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Diane Miller
08-31-2015, 06:37 PM
I'm getting in the mood for another trip to the mountains for the upcoming new moon, weather and smoke from fires permitting. Pulled up an older Milky Way for more processing practice (shot a year ago from the Patriarch Grove in the White Mountains at 11,0000 ft. The lovely gradient in the sky is smoke from a forest burning well to the southwest with illumination provided by Bishop, CA far below.

Although I tracked, shooting 90-second exposures for over an hour, I have yet to master the software to do a good noise-reduction composite, so for now this is a single exposure. The FG is composited, shot last April, but from down in the valley approximately below the view of the Milky Way.

The Milky Way is with the Canon 17mm TS-E, ISO 1600, f/4, Canon 5D3. The mountains are same camera, Canon 100-400 at 100, ISO 800, 1/13 at f/6.3, pre-sunrise light.

(As a woman, I reserve the right to cheat on appearances as much as possible. :S3: )

Don Railton
08-31-2015, 06:54 PM
Hi Diane, I really like this, the composition is working well for me... I like that the center of the milky way is well defined (is that what they call the core?) and I also like that the stars are finer/smaller. I have see a few posts lately where the stars look blocky, they have less appeal to me.
BTW, as a bloke I appreciate and support that some women cheat on their appearance:t3

DON

Tobie Schalkwyk
09-01-2015, 12:06 AM
Excellent shot(s) and you've done well to get this sharpness over 90s, Diane! I'm sure you can get even more from it with a little more PP effort. You make me itch to get out and do my first astro excercise!

Morkel Erasmus
09-01-2015, 04:50 AM
Nice job on the composite, Daine.
I like the overall look & feel, but would perhaps go darker/more contrast on the mountains?

Diane Miller
09-01-2015, 11:33 AM
Thanks, guys!

Don, :S3:

Morkel, I went in circles with the mountains, but will look again. With layers preserved in the final image, it's very flexible.

Tobie, go for it!! But to do a 90s exposure I had to track the star motion (with an Astrortac). It has the additional advantage of shooting many frames over an hour or more, which remain aligned within the error of the setup (mostly polar alignment accuracy). Then those frames are pin-registered and some sophisticated corrections made in specialized astro software, where several kinds of noise are hugely reduced, allowing subtle detail to be pulled out by stretching the histogram. (ISO 1600 is recommended for the best s/n ratio.)

But there is a Mac app called StarryLandscapeStacker that lets you shoot a series of 10-15 sec exposures on a fixed tripod and it will align them and get rid of a lot of noise. I've just gotten it and tried it once, but it looks to be amazing. And it's only $10!

Critical focus is very important, as is finding the best aperture for the lens for minimizing odd shaped stars. (Lenses just weren't designed to render pinpoints of light well.) Helicon Remote is the best focusing aid I've found, and monitoring the shoot with Lightroom's tethered capture avoids a lot of "Uh-oh" sessions.

It's the alignment step that I'm stuck at now, with more limited choices on a Mac platform. Need to crawl back in the castle, raise the drawbridge and flood the moat, and tackle PixInsight. Also need to get better at "star shaping" which gives lovely soft stars and reduces their size to avoid that blocky look Don refers to.

Don Lacy
09-04-2015, 02:04 PM
Hi Diane, i love the crisp stars you got with the tracker being able to shoot at 1600 ISO and stopping the lens down a stop or two make post so much easier. As far as focusing I just set the hyper focal scale for infinity and make sure my foreground elements are at the right distance from the camera it helps to test this during the day with live view so you can mark the exact spot on the lens since they can be off a little at least with the Samyang brands. Also agree with Morkel on the mountains I would darken them just a bit more.

Diane Miller
09-04-2015, 09:24 PM
Here's a look at darkening the mountains -- I like it -- thanks!

155302

If I were doing a single exposure, it would seem intuitive to go for a lower ISO and track longer. But ISO 1600 is recommended for the situation of stacking many (60-90 if possible) exposures to reduce noise. The best s/n ratio is obtained there, counterintuitive as it seems. As I understand it, that's because dark current and fixed pattern noise also enter the equation. They aren't usually a concern for us, but become important when an image is noise-reduced to the point the histogram can be stretched to bring out detail that was barely visible in a single exposure.

I should be able to track for well over 10-15 minutes with wide angle without star trailing, but haven't experimented to see where the balance might lie in noise, and if it would be better than 1600 when processing just a single exposure. Might try that soon, just out of curiosity. But for now I'm working on the stacking software. Makes PS look like kindergarten.

Judy Howle
09-07-2015, 05:45 PM
I think this is outstanding Diane!! I like the darker mountains.

Andrew McLachlan
09-07-2015, 07:04 PM
Hi Diane, the repost in Pane #7 is beautiful with just the right amount of brightness to the mountains...very nice details in the Milky Way.

Diane Miller
09-12-2015, 10:22 PM
Thanks, everyone! Last week I made the trek to my high ground in the Sierra and had skies obscured with smoke and then clouds too. It seems every time I try this, wildfires start downwind. This time it was three of them! I got in one run one night, of the Trifid and Lagoon nebulae, in the central Milky Way, framed together at 300mm, but that leaves neither large enough for my tastes. Haven't had time to process it yet. By the time I switched to the 600 to try more magnification the area had sunk into the low-lying haze of smoke.

I feel like someone who has taken up sailing in an area where there is no wind.