can go into this more later, but i dont want to bog this down with that issue right now, just make sure if anything DOES wobble that it is the motor, NOT the threaded brass rod.

Tonight i plan to replace my current stepper driver with an arduino based system.

So once you have a tracker, the world (galaxy) is your oyster. all you have to do is figure out where something is at, and start playing with your exposure and shooting duration.

You HAVE to use a tracked system to get pictures of other galaxies, nebulas, clusters, etc. And the more accurrate the better of course. You can run lower ISO, longer exposures, you will have less noise to deal with, and you can image some very very faint Deep space objects. Ive bagged nebulas, the pleadies cloud, and even other galaxies. As soon as i get my tracker pegged down, ill be able to get some real fantastic stuff.



STACKING <- Yes, you NEED to learn this.

Stacking enables you to get images that look like they came from the hubble space scope. It is hands down flat out the absolute best tool for astrophotography and makes the difference between "thats pretty cool" to "That is freaking amazing!!!"

A stacking program basically will take multiple images and overlay them, it will get an average value for each pixel through some algorythm i dont understand, and it will drop the noise level through the floor and pull out detail you cannot see on a single frame no matter how much post processing you do. NOTHING BEATS STACKING PERIOD!!!!

Basic sstacking tutorial, you need as many lights as you can get and at least a dozen darks.

Lights = A "Light" frame is a single image of a starfield.
Darks = A "Dark" is an image of the back of your lens cap done at the same settings.

Example. When i get out to my favorite shooting location i will set up my tracker, get the polar alignment done, then i will aim the camera to the target i am trying to shoot then start gathering my "lights" which is basically the same image taken as many times as you can, i try to go for 30-40 light frames, this is where HIGH ISO rocks, because you dont have to worry about noise, the stacking program will get rid of the noise for you. So for this example sake i start shooting 15 second exposures at Orions belt at f/2.8 ISO 3200.

After i get 40-50 of these i will then put the lens cap, and do the same shots just shooting images of the back of the lens cap, these are the darks, they HAVE to be done after the lights, immediatly if possible, with the same shutter speed, same iso, same everything, dont change a thing just put the lens cap on. It has to be the same ambient temp as well. The stacker program uses these "Darks" to build a sensor profile to map out where the sensor is misbehaving, THIS is what the Stacking program uses to take that noise level and drop it through the floor. It is amazing how well it works, and in the process of eliminating the noise it understands what IS suppose to be there, so you will start getting nebulae, galaxies, and stars that you did not see on your "light" frames.

I use DSS (Deep Sky Stacker), it is free. Just google it. There is another program called registax (also free)that i havent figured out but others have great results with. Also Nebulosity is a pay-program but apparently it kicks ass. There are plenty of Youtube tutorials on how to use any of these, as well as youtube tutorials on how to do the post processing.

here is a simple Stacked vs Non Stacked comparison.

Image

Image

Here is a stacked starfield, notice how clean it is, you can even see a galaxy about an inch up from the "S on "chris" btw thats me, chris field. That galaxy was not visable on the individual frames, and not nEARLY the amount of stars.

My settings on this were 12mm for about 20-30 seconds ISO 3200, i think i had about 20-30 frames that i stacked.

So if you dont want to waste your time, make sure you plan to stack.

Image





CAMERA SETTINGS
White Balance = 5000-5500k
Noise reduction OFF
Shoot MANUAL


POLAR ALIGNMENT

Your stacker wont work for crap if you cant align it very well. In a nutshell you want the hinge of your tracker aligned up with celestial north and south. I dont know how to align on the southern hemisphere. but there are resources for it online.

Polaris is very close to celestial north, but it is not true north. (forget magnetic north it is useless) To find TRUE north find Polaris (I use a droid application called "Google sky map" that i STRONGLY reccommend getting) Polaruis (the north star) is the last star on the handle of the little dipper. Moving FROM polaris towards the direction of the next star o the handle, only move out 3/4 degrees (1.5 moon widths) towards that next star, then using Polaris as the center, swing out 30 degrees counterclockwise. That gets you to TRUE CELESTIAL NORTH. it sounds more complicated than it is.

NCP iss true north, this image may help...

http://www.optcorp.com/pdf/webphotos/CEAlign4.jpg

To align, i have a 100mw laser attached to my tracker, at night the beam is clearly visable, i use my mafrotto 410 geared head to get the lazer pointing at true north, then presto, polar alignment is achieved. You can see my laser in this image.

