@ravnostic
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ravnostic
ParticipantThat’s awesome. Shoulda taken it from the passengers side (you know…for the contest that is sure to occur as it’s the most popular suggested thread recently.)
ParticipantI’m no judge, but if Stapler posts that, I’ll bet we’ll have already seen the winner!
ParticipantI’ll keep Cameraflage in mine, should I ever take a picture that must be framed…
ParticipantOkay if there’s just ‘one’ manmade thing? I have a thought of a mountain range, one of which has a big “<—Phoenix" sign on it (back in the days before there were many roads, it's how people knew they were on the right track and not just lost in the desert). It should look lovely at sunset–if it's okay to use.
That’s actually for aircraft – the whole story is here.
Interesting, I did not know that!
ParticipantI have a set of Opteka tubes, short $$ like 79 bucks. They work just fine. Hunt’s wanted to sell me a set of Kenkos for $165.00 I laughed walked out and bought these from Amazon.
Dear lord, now I have to add another toy to my list!!
May 14, 2010 at 5:19 pm in reply to: My first little foray into long exposure astrophotography #27869ParticipantI thought of this myself. I’m basically 33.5 degrees north of the equator. Could I not extend 1 leg of my mount by that much (It’s a robust mount, but I’ve never extended the legs as I’ve never needed to given the ensemble’s natural height, so I don’t know how far they go), wedge some contraption firmly in place to keep things from falling over, and make do? I think I can. The risk, of course, is it’s a $3k scope. But the rewards, dollar per dollar, could be really phenomenal. It comes down to a widely based tripod with some sort of mounted bracket for the tilted tripod to rest upon safely. If the load is evened out, I should be okay. I’m toying with the idea. It could actually even be somewhat adjustable, really, on the longitude axis, but the rub would be the proper alignment with the true polar north. But I think for any decent 10 minute exposure, a good visual siting would be sufficiently better than what I’ve got now, so long as you knew in which direction Polaris rested away from the true north when setting things up, and aimed the N-S axis accordingly.
On a similar note, neighbors always have lights on that interfere; I came up with a very simple baffle to block them; sheet aluminum crimped (riveted, really) at the right diameter, with notches every 60 degrees to wedge within my telescope’s opening. I’d bend the notches back so there wouldn’t be sharp edges and so that they wouldn’t touch the glass; about a 12″ length would block out most of the incidental light that I’m trying to avoid (that and a can of flat black paint). I haven’t employed it yet (a time issue, mainly), but I’m sure it would work, and with care, quite safely.
ParticipantElsinore – we’ve got broken images (at least one) going on again. I’m so sorry our server is being dicky. Please to fix? Thanks.
Not to quibble, but you guys need to buy your own domain for $10, complete with free hosting account (and I KNOW you would know how to use it). This hardly ever ever ever happens to me (maybe twice in the past 5 years.)
May 14, 2010 at 3:51 pm in reply to: My first little foray into long exposure astrophotography #27867ParticipantFor my setup, the wedge is the way to go; same result, really; the scope’s software is built for it; I’d reduce by one axis of rotation (in aligning to Polaris, it even accounts for the fact that P. is about 3/4 degree from the true axis of rotation, thus eliminating that iota of smudge factor you’d expect if not so).
And, I learned, there was no supernova in W. Galaxy. Has to do with filters, et al, in processing. Oh well.
ParticipantOrionid; like I said, I need new toys.
On that note, I just purchased online a reducer for the scope. It seems that in prime focus, my setup is the equivalent to an f-10. This, in addition to a very limited FOV, means that the 4 minute exposure came out pretty dark. The reducer drops me to an f-6.3, and widens my FOV considerably. That will shorten my exposure time by a factor of 3, and allow me to capture more nearly the entire Orion nebula (and dang if it isn’t moving right towards the sun as we speak! Oh well…). I’m hoping, as they are shipping USPS priority, that I get it Monday (if it ships today, maybe), so I can try it out. As my original Whirlpool nebula was plenty big enough, I’m hoping the reduced exposure time allows for less star travel during exposure, yet also allows for a brighter, less noisy picture. We’ll see.
