Astrophotos, anyone?

[Jon Ruyle]

There haven't been a lot of astro pics on this forum... mine are not very good but I'd like to share a couple, and ask anyone else who has tried astrophotography to post their (probably more successful) attempts.


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Dumbell Nebula


5DII, Takahashi fs102 816mm f/8 iso 400 43min (autoguided)





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Veil Nebula


5DII, 816mm @ f/8 iso 800 28 exposures 8 min each Lumicon OIII filter





The first picture is far more heavily cropped: the veil nebula is a supernova remnant and stretches across multiple degress of sky. The dumbell nebula is a planetary and is only about 8 arcminutes across (still big for a planetary).


Both pictures were taken with a canon 5DII and a little takahashi
fs102 refractor mounted on an astrophysics mach 1 GTO mount. For the dumbell, autogouding was done with an orion short tube 80 (400mm f/5) and an
orion starshoot autoguider. The 28 veil frames were stacked with deep sky stacker.


These pictures are kind of crappy because they were taken from my light polluted back yard, and also because I don't really know what I'm doing. Tips and comments are welcome. Postings of your own astrophotos even more welcome :)

[Daniel Browning]

Looks great, Jon. Nice shots! I haven't tried anything outside our solar system yet, except at ultra wide angles.

[Jon Ruyle]

Thanks, Daniel.


You can see the stars in the dumbell shot are not perfectly round. I was autoguiding at 400mm, probably should have barlowed it. I'm still a little clumsy at finding guidestars, however, so I find the shorter focal length easier. I wasn't polar alligned very well, don't know how much that matters. Rather than one 43 minute exposure, three 15 minute exposures might have worked better, even when guiding (though it was my first autoguided shot, so I wanted to see what was possible).


And I need to get to a dark site [:)]


Hope to get better results as time goes on.


BTW, why not post some of your solar system shots, Daniel? I'd like to see them.

[wusstigphoto]

okay... I'll bite


Not sure why i want to embarrass myself but here goes...


Several years back, Grandma bought the kids a Meade ETX-125. At the time, my only good camera was a Sony F707 so these were taken with that. Heck, I don't even remember how I took them but I have been meaning to get the Canon set up on this tele to see what it can do... whenever I get around to ordering what I need, I'll try and post similar pics to compare.


Moonscape...


http://farm4.static.flickr.com/3594/3781731937_0497c8d509_o.jpg


Jupiter...


http://farm3.static.flickr.com/2512/3781731803_0704bbd100_o.jpg

[Jon Ruyle]

I wouldn't worry about embarrassing yourself... we're not trying to rival Hubble, are we? [:)]


Both the moon and jupiter are bright objects, so maybe you just aimed the camera at the eyepiece and took the picutre. I did a little of that with my canon G2 and 12 1/2" f/5 reflector.


Assuming "the canon" is a dslr, you could try prime focus photography with it, though if I remember correctly, the ETX only has a 1 1/4" focuser so you probably wouldn't be able to illuminate the whole ccd. But who cares? :)


There is a fair amount of detail visible in your picture of Jupiter. Did you try a little sharpening and turning up the saturation?


The ETX-125 is a nice scope... my kids aren't getting one that nice :)

[btaylor]

Not quite as close up as some of the others here but this is one I got on Friday night.


Not the greatest in terms of how many stars are in the sky as there was a 3/4 moon. Mostly took this one to try out stacking in CS4.


Setup was: Canon 40D, Canon 10-22mm @ 11mm and f/3.5, Exposure: 10sec, ISO 250


This was a total of 426 (that's not a typo) images stacked together and the foreground image (some light painting with a flashlight) put over the top. Took a VERY long time for CS4 to process by the way. I think there was about 6 hours in post for this one, probably more a function of me learning to use photoshop than anything else.


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[Oren]

Very cool btaylor, "wow" is what came to my mind the moment I saw it.

[alex]

So I've always been interested in astrophotography, and ever since I've had the 450D, I've wanted to try it out. Is getting star trails as easy as putting the camera on a sturdy tripod and using BULB to get an exposure upwards of say 30 min?

[btaylor]

Yes and No Alex. It all depends on the conditions when you are taking the shot. One thing that makes a big difference is the moon. If you have a lot of moonlight filtering across the sky or even onto the foreground you will end up with a very light sky/ foreground and the actual stars will be washed out. Another thing is that when taking very long exposures (I would say 25min +) the internals of the camera start to heat up and once the sensor heats up you tend to get a lot of image noise. That's where stacking images comes into play. You can take a series of shorter exposures without over exposing the sky while retaining the light from the stars and minimising noise.


The other thing is trying to get a nice composition. A straight up shot of just the sky won't be overly interesting so you need to try to add something to the foreground (as I've done in my previous post) to mix things up a bit and put everything into perspective.


If have you a nice clear night and a decent tripod then just head out and have a go using bulb as you mentioned (I've done that a number of times when the conditions are right). That's the best way to find out. Have fun mate.

[Jon Ruyle]

Very nice shot. Of all the stuff you mentioned, composition is the most important IMO (and the one that gives me the most trouble), and yours is great.


Another thing I would mention is light pollution. Just like the moon, it washes out the sky, making it difficult to isolate the stars. If you live in a big city, even a moonless night is bright.


Note also that the longer the focal length, the more quickly you get trails. With a wide lens, it takes a while.


I have to think a little more about what you said about stacking. My dumbell nebula picture, for example, was a 43 minute exposure in a light polluted sky (at a slow f/8, however). Sure the sky could be darker in that pic, but it takes a lot to actually overexpose the sky at low iso. Also, does the camera actually heat up less if you do 10 1 min exposures in succession than 1 ten minute exposure? (If so, then I should be doing shorter exposures).

[btaylor]

Also, does the camera actually heat up less if you do 10 1 min exposures in succession than 1 ten minute exposure?


That's a good point Jon, I didn't think of it that way. I guess from experience I have seen less noise from the shorter exposures than one long exposure. I could probably borrow a mechanic's IR thermometer and do some field tests but that might be going over the top.


Also, your absolutely right about wide lenses taking a while to get the trails. That one of mine took around 1.5 hrs and the trails aren't overly long. I guess it's a trade off between the number of stars in the shot and the length of the trails. Might try it out close to 20mm with the same lens next time and see how I go.

[Jorn]

Nice.


Can you post a picture of your equipment?

[Jon Ruyle]

Hi Jorn,


Not sure if you meant me or btaylor, but here are a couple of pics of the 5DII attached to the telescope. The little telescope on top (and the little camera attached to it) is for guiding.


I guess even a small telescope makes a pretty big camera lens.





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[Jorn]

Exactly what I was looking for :) Thanks!


Is the camera adapter home made or could i be bought?

[Jon Ruyle]

Is the camera adapter home made or could i be bought?


I'm not nearly clever enough to have made the thing :) I think I got it at astronomics, (www.astronomics.com). I'm sure orion (www.telescope.com) would have it, too. I believe it's called a t-ring but you might want to call to make sure. I also needed a 2" extension tube to reach focus at infinity. (As Bryan might say, it's not going be cofused with a macro lens.)