My photo
This is my photographer’s blog, for your consideration. I post some of my favorite shots here, usually along with some comments about how the photo was taken or post-processed. (Occasionally I have the vain thought that someone might like to read about that.)

If you like what you see here, feel free to check out my Flickr site and YouTube channel.

Wednesday, September 10, 2008

If Jupiter Hugged Luna

IMG_8585_8559_composite_jupiter_hug_moon_cp2

This picture cannot be taken with a single exposure.  There is a 128x difference in brightness between our Moon and the moons of Jupiter. The only way to get a photo like this is to take separate exposures of Jupiter and the Moon, then combine them into the same picture.

In this case, I placed placed the celestial objects right next to each other to enable size comparison.  Both objects were captured with the same magnification. Seen side-by-side, you can see that the Jovian system is spread out at about 1/3 the apparent lunar diameter.

Click on the picture above for a larger view. Or, here is the full-res version and the full-frame version. Technical details, if anyone cares:

* Lens (both shots): Canon 70-300mm zoom at 300 (480mm equivalent for 35mm magnification).

* Moon: 1/45 second, f/9.5, ISO-200. 25 shots stacked with RegiStax.

* Jupiter: 1/2 second, f/5.6, ISO-800. 25 shots pared down to 10, then stacked with RegiStax.

In case you hadn't noticed, I'm really enjoying astrophotography with a camera and tripod! But of course it won't last much longer -- this is Oregon, after all, and the rainy season is on the way. Oh well; fortunately we have APOD, rain or shine!