How would you edit this star trail photo?

[Archbob]

http://goodfreephotos.com/DSC_0641.dng

When I edit in Lightroom/Photoshop CC, I get this:

https://www.goodfreephotos.com/final8.jpg

The trees/truck don't really show up that well and most of all if you peer in and look closely you see a lot of RGB dots on the trees and anywhere besides the star vortex.

I was wondering how you edit to get photos like this:

http://ecophotography.photoshelter.com/image/I0000xp7wNtUSStM

Even if you look closely at his photo, there is not noise.

I shot my photo with a Nikon D750 at Rokinon 24mm f5.6 and 40 minute exposure with ISO 100.

Any help on how to edit my original photo would be helpful.

 

[Tom Mann]

Note: To ensure that the OP's images remain visible in the future when the links provided may become broken, I've reproduced some of the OP's links below.

The OP's goal is to produce an image like this:




The result of the OP's raw conversion of a single time exposure is:


01b


I re-did his raw conversion with my settings and came up with this:


02

There was considerable popcorn noise throughout the image. This was almost certainly due to hot pixels in his sensor. The best way to remove this is to do a dark frame subtraction, but this can double the time for each exposure, so sometimes it isn't practical. Instead, I used PS's Dust and Scratches filter on a duplicate layer set to "darken" layer blend mode. That tremendously reduced the hot pixels (especially visible in the very tree area).


03

The best way to capture loads and loads of star trails is to overlay many separate exposures. The simplest way is to put each on a separate layer in "lighten" mode, but specialized astro photography software is available to do this as well as many other functions. Since the OP only gave us one exposure, I tried to get a bit closer to the high contrast look with many star trails by using Topaz Clarity on the preceding image:


04

I used the following settings:


05

I'm not sure if the OP wanted the trees and parked vehicle to be visible (ie, as in his raw conversion), or in complete shadow (ie, pretty much as in the image he presented as a goal). I would suggest that if you want the trees and car to be visible (and nicely exposed), you take a separate exposure optimized for them. I would probably do this by doing light painting using many shots from a handheld flash unit as you walk well away from the camera towards the tree line. You can overlay it on the other exposures at whatever level you like.

HTH,

Tom M

PS - I realize that it can be difficult to precisely focus your lens at infinity in a situation like this, but if you had been able to focus it a bit better, it would be easier to achieve the nice high contrast look in the goal image. Also, if I was able to achieve better focus, I probably would have opened the f-stop from 5.6 to f/4, or even wider. This would have shortened the length of the time exposure and vastly reduced the dark pixel noise.

 

[Archbob]

I think F4 would have been reasonable. Focusing is always though in the dark on a manual lens on the Rokinon. The f1.4 is great but manual focus is pretty tough in the dark.

What software would you recommend for doing dark-frame cancellation of noise in general.


Also I think I saw tutorials in PS where you could select part of an image with magic wand and bright or overexpose that part of the image, I'm trying to figure that one out.

 

[Tom Mann]

I think F4 would have been reasonable. Focusing is always though in the dark on a manual lens on the Rokinon. The f1.4 is great but manual focus is pretty tough in the dark. ...

The trick that I've always used to get good infinity focus on (dim) stars is to:

(a) Let the camera sit outside for a half-hour or more, on the tripod, in the same position as where you will take your photo. This is to let it reach a steady temperature, the temperature at which it will take the long exposures needed. The reason for this is that the focus of most cameras changes slightly with temperature changes due to thermal expansion and contraction of the various components in the lens and camera body;

(b) Get a magnifier for the camera's eyepiece and mount it on your camera. Often, a magnifying function is combined with a right-angle viewing adapter which is itself very convenient when you are shooting up at the sky at a steep angle and want to avoid a crick in your neck from trying to position yourself where you can look through the viewfinder.

(c) Even in dark sky locations, you can find usually some bright point source of light on the ground, eg, an outside light on a barn, a window on a distant house. With the lens wide open (ie, f/1.4) use that to focus on. Since it will be brighter than the stars, it should be much easier to focus on than dim stars. It should be at least a 1/4 mile or more away.

