[Android Tips] Capture clean low light photos, hand held and without long exposure.

razor512razor512 New York Posts: 2,223 ✭✭✭✭✭✭✭✭

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This tutorial takes a different approach to low light photos. Since capturing the moment is very important, my tutorial focuses on adding no additional prep time to your photography. You will shoot as you usually do, with one small difference, you will press and hold the shutter button, instead of quickly releasing it, the rest of the work can be done at a later time.

What you will need:

  • Smartphone, or any camera, this will work on any camera that can take multiple images, including film (if you are willing to scan images).
  • Any image editing program which allows you to work in layers, and supports stacking. For a free solution, Gimp can be used do a median stack for similar results, but for this tutorial, I will be using photoshop.

Often we will find ourselves needing to take a still image, in a low light situation, with no available way to stabilize the camera for a long exposure low ISO image. This all usually means that we take high ISO photos which end up grainy.

Lucky for us, there is a way to decrease image noise, and improve detail. Since smartphone cameras have gotten faster in terms of how many images they can take per second, it is possible to take multiple properly exposed, high ISO images, and then use mean stacking to improve the effective SNR in the image.

Best of all, it requires no extra prep time to do, just about all of the work takes place in post production.

While this process is simple to start, there are some limitation, it is very forgiving to horizontal and vertical shifts in an image, as well as minor perspective shifts as a result from hand holding. This process will not work if the scene itself is constantly changing.

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1: To start, open your favorite camera app (anything that does burst shooting will do fine). Most camera apps will do burst shooting is you simply hold the shutter button down.

2: Take a picture as you normally would, but instead of pressing the shutter button once, and releasing, keep it held down, and the phone can quickly do a burst of 20 or more images if needed.

  • You are now done with the smartphone side of things.

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Post production:

I will supplement the text, with a video demonstration of this process.

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1: Copy the burst of images that you have taken, to a folder on your PC.

2: Import all of the images as layers (Adobe bridge makes this process simple)

3: Ensure that all of the images are aligned. If you took a picture of a person, who moved slightly during the burst shot, and background elements are out of focus, then the image can be aligned around the person, as out of focus elements are more forgiving to misalignment.

4: Crop away any transparent parts of the image that appear after aligning the photo.

4: After aligning the layers, we can now proceed stack them.

  • In photoshop, select all of the layers in the list, then right click on any of them, then click on "Convert to Smart Object"

5:  Now we can proceed to find the mean of the stack.

  • In photoshop, click on Layer > Smart Objects >  Stack Mode > Mean

6: You are now done, save your now noise free image.

You should now have a cleaner high ISO image, without the motion blur that comes from a long exposure.

While there are many low light tips for smartphones, which rely on low ISO, and long shutter speeds, the setup for this, often requires many additional steps to be taken before you actually snap the photo. Whether you are moving to a wall to lean on in order to reduce shake, or using a weighted grip in order to reduce the faster small movements which come from hand holding, they all get in the way of taking the image in a timely manner, and for spontaneous moments, you simply do not have the time to prepare all of that.

By making use of the simple tip of burst shooting, you start shooting immediately, thus you are less likely to miss the moment, and since you are burst shooting, if you need less noise and more detail, you now have the option to do a mean stack, and improve the image. Furthermore, if for any reason, you decide not to do through with the mean stack, you at least captured the moment, and did not risk missing it by finding a location to prop the camera on, or finding a structure to lean on, and still risking a ruined image from motion blur.

I attached full resolution, un-cropped images of the before and after for those who want to pixel peep.

PS, this process can also be made into a macro if you would like to automate it for multiple burst shots. Just be sure to set the crop to be based on transparent pixels when you make it.

Comments

  • razor512razor512 New York Posts: 2,223 ✭✭✭✭✭✭✭✭

    Wanted to also add that Median can also reduce noise (though it does not average like with the mean process), and is also good at removing moving objects from an image, which is great if you want a clean image of a location or building that is normally crowded.

  • razor512razor512 New York Posts: 2,223 ✭✭✭✭✭✭✭✭

    Seems with the forum software update, old embedded videos were removed:

  • coldheat06coldheat06 Fort Worth, Texas Posts: 1,527 ✭✭✭✭✭✭✭✭

    Good video, thanks for the post!!

  • jimlloyd40jimlloyd40 Phoenix, AZ Posts: 15,863 ✭✭✭✭✭✭✭✭

    @razor512 do you happen to be a 10 CC fan?

  • razor512razor512 New York Posts: 2,223 ✭✭✭✭✭✭✭✭

    @jimlloyd40 said:
    @razor512 do you happen to be a 10 CC fan?

    Not sure what you mean, though most of my post processing experience is with the adobe creative suit.

  • jimlloyd40jimlloyd40 Phoenix, AZ Posts: 15,863 ✭✭✭✭✭✭✭✭

    @razor512 said:

    @jimlloyd40 said:
    @razor512 do you happen to be a 10 CC fan?

    Not sure what you mean, though most of my post processing experience is with the adobe creative suit.

    When your video finishes it shows a bunch of other videos from the band 10 CC.

  • razor512razor512 New York Posts: 2,223 ✭✭✭✭✭✭✭✭

    When the video ends, those are just random recommendations from youtube, it is based on the title and keywords from the video that just ended with a bias towards content that is also related to your "recommended" list. It is basically a change youtube made in an attempt to keep people on the site longer.

  • jimlloyd40jimlloyd40 Phoenix, AZ Posts: 15,863 ✭✭✭✭✭✭✭✭

    @razor512 said:
    When the video ends, those are just random recommendations from youtube, it is based on the title and keywords from the video that just ended with a bias towards content that is also related to your "recommended" list. It is basically a change youtube made in an attempt to keep people on the site longer.

    The videos that were there were so unrelated to your video that it confused me because I don't allow my history to be stored so it wouldn't be related to a recommended list for me. Just a coincidence I suppose.

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