20

A digital sensor isn't really best described as "reading data". A much better way to describe it is "collecting photons" that are then converted into data by measuring the microscopic electrical charges they produce once the collection period is over. They do not have the capability to continuously record the changing state of each pixel well as they collect ...


13

We already have some of the technology for this. Our term for remembering the sensor readings at each exposure point is "video", and what you are asking for is reconstruction of an optimal still image from multiple video frames. For an overview of Microsoft Research work on this, start here: http://research.microsoft.com/en-us/um/redmond/groups/ivm/...


10

The original question is based on incorrect assumption (about digital sensor not changing state during the exposure) but the concept is related to the Quanta Image Sensor (QIS) idea researched by Eric Fossum. http://engineering.dartmouth.edu/research/advanced-image-sensors-and-camera-systems/ The QIS is a revolutionary change in the way we collect images ...


9

You are not actually adding light, you are simply enhancing what little light you gathered. With a JPEG, "stretching" or "pushing" and "attenuating" are all done in the camera, and those enhancements are baked into the JPEG file, which is then lossy compressed and stored in a low precision format (8-bpc, 0-255). With a RAW image, you are storing the ...


7

There is nothing special or magical in RAW files. When it comes to exposure and balance, RAW files just store more information about colors, than JPEG files do. Either way, these colors consist of Red, Green, and Blue values and by manipulating these values you can always adjust white balance or exposure, regardless of the file type... in the ideal world. ...


7

Just perform regular post-processing. For reference, here is your first picture with all the boarder fluff stripped off: Simply making the darkest spot black and the lightest white fixes a lot: The snow looks a little yellowish, so here I'm using one area of the snow that looks like it should be white as the white balance reference. I also brought the ...


6

The terms push and pull are still relevant in the sense that they are still used and understood by many enthusiast photographers. But they are probably not as common as they once were. New terms, such as expose to the right describe the same concept using different words. If you underexpose when taking the shot, then you push the exposure in editing to ...


5

What you call originals are the preview jpegs created in-camera and attached to the raw file. These are the images that will have Auto Lighting Optimizer applied. Lightroom displays these preview thumbnails while it is waiting for your computer to generate a high quality preview of the raw file based on the current Lr settings. Once your computer has ...


5

I'm not sure why you awarded that answer. It's absolutely fixable easily with aperture. I've spent less than 5 minutes on this and already got decent result. This is your exposure -2EV: This is what I got to (different from above but it's even better imo): All I did was brush in levels set to: Followed by setting recovery to 0.14 (because some area was ...


5

18% reflectivity means it should reflect 18% of whatever linear light is actually on it. Gamma should compute 117 at 46%, but your picture shows the card to be in some shadows, so then it can't be 18% of the brightest 255 (expecting gamma to 46%). But the histogram won't be the exact computation, because the camera is busy doing other things too, like your ...


4

Most definitely not a stupid question: I actually wondered the same thing when I first got into shooting raw. Before you can really understand what's happening when you adjust exposure in software, you first need to know what a digital camera's sensor and electronics do when you take a photo: count photons. Each pixel of the sensor essentially records the ...


4

In your case you are adding artificial lighting into the mix and that seems to be where the vast majority of the flickering is coming from. Some light sources powered by alternating current can vary by more than a stop between the peak and the trough of their AC cycle. And since metering is done at a different instant than exposure, a conventional meter can'...


4

The equation is: f-number² illuminance × ISO value ───────────── = ─────────────────────── exposure time incident-light meter in seconds calibration constant Or N² = E*S*t/C, as you've summarized it with N as aperture on the left. Note that the calibration constant ("C") corresponds to your meter, not to the camera,...


3

Your camera has the ability to manually set the white balance. Under most circumstances, the auto white balance feature works fine, but since it's very likely you're shooting JPEG, correction after the fact when it does get it wrong is probably going to degrade your image quality a bit. at any rate, page 90 of the English version of the manual for your ...


3

Light fall-off depends on a particular lens at a certain aperture and for some focal-length. There are a number of cameras which can do this but they must be able to recognize the lens. This is a profile based approach and can usually be enabled some cameras with electronic lens mounts. A few other cameras allow to apply an amount of compensation, probably ...


