Complete noob, asking help for timelapse astrophotography

[Nautilus]

Hey guys,

I'm kind of an semi-experienced video shooter but a beginner in terms of photography. So please bear with me. I have found a very good corner of nature for timelapse videos. No residential areas around and no light pollution! So I would like to know more about timelapse shooting at night sky.

First of all, how can I do it in post production? The camera takes pictures in certain time intervals, yeah i get it. But how can i get these pictures together in Premiere Pro to make a fluid movie? That's the part i don't understand.

Secondly what are the safe values for astrophotography? The highest iso i can set, right exposure settings etc...

Edit: There also people who shoot HDR timelapse. How do you do it?

Is there anything else I should know?

[mageye]

I am assuming that you will be shooting your images in RAW? You will won't you!

Anyway I don't really know about compiling a time lapse in Premiere Pro (maybe it's possible?) but I personally use After Effects. I think that many people use this method because it allows you to use ACR to change settings in your images as you import them.

It's pretty simple to do once you learn the few steps involved.

I found a little video that covers the process. There may be many more videos for the same task but I think this one just about covers how to do it:

https://www.youtube.com/watch?v=mRxyMZfSMqY

Also it's possible to use Quicktime Pro to compile image sequences but it can't handle the RAW files directly so if you converted them from RAW to TIFF or PNG or something then you can easily create a compiled movie file from that.

To be honest the compiling of the sequence is the easy part of time lapse!

As for safe values for astrophotography, I would say that's open for debate. There are plenty of variables here. The wider your lens, the longer you can expose for before you get trails. Obviously faster glass is also recommended to let in much more light and allow shorter exposures (to counter star trails).

Pretty high ISO's are actually acceptable for astro stuff (say 800, 1600). Securing a sturdy tripod (even with weights) is premium. As is 'mirror lockup' mode so you don't get the vibration from the mirror actuation (this can cause blurry trails like when you do long exposure and move the cam on light sources).

I have used pretty wide open settings on my camera before but also realise that some lenses have poor performance (soft) wide open. It's maybe an idea to stop up one or two stops. Like from f1.4 to f1.8, f2.0.

Oh and exposure time is variable. But I have used 30 second exposures before. Sometimes even longer, but you will face the problem of star trails. Try and get it as long as you can before trailing. if I can remember I get reasonable results at around 15 - 20 second exposures.

For me the problems have been more to do with the logistics. Getting there with all the kit, the cold, the lens surface condensing, batteries and where I live in the UK the biggest of all the problems is finding a place where you can actually see the sky without all the damned light pollution.

It's everywhere around where I live. I live in between 3 major cities in the UK and it's unavoidable!

[Nautilus]

Thanks.

I have Sigma 30mm f1.4. Do you think my lens is wide enough to capture the night sky?

[dmilligan]

First of all, how can I do it in post production?

mageye has some good advice, also just a few things I would add:

Look at all the raw video workflow threads on this forum, b/c you will basically be doing the same thing. When folks shoot raw they end up with a bunch of dngs, one for each frame, basically the same thing you'll end up with (except .cr2, but there's not much difference and easy to convert to dng). There are lots of different workflows that use different tools, but you should be able to do basically the same thing they are. I agree with mageye, AE is great and is what I use, but it is terribly slow compared to some other tools.

I also have a script that you might find helpful: http://www.magiclantern.fm/forum/index.php?topic=8850.0
The ACR settings that are set by this script in Bridge (and stored in XMP sidecar files), are automatically used by AE if you import the sequence into AE. Bridge also quickly generates preview thumbnails that you can scroll through at pretty close to realtime speed, so you can get a basic preview of your timelapse. AE won't do this and you have to wait for it to slowly render each frame before you can see any kind of preview (this may take minutes even for a very short clip). Alternatively you can skip AE and export to a TIFF or JPEG sequence from Bridge (via Photoshop), then load that sequence directly in Pr Pro.

See also:
http://www.magiclantern.fm/forum/index.php?topic=5705.0

There also people who shoot HDR timelapse. How do you do it?

In ML just turn the advanced bracketing on, I like to use 2 exposures, one normal and one +4 ev. That should give you plenty of DR for most any situation without killing your shutter. The intervalometer will use the advanced bracket settings and take however many shots per interval you have it setup with (in this case 2). You'll end up with a sequence of images something like (0, +4, 0, +4, 0, +4, ...).