(d) Lock the focus by placing a piece of painter's low tack masking tape over the focusing dial, then manually stop down to f/2.8 or f/4, your shooting aperture. To give you an idea of how well this technique works, I've used it on some of my f/1.4 primes, and stopping down to f/2 is all that is necessary to have pin sharp focus, at least in the center of the frame. One will typically need to stop down a bit more to have good edge and corner sharpness.

...What software would you recommend for doing dark-frame cancellation of noise in general....

Most decent quality digital cameras have this function built in. This is, by far, the best way to go. To find out if it is available on your camera, read your instruction manual.

If this option is not available, I would recommend:
https://www.projects-software.com/denoise
https://www.projects-software.com/wp-content/uploads/DENOISE_projects_professional_EN.pdf (page 39)

This is one of the best, general purpose, de-noising software packages currently available. Unfortunately, it is much more difficult to use than more popular and better known de-noising software such as Topaz deNoise. The problem is that these other software packages don't include dark and bright frame corrections, nor are they as good at removing all the different types of noise.

... Also I think I saw tutorials in PS where you could select part of an image with magic wand and bright or overexpose that part of the image, I'm trying to figure that one out.

Yes, this is one of the most basic things that is taught to someone just learning Photoshop. The only problem is that there are many, many different methods to (a) make the selection, and (b) brighten the selected areas depending on whether the darks, mids, or lights should be brightened, what effects it will have on colors, etc. etc. I'm not sure exactly what you want to do with this, but just Google {lighten certain areas photoshop tutorial} and you find lots of discussions of this.

HTH,

Tom M

 

[Archbob]

Thanks,
For many of my dark locations, there really is no point of light. I can usually see the brighest stars in the viewfinder. Usually what I do is I turn my car headlights on, walk 100-200 yards away and then use that to focus . I find that the infinity point is pretty chose to where my Rokinon has the infinity marker.

Also I'm not how you get such a clear, sharp foregrounds, either with or without LED. Like
https://www.flickr.com/photos/cfaobam/12018389294

Doesn't the Camera have to be in the same position for the foreground and background shots to blend together? Do you change the focus ring then to focus on the foreground instead of the background?

Anyways, using chromatic reduction in LR and the Noise filter in PS, I was able to get this:

https://www.goodfreephotos.com/final8t.jpg

About the best I could do, even with all the sharpening, I doubt I could bring above a good foreground. I'll try harder next time I'm out in the forest up north.

 

[Tom Mann]

IMHO, the best way to get a frame with a sharp, relatively near foreground (ie, like in your earlier image) is to use multiple pops from a hand-held flash. The intensity of the flash is so great that you will be able to stop down to f/11 or 16 and get much deeper DoF while completely stopping wind induced movement of the leaves on each pop.

OTOH, for the example photo you just posted, obviously, the hills were too far away to use this technique, so my guess was that they just took a nice f/8 or f/11 exposure at low ISO while there was still a bit of light in the sky, and then, presumably, without moving the camera, composited it with the star trails exposure(s).

Tom M

PS - just saw your other questions ...

a) Yes, the camera should be in the same position for background and foreground shots otherwise you'll have odd transitions between the two due to parallax.

b) I greatly prefer multiple pops from a flash over continuous LED lights (for the reasons I stated above, plus others).

c) No, never change the focus ring going between foreground and background shots. Most lenses "breathe", ie, slightly change magnification ratio as you adjust the focus, so this will introduce other problems when you go to composite together the two areas. The only things you should change are the f-number and possibly the shutter speed (if you really want to use continuous LEDs to do your light painting).

d) WRT sharpening and the last example in your last post, a suggestion: Make a nice foreground exposure with multiple pops from a flash unit the leaves should be frozen and the sky should be absolutely black. Make a mask out of this exposure and use it to mask your long exposure(s) for the sky. The sharp edges of leaves on this mask will make your sky exposure(s) look like the leaves are frozen in place, not waving around in the breeze.

 

[Archbob]

I'm still confused about not changing the focus ring between foreground and the sky since for the sky, you want to set focus to infinity. But for things in the foreground, it may be blurry if the lens is focused to infinity, would it not?

 

[Archbob]

I've also seen photos like this one:



Where the photographer is just using a rising full moon to illuminate the foreground. Didn't know you can shoot star trails with a full moon out.