Getting into astrophotography

[Fuzz]

Anyone else into astrophotography? I've been dipping my toes into it since getting a telescope several weeks ago.

First attempts were at simply pointing the camera at the sky with long exposures (fortunately it's pretty dark from my backyard).

Milky Way through Ophiucus (45-sec exposure):


Milky Way through Sagittarius (54-sec exposure) -- you can see the light pollution from I-70/Dillon in bottom center:


Star trails around Polaris (30-min exposure):


Finally hooked up the camera to the telescope through a T-ring. Focusing is very hard, and this is the best I could get of Jupiter and it's three moons (L to R), Ganymede, Io, and Europa:


Anyone into similar stuff? Any thoughts, comments, insights to share?

[huckster989]

I've I always wanted to try some of those shots, they look pretty damn good very impressive work with the telescope and camera

[summit]

Ooooh! Aaaah!

Awesome in my book!

[Game Over]

nice man.

my step-dad is really into this. he shoots thru some big ass meade telescope. he used to drag us to expos where tons of these deep space photos would be displayed.

my parents are somewhere in the US on vacation, but when they get back ill try to post up some of his stuff.

he has some insane shots of this solar eclipse we went to in baja when i was a kid. also lots of the moon and planets and just the normal time lapses. also some cool northern lights stuff from my grandparents in ND.

[dipstik]

Really cool stuff. Didn't Canon release a modified 20d or something a few years ago specifically for astrophotography? I'm wondering what the advantages would be of an astrophoto specific camera.

[Fuzz]

I've come to the conclusion that to do decent astrophotography, I'll have to invest in equipment.

For planetary shots, a webcam (<$100) that screws into the eyepiece will do. Taking videos with the webcam and stacking them seems to be the way to get good planet shots.

For deep-space objects however, I'll need to spend $500+ on an good equatorial mount which will allow precise long-exposure tracking. The telescope itself is adequate (8" Schmidt-Cassegrain).

I could also do with a better camera. Currently using my 6-megapixel Nikon D50, but after spending on the telescope, can't afford a camera right now.

Yes, Canon did come out with a 20Da for astrophotography several years ago (same as the 20D but with a low-pass filter to enhance contrast and transmission of light at a specific wavelength suited for astrophotography). Not sure if they're still making it.

[summit]

You could effectively create a 20Da... it's a 20D with the hot mirror (IR cutoff filter) removed, but I'm not performing sensor surgery on an expensive DSLR.

[Fuzz]

A few more of the moon through the telescope from last night. Shows Mare Serenitatis, Tranquillitatis (Apollo 11 landing site), Fecunditatis, Crisium, and Nectaris.

[spindrift]

I've come to the conclusion that to do decent astrophotography, I'll have to invest in equipment.

Bwa! As predicted...

[Fuzz]

Piggybacked the camera on the telescope and got a few more shots tonight...

Andromeda rising:


Andromeda close-up:

[bklyn]

Love it, more please.

[summit]

Very cool!!!

[Fuzz]

Very bad turbulence last night along the horizon, making it very hard to focus, but got some interesting moonrise shots. All shot with Nikon D50 attached to Celestron NexStar 8SE telescope:





Once it got a little higher, the turbulence was less, making it easier to focus.

[BeanDip4All]

astrophotography

$ound$ expen$ive.

but, i love your shots! thank you for posting these up, they're awesome.

[nihiles]

maine. about 2 hours north of portland. over 30 minute exposure.

[Fuzz]

Tried out my new (to me) Canon 40D with Tamron 18-270mm lens last night. Shot static on tripod, 5 x 30-sec exposures, f/4, ISO1600.

Andromeda wide-field:


Andromeda close-up:

[advres]

how in the fuck did I ever miss this thread???

Wow, I am stoked to see this stuff. I have a roll of film I shot with my holga, long exposure from the village in Jackson Hole. I've been lazy and haven't exposed them but this is putting a fire under my ass. Good Stuff!!!

[Fuzz]

Got the new Canon 40D hooked up prime focus to the telescope. Controlled the camera using Nebulosity on the laptop, and was finally able to get some proper DSO shots. Unfortunately, with an alt-az mount, tracking is quite imprecise, so I could only do 5-second exposures at most.

M13 Great Globular Cluster in Hercules
A cluster of several hundred thousand stars, located 25,000 light-years from Earth. The cluster is 145 light-years across, with an estimated age of 14 billion years.
10 subs x 5 seconds at ISO1600 (plus 10 darks)


M31 Andromeda Galaxy
Nearest spiral galaxy to us, 2.5 million light-years away. Estimated to contain 1 trillion stars, Andromeda actually spans the width of about 5 full moons in our night sky. It is relatively bright, and is visible to naked eye even with moderate light pollution. Andromeda and the Milky Way are estimated to collide with each other in 2.5 billion years.
20 subs x 5 seconds at ISO1600 (plus 20 darks). I was hoping to get more detail out of Andromeda, but being limited to 5 seconds for each sub-frame probably prevented it.

[Fuzz]

Another clear night. Got up at 4am and was treated to a magnificent sky with Orion the hunter the prominent feature.

Orion wide-field (stack of 30 subs):


Orion wide-field annotated:


M42 Orion Nebula
A massive star formation region (24 light-years across) about 1,300 light-years from Earth.
Stack of 30 subs + single-frame composite to bring out more definition in the central "trapezium". Still trying to figure out how to get definition and reduce noise at the same time.