Image





LIGHT POLLUTION

Light pollution is your enemy, sorry Florida, yer boned. Lol.

Here is a light pollution map for the US.
http://www.jshine.net/astronomy/dark_sky/

I preffer to shoot in a black zone, simply because i can drive an hour and a half and be at one. If this is not something available to you, worry not, that shot of the Pleadies you saw on the "Stacked vs non stacked" images was shot in my backyard which is on the edge of a white/red zone, and is right smack in denver colorado. you CAN get nebula, star clusters, etc, with a pretty moderate level of light pollution, just shoot on moonless nights to try to reduce the amount, and find as dark area as you can.



Im not a pro at this by any means, but ive spent a lot of time figure this crap out. If you have questions please ask, if you have tips please leave them here for everyone, if you have any images you want to showcase, i would love to have them posted on this thread!


Happy hunting!

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Fri Apr 29, 2011 8:23 am
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Post Re: ULTIMATE Astrophotography Resource Thread
Nice thread with a lot of good information. The stacking seems to be the trick now that we have digital cameras.
Keep up the great work.


Fri Apr 29, 2011 4:36 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Good information. You should start a blog, I would read it.

Going out to the desert for the new moon. Can't wait.

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Fri Apr 29, 2011 9:33 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Nice article, we need to get the moderators to pin it. Thanks for posting all that good info.

Florida isn't so bad, I was out in the driveway the other night trying to figure out how to shoot stars with no noise reduction. Got some really pretty ones, they were all red or green. My neighbor even had red stars in his tree that I've never seen before :D


Sat Apr 30, 2011 12:22 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
craaaaaaaaap.
I was working on my tracker and screwed up and le the smoke out of an arduino board. It toasted half of my motor shield in the process so I can't trust that anymore. 60 bucks down the drain. No spare arduino either.

My dumbass forgot to seperate the boards before I plugged it in. I think it had my timelapse program on it which is not for that motor shield.

I wish I could get a replacement locally. Damn. Lol

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Sat Apr 30, 2011 8:36 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Thank you for the feedback, i think I'm going to miss this new moon, overcast skies, gives me time to work on my tracker. :p

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Sat Apr 30, 2011 8:41 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Got my tracker up and working, new ardunio board, im running an easydriver v 4.2 (red board) for the stepper. The laser is 100mw and shoiots a glorious very visable beam of light into the sky for alignment. Tonight if the skys remain clear imj going to take it outside and set it up then work on getting the system aligned, then working on the speedy of the motor. My goal is to get 2 minutes at 200mm and have dot shaped stars.
here are some pics

If anyone is interested i could put together a list of parts and prices, anyone is welcome to use my ardunio sketch as well once i get it nailed down.


Image

Image

Image

Image

Image

Image

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Sun May 08, 2011 2:05 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
that rig is so sick. i'd love to shoot with one of those. was out in the desert and nailed some

pretty decent exposures. the stars 'are' pill shaped, but it's strange how from normal view

they appear to be sharp. perhaps even sharper than just dots. some sort of illusion.

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Sun May 08, 2011 5:24 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Those are sweet.
I suppose you could go for 2 high ISO shots for each frame then get a bunch of dark frames, thestack the double frames and appy the dark to each image. That should eliminate a bulk of the noise and get some great detail. But it would take a long time to stack each frame like that

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Sun May 08, 2011 6:03 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Jack,
Thanks for a great tutorial. It's posts like this that save the rest of us raw (sorry, no pun intended) beginners the first few weeks or months of trial and error.
I'm so glad someone else is building equipment out of wood! It encourages me to put up some pictures of my own work-in-progress.

Richard,
I'll be very pleased when I get the point of creating videos like those.
There is a definite difference between what is best as a still image and what makes a good video frame. You really do want that motion blur! My professional background is in broadcast engineering, a lot of TV and video stuff, while photography has long been a hobby. Timelapse is a great way to combine what I know about both, though I'm rapidly discovering I still have a lot to learn.
Can you give some more details on CRAW, I cant find anything on this specifically? Dou you mean Adobe Camera RAW?

Kit

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Mon May 09, 2011 7:25 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Jack,
I see that you may have problems with the control of the your system. Have you tried the drive system specified in the http://www.garyseronik.com/?q=node/52 article?