3

If you're holding all exposure parameters constant, then the next suspect for me would be your white-balance setting, which I don't see mentioned above; e.g., do you have auto-white-balance (AWB) enabled, or set to a fixed temp? Remember that most cameras are designed to interpret any scene you throw at them as 18% gray and compensate for that. If that's ...


2

Some cameras now have lens correction features built in, but many do not. And sometimes those corrections extend to light fall off, but not always. For example, the Pentax K-5ii and a few prior models correct for distortion and lateral chromatic aberration. The K-3 adds "Peripheral Illumination" to correct light falloff in the corners. More on this in the ...


2

Film physically changes over the period of time it's exposed. A digital sensor, though, doesn't; it's just reading data. That really depends on the type of sensor. The kind of CMOS sensors that are used in today's DSLR's accumulate an electrical charge in each pixel over time, so they do, in fact, change over time much like film does. If they didn't work ...


2

Adjusting the exposure is a basic feature of the "developing" software. If you are shooting RAW images, you have more latitude in the image data than the normal presentation of such an image can handle, so you have some artistic interpretation to make there even when the photo captures the entire range of light available without error. There is a slider ...


2

Your entire exercise seems to be built on somewhat of a false premise: That the initial image you see on your screen when opening a raw image file in ACR is a linear representation of the luminance values collected by each sensel of the camera's sensor. This is not the case. This is not even remotely the case. What you have labeled, "RAW file in ACR with EV ...


2

It looks like you've probably got 'Safety Shift' enabled and set to option 1: 'Shutter speed/Aperture' in your 70D's menu. It's found under the "Custom Functions" menu at 'Menu → Custom Functions (Orange Tab) → C.Fn I: Exposure → C.Fn I -6 Safety Shift'. It also looks like you're using a manual flash triggering method that the camera does not detect. Thus ...


1

Q: "How do I compensate the exposure of a bunch of photos so I can stitch them together?". I too disagree with the formula, shouldn't it be: p' = p + (p * (k^2)/(t*k)) ? [Note: You would want to correct "t" as mentioned above in @Michael Clark 's comment.] In any event, your "compensation method" is to simply make every pixel in a particular photo a bit ...


1

Yes, it is possible, especially if you also have a NEF file besides the JPEG - Adobe Camera RAW (inside Photoshop or Lightroom) allows you to bring down highlights without affecting the darker areas of the frame - and if the said highlights are not blown out (i.e. clipped to a point where information is lost), you've got a fair chance of ending up with a ...


1

Let's simplify the problem to understand why we will always have to make compromises. Let's invent the camera you want, but with only one monochrome pixel. It needs to be able to reliably receive and notify the processor of the reception of a single photon. It also needs to be able to receive and notify the processor of the reception of, practically ...


1

Others have already explained why this won't work, technically. I want to touch on why it wouldn't work practically. If data storage were not an issue, is there any reason this couldn't be the norm, at least for professional and art photography? Consider the magnitude of different lighting conditions that we may want to take photographs of. Even ignoring ...


1

I have experienced the same problem with flickering timelapse videos and I have found that for some scenarios the temporal filter offered by Virtualdub can greatly help. This filter looks for unnatural changes between frames as the video plays and tries to eliminate them. It has a strength setting that you can use to try a lighter approach first. Virtualdub ...


1

For next time, you might want to take a closer look at your manual to figure out how to improve capture. Snow throws off most auto camera settings, and many cameras now have an automatic snow/beach mode to adjust (or at least an exposure adjustment setting), but if you understand what's going on even the basic adjustments available on your camera can be ...


1

You might also try "place and fall" as an exposure technique. In traditional photography this usually means exposing for your shadows and letting the midtones and hightlights fall accordingly. With digital, overexposure is more of a problem than under so you can "place" the brightest part of your scene. For instance: in manual mode spotmeter the brightest ...


1

For a shot like this, I would either use evaluative metering and dial in an EC to adjust for any issue the sky provided or I'd do spot metering on the outer leaves of the tree. As it is currently, it looks like it metered too much on the shadows and over exposed slightly, leading to a weak black point and wasted dynamic range in an already very wide dynamic ...


1

Along other expressions like unsharp mask etc. they are used in the digital environment in an analogus way to their classic usage. Most common is "pushing" by correcting to the plus, preferrably while "developing" (another of these expressions) a jpeg or tiff out of a raw. Correction to the minus corresponds to "pulling".


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