Here is M42 again but with just the stacked shots. Noise is much less, but so is definition:

[Neezer]

Simply Amazing Fuzz!!! I have the celestron 130...quite a bit smaller...5" newtonian, but It should be great for planetary stuff....I love the picture of jupiter....What power eyepiece did you use in that one?

[Neezer]

Here is one that I took of a full moon a while back....

D90, 300mm, not sure on exposure settings...Just used a tripod though, so it was a short exposure...






Is it better to go to a slower f-stop if you can with something very bright like the moon and take a longer exposure or should I be ramping up my shudder speed at the fastest f-stop possible?

Also, I think I had my ISO set at 100 or 200..I remember reading something about wanting the gain on my camera to be near unity for best quality. which ISO is that for the D90?

[Fuzz]

Simply Amazing Fuzz!!! I have the celestron 130...quite a bit smaller...5" newtonian, but It should be great for planetary stuff....I love the picture of jupiter....What power eyepiece did you use in that one?

Thanks. I have an 8" Schmidt-Cassegrain (Celestron NexStar 8SE). It was the best combo of aperture, ease of use, portability (only 33lbs including tripod), and price.

The Jupiter shot was prime focus. That is, I took the lens off the camera and attached the camera body directly to the visual back of the telescope (i.e. no eyepiece in telescope either). Essentially, the telescope becomes the lens for the camera. For this, I have a T-ring and T-adapter for my camera/scope combination (both relatively cheap).

There are accessories you can buy that will allow you to hold and place your camera (with lens) over the telescope eyepiece and shoot through the eyepiece. This is called afocal photography. This works best for point-and-shoot cameras and webcams (since DSLRs are too heavy).

For planetary imaging, webcams are actually the best. Even DSLRs cannot get the images that you can get with a cheapo webcam. Because with a webcam, you can get lots of frames and can then pick out the ones which are the sharpest. Planetary images (and viewing) suffer greatly from air quality (especially turbulence). So with a webcam shooting several dozen fps, you increase your chances of getting those two frames where the air was perfectly still. With a DSLR, you have to get really lucky. The best amateur planetary images are almost 100% done with webcams.

[Fuzz]

Is it better to go to a slower f-stop if you can with something very bright like the moon and take a longer exposure or should I be ramping up my shudder speed at the fastest f-stop possible?

Also, I think I had my ISO set at 100 or 200..I remember reading something about wanting the gain on my camera to be near unity for best quality. which ISO is that for the D90?

Nice one of the moon. The 300mm really gets your close! The best time to photograph the moon is actually when it is not full, because then you can get the sunlight coming in at an angle to create interesting shadows and depth. At full moon, the sunlight is straight on and creates a "flat" image.

If you don't already have one, you definitely want to get a remote to avoid vibrations from pressing the shutter button. Or at least use the self-timer to let any vibrations die down.

With all unguided astrophotography, long exposures run you the risk of trailing as the objects move across the field of view. And with big objects like the moon (and even planets), even if you keep shutter speed fast enough to avoid trailing, air turbulence will create an out-of-focus/underwater effect with slower shutter speeds. For solar system imaging therefore I usually try to go for the fastest shutter speed possible, keeping the aperture open as wide as possible.

For stellar and DSO imaging, I go with the slowest possible shutter speed that I can get away with, without trailing (obviously that shutter speed will vary with the focal length -- at 18mm I can do a 60-sec exposure fine, but at 35mm, anything longer than 30 seconds introduces trailing). Aperture is also at widest open, because I want to capture as much light as possible.

For astrophotography, there is an optimal ISO setting for each camera to get the best signal/noise ratio. This thread on www.cloudynights.com has a lot more detail (some of the posters on that thread are well-known professional astrophotographers).

The best thing you can do to get good astro shots is stacking and using dark frames. Take lots of shots of the same image (same setting for each shot). Then take several shots with the same settings, but with the camera lens cap on (= dark frames). Put them all in a free software like DeepSkyStacker and stack them. Stacking layers all the shots, essentially adding exposure time from all the frames (e.g. you can take a 1-hour exposure by taking 120 sub-frames at 30 seconds each). The dark frames allow DSS to subtract noise (both thermal and random) from the images.

Compare the Orion wide-field image I posted this morning, which is stacked, against the Andromeda wide-field image from July 19, which is a single frame (not stacked). The Orion image is much sharper and cleaner due to stacking and dark frame subtraction.

[Neezer]

Thanks Fuzz...Cloudynights looks pretty cool.

I actually just ordered a remote for my camera the other day and it made it home, but I'm in North Dakota for work for another week or so...It was pretty cheap 8.99 so hopefully it will work...it has a lock setting for bulb also...but it doesn't seem like i'll need anything over 30 second exposure.


I'm actually thinking about going up to horseshoe campground when I get back with my fiance for a weekend and taking the telescope up to ute pass. I'll have to play around with it then..

I've read reviews of people form new york city getting great views in the city with the telescope i have though...so who knows maybe I can get some good stuff from colorado springs too...

[Crystal_Mt_Dreamin]

Damn...sick sick sick stuff! ANd glad I found this thread, took a night shot up at St Helens and saw what 'kinda looked like Saturn', but apparently that's Andromeda