Need help for processing night sky

[fazhar]

Hello

I’m having trouble trying to post-process a good night sky photo. I tried a few times but I’m not successful in getting a good photo or end-result.

Firstly I had difficulty in taking a picture as well. Most people say use a prime lens and set the manual focus to infinity with F-stop set to lowest possible. I used my 50mm 1.4 prime for it, that was an utter failure because my lens kept creating bokeh [picture]. I tried the 16-35mm 1.4 with infinity focus, that also created botched results with a yellowish photo (yellow is not a problem, photo temperature can be changed later) [picture]. Lastly I tried my 24-105mm 1.4, that produced much better result for me, much more sharper than the previous two lens I was expecting to produce good results [picture].

Anyway I followed many videos on YouTube to create a colorful nightsky photo. I wanted to create something like this [sample], but the max I've able to reach is this [picture].

I need help from experts in two things:

1) Have a look at these raw files please [dropbox folder] and tell me if they're taken in good enough shape to be processed into what I wanted. What more could I have done to make these better for processing.

2) How do I go about to process these photos. Can anyone guide me or lead me to a decent guide. I tried to search on Google and tried various guides, I can't develop it into a decent night sky photo. Can you use this photo and create it into something, I'd like to see if these photos are any useful so I know how to take the night sky photo next time.

Thanks everyone.
-Faraz

 

[fazhar]

Folks, would really appreciate help here.

 

[astroNikon]

let me compile some info ... there's threads that already cover this in detail.

I assume you are using a DSLR?
tripod, remote release ?
have you heard of stacking ?

where are you taking pictures (in the city, near a city [light pollution], in a location that is very dark, etc).

 

[astroNikon]

This will be total overload of information for you but ....

read this first (probably a couple hundred times until it sinks in as you experiment) ==> Astrophotography Without a Telescope

==> How to Pick a Lens for Milky Way Photography Lonely Speck

as you move along and read you'll see info about stacking software ==> DeepSkyStacker - Free

 

[fazhar]

let me compile some info ... there's threads that already cover this in detail.

I assume you are using a DSLR?
tripod, remote release ?
have you heard of stacking ?

where are you taking pictures (in the city, near a city [light pollution], in a location that is very dark, etc).

Yes I'm using a DSLR of course because I've mentioned all those lenses... my camera is Canon 600D.

I am using a tripod with remote shooting, using the infrared controller.

I took those photos far far away from the city light pollution and in the mountains, no city light can be seen there; thats why the stars are so bright in my picture. I hope you have looked at my linked images.

Yes I've heard of stacking.. but my single image isn't coming out good so I didn't try taking a series of photos for stacking.

 

[fazhar]

This will be total overload of information for you but ....

read this first (probably a couple hundred times until it sinks in as you experiment) ==> Astrophotography Without a Telescope

==> How to Pick a Lens for Milky Way Photography Lonely Speck

as you move along and read you'll see info about stacking software ==> DeepSkyStacker - Free

Are you saying that everyone who takes photos of the night sky always does stacking? You cannot make out colored night sky from one image?

 

[GDHLEWIS]

The best way to get focus is to use live view, use any star close to the centre zoom in on the image on the screen as much as possible and feather the focus bit by bit until you hit the best focus you can. I always find going to infinity never gets things focused correctly. ISO and exposure times are always a guess as the light pollution can never properly be judged by the naked eye.
Processing will be a huge experiment at fist but there are a huge amount of vids online to get you started.
Next step is just to practise by taking a ton of pics playing with the settings ever so slightly on the camera until you hit the sweet spot.
Iv attached the best I have been able to do so far, as you will see I am also still climbing that horrific learning curve, but it is always worth it in the end.

 

[astroNikon]

Are you saying that everyone who takes photos of the night sky always does stacking? You cannot make out colored night sky from one image?

No, not everyone uses stacking. It's just another tool that one can use. There's plenty of examples of people doing astro work in color.

Alot of it also comes down to post processing the image to bring out the colors and make the blacks blacker.
This is from a single 10 second image with a Nikon d600 and a 2,000mm 12inch telescope. PP (PostProcessing) done in Lightroom.
20140923-01 Orion Nebula by Steve Sklar, on Flickr

 

[fazhar]

Ohk. Well thanks everyone for the all the info and reading material. I'll make sure I read all that before I try my next star gazing again.

Problem is I live in a highly illuminated city and country (Dubai). And I have to travel across continents to get to a place where I can clearly see the sky, and then I take photos and they don't come out right. It's like a wasteful effort. But thats all part of the learning process, so maybe next time it'll be better.

 

[astroNikon]

I live near a major city. And I have alot of light pollution (and sky pollutions) just in my backyard.
But, I don't venture out to the "country" very often.
So start with short time captures, and try to expand the time (shutter) and increase the ISO until it starts looking bad. You'll then find your "max" shutter/ISO for your area.

Then in the sky you have to wait for clear nights. There's really no option. I don't get very many opportunities in my back yard for really clear nights (with other evening limitations too).

I also try to block a few bright street lights with black construction paper around the hood to try and minimize inadvertent light exposure (but doesn't help with what is in the sky directly in front of you). It all helps but if you have a lot of light pollution then you are limited. The more colors in your photo generally the longer an exposure it is. Some of my longer exposure definitely shows the local bright lights, so it's always best to shoot way outside of a city.

So you have to try and plan in advance what nights would be good for which part of the sky you want to try and photograph. Then hope that night is clear and such.

 

[fjrabon]

alright, I downloaded one of the raw files, image 8914.

First: 30 seconds is a touch too long of an exposure. This will cause start photos to have a bit of a streak to them as the night sky starts to rotate.