I'd like to get into some astrophotography as well, but don't have the money for the Astrotrac. So building Gary's version is much more doable.


Sat May 14, 2011 1:13 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
HionHiFi wrote:
Jack,
I see that you may have problems with the control of the your system. Have you tried the drive system specified in the http://www.garyseronik.com/?q=node/52 article?

I'd like to get into some astrophotography as well, but don't have the money for the Astrotrac. So building Gary's version is much more doable.


yes, that was the first drive control i used, it worked well when calibrated with a new battery but had weight problems, meaning lens weight bogged it down and required calibration after every lens change, also as the battery depleted it would slow down. so it required attenion. once i get a clear sky to calibrate the speed with the aarduino controlled stepper i should be able to get 200mm for 2 min which i never got with gary seronics system.

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Sat May 14, 2011 1:59 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Image

Mixed success last night, i managed to get what i was looking for which is accurate tracking at 200mm, but not jut 2 minutes i got 3 minutes!

On the image you can see tracked vs untracked and see the amount of correction the tracker accomplishes.

However, that wheel wobble is still present, albeit far less pronounced i have to zoom in at the pixel level to see it. What is happening here is the nut that pulls up the threaded rod is not 100% centered in the gear, so it causes the rod to wobble ever so slightly. Note this is only seen when zoomed in, at 100mm this is hardly noticable, at wide angles 24mm -10.5mm this is undetectable as the star is the size of a single pixel.

So telephoto work is still out untill i cant find a way to correct that wobble, i think the entire desgin is the problem. i may need to re-invent the wheel on this.

For wideangle work this tracker is perfect. here is a estimated exposure i time i can manage at the following focal lengths

200 = 3 min

100 = 6 min

50mm = 12 min

24mm = 24 min

12mm = 48 min

10.5 = over 50 minutes.

that is awesome!!!!! Once the outer band of the milkyway is visable i should be able to get some very low noise and extremly stunning images. :) Im very excited!

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Sat May 21, 2011 8:24 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Polar Alignment

(sorry, most of this applies to northern hemisphere only)


Image

This is an important one to learn, when i first started looking into this i saw all kinds of information about drift alignment, the kachob wheel, etc, and a lot of it seemed to be over complicated.

In a nut shell, in porlar alignment you want your movement of rotation to be perpendicular to the axis of earths rotation. Say what?? its not that complicated. With my tracker shown here i want the hinge of the tracker to line up with the rotational axis of earth, meaning the hinge needs to be pointed to celestial north.

My method of achieving this is rediculously easy. I use a laser, its like having a straight edge ruler that shoots out 5 miles. I point the laser at celestial north, and presto, i have instant polar alignment. Last time i had my setup in my yard and was testing there were clouds in front of polaris, finally they parted and in under 30 seconds it was clouded over again, but i already had polar alignment nailed down to whe point i could shoot 3 minutes at 200mm with no visable error. Keep in mind at 200mm stars start taking a pill shape in 3 seconds. Not bad for 30 seconds!

Things to keep in mind, i get the impression that astronomy clubs dont allow lasers at thier viewing locations, if you plan to go out with your local astronomy club, check thier rules, they may not allow you to use this.

Image

Image

The "laser"

The laser should be a 100mw laser, and you want to use something tactical like a laser site for a sniper rifle, this should be bright enough to see (100mw is perfect) and should have elevation and windage adjustments which are CRITICAL to center the laser.

To center the laser you just need to find a way to rotate the laser without adjusting its pitch. The method i used was to drill a hole the exact same diameter as my laser (the housing not the beam) into a 2x4. Then i secured the 2x4 to my work bench and put the laser into the hole so it was shooting at the far wall, then i rotated the laser and sure enough the dot went in a circle. I adjusted the windage and elevation screws untill i could rotate the laser a full 360 degrees without the dot moving. then i knew the laser was pointing perfectly straight,.

Next, i attached a rail mount (the same kind that scopes mount to on rifles) onto my tracker right along the hinged side taking time to ensure it was perfectly straight.

Now i know when i attach my laser that it is in perfect alignment with my hinge.


Next, i need to find Polaris. This is the north star, you should be able to find the north star, if not, well, go read up on some astronomy. Here is a clue, whatever your current latatude is, look north and the same angle up as your latitude, in colorado i think im at 39 degrees, so if i look north and up 39 degrees, i should be looking almost right at polaris.


