Another TripleBlack Space Pic

[TripleBlack]

The "Post a random photo that you took" thread has faded away so putting this in a new thread. This is kinda version 0.9 as I have a little more editing to do but thought I'd post as doubt the improvement I hope for will show online.

This is the Triangulum Galaxy, AKA M33. It's radius is bout 30,000 light years and it's 2.7 million light years away. But it's closing "fast". Headed for the Milky Way at 62,000 MPH.

For the 2 or 3 who might be interested, this is just under 3 hours of exposure - 34x5 minute exposures. My scope has an effective focal length (in camera lens terms) of 537mm @ f4.6. Shot at ISO1600 but should have probably dropped that back to 800 as it was plenty bright but had lots of noise, some of which is still evident.

[markids77]

Please explain what setup you have to so accurately track the movement of these things across the sky. After a three hour static exposure I would expect to see only a pattern of smears across the image. Whatever you use synchs damn near perfectly!

[99 pewtercoupe]

This is the Triangulum Galaxy, AKA M33. It's radius is bout 30,000 light years and it's 2.7 million light years away. But it's closing "fast". Headed for the Milky Way at 62,000 MPH.

At that distance and speed I don’t think any of us have to lose sleep over the impending collision

[TripleBlack]

Originally Posted by markids77

Please explain what setup you have to so accurately track the movement of these things across the sky. After a three hour static exposure I would expect to see only a pattern of smears across the image. Whatever you use synchs damn near perfectly!

Good catch! There's a rule called the 500 rule where you divide 500 into the effective focal length of your lens/telescope. [Edit: Got the backwards... Divide the focal length into 500] The result is approximately the number of seconds you can expose before the stars start to streak. So a 500mm lens on a full frame camera can only take about a 1 second exposure without some kind of tracking mount.

I use an equatorial mount that tracks the target at a rate to compensate for the earth's rotation. The mount must be carefully aligned with the North Celestial Pole - almost Polaris, but not quite. The stars appear to move in a circle with the center being the celestial pole. With the mount aligned the camera and scope move in an arc identical to the apparent movement of the stars. I can frame and focus an object and track it visually all night, though not accurately enough for really long exposures. With just the mount, 1-2 minute exposures are possible. That's limited by the mechanical integrity of the mount. Hey, it comes from China - enough said. To improve this, I have added a separate guiding scope and camera that locks on a single star and sends small corrections to the equatorial mount every few seconds to correct for gear lash etc. in the mechanism. With a guide scope (connector to a computer) it's pretty easy to get 5-10 minute exposures. 20-30 minute exposures are possible with higher end hardware.

The trick is to take many exposures and stack them with a software package that examines each frame and determines what is noise from the camera sensor and what is good signal. The software uses "dark frames", exposures taken with the lens cap on, from the camera to subtract the camera sensor noise from the actual exposures.

The processing is considerably more time consuming than the image capture.

It's really cool to point your telescope at something you can't see with the naked eye and see an image pop up on the camera LCD or computer screen. Especially when it took the light from that object 2.7 millions years to get here.

The camera, guide scope/camera, and the mount are all controlled by a laptop via USB. Once I set up the session, I can kick back and just look at the stars or go to the car for a nap.

Here's a pic of the setup.

[TripleBlack]

Originally Posted by 99 pewtercoupe

This is the Triangulum Galaxy, AKA M33. It's radius is bout 30,000 light years and it's 2.7 million light years away. But it's closing "fast". Headed for the Milky Way at 62,000 MPH.

At that distance and speed I don’t think any of us have to lose sleep over the impending collision

Yeah, I ain't too worried about it. If aliens there are watching the earth with some SuperAlienHubbleScope, all they are seeing is dinosaurs.

[Olustee bus]

amazing stuff here. Thanks

[Giraffe (He/Him)]

I love these shots. One of these days I'm gonna try some of this shooting. Just some basic Milky Way shots, nothing fancy.

[TripleBlack]

Originally Posted by Thomas

I love these shots. One of these days I'm gonna try some of this shooting. Just some basic Milky Way shots, nothing fancy.

Just find a dark location when the moon is new or nearly new. Shoot your widest lens (you have a 16-35mm right?)at 2.8 for 20-25 seconds at ISO 3600 or maybe even 1600 with your Mark IV. You may need to spend more time in PS or LR than you like. Ping if you do and I'll give you some short cuts. Or just check out LonelySpeck.com. Milky Way "season" is April - October. Other times the core won't be visible.

BTW, I'm hoping for a major improvement in this one. I did something really wrong processing and on a big monitore the background looks like someone blew chunks then sprinkled glitter on it. There's a much better image there... just gotta figure out how to find it.

[Wathen1955]

Nice pic! For those interested, there is a cool web forum for this:
https://www.cloudynights.com/

[Grey Ghost]

That one should be printed on glass and hanging on your wall. Incredible.

[TripleBlack]

Originally Posted by Grey Ghost

That one should be printed on glass and hanging on your wall. Incredible.

Thanks! I'm planning to go get additional exposures of it Tuesday evening. Hopefully another 3-4 hours worth and those will get added into the stack. Should enable me to bring out more detail in the galaxy with less noise in the background. That'll make a much cleaner print. I may try a glass or acrylic print. I have one on metal that looks pretty cool.

[Jeff '79]

Great pic and great education.
I had no idea it was that involved. Very

[TripleBlack]

Originally Posted by Jeff '79

Great pic and great education.
I had no idea it was that involved. Very

Thanks! I had no idea it was this involved when I started messing with it either. The guys that are really serious use special monochrome cameras that are much sharper than color cameras. To get color images, they have to shoot everything at least 3 times (red, blue, and green). So an object that needs 4 hours of exposure time takes them 12 hours, plus it complicates the processing considerably because those have to be combined to create a color image.

I'm just learning. Thought I knew a little about photography but this is a whole new game.

[erickpl]

Very nice!!!!!!