Second: something is off with your focus, this isn't focused at infinity. Or maybe there's vibration. But this image is clearly more blurry than it should be. The EXIF is missing the focusing distance, so I can't say for sure, but something is amiss.

Third you overexposed this by a few stops. this will mean that you get pretty sever banding around the edges of the stars if you try to adjust color. The stars are completely blown out. Part is your overly long exposure. Part might be the high ISO.

Fourth, generally you want a wider frame than 50mm on a crop frame. On a crop frame try to aim for 11-20mm. If you want to show the milky way at least. You can zoom in more, but to really get much that way you probably need a telescope. Space tends to be interesting when looked at very wide, or very close, but from 24-300mm it's probably at its weakest. Not wide enough to get the feeling of immensity, but not zoomed in enough to get any more detail.

 

[wfooshee]

None of your pictures linked in your first post are focused. When you say the 50mm produced only bokeh, it's just completely not even remotely close to anything resembling being in focus. Are you sure you focused at infinity, or did it get cranked to minimum distance?

Whacking the lens over to infinity is not necessarily actually infinity focus. For manufacturing tolerances most lenses can move past that point. Finding the actual infinity focus point means actually looking through the lens and focusing. As stated above, Live View works well because you can zoom the electronic image and see the point of focus as you adjust back and forth.

Anything over 15 seconds is going to show streaking. If the lens is long enough, streaking shows at 5 seconds!

Overly high ISO will turn the black sky to noise.

White balance should be extremely well over to the cool side. Probably not as far as it can go, but pretty far down the K scale.

Also, while it may seem that you want the largest aperture you can get, be aware that most lenses perform at their worst when wide open. Treat a 1.4 lens like it was a 2 or 2.8. Maybe even a 4. Sharpness usually suffers wide open, especially at the edges.

 

[Usul]

I agree with previuos posters all I can add about technic don't forget to turn off IS when using tripod and long exposures. I don't know whether you made such error or not but sometimes I did and it ruined many images.
It's about technic but my point that the most importan thing is composition. As fjrabon said wide angle is what you want and the image you shown as exapmle was made with wide angle lens. First of all choose right place and time there are lot of sites or aplications that can help you to determine stars disposition is certain time and place. Second - choose foreground. Just stars alone won't give you picture I'll be satisfied with in most of cases it just my opinion but interesting foreground is good strating point for getting good night pictures. I'm not familiar with the area you live in but I guess you can find rocks or trees or maybe old ruins in the desert wich can serve you as a foregound.

 

[fazhar]

alright, I downloaded one of the raw files, image 8914.

First: 30 seconds is a touch too long of an exposure. This will cause start photos to have a bit of a streak to them as the night sky starts to rotate.

Second: something is off with your focus, this isn't focused at infinity. Or maybe there's vibration. But this image is clearly more blurry than it should be. The EXIF is missing the focusing distance, so I can't say for sure, but something is amiss.

Third you overexposed this by a few stops. this will mean that you get pretty sever banding around the edges of the stars if you try to adjust color. The stars are completely blown out. Part is your overly long exposure. Part might be the high ISO.

Fourth, generally you want a wider frame than 50mm on a crop frame. On a crop frame try to aim for 11-20mm. If you want to show the milky way at least. You can zoom in more, but to really get much that way you probably need a telescope. Space tends to be interesting when looked at very wide, or very close, but from 24-300mm it's probably at its weakest. Not wide enough to get the feeling of immensity, but not zoomed in enough to get any more detail.

Well after reading all the material that ASTRONIKON shared in his post, my 30 second exposure was overkill after all. I missed in my previous readings that most tutorials for sky photography are made for full frame cameras. Mine is a 1.6x crop sensor. I also tried other lenses like 16-35mm and set focal length to 16 to get the widest view of the sky (if you can have a look at IMG_8930 raw file), banding around stars didn't happen in that one, in this I thought the ISO 3200 is too high but still the stars weren't bright enough for me here.

I do set the lens directly to the infinity focus icon without actually checking through the viewfinder. I'll start using the live view option now. I understand every lens has it's sweet spots that are not actually at what they're described.

 

[fazhar]

alright, I downloaded one of the raw files, image 8914.

First: 30 seconds is a touch too long of an exposure. This will cause start photos to have a bit of a streak to them as the night sky starts to rotate.

Second: something is off with your focus, this isn't focused at infinity. Or maybe there's vibration. But this image is clearly more blurry than it should be. The EXIF is missing the focusing distance, so I can't say for sure, but something is amiss.

Third you overexposed this by a few stops. this will mean that you get pretty sever banding around the edges of the stars if you try to adjust color. The stars are completely blown out. Part is your overly long exposure. Part might be the high ISO.

Fourth, generally you want a wider frame than 50mm on a crop frame. On a crop frame try to aim for 11-20mm. If you want to show the milky way at least. You can zoom in more, but to really get much that way you probably need a telescope. Space tends to be interesting when looked at very wide, or very close, but from 24-300mm it's probably at its weakest. Not wide enough to get the feeling of immensity, but not zoomed in enough to get any more detail.

Well after reading all the material that ASTRONIKON shared in his post, my 30 second exposure was overkill after all. I missed in my previous readings that most tutorials for sky photography are made for full frame cameras. Mine is a 1.6x crop sensor. I also tried other lenses like 16-35mm and set focal length to 16 to get the widest view of the sky (if you can have a look at IMG_8930 raw file), banding around stars didn't happen in that one, in this I thought the ISO 3200 is too high but still the stars weren't bright enough for me here.

I do set the lens directly to the infinity focus icon without actually checking through the viewfinder. I'll start using the live view option now. I understand every lens has it's sweet spots that are not actually at what they're described.