But polaris is not TRUE celestial north. it is just real close. Depending on what you are shooting. If you plan to image wide angle star fields you can just point the laser at polaris and that is "good nuff". if you want to zoom in and image real faint deep space objects "good nuff" just wont cut it.



How to find true celestial north.

Image

Find Polaris. Polaris is actually the last star on the little dippers handle (ursa minor) Trace back along the path of stars untill you reach the star Kachob, (see picture). If you draw an imaginary line between Kachob and Polaris, the NCP (north celestial pole) is on this line, approcimately 45 arc minutes out from polaris. Arc seconds? ***? ok, if you dont know arc seconds, the moon is approximatly 30 arc minutes across. So you want to trace from Polaris TO Kochab one and one half moon widths length, and you are pretty much dead on polaris.

If your tracker is moving at the correct rate, pointing right there with the laser is going to get you some pretty good accuracy. With my current rig i should be able to do....
200mm at 3 minutes,
400mm at 1.5 min,
800mm at 45 seconds,
1600mm at 22.5 seconds.

There are applications that can help with this, such as Google Sky Maps.
Image

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Thu Jun 02, 2011 6:54 am
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Post Re: ULTIMATE Astrophotography Resource Thread
Recent shot of the milkyway, not overly happy with it, but there is improvement.

Image

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Wed Jun 29, 2011 1:13 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Shot last night, 15 light frames, 5 darks, D7000 12-24 tokina f/4

Image

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Mon Jul 04, 2011 11:44 am
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Post Re: ULTIMATE Astrophotography Resource Thread
if i'm not stacking or tracking (dont have a tracker just yet) and i'm using a canon xti 400D with an 18-55mm f/3.5-5.6 lens what should i expect? i'm in a 100% dead light zone. there is absolutely nothing around, even using the light pollution map you have linked shows that i'm like 40 mins from 100% darkness.

i plan on doing 30 second exposures, with the ISO at 1600 (max), at 18mm f/3.5, with the WB at 5200.

i'm going to mess around with the settings, but tonight is the first night i'm going out, so i'll post results. i just really dont know what to expect and i have a tendency to disappoint myself.


Sat Jul 09, 2011 6:19 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
I would keep the shutter speed to 20 seconds. With what you have you would be amazed what you can get stacking. In that dark of an area you can get some killer shots.

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Sat Jul 23, 2011 7:05 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Hello,
I am new to astro timelapse, and I will be trying to shoot some milky way timelapse videos next weekend. Is there an app, or easy way to find out when where the milky way will be visible given a certain location? I'm sure this is a newb question, but I had to ask. Thanks for any help!


Sun Jul 24, 2011 3:11 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Hey Jack, you ever been rousted by the cops for using that laser pointer? I keep reading about people getting busted for using them around LA, so I am worried about violating some FAA reg or something.

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Sun Jul 24, 2011 8:58 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
apogeecs wrote:
Hello,
I am new to astro timelapse, and I will be trying to shoot some milky way timelapse videos next weekend. Is there an app, or easy way to find out when where the milky way will be visible given a certain location? I'm sure this is a newb question, but I had to ask. Thanks for any help!


There are good free astronomy/planetarium apps out there, so (IMHO) there is no need to go out and purchase anything. Here are some great cross-platform examples:

http://www.ap-i.net/skychart/
http://www.stellarium.org/

If you know your location and date/time, they can show you where the MW is in the sky (or where it 'will be').

I run Linux, so there are some Linux-specific ones out there too -- just like there are some Windows and OSX ones, I guess :)

EDIT: With my 8mm fisheye and running an all-night timelapse, I can afford to be 'lazy' when it comes to planning for the MW, since it is bound to show up in the field of view. On the other hand, my backyard has bad light pollution problems, so my darkest views are restricted to the south and west -- regardless of where the MW might be 'best' on a particular night.


Mon Jul 25, 2011 5:03 am
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Post Re: ULTIMATE Astrophotography Resource Thread
apogeecs, good morning...

I have a number of apps on my android phone that track the positions of objects in the sky, day or night. My favorite is the Sundroid app that tracks the sun, moon, and planets, but not the MW (no galactic plain ref). For MW positioning I use "Star Chart" ( http://www.escapistgames.com/ ) because it has a nice MW image overlay that gives me an idea of how a shot might look and where it is with respect to the horizon. It is nice not to need a laptop in the field, and most of these types of apps work w/o cel reception.

