Luminous Landscape Forum

Equipment & Techniques => Landscape & Nature Photography => Topic started by: acktdi on March 13, 2013, 03:12:50 pm

Title: Comet C/2011 L4 and Moon
Post by: acktdi on March 13, 2013, 03:12:50 pm
I spent a week planning this shot.  Thinking about it kept me awake at night.  In the end, it was worth it.  I've very happy with how it turned out.  I've still got a pano stitch of the entire Las Vegas strip to put together but here's the first one.

(http://alvinchanphoto.com/20130312_cometc2011l4_moon_alvinchan_web.jpg)

exposure info
5DM3, iso 400, 1.6s
70-200f2.8L @ 160mm, f5.6
Title: Re: Comet C/2011 L4 and Moon
Post by: Chairman Bill on March 13, 2013, 04:04:37 pm
Really nice. I post on a forum that includes an 'Astronomy photograph of the day' thread. Would you mind if I linked to this on that site?
Title: Re: Comet C/2011 L4 and Moon
Post by: Jaffy on March 13, 2013, 04:07:13 pm
Excellent image, especially the detail in the moon. All-round good balance and exposure.
 We've just had cloud and rain - good rainbow as the sun set but it's not the same >:(
Title: Re: Comet C/2011 L4 and Moon
Post by: acktdi on March 13, 2013, 04:31:58 pm
Chairman Bill, go right ahead.  This is one of the best photos I've taken in my life.
Title: Re: Comet C/2011 L4 and Moon
Post by: Justan on March 13, 2013, 04:34:33 pm
A delicious work. Give yourself a treat for this.

Definitely print and submit to local galleries, if you haven’t done so already.

I’ve found that locals love my night shots of the city and I’m sure you’ll experience the same

Title: Re: Comet C/2011 L4 and Moon
Post by: framah on March 13, 2013, 04:50:49 pm
I don't even bother trying anymore. Up here in Maine, seems no matter  what fantastic celestial event happens, we have overcast skies.

I mark my calendar for every meteor shower and... sure enough... cloudy nights.
Auroras supposed to be at their peak?? no problem... cloudy.

This time it was cloudy all day and THEN it started raining.


I'm glad you got the shot and that you shared it with us!!!
Title: Re: Comet C/2011 L4 and Moon
Post by: luxborealis on March 13, 2013, 11:37:16 pm
Is anyone else unsettled by the movement of the comet compared to the sharpness of the moon? This is the first time I've seen the moon so sharp with a 1.6sec exposure. Usually, it starts to slightly blur at 1/30th and is unrecoverably blurred at 1/2sec or longer. Any thoughts/comments?
Title: Re: Comet C/2011 L4 and Moon
Post by: RawheaD on March 14, 2013, 12:15:37 am
After seeing the OP shot earlier today, I had to go out :)

@framah: sorry to hear, down here in Boston, we had a perfect day for viewing.  Went out with a NEX6, SpeedBooster, and a CZ85/1.4, not knowing what I'd get, and did pretty well :)



(http://farm9.staticflickr.com/8235/8556351394_ee5f9577fd_b.jpg) (http://www.flickr.com/photos/rawhead/8556351394/)
Comet Pan-STARRS (http://www.flickr.com/photos/rawhead/8556351394/) by Dr. RawheaD (http://www.flickr.com/people/rawhead/), on Flickr
Title: Re: Comet C/2011 L4 and Moon
Post by: Walt Roycraft on March 14, 2013, 07:14:39 am
Alvin, very nice indeed!
Title: Re: Comet C/2011 L4 and Moon
Post by: Justan on March 14, 2013, 08:25:12 am
Great capture, Rawhead!
Title: Re: Comet C/2011 L4 and Moon
Post by: Isaac on March 14, 2013, 11:44:48 am
Usually, it starts to slightly blur at 1/30th and is unrecoverably blurred at 1/2sec or longer.

Unsettled? No.

But I think you've posed an interesting question about why the moon isn't blurred.
Title: Re: Comet C/2011 L4 and Moon
Post by: acktdi on March 14, 2013, 01:39:28 pm
This article is helpful in explaining the lack of blur
http://www.luminous-landscape.com/tutorials/d60-night.shtml

The Rule of "600"

As discussed in detail in my article on meteor shower photography, the quickest way to determine the longest exposure that is possible for any given focal length lens, without the stars streaking, is to divide that focal length into 600. (This is the formula for 35mm. Larger formats are laxer, smaller formats more unforgiving). Since the 35mm focal length equivalent for the 14mm lens that I was using on the D60 is 22mm, I used a 30 second exposure (600/22=27 seconds. Close enough).


The moon moves at a slightly different speed in relation to the stars, but this is close enough.  I would have been fine up to about 3.75 seconds at 160mm.
Title: Re: Comet C/2011 L4 and Moon
Post by: Isaac on March 14, 2013, 02:33:45 pm
Thanks, I might even be able to remember that :-)
Title: Re: Comet C/2011 L4 and Moon
Post by: Roman Racela on March 15, 2013, 03:48:03 am
This is great!
Title: Re: Comet C/2011 L4 and Moon
Post by: acktdi on March 15, 2013, 10:48:03 am
.. and here is the panoramic version.  5 images merged with Photoshop.

(http://alvinchanphoto.com/20130312_Comet_Moon_Las_Vegas_pano-Alvin_Chan.jpg)

http://alvinchanphoto.com/20130312_Comet_Moon_Las_Vegas_pano-Alvin_Chan.jpg (http://alvinchanphoto.com/20130312_Comet_Moon_Las_Vegas_pano-Alvin_Chan.jpg)
Title: Re: Comet C/2011 L4 and Moon
Post by: Roman Racela on March 15, 2013, 07:56:22 pm
Were you shooting from a hill in South Las Vegas? Great job!

.. and here is the panoramic version.  5 images merged with Photoshop.

(http://alvinchanphoto.com/20130312_Comet_Moon_Las_Vegas_pano-Alvin_Chan.jpg)

http://alvinchanphoto.com/20130312_Comet_Moon_Las_Vegas_pano-Alvin_Chan.jpg (http://alvinchanphoto.com/20130312_Comet_Moon_Las_Vegas_pano-Alvin_Chan.jpg)
Title: Re: Comet C/2011 L4 and Moon
Post by: NancyP on March 16, 2013, 10:54:22 pm
Very nice indeed. I tried to ID this comet, but the weather failed me, clouds obscured that sector of the sky on the evenings I had available to shoot it. (Midwest - I won't complain about the rain or snow,though, after last year's drought).
Title: Re: Comet C/2011 L4 and Moon
Post by: Ctein Photo on March 19, 2013, 10:38:03 pm
Dear Lux,

It all depends on how large the moon is in your photograph and how sharp you need it to be.

The moon takes a bit over 2 minutes to move its diameter in the sky. A 1.6 sec exposure will blur the moon by about 1/80th its diameter. In Alvin's magnificent photo, as posted here, the moon's only about 30 pixels (est.) in size. So, the blur is less than half a pixel. He'd have to be up around 3 seconds for you to see any blurring.

I'm not sure what you mean by the "movement" of the comet. It looks equally sharp to me in this photo. I don't mean this to be condescending, but are you perhaps confusing the fan of the tail with some kind of blurring?

pax / Ctein