[chupathingie]

Oh my… that’s gorgeous! By all means, re-impregnate.

So spill the beans: number of exposures, duration, ISO, procedure, etc…

Looks like you nailed the focus (that’s a lot harder than folks realize) and your scope’s color correction is very tight… no halos.

What did you stack with? Did you shoot darks? There are a few hot pixels, so I’m guessing no darks…

AND…. M42 is a magnet for satellites, ain’t it? 😆

Is this full-frame or a crop?

This is a seriously good first image… You should be addicted after this. None of my images look this good, even considering I’ve only shot wide-field sans scope, but now I have something to shoot for 😉

[chupathingie]

When I get a round ‘tuit, I’ll add to my gallery here.

Oh yeah, please do!

I spent part of the weekend trying to come to grips with Theli, but between the flu and language difficulties and trying to adapt it to DSLR use I’m not making much headway. One of the guys at the Gemini Observatory has offered assistance, but I really hate to impose with a bunch of hand-holding requests.

I’m thinking I need to learn some basic scripting in linux; since basic stacking and dark frame subtraction can be accomplished easily with align_image_stack and imagemagic (which can do what I’m looking for in 16bit/channel) but I’ll be damned if I won’t be lazy and find a way to avoid doing this one frame at a time via the command line! 😆

[chupathingie]

hahahahah… loved the last few seconds.

Great thinking, though.

[chupathingie]

$1700 body only… but what a sexy little beast…

Am I wrong by my first thought being “I’ll bet that box has an extremely short flange-sensor throw and could mate with almost any lens with an adapter”?

[chupathingie]

For me, a phone just doesn’t cut it for picture taking. Now, I don’t own an iphone/android (which is pretty ironic considering I get a discount for working for one of the larger telecoms), and I have to admit that the iphone’s resolution and optics are pretty impressive for a phone. But functionally it doesn’t even come close to a middle-of-the-road PNS’s zoom capabilities and rudimentary semi-manual settings. I’ve always got my PNS with me because A: Phone cams suck, and B: I can’t lug a DSLR around with me everywhere.

A phonecamera is the Instamatic of the new age, and like the Instamatic was, phonecams are ubiquitous. They are the currency of most peoples’ vacation, birthday party and pub crawl memories. Most people are picture-takers, not photographers, so this is the same cycle we went through with film. I hate to admit it, but Yugo is right, it’s not going away. But it will always be different, and it will always separate the picture-takers from the photographers.

[chupathingie]

I don’t hate it, I just think it’s a fad that’s going away before long. Hopefully way before long. I showed one of Orionid‘s frankenpictures to a friend (one of the wrong-size-film-in-a-different-camera-body shots) and his first assumption was Hipstamatic. 😕

[chupathingie]

re: video… There’s a whole new ball of wax.

If you have a bracket mount, you can go the eyepiece projection route, and in addition use whatever optical zoom the camera has to give you high-rez and high detail.

~or~

You can pick up a ToUcam (cheap webcam). Custom drivers have been written, and once you tear off the old lens the tiny sensor makes a perfect match for prime astrophotography of planets. When I was a kid, the science textbooks showed pictures of planets taken with the (at-the-time-largest) 200″ telescope. Those are put to shame with the images you can get with an 8″ Newt and a $50 webcam.

I haven’t done anything with video stacking, since I don’t have a usable mount for my dinky 4.25″ f10.6 Newt. Even so, you don’t need to track accurately to do planetary, since the stacking software aligns frames and the exposures for each frame are <1/30". You can even do it with a Dob. I've been wanting to play with that whole process, but it's going to be a while (end of next year, perhaps) before I manage the scratch for mirrors, hardware, and a good GEM.

[chupathingie]

well here’s to ya! I’ve got a week before my toys arrive, and I still need to scare up a power supply for the astrotrac.

CSB segue: I was lamenting not having the FOV crop of the Rebel making a long lens longer, but since the 5dII is at 21mp, my FOV is actually tighter pixel-for-pixel.