FYI: I am in the planetarium field, and I still cannot memorize where the MW is on a particular day, so it's not a nubie question, it is a rather difficult bit of data to process.

Good luck.
BDU

apogeecs wrote:
Hello,
I am new to astro timelapse, and I will be trying to shoot some milky way timelapse videos next weekend. Is there an app, or easy way to find out when where the milky way will be visible given a certain location? I'm sure this is a newb question, but I had to ask. Thanks for any help!

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Mon Jul 25, 2011 6:30 am
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Post Re: ULTIMATE Astrophotography Resource Thread
BerthaDUniverse wrote:
Hey Jack, you ever been rousted by the cops for using that laser pointer? I keep reading about people getting busted for using them around LA, so I am worried about violating some FAA reg or something.



So far no, i live about 50 miles from the airport though, and there are no airplane routes between my house and celestial north. When i go to my dark zone ill drive about 30 miles east of DIA, and so far i have never been accosted, however, i dont have it on longer than absolutly needed. My understanding is as long as you are not pointing at airplanes or an airport you are fine. Be sure to check your local laws though

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Mon Jul 25, 2011 7:38 am
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Post Re: ULTIMATE Astrophotography Resource Thread
Jack Ripper wrote:
I would keep the shutter speed to 20 seconds. With what you have you would be amazed what you can get stacking. In that dark of an area you can get some killer shots.


i dont have a tracking rig so can i still stack images? if so, what program should i use (preferably something simple).


Mon Jul 25, 2011 12:54 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Yes definatly stack if you don't have a tracker, go for 30--40 light frames and 10-15 daks. I use DSS (deep sky Stacker) Google it. Its a free program. Check YouTube for tutorials on how to use it. Its pretty easy

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Mon Jul 25, 2011 8:20 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Jack Ripper wrote:
Yes definatly stack if you don't have a tracker, go for 30--40 light frames and 10-15 daks. I use DSS (deep sky Stacker) Google it. Its a free program. Check YouTube for tutorials on how to use it. Its pretty easy


thanks for the advice. now what do you mean exactly by light and dark frames? would you mean for example, 1600ISO for light and say 400 or 800 ISO for dark? or should i do this with the exposure or aperature?


Tue Jul 26, 2011 6:38 am
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Post Re: ULTIMATE Astrophotography Resource Thread
pkurk wrote:
Jack Ripper wrote:
Yes definatly stack if you don't have a tracker, go for 30--40 light frames and 10-15 daks. I use DSS (deep sky Stacker) Google it. Its a free program. Check YouTube for tutorials on how to use it. Its pretty easy


thanks for the advice. now what do you mean exactly by light and dark frames? would you mean for example, 1600ISO for light and say 400 or 800 ISO for dark? or should i do this with the exposure or aperature?


Darks are takenwith exactly same shutter,ISO,aperature, all identical settings. But u have the lens cap on. They are used to create a profile for the ssensor performance and used to vastly reduce noise and hot pixels. They have to be doneeither before or preferably after at the same ambient temperature

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Tue Jul 26, 2011 5:39 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Jack Ripper wrote:
pkurk wrote:
Jack Ripper wrote:
Yes definatly stack if you don't have a tracker, go for 30--40 light frames and 10-15 daks. I use DSS (deep sky Stacker) Google it. Its a free program. Check YouTube for tutorials on how to use it. Its pretty easy


thanks for the advice. now what do you mean exactly by light and dark frames? would you mean for example, 1600ISO for light and say 400 or 800 ISO for dark? or should i do this with the exposure or aperature?