Now you need to merge every other frame together, that's where this script comes in (some folks also use other tools that support hdr sequences, you could use a1ex's cero noice script). With my script you have the option of doing your toning in photoshop and exporting to jpeg or tiff, or simply doing the merge in photoshop and saving in an hdri (exponential) format like 32bit float TIFF or EXR. If you want to do your toning in ACR, you can export as 32bit TIFF, then simply open those up in the ACR dialog in Bridge, just like I described previously, you can even use that Bridge script on them. Here's an example: http://www.magiclantern.fm/forum/index.php?topic=9394.0

Thanks.

I have Sigma 30mm f1.4. Do you think my lens is wide enough to capture the night sky?

On a FF or APS-C? On a FF, probably, but you're might want something a little wider on a cropped body. You can make any focal length work though, it just depends on what you're going for. The 1.4 aperture would certainly be helpful as photons are at a premimum when shooting the night sky. I have only cropped bodies, so I mainly use an 8mm fisheye and the Canon 10-22mm.

[Nautilus]

Great, thanks everyone for wonderful advices and suggestions.

dmilligan, I'd like to ask one thing about lenses though. If 30mm on cropped camera like my 650D isn't gonna be wide enough for astrophotography, then is it a wise to go for a cheap Canon kit lens (such as 18-55mm f/3.5-5.6)?

I was browsing the online stores and came across few fisheye lenses which also has a minumum f/3.5 aperture.  So in terms of minimum aperture the kit lens and fisheye lenses are the same. 8mm Rokinon f/3.5 is a good example and it costs around 250-300 bucks. But a 18-55mm kit lens only cost around hundred bucks. I can have wide angle for cheap!

I don't have much cash to spend on glass you know and all i have with me is this 30mm Sigma f1.4.

Thanks

[mageye]

I have the 18 - 55 kit lens that you are talking about. It's on my 500D. I think it's a great for quick snaps of stuff bit when it comes to focus on there it's not much fun to use. It is ok for general usage and with auto focus can take surprisingly (within reason) good images. As long as you accept that it's not really a premium product.

It's pretty bottom of the range, lowest common denominator really!

You are correct that this lens will be pretty reasonable as far as field of view is concerned. When it's wide you can see a reasonable amount of sky.

One of the main considerations with this lens is that it's an EF-S as opposed to the EF lenses (which in simple terms are better).

Be aware that if you buy an EF-S lens, that you will only be able to use it on APS-C camera's. So if you wanted to get a full frame camera, at some point, you would not be able to use them at all on a 5D2, 5D3 or whatever. There is no way (to my knowledge at least) that you can adapt an EF-S to fit on a full frame sensor. In fact apparently trying this can/will cause damage! It's a physical thing.

So from a point of future proof don't go with the cheapy thing!

I think I have looked at the 8mm Rokinon before and I am not sure but I think it's the same brand as samyang? (I may be completely wrong here! forgive me!)

Anyway I have been pretty happy with my samyang and I think it's in the same league if you know what I mean. I have considered similar glass myself and would always say that invest more in your glass.

So get the rokinon (once you have got it you will not regret). I know I don't own one but I can guarantee that it will be considerably better than the kit lens.

Look after your glass and your glass will look after you!

In my humble opinion anyway!

EDIT: In fact I just did a check and yes it is basically marketed as a samyang. So I would definately say go with the rokinon. For sure. No regrets! LOL

EDIT: Actually looking at it I am wondering if a fish eye is really a good idea. I forgot that 8mm is basically so wide it become distorted (fish eye). If that's the effect you are going for then fine, but maybe you should consider a touch less wide with something like the rokinin 14mm? (which is still regarded as 'Ultra Wide')

[Nautilus]

If that's the effect you are going for then fine, but maybe you should consider a touch less wide with something like the rokinin 14mm?

Well, i don't have the cash unfortunately. Unless you're gonna send me yours for free

[mbarrett5076]

So I have done 3 of these each learning 100% each time.

600/focal length = approx shutter max before trails. (unless you have a tracking mount - more on that later)
ISO 1600 is likely the minimum
Shoot RAW stills
Use the ML Intervalometer
I used my 17-55 2.8

Simple solution is to use Canon DPP to convert to JPG in batch and the combine with your favorite Post software (my first 2 I did w MS movie maker didn't look too bad)

noise reduction is going to be the challenge.

