Saturday, November 01, 2008

The Story Behind The Full Moon Shot

So... I promised you the story behind the photo, and here it is.

The plan was to head out to Lake Crabtree on 10/13 to catch the rise of the full moon over the lake, with the twinkling lights of a couple of low-rise office buildings on the far shore for added interest. I'd passed this place a few times under a full and rising moon and was always struck by it. But I'd never had a camera along when this happened.

So I was determined that now that fall had arrived and the moon was closer, the darkness earlier in the day, and all things right for a full mooning photographic experience that I would capture this scene once and for all. And it started out going exactly according to plan. I loaded my camera, tripod and other gear in the front seat, my faithful companion and truck guard Tonka in the back seat and we set out exactly on a schedule that would put us at the designated point just at sunset.

Everything was great until we left the interstate and turned onto Aviation Parkway at which point I began to hear a strange, but familiar "tock-tock-tock" noise coming from the right rear corner of the truck. This, I reasoned, could not be good. So quickly I pulled off the parkway and made a walkaround inspection. No visible signs of anything amiss... but what was making that noise?

The noise that did not abate when we left my impromptu inspection station. But since I had already checked all four corners, we went on to our scheduled stop. I squeezed the truck onto the shoulder (not making the guy riding my back bumper very happy I'm sure, but he should know better than to tailgate), cut the engine and climbed out to begin setup for the big shot. And it was exactly at this time that traffic disappeared for a moment allowing me to hear the "ssssssss" coming from my right rear tire. Whether it was the tire sitting on the leak or the traffic, something was drowning out the noise during my previous walkaround. But I could clearly hear now what I couldn't hear before.

This, I decided quickly, was the last place I wanted to try changing a tire. There was barely enough room to park between the road and the guardrail, much less park and work. So I tossed the tripod back in the front seat and jumped back in so I could reach a safely-off-the-road place to work before the tire went completely flat. That, as it turned out, was the parking area for the Lake Crabtree County Park. A parking area that closes at 7:30 PM. It was now 7:05. No problem... I've done this tire changing thing enough times that I can surely accomplish the job in under 25 minutes!

Which I did. Once I convinced Tonka that it was not time for him to get out of the truck and dislodged my jack from the idiotic storage location Dodge assigned to it the rest was easy. Fifteen minutes later, the spare was on the ground, the still-hissing flat was in the bed and I might still be able to get my shot.

But it wasn't going to be on the shoulder of the road. Getting off there in daylight was tricky enough, in the dark I wasn't going to attempt it. Plus once I was on the ground I couldn't help noticing the mid-shin-high grass that -- being right next to a large body of water -- is no doubt either home or at least a takeout restaurant for various varieties of snakes... none of which do I wish to disturb (thinking water moccasins here people). The park itself was too wooded to give me an unhindered view, plus it was on the wrong side of the lake. And 10 minutes from being locked up with me in it. So finally I decided I'd just start back home and the first place I saw with an unobstructed view of the moon would be my new location.

I snapped this shot (and 49 others) from the on ramp to I-40 from Aviation Parkway. Not the sexy lake view I was after, but by this point I didn't really care a helluva lot. I got a few shots I could live with, spent $150 on a new tire the next day and then -- just to add insult to injury -- found out that the actual full moon was on the 14th, not the 13th.

Updated: Since a lot of people have asked for technical data on this shot I decided to add it to this post. Getting a good moon shot, I've found, is a tricky proposition. The most common problem I see is overexposure of the moon itself, leaving it a white fuzzy blob in the sky. This usually results from letting the camera decide on the exposure by using one of the automatic modes.

Here's the deal. You want a good moon shot, you're pretty much going to have to do it old school. And experiment. A lot. Because even if you do everything the way I did it here, you may not get the same shot. the moon, as we know, is not stationary in the sky, nor in its orbit. Some months it's closer to us, others less close. Lattitude, relative humidity (and air density), cloud cover... any number of environmental factors can cause your shot to be a half stop or more off. So be prepared to take several shots and adjust as you go. If you cover enough different exposures, you should be able to get something you like.

So here's what went into this shot. I used a Canon 30D dSLR coupled to a Canon 200mm f/2.8L telephoto lens with the hood attached to minimize ambient light at ground level. (You want as little of that as possible in any case, and considering my location I stood a good chance of getting a lot more of it than I wanted.) I set up on a tripod and began shooting. I started by stopping the aperture down to f/9.0 and (based on my experiments the night before) started at 1/125 second shutter speed, dialing in -1/3 stop worth of shutter (1/125, 1/160, 1/200, 1/250... etc.) with each successive shot. I didn't pay a lot of attention to the LCD other than to watch to see when the moon began to dim out (seems like that started to happen at around 1/320 or 1/400 second). At that point, I changed apertures and repeated the process. I tried several different apertures with a range of shutter speeds, just watching for when the moon became too under or overexposed before starting the next series. This particular shot was taken at f/8.0 at 1/200 second shutter speed.

But I wasn't done yet. I had a shot with good definition and a good exposure, but the color temperature looked pretty frigid. I wanted that golden glow (even though that's not what I was seeing with the naked eye) so I tuned the color balance with Photoshop, dialing in a tick more red and a couple of ticks more yellow. Finally I cropped it close. The original image was something like 3500 pixels wide, and most of it black. I cropped it to 600x400 -- or as close as I could get to those dimensions without cropping out part of the subject. And I don't remember for sure, but I probably tweaked the contrast just a touch to recover any definition lost during the color balancing act. Normally I'll handle this with compensation curves, but whatever works for you I'd say use it.

At the end of it all, I got a big golden Harvest Moon... in October. And now you know how.

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smarmoofus said...

Very nice shot, Mojo... and I was wondering about your lens. Thanks for the technical details! I really wish my zoom had image stabilization. I'll give this a try, anyway, but I don't think I'll have the same result as you. I wish I'd taken this... truly. *wistful*


lisaschaos said...

Well that's a beautiful moon! I like how you adjusted the color. :)

Farrago said...

Okay, but at which ISO were you set for those aperture and shutter speed parameters?


And how's it going? Sorry it took me all this time to get over to your blog.

Mojo said...

Oh you people are SO picky. I was pretty sure I'd shot it at ISO 100, but I went back and checked the original file to be sure. For once, memory served. It was in fact ISO 100.

And Smoofus, none of my lenses are image stabilization capable. I can't afford the extra cake for IS, so I rely on doing it the old fashioned way. In this case, a tripod. What I didn't do was use the mirror lockup function and self-timer (or remote) which would have been beneficial, but not a strict requirement at 1/200 second shutter. And frankly by the time I finally got to a place where the shot was possible, I was too annoyed to screw around with it anyway. And since this was before I got my wireless remote I'd have been stuck using the self-timer which would have added a minimum of 10 seconds to take each shot. Even though using the self-timer with mirror lockup cuts the delay from 10 seconds to 2, you have to reset mirror lockup for each shot so there would be the added tie of accessing the Cf menu, setting the option blah,blah ...blah. Sooo I didn't do it. But it worked out okay.

Jenn Jilks said...

Once again with feeling...