Darks are takenwith exactly same shutter,ISO,aperature, all identical settings. But u have the lens cap on. They are used to create a profile for the ssensor performance and used to vastly reduce noise and hot pixels. They have to be doneeither before or preferably after at the same ambient temperature


a little confusing because im a newbie. but i somewhat understand. so basically take 30 20 second exposures with the cap on so its pure black, then go and take 10-15 regular normal 20 second exposures of the sky with the stars etc. then stack those 10-15 images?
thanks for the advice :D


Wed Jul 27, 2011 2:00 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
pkurk wrote:
a little confusing because im a newbie. but i somewhat understand. so basically take 30 20 second exposures with the cap on so its pure black, then go and take 10-15 regular normal 20 second exposures of the sky with the stars etc. then stack those 10-15 images?
thanks for the advice :D


I've only dabbled with it a bit myself so far, but the idea is that the 'stacking' software that you use for this purpose accepts *both* the 'lights' and 'darks' (you have to input them into the appropriate categories), and processes them collectively into a final stacked result. The 'dark' exposures need to be under the same conditions as the 'lights' (ISO & exposure time, as stated) -- but after reading various web sites it may not be 100% necessary to take an *equal* amount of darks. In my case -- just for dabbling -- I had no 'darks' at all i.e. I just used some of the pics from a long timelapse session and stacked them. I also understand that it is also not necessary to have 100% correctly rotated/aligned pics to do stacking -- the software can handle that for you. I imagine that getting the most 'area' out of each pic is optimized if each picture needs the least amount of rotation correction -- if you know what I mean :)


Wed Jul 27, 2011 2:39 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
pkurk wrote:
a little confusing because im a newbie. but i somewhat understand. so basically take 30 20 second exposures with the cap on so its pure black, then go and take 10-15 regular normal 20 second exposures of the sky with the stars etc. then stack those 10-15 images?
thanks for the advice :D


no dude, check the beginning of this thread, page one, i go over stacking on it.
the light frames are the images you are getting. you want as many as possible, some people go with literally hundreds. Ill try to do as many as i can but time is a limiting factor, i usually try to get 1 dark for every 3 lights.. So if i only have 30 minutes to shoot, ill go for maybe 18 lights and 6 darks. Darks have to have all identical settings, just leave the lens cap on, the stacking software uses these to create a profile sensor which vastly reduces noise and artifacts. The 3:1 ratio is not critical, thats why the rule of thumb i use. Remember darks have to be taken that same time, immediatly following the lights, so the sensor is warmed up, the camera has the same ambient temp, same aperature, iso, shutter speed, etc.

and make sure you shut off long exposure noise reduction, and high iso noise reduction.

the lights are stacked almost like a set of transparencies stacked on eachother, it reads each pixel value through the stack of images to come up with an average value. this also helps eliminate noise.

Just read that whole first post i put in the beginning of the thread. It explains all of this

once yer done there if you have any more questions ask and ill try to explain what i know.

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Wed Jul 27, 2011 3:55 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
awesome information and thank you all. i'll go out shooting tonight and try it out.


Thu Jul 28, 2011 7:21 am
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Post Re: ULTIMATE Astrophotography Resource Thread
Good luck and post your results.

If you have an Android phone (maybe with iPhone), look for these apps

Google Sky Map = Free star and constellation finder, pretty basic, works well, works as a visual overlay with accelleromoter and GPS. Shows constellations, some messiers, etc.

Star Chart = $2.99, well worth it, it is like Google Sky map on a very heavy regiment of hard core steroids. Shows all planets, all messiers, all constellations, far better visual reference, you can even zoom in on the messier object to see if it is something you want to shoot.


Dont get discouraged, keep trying. It takes a little practice, and it takes a bit of time. Right now in the northern hemisphere is a great time to see the outer band of the milkyway, once fall and winter approach and orion out you will have a great time nebula hunting.

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Thu Jul 28, 2011 8:32 am
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Post Re: ULTIMATE Astrophotography Resource Thread
Why when i shoot the dark sky i don't get any color, while on most astrophotography pics people get some nice shades?Is it a post processing issue the most?

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Some threads you might wanna check:
Nightsky Timelapse Tutorial.
Camera Settings for Astrophotography.


Thu Jul 28, 2011 12:47 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Jack Ripper wrote:
Good luck and post your results.

If you have an Android phone (maybe with iPhone), look for these apps

Google Sky Map = Free star and constellation finder, pretty basic, works well, works as a visual overlay with accelleromoter and GPS. Shows constellations, some messiers, etc.

Star Chart = $2.99, well worth it, it is like Google Sky map on a very heavy regiment of hard core steroids. Shows all planets, all messiers, all constellations, far better visual reference, you can even zoom in on the messier object to see if it is something you want to shoot.