I have yet to do a night of star shots without at least one unseen meteor streaking through a frame - kind of cool

[mbarrett5076]

Tracking mount - sorry forgot.

One of those fancy dancy mounts that track the stars the the $$ telescopes have. 

If you get way into it......

[Nautilus]

1600 iso seemed kind of too high to me. I'm very sure that'll produce very grainy images at night.

What about keeping iso as low as possible and cranking up the exposure time before trails? Wouldn't that be enough to see stars?

Well, if I end up using 1600 iso, i guess i'll use my trusty Neat video and Neat Image noise remover.

[dmilligan]

1600 iso seemed kind of too high to me. I'm very sure that'll produce very grainy images at night.

There's just not enough light, you don't have choice. Using a lower ISO would just make things worse.

What about keeping iso as low as possible and cranking up the exposure time before trails? Wouldn't that be enough to see stars?

You won't be able to crank the exposure long enough (unless you have a tracking mount and can take 5-10 minute exposures), at least not somewhere with dark skies. Higher ISOs have less read noise and the same amount of photon noise (since ISO doesn't affect the number of photons collected). Therefore, it is always in your best interest to use the highest (analog) ISO that doesn't clip (ETTR). Even with my fast lenses, it is almost impossible to clip anything at ISO 1600 and 30 second exposures (usually about the limit before star trails at the widest angles), from somewhere with dark skies.

Also remember that reducing resolution (which you'll be reducing down to video resolutions like 1080p) also reduces noise. So noisy shots are not as objectionable played back as video and at lower resolutions.

[Nautilus]

Just swapped my 50mm f/1.8 II backup lens for a 18-55mm IS II lens online. This is gonna be my first zoom lens with stabilisation. I always used primes without stabilisation before. Going to do timelapse in a week or so. Will post results

[Walter Schulz]

Lens stabilization by integrated antishake mechanism is next to useless in astrophotography. IS is designed to reduce blur induced by handshake and works up to ca. 1/8 seconds (typically, depends on focal length) when shooting handheld.
No person participating in this thread advocated such a lens to be used in astrophotography.

[Janke]

Here's a video I shot with my T2i/550D a couple of years ago - unfortunately, YouTube compression is horrible...

Exposure 15 sec/frame, interval 20 seconds. Lens was Tamron 10-24mm at f/3.5. Not shot with ML, but a plug-in intervalometer.

[Nautilus]

You know Troy? The ancient city in minor Asia that Greeks tried to conquer using a Trojan Horse? It is located in Çanakkale (in modern Turkey) and I'm right on there for a conference about philosophy and i got some free time this night to do some shooting. Light pollution is minimal to none, depends on where you point your camera.

So i used the Sigma 30mm f/1.4 and set the exposure 10"  (going higher caused trails for some reason), iso 800, aperture f/1.4. Intervalometer interval was 25 seconds (is it too much or too less?)

Shot some pics but then clouds came, obscured my nice star view. So i ended with about 120 pics which is not very good. I was planning to shoot around 300 pics for each scene.

This one is taken from the 120 pics i shot. Please rate this pic, is it too dark or anything particularly bad looking about it?


Tomorrow i'm going to shoot again (if it's not cloudy) but this time it will be in the temple of Athene. Which has a great view of a greek island, some portion of Aegean sea, couple of olive trees and broad sky.

[Audionut]

The intervalometer only needs to be set long enough for the exposure and some time for processing (post deflicker and such), otherwise you can just set it to "take pics like crazy" and it will fire off shots as fast as possible.

Have you done any levels adjustments on that image?  The foreground suggests there was moon/ambient light.  If you aren't aware, the pink cast in the star field is light pollution.

Looks to me like you had some camera movement (probably from wind).  The movement of the stars is random, and in nature this does not occur.

Using such a narrow aperture with foreground detail at a close focal length, means that you either have the foreground in focus, or the stars, not both.  If you move the camera further away from your foreground object, you may be able to increase the DOF sufficiently to capture both objects with sufficient sharpness.  In this case, it looks like you missed the focus on the foreground slightly, although the slight softness is probably from the camera movement.

IMO, a wider FOV would be beneficial here.  I photomerge to get around lens limits.

Also keep the maximum image size under 900 pixels in each dimension please.  You can use the [img width=] tag.