On Saturday night I trekked out to the Sheephole Wilderness Area, allegedly the darkest spot in Southern California. It was dark, but I'm not sure it was really any darker than other areas that I've been to around here.
This was, naturally, a mission to take pictures of the Milky Way. The biggest problem I have with my little camera is sensor noise, which can be improved by a process called stacking. Basically, you take a dozen identical pictures and then let Photoshop put them all together. Since noise is random, Photoshop aligns the photos and then looks for areas that differ, figuring that these areas represent noise. Everything left over is part of the genuine image, and is (more or less) left alone.
Anyway, this is what I did. I tried taking photos in RAW mode, JPG mode, and JPG mode without using the camera's built-in noise processing. RAW mode is supposed to be the best, but mine turned out terribly. I don't know why. The best results used the camera's noise processing plus stacking plus a noise reducing algorithm from a piece of third-party software I own.
Even at that they still weren't all that great. The top photo was shot with a cell tower in the foreground just so I could have something there. Unlike, say, Death Valley, which has lots of cool stone formations, Sheephole has nothing but scrub. The bottom photo was shot in front of that scrub.
All six of the final photos sported a different color palette, in some cases wildly different. In these two, the top one has the colors that I've come to think of as normal, while the bottom one is blue heavy. Others were washed out with red or green or something else entirely. Very strange. All of them were underexposed, and the next time I do this I'm just going to crank my ISO all the way to its max and accept the noise that comes with it. Then we'll really see how good all this anti-noise technology is.
So, where's the sheep?
The sheep can get in but they can't get out?
If you want me I'll be in Sheephole, is something you never hear.
There was a great series called Frankenhole, it would be great if it were like that, but for sheep.
IMO, you have discovered the reason why some people spend thousands of dollars on the best lens. It's not about the focal length; it's about the aperture size.
BTW, you can really make things cool if you bring along a super intense LED flashlight to highlight selected foreground on a very dark (moonless) night.
Is that the Pleiades star cluster above and to the left of the bright region?
No, but the teapot of Sagittarius is below it and to the left.
Stacking seems to work on the same principle as "the wisdom of crowds." Take a glass jar full of beans and let people guess how many there are. As the number of guesses increases, the average guess come closer to the real number. Individual guesses have a component that is genuine knowledge and another that is noise. Since noise is random, it tends to cancel out. Knowledge doesn't and it tends to get reinforced as the number of guesses increases.
I'm only guessing a bit based on your description of your process and the two photos you've shown, but I think a few things are at issue here. First, including the tower lights probably compromised whatever meter reading your exposures were based on. (The fact that your JPG images were better than the RAW ones reinforces this analysis.) The glow along the horizon (especially in the second photo) also seems to indicate either city lights or remnants of the sunset, which means the sky wasn't really at its blackest. Judging by the obvious movement of the stars, it looks like you didn't use a motorized equatorial mount. Such movement would likely decrease any stacking algorithm's capability to recognize noise.
All in all, however, the results are pretty spectacular. I think you should be very pleased. To get much clearer images of the Milky Way, I really think you'd have to go to a camera mounted on a telescope with an equatorial mount.
Perhaps there are some things which can be appreciated only in person rather than through technology.
There is a spot called The Black Hole near, I think, Paso Robles. My grandpa wrote of a great deer slaughter there back in the late 1890's.
For people that might need to know or be curious, the EXIF on the 2nd image is:
Original date/time: 2021:06:05 23:40:14
Exposure time: 15/1
Shutter speed: 15.00
F-stop: 4.0
ISO speed: 6400
Focal length: 8.8000
However, as you must know, at 100% the noise is bad and unacceptable. The image certainly couldn't be printed well. (ps I personally have not done as well as you...even driving to Joshua Tree or up North by Paso Robles)
But I have a suggestion beyond getting yourself one of those equatorial mount thingies.
Go to Sammy's Camera or other such shop and rent yourself one of the new Sony Alpha 1, 50mp camera, full frame.
I am not sure how much something like this would cost per day...but it is an idea. (since I am a Canon person, I'd rent a Canon 1D X since I have lenses for it)
As noted, I have never successfully shot the Milky Way...but I wish you luck.
Best Wishes, Traveller
PS What the Heck...call a Sony Rep here in So Cal, tell them you are Kevin Drum and you want to display anything shot on your popular blog....and maybe they will give you one for a day.
Who knows, why not?
Traveller
You've got some good stuff there, Kevin. Small sensor gonna have noise problems, no two ways about it. The dust lanes are looking pretty nice and the bright areas of the core aren't blown out -- pretty amazing for such a small stack.
I am gobsmacked that your raw frames didn't give you better results. Usually JPEG compression leaves terrible artifacts when you start pulling the contrast up to levels Mother Nature never intended, and the format also sacrifices a bit of dynamic range for smaller file sizes.
If I may be so bold as to offer suggestions, total integration time is key for deep-sky work, which is really what you've got going on here. As you probably know, we telescopic crazy-people think in terms of hours, not seconds. The Milky Way is bright, yes, but it's still a deep-sky object!
Fortunately you don't have to have whack equipment or expensive software to exploit stacking more fully, though. You can just shoot a metric ****-ton of 15-second frames on your tripod, repointing the camera occasionally to recenter the MW, and fix it in post. Sequator is great for this on Windows, Starry Landscape Stacker for Macs (but you probably knew that).
This link isn't a brag, it's merely to help you evaluate whether I know what I'm talking about -- or not! rickwayne.zenfolio.com/astrofavorites.
Beautiful work!
These pictures touch my heart, and I don't care if you -- or anyone -- has technical reservations. The pix remind me that I have rarely really seen the night sky since my family moved to Southern California from Minnesota decades ago. It's beautiful and awe-inspiring. I'm glad Elon's thousands of bright little satellites didn't zip past while you were out there. Thank you!