Dont get discouraged, keep trying. It takes a little practice, and it takes a bit of time. Right now in the northern hemisphere is a great time to see the outer band of the milkyway, once fall and winter approach and orion out you will have a great time nebula hunting.



well thanks for the info, and i dont have a good phone like that. i live in the woods so i dont really get cell service around here so its almost pointless to have. but i do have a strong grasp of whats what in the night sky and where the milky way is rising now.

i do have some pictures from a few nights ago on my flickr. just look at the second page if interested: http://www.flickr.com/photos/64739921@N04/


Thu Jul 28, 2011 1:17 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
TheoKondak wrote:
Why when i shoot the dark sky i don't get any color, while on most astrophotography pics people get some nice shades?Is it a post processing issue the most?


i dont know what it could be but where do you shoot?

when i shoot the raw images before post have plenty of color in them, blue, purple, orange hues to the dusty milky way. sometimes even green stars.


Thu Jul 28, 2011 1:19 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
also, what gear selection do you think i should use? i have a 28mm f/2.8 a 50mm f/1.8 an 18-55mm f3.5-5.6 and 35mm f/2.8

the 50mm and 18mm doesnt have an infinity marker so shooting in focus with those is real hard so i prefer above all the 28mm f/2.8 it takes beautiful images.

so if i use that lens would i keep my exposures down to 15 seconds for best results? i'm using a canon 400D at 1600iso 5200k WB and the aperature is always wide open.

sorry i'm asking so many questions, i just wanna get good at this and do it right :lol:

and i was planning on doing 3L:1D ratio


Thu Jul 28, 2011 2:16 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
pkurk wrote:
TheoKondak wrote:
Why when i shoot the dark sky i don't get any color, while on most astrophotography pics people get some nice shades?Is it a post processing issue the most?


i dont know what it could be but where do you shoot?

when i shoot the raw images before post have plenty of color in them, blue, purple, orange hues to the dusty milky way. sometimes even green stars.



Well i played a bit with my RAW files in PS and its more than clear that i have some colors.The colors are gone when i process files with DSS.Its some kind of setting i believe.

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Some threads you might wanna check:
Nightsky Timelapse Tutorial.
Camera Settings for Astrophotography.


Thu Jul 28, 2011 4:16 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
TheoKondak wrote:
pkurk wrote:
TheoKondak wrote:
Why when i shoot the dark sky i don't get any color, while on most astrophotography pics people get some nice shades?Is it a post processing issue the most?


i dont know what it could be but where do you shoot?

when i shoot the raw images before post have plenty of color in them, blue, purple, orange hues to the dusty milky way. sometimes even green stars.



Well i played a bit with my RAW files in PS and its more than clear that i have some colors.The colors are gone when i process files with DSS.Its some kind of setting i believe.


Exactly, when it is done stacking it gives you options for post processing, set the saturation at 23 to 24

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Thu Jul 28, 2011 5:02 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Many of those shots are both very long and done with specific filters to enhance certian gasses, the series of images are then post-processed as B&W, then rebuilt in color in something like Photoshop. Often these folks are using a tracking head or piggy backed to a scope. If you want to learn more, find a "Star Party", it's geek heaven, and since there is lots of standing around time, they'll talk your ear off.

TheoKondak wrote:
pkurk wrote:
TheoKondak wrote:
Why when i shoot the dark sky i don't get any color, while on most astrophotography pics people get some nice shades?Is it a post processing issue the most?


i dont know what it could be but where do you shoot?

when i shoot the raw images before post have plenty of color in them, blue, purple, orange hues to the dusty milky way. sometimes even green stars.



Well i played a bit with my RAW files in PS and its more than clear that i have some colors.The colors are gone when i process files with DSS.Its some kind of setting i believe.

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Thu Jul 28, 2011 7:51 pm
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Post Re: ULTIMATE Astrophotography Resource Thread
Great info in this thread...thanx alot for sharing guys....
Ive been taking photos a few years now , my first dig camera was an intel 1.3 mp back in the days lol ,I have a 60d now and I never quite understood why i couldnt get a good shot of the moon at last years total lunar eclipse , tnx to this thread i now understand that it was because i was using a 2 sec exposure while zoomed in @300 mm lol and the earth was spinning all the time. I still have alot to learn but u guys make it alot easier. Im getting ready for a night shoot in a few weeks, ill do a time lapse and some stills (stacked) , ill post the results....


Thu Sep 08, 2011 7:31 am
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