You are correct about the filters. I gotta get me some filters! Those and a wedge mount and some decent software and I’ll perhaps be golden to rival IJ’s photos. I do have one red-spectrum filter, but without the polar mount setup, I’ll never get the exposure time I’d need to make a decent picture. My retail seller of my scope has the wedge kit and the extra kit for easier fine-polarity alignment for $395. It’s on my list (if overtime at work holds up, I’ll have it by the end of June.)
Between all these things, I could possibly rival IJ’s pictures, and I look forward to that possibility. But regardless, it’s a fun process to have have already done more photographically than I’d ever done before, and I look forward to whatever strides I make in improving upon the results.
ParticipantOBOs?
ParticipantHere’s one taken through a 200 inch telescope using adaptive optics (to reduce atmospheric distortion), showing Neptune. And it’s still a bit fuzzy.
ParticipantWell, not with 36 of them. Usually it’s just a stack of red, blue and violet filters (for hydrogen balmer lines, or green, for oxygen ion lines). Taking a shot in each of the three eliminates possible chromatic abberations, which is the nature of glass to only focus on one color in the spectrum (you only notice such things in highly magnified instances, such as in telscope views). Most good quality lenses have two types of glass, to focus two wavelengths of light, but the third would still be out of focus. So by doing them one color at a time, each color is in perfect focus. There are instances where they do more, though, such as Hubble’s ultra-deep field, where they stacked two hour exposures over and over to create an image with over a million seconds (10 days) exposure time. Stacking for amateurs is mostly used to increase resolution and eliminate noise, ala use-a-web-cam-and-let-the-computer-compile-the-clearest-shots. This will get you down below that 1/2 arc second limit by up to 10fold, which is huge.
This shot was certainly not composed that way. And unless he has a $10k (or more) polar mount, there would be at least some vibration caused by the little gears keeping the skypoint in view. But who knows? Perhaps he has a really, really, really awesome telescope. I just can’t picture that picture not being something from a professional telescope. It’s just too damned good; the detail is far more than one would expect from an amateur. This, for example, is an image from Palomar:
http://antwrp.gsfc.nasa.gov/apod/image/0509/IC1396_demartin_f.jpg
Taken through a 48″ telescope, it’s more what one expects to see when astropicing.
ParticipantI might have to recind that statement; Extremely energized ionized hydrogen coupled with similarly excited oxygen could product the yellow-green seen there (same as the Rosetta nebula). But even so; a picture of not nearly this quality is found here;
http://www.cfht.hawaii.edu/News/MegaPrime/MegaPrime-PR-AstroImage-Rosette.html
…and it’s stacked of 36 images, exposed 5 minutes each. I didn’t find the Hubble match, but then, the hubble site is emmense and it’s likely the guy’s shot is just a cropped portion of a larger image. Personally, I would delete it and then wait for his response to validate his picture. But I don’t think he can, and there’s no way it’s not at least a stacked composite, which goes against the rules.
The other possibility is he’s one of the super-lucky persons who’s submitted an idea for Hubble and got it–but even then, he wouldn’t be the one taking the picture.
ParticipantNot a chance, Elsinore. There’s no filter that will make yellow from red, green, or violet, and the level of detail is far superior to what you can get with even a 24 inch scope, even if it had the anti-blurring software that corrects for atmospheric distortion. Those nebular clouds are on the order of maybe an arc second in diameter, yet he’s got detail of 50 pixels across them. That’s unheard of from an Earthbound scope. I’ll poke around hubble and see if I can find it.
May 13, 2010 at 8:58 am in reply to: My first little foray into long exposure astrophotography #27865ParticipantA couple more things; I think the star in my Whirlpool shot at the 10 oclock position is probably a supernova; it’s not in Hubble’s 1994 shot (I think that was the year, it may be the bright star that is visible, but obviously it’s now significantly brighter by 5 or more magnitudes), and if Hubble didn’t catch it, it wasn’t there. So that’s my guess.
As for Jupiter, I should clarify that south is up and north is down in my image (telescopes do that sort of thing). The dark band is where the Great Red Spot is located, but it’s not as great as it used to be. It’s either not visible, or on the other side of the planet.
Carry on!
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