Posts Tagged Christmas lights
Posted by renm in photography, Technical on November 27, 2012
About a month-and-a-half ago, I did something I don’t usually do: I purchased an iPhone camera app for $2.99. I’m certainly no stranger to purchasing apps, but I typically pay little attention to alternative camera apps and I seldom purchase an app — particularly for more than 99¢ — without either a friend’s suggestion or a trial version.
However, something about a mini-review of Cortex Camera convinced me to buy it. What this camera app does is take a quick burst of photos, lasting a few seconds, and then quickly processes those into a single photo. The result is supposed to be a higher quality photo than the built-in camera can provide in lower light settings.
My initial testing was basically positive, but I found it to have fairly limited use. It didn’t support iOS 6’s new low-light functionality, so it really only worked in moderate lighting. In such lighting, Cortex Camera’s results did have more detail and less noise than photos from the built-in camera, but the built-in results were really “good enough”. In true low-light, the built-in camera’s boosted ISO produced much better results. I didn’t delete the app, but wasn’t sure I would be likely to use it.
About a month ago, Cortex Camera received an update with several enhancements. The most notable was support for iOS6’s low-light mode. With this change, the app has become much more useful, as I will now demonstrate.
I took these two photos from the same spot. I had to back up extra so that the trees would block fewer lights, so I zoomed-in when taking both photos, though not by exactly the same amount as you can see. Even in these very-scaled-down versions (click them for full-size), you can see how much smoother the sky is in the Cortex shot.
I did the crops below on the iPad and tried to get them to be the same. One disadvantage of using the iPad is that I can’t look at one crop while I do the other. In retrospect, I could have easily used my iPhone to check the other crop (though I would have had to pause The Daily Show). Even then, the sizes would still have been different due to the slightly different zoom of the original images. I do not think these differences have any effect on the obvious quality win of the Cortex versions.
From these crops you can see that the built-in camera produced very muddy results, presumably due to some aggressive noise correction. Also, there is appreciably more motion blur. I’m not certain, but I think that Cortex uses a shorter exposer and then relies on a certain amount of additive combination of the composite photos to increase the effective exposure. In any event, I’m quite please with the results; well worth $3.
In case it isn’t obvious, this technique — and thus, Cortex Camera — isn’t useful for photos of moving objects.
One other point: some of Cortex Camera’s functionality is iPhone 5 only. On older iPhones, I believe it takes a video rather than multiple photos, so the final resolution is a bit lower (though higher than the video resolution). Also, it’s supposed to support 12.5MP on the iPhone 5, but with that enabled, the app consistently crashes for me.
Christmas Day Lights
Posted by renm in photography on December 25, 2011
Christmas Lights Day 24
Posted by renm in photography on December 24, 2011
Christmas Lights Day 23
Posted by renm in photography on December 23, 2011
Christmas Lights Day 22
Posted by renm in photography on December 22, 2011
Christmas Lights Day 21
Posted by renm in photography on December 21, 2011
Christmas Lights Day 20
Posted by renm in photography on December 20, 2011
Christmas Lights Day 19
Christmas Lights Day 18
Christmas Lights Day 17