Yachats, Oregon
Yachats, Oregon, is about a six hour drive from Seattle and if you get full cooperation from the clouds, the tides, the moon, etc, it’s worth every minute of it. But as rare as the confluence of naturally occurring factors is, it’s even more rare to see me up at five in the morning - I like to do the night photography thing before going to bed.
The sun was set to rise at 7:30AM and the moon would set at 10:30AM so the moon would still be high in the sky around 5:00AM and would be bright enough to back-light the clouds. The clouds turned out to be a little thicker than I hoped but there was still enough light to provide backing to the clouds and also to squeeze in a couple night photography hours before the sun rose.
This is three 90 second exposures at ISO 400 averaged to reduce noise. Shorter, averaged exposures are often a better option on the coast because you never know (if you’re close enough) when you’ll have to grab everything and run to get out of the way of the ocean. It’s better in my opinion to use a higher ISO and stack/average n well exposed images to improve the quality of a “good” exposure than to try one really long exposure at the lowest ISO that only lasts half as long as it needs to. A single image at ISO 400 using the “expose to the right” technique will be better than an under-exposed ISO 100 exposure pushed two stops to match.
October 20th, 2008 at 9:10 am
Thanks for this post. I hadn’t thought much about backlighting clouds with the moon for night photography–that’s something I’ll have to try.
A technical question–how are you stacking exposures? Do you have problems with movement between exposures using this method (like with the clouds)?
October 21st, 2008 at 7:30 am
Brian,
This is a beautiful image, and a great write-up about why it’s valuable to average images. But I’m wondering exactly what the process is to do that? Do you just stack them in Lighten mode?
Thanks
Andy Frazer
October 21st, 2008 at 2:11 pm
Thanks!
I’m actually “averaging” the images but part of that process is stacking them on top of each other. I’m using the technique described here…
http://www.cambridgeincolour.com/tutorials/image-averaging-noise.htm
…which also has a great technical explanation of the process if you’re interested. The basic formula is to choose a base image and then set the opacity of the images in layers above it using the averaging formula in the post which for four images would be 100% (base image), 50% (layer 2), 33% (layer 3), 25% (layer 4), etc.
If you want a clear depiction of the result add a curves layer on top while you’re changing the opacity to brighten the mids and shadows where the most apparent difference is.
Moving objects sometimes cause issues - not so much in this case because the movement in the clouds/water was pretty consistent and smoothed things out enough during each exposure that I ended up with four very similar exposures. You can always use layer masks to block out the areas you don’t want averaged.
I should add that this won’t work for star trails because you’ll have each segment getting progressively lighter in the upper layers although there is no reason you couldn’t use it for the non-star-trail parts of the image.
Brian
October 23rd, 2008 at 6:33 pm
This technique sounds a lot like the software program called PhotoAcute. (see http://www.photoacute.com/studio/index.html)
I have just started experimenting with it, and it seems to work pretty well for static objects. Moving objects, like tree branches in the wind, cause pretty noticeable ghosting, although some objects, like people walking by, can be averaged out of the image. Maybe this Photoshop averaging technique gives more control for moving objects. And PhotoAcute seems to work for star trails (if the no alignment option is selected). When I have a chance, I’ll have to compare the Photoshop averaging technique and PhotoAcute.
Note that you can get a free license for PhotoAcute if you add to their lens profile database.
Grant Kinney
October 27th, 2008 at 9:40 am
Thanks Grant - I’ll have to try that out, it looks promising. I suspect their technique combining multiple images to reduce noise is doing averaging behind the scenes.
Water is actually the easiest “moving object” to work with in combining images. Tree branches, etc, as you mention, are much more difficult and it’s usually some type of excruciatingly slow manual process that’s necessary (and in many cases not even worth trying.)
In any case, I’ve used a variety of external tools - Photomatix, etc - to process images and then include the result as a layer in Photoshop to use in further processing.
October 29th, 2008 at 9:24 pm
[…] probably recognize this location from either the previous blog post or possibly some other images on my flickr account. This was taken about five minutes before the […]
November 5th, 2008 at 7:43 pm
[…] is one of the three images, each ISO 400, that were averaged together to create the final image in this post. One important thing to mention is that my current camera (hurry up with that 5D Mark II Canon!), […]