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Are RAW images by nature slightly blurry prior to processing? If I open them up in Lightroom and zoom into the photo, my photos are not tack sharp but a bit blurry. Once I process, it comes out looking pretty sharp.

As an amateur I am trying to figure out at what point is the blur a product of user error or if it's natural? I shoot with a Sony A7RII if that makes any difference.

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Are RAW images by nature slightly blurry prior to processing? If I open them up in Lightroom and zoom into the photo, my photos are not tack sharp but a bit blurry. Once I process, it comes out looking pretty sharp.

Wait wait wait — let me stop you right there. When you open up RAW files in Lightroom, you are seeing a processed image. Lightroom does not have a RAW data viewer, and the unprocessed RAW data doesn't look very interesting even if it did. What you're seeing is either a JPEG preview (processed by the camera) or the default processing you have configured in Lightroom.

It sounds like the settings for that default rendering include less sharpening than you like. Behind all of this is your fundamental question: is sharpening a necessary part of a RAW workflow (assuming sharp images are desired)? The answer is yes — see Why should my last post-processing step be sharpening?, which is partly about the order but also gives some explanation as to why.

Digital cameras (with the mostly-obscure exception of Foveon) use a pattern of colored filters to create color images. This means color in the final image is produced via algorithms which infer complete color information from neighboring photosites. A final sharpening pass usually makes the results of these algorithms more snappy. And, although it's less common now that higher-resolution sensors make it less necessary, many digital cameras contain an (optical) low-pass filter, which intentionally blurs the image slightly to avoid moire. (See Why is a physical anti-aliasing filter still needed on modern DSLRs?.)

Additionally, digital sharpening (especially the magic that is Richardson–Lucy deconvolution) can compensate for other sharpness factors: missed focus, soft optics, or even motion blur.

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    thanks for info! I have always assumed RAW photos have a "default" look. So if I viewed a RAW file on different viewers/editing programs, they would not be identical? If so, then I mean the default processing when using Lightroom CC for iPad. I press the Auto button as a starting point and it seems to get it 70% of the way there to what I would want it to look like. – Alan Feb 20 at 21:25
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    Right, that's absolutely the case. There's no default look. This leads some people to say that RAW files aren't even really images. They're... potential pre-images or something. Usually, cameras encode some basic information about camera color settings that can be used by RAW converters, but often that's just ignored, and even when it isn't, each program has its own way of interpreting what that might mean. – mattdm Feb 20 at 21:41
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    Alan: I've made another Q&A about what exactly an unprocessed RAW file looks like... photo.stackexchange.com/questions/105271/… – mattdm Feb 21 at 2:51
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There are two questions here:

  • is it normal that the final processed photo is more sharp than what was captured by the lens?

  • is it normal that the RAW sensor readings are more blurry than the image focused by the lens?

And the answer is YES - both the lens and the sensors are not perfect and digital processing is used (and sometimes overused) to make up the imperfections.

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If I open them up in Lightroom and zoom into the photo, my photos are not tack sharp but a bit blurry. Once I process, it comes out looking pretty sharp.

When you "open them up in Lightroom," whatever you see on your screen is a processed interpretation of the data in your raw image file.

If you are viewing an image on a screen, you are not looking at an "unprocessed" raw file. What you are seeing is one possible interpretation of the raw data collected by a camera sensor. That interpretation may be one of several things:

  • A jpeg produced by the camera using the raw data from the sensor and the camera's settings current at the time the image was captured.
  • A jpeg preview image attached to a raw image file. The jpeg preview is also produced by the camera's internal processor using the camera's settings current at the time the image was captured. It is attached to the raw image file. This preview is normally what one sees when looking at an image on the LCD on the back of the camera when images are recorded as "raw" files. This preview is also what many photo applications will show when you are viewing thumbnails of raw image files on your computer.
  • A fresh interpretation of the raw image data by a raw processing application such as Lightroom. Depending on your program settings, when you first open a raw image file, you may see either the jpeg preview image or you may see a new conversion of the raw data based on the current settings of the application with which you opened the image file. If you are seeing a fresh interpretation of the raw image data, it is still in a form that has had the same type of processing applied to it that a jpeg image produced with the same settings would have had.

The thing to keep in mind is that there is no single interpretation of a raw image file that is "THE raw image." Raw data must be processed to be viewed as any meaningful image. The settings of the various processing steps will determine how the result looks. There is no single inherently "correct" way to process the raw data. Things such as color temperature and white balance, contrast, white point, black point, etc. must be applied to the raw data collected by the sensor before it looks anything like what we call a "photograph." This includes what we refer to as "sharpening."

In general, the default behavior of most raw conversion applications, including Lightroom is to not apply very much sharpening.

One reason for this is to avoid visible moire/aliasing when we first assess an image. Moire/aliasing is caused by repeating patterns in the scene that match up with the pitch of the camera sensor's grid of sensels (a/k/a pixel wells or photosites). If we open an image with mild aliasing that has had very aggressive sharpening applied, we'd probably reject the image as unusable without further investigation. In reality, the image might still be very usable for our purposes with less sharpening applied.

Another reason is that final sharpening should be optimized for the intended viewing conditions (particularly the intended display size). If an image is sharpened in a way that is optimal for a large display screen, such as a 60" 8K television, and it is instead displayed on a small smartphone screen, there will likely be scaling errors that will introduce something very similar to moire when the image is converted from higher to lower resolution. Depending on the details of the scene included in the image, it will probably look "rough" or "jagged" on the smaller, lower resolution screen.


A little more background in what a raw image file is:

Raw image files contain enough data to create a near infinite number of interpretations of that data that will fit in an 8-bit jpeg file.¹ Anytime you open a raw file and look at it on your screen, you are not viewing "THE raw file." You are viewing one among countless possible interpretations of the data in the raw file. The raw data itself contains a single (monochrome) brightness value measured by each pixel well. With Bayer masked camera sensors (the vast majority of color digital cameras use Bayer filters) each pixel well has a color filter in front of it that is either red, green, or blue. For a more complete discussion of how we get color information out of the single brightness values measured at each pixel well, please see RAW files store 3 colors per pixel, or only one?

How the image you see on your monitor when you open a raw file will look is determined by how the application you used to open the file chose to interpret the raw data in the file to produce a viewable image. Each application has its own set of default parameters that determine how the raw data is processed. One of the most significant parameters is how the white balance that is used to convert the raw data is selected. Most applications have many different sets of parameters that can be selected by the user, who is then free to alter individual settings within the set of instructions used to initially interpret the data in the raw file.

For more detailed discussions about what the data in a raw image file is and is not, please see these other questions here at Photography at Stack Exchange:

RAW files store 3 colors per pixel, or only one?
Why can software correct white balance more accurately for RAW files than it can with JPEGs?
RAW in ACR vs JPG in ACR
While shooting in RAW, do you have to post-process it to make the picture look good?
Why do RAW images look worse than JPEGs in editing programs?
Why does my Lightroom/Photoshop preview change after loading?
Why is Lightroom changing all the settings on my imported RAWs?

¹ Sure, you could take a picture that contains a single pure color within the entire field of view. but most photos contain a wide variation of hues, tints, and brightness levels.

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