[chupathingie]

So lemme guess, Rav’s gonna be out-of-pocket all weekend? 😆

[chupathingie]

Good advice (and some great photos). If you’re planning on just publishing to the web, or reduced sized prints, run that ISO up as high as you can get. Reduction hides noise very well.

Only thing I’d add to what he said is that depending on the quality of your glass, you may want to close the aperture by 1 or 2 stops if you’re using a long lens to cut down on chromatic aberration. I’ve got a 75-300mm EF lens that shows very obvious purple halos around stars when used wide open. It’s only an issue at full resolution (or close to it), so disregard if you’re planning on reducing the image size for something like a 1080 timelapse video.

[chupathingie]

chupa; Celestron, I found, has an awesome FAQ on how to set their scopes up for optimal tracking. Man, I can’t WAIT!! Aligning the mount, initially; not so much. I’m going to ask the folks at Starizona if they’ll do it for me. :o)

well, alignment has to be done at the beginning of every session, and the declination of your wedge varies by location. ie, your wedge angle will be slightly different between Phoenix, Flagstaff, Tuscon etc. Phoenix and Flagstaff, for instance, are a full degree and a half off each other… alignment is one of those things you just can’t avoid. 🙂

edit: I’ve never dealt with a fork mount, my old (now deceased) mount was a German Equatorial. Since I was shooting widefield with it, I could eyeball the polar axis and get aligned close enough for 3 minute exposures at 300mm. I still had to toss over half my exposures because the periodic error was so bad on that mount that most of my images were unusable. The error in my estimation would have been obvious with a modern mount, I’m thinking.

[chupathingie]

Yeah, polaris is ~1/2 degree off true north. All of the griping I’ve heard about drift alignment comes from those trying to master it. Before long most are talking about it taking them maybe 10-15 minutes to get aligned for the night. An illuminated reticle eyepiece helps a lot, but simply using exposures from the camera works as well. That long focal length is a benefit there, aligning without the focal reducer (if it’s easily removed) will give you greater precision.

/damn but I gotta stop derailing threads… 😉

[chupathingie]

Rav, a lot of folks use that scope and I have to agree, you can get great results with it. At f10, you’re looking at basically a 2800mm lens, there, so your polar alignment needs to be as close as you can manage if you’re going to expose beyond say 3 minutes. Dunno if you already know about drift alignment, but if not look it up. It’s a bit complex at first, but it’s about as accurate a method of alignment as you can get.

Didn’t I ask you about using a Hyperstar system sometime in the way-back? The thought of an 11″ at f2 just makes me drool…

[chupathingie]

Thanks for the input, it seems like the collective view is “poop”. 😆

As far as the lens goes, it’s basically a mini-Celestron or Meade telescope with a focal reducer (I’m only comparing the design). The reason why I was guessing the focus would be soft is because when you make one of these that small, the central obstruction formed by the secondary mirror is such a high percentage of the surface area of the primary that you lose a lot of contrast and increase the diffraction dramatically. All other things being equal, bigger is pretty much always better with optics… as you scale this design up, the % of obstruction by the secondary decreases. This thing’s only got a ~3″ primary. It’s not much of an issue at the 8″ scale, and even less so at 11″ or 16″.

[chupathingie]

‘Grats!And don’t be too afraid of the RAW file size, the real issue is going to be dealing with the images in 16bpc TIF… I’m guessing over 100MB each. If you’re going to be doing any stacking make sure you’ve got a 64bit OS and as much ram as you can manage! 😆

I just ordered a doubler, heads, astrotrac and polar scope so I’m going to be doing much the same as you after they arrive. No scope here, but I plan on making use of the 70-200 f2.8L and doubler on DSOs.

There’s a trade-off on ISO/noise. For AP, you may want to limit yourself to 1600 or 3200; going higher than that with that camera will most likely mean you’ll need many more subs to cancel the additional noise. My old rebel would hit 1600, but I quickly found that shooting above 800 meant spending more time imaging to smooth out the noise floor. The exception to this is that you may need the higher ISO to keep exposure times down to compensate for the tracking error of your mount. Periodic error really starts to stack up after 3 minutes or so.

I get the feeling we’re going to start seeing some astro-stuff on the boards here in the next couple months!

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