Hot answers tagged

10

This is completely normal. Unlike many makers, though, Olympus includes the hot-pixel mapping function on all their cameras, so you can just use that. Remember, a full resolution JPEG from this camera has 15,925,248 pixels. If, say, a dozen of them are defective, that will have a 0.000075% impact on your final results. It's really a non-issue, and not ...


8

It is a hot pixel. The reason it makes that little checkerboard shaped mark is because of the way digital cameras use single luminance values for each pixel to create color information by filtering some pixels for red, some for blue, and some for green and then doing a process known as demosaicing to assign a luminance value for each of those three color ...


8

Why work so hard? I think you are making this much harder than it has to be. Getting something to be exactly 640 pixels in the image will be difficult, require careful measurements and accurate calculations and is very error prone (and for something really close the internal construction of the lens makes a huge difference and this will be impossible to ...


7

Your intuition is correct. What happened is that technology has improved. There has been lots of small improvements piling up, things like better micro-lenses, gapless microlenses, cleaner read paths, on-chip noise-reduction, less noise gain circuits. All this and more adds up to substantial improvement. Increasing megapixels which reduce pixel-sizes takes ...


7

You don't. The camera can save files in three resolutions: 4,928 x 3,264 [L] 3,696 x 2,448 [M] 2,464 x 1,632 [S] After taking a photo, you can use the "Retouch" menu's options to help you, though. The "Resize" option will let you resize an image down to 320 x 216. (Consult page 184 of the manual for specific steps.) To be honest, I would not use this ...


5

That is a hot pixel, not something different. See Are hot pixels just one pixel? for some explanation, or What could cause this white speck in a blue sky? for an example where the pixel shows up as a distinctive "×" shape.


5

There is no right answer. It's up to you how you compromise, considering the following: 3840x2160 is the highest resolution for consumer displays. This is known as 4K Ultra-HD and is not widely adopted yet. If you are sending a landscape image at 3840 pixels wide or a portrait one at 2160 tall, nearly every one will be able to see full details that their ...


5

Most depth of field (DoF) calculations are based on the assumption that the image will be viewed as an 8X10 print at a viewing distance of about 10 inches (25cm) by a person with 20/20 vision. For a 35mm film sized image, that means about an 8X magnification factor. For a blur circle to be perceived as a point at that display size and viewing distance, it ...


5

The only thing in the world that dictates how many pixels are you getting while taking a picture with a digital camera is... The camera. 1) First of all: read the specifications on your camera. If it is a simple camera, or a photo taken with a smart phone, the measure is for example 5 Megapixels, 10 Megapixels or something like that. I'm going to use a ...


5

All versions of the iPhone 8 have a 12 MP rearward facing camera with a 4:3 aspect ratio. That figures to about 3000 pixels x 4000 pixels in vertical (portrait) orientation. That's more than enough to furnish an image that is 2,400 pixels high and 1,600 pixels wide as recommended by Smashwords. It is just over twice as wide as the stated minimum width ...


5

... why don't we just have big pixels (and thus large sensor surfaces, because we keep the number of pixels fixed)? There are camera models with lower resolution sensors, but the reason they are made is for increased light sensitivity, not DOF. If you want deeper depth of field, consider small sensors, wide-angle lenses, and small apertures. This ...


4

What it means is that whoever wrote the rules probably doesn't have a clue how JPEGs are rendered using most current image viewing applications. DPI (dots per inch) is a term that, when used properly, refers to printer hardware. PPI (pixels per inch) is the way we refer to how many pixels of a digital image should be rendered per inch when the image is ...


4

Assuming the photo is square (from the 36" x 36" max) It sounds like the largest photo they want is a 1200 x 1200 pixel image. You will need to compress your photo down to under 1200 x 1200 pixels and save it as a JPEG. The Dots Per Inch (DPI) is a way of telling the image viewing program the scale of each pixel. Some software programs allow you to view ...


4

Image resolution (amount of pixels) and bit depth (bits per pixel) can be changed independently. Any combination of high/low resolution and more/less bits per pixel is possible. Sometimes, however, higher resolution can make up for lower bit depth. Individual pixels become invisible and we start perceiving patterns of pixels as shades, as if the color depth ...


4

A pixel can be understood as a 3-dimensional thing. A pixel holds information. How "deep" this information can be is the trick. Pixel Depth Here is a representation of one pixel. On the left, it can potentially hold information about any of 4 stages. On the right, it can have more options or levels to choose from. But "resolution" is having more pixels, ...


3

Both approaches are correct. At least as I understand what I think you are trying to say. I'm not sure, though, what you mean by, "(4 time bigger)". Raw luminance values are monochromatic in the sense that there is only one intensity value for each sensel (what we call a pixel well). But every one of those monochromatic luminance values is the result of ...


3

It's near impossible to tell exactly what the spots in your picture are. It is fairly easy to look at them and eliminate what they are not: hot or dead pixels. Due to the sharp outlines and well defined irregular shapes of the different spots it is fairly safe to say that they are on or very close to the actual sensor itself, and not on top of the stack of ...


3

885x1024 sounds like your contact emailed the image to you and his email software/system has resized the image. Ask them to zip the image file and send it again, or use an online service like dropbox or OneDrive.


3

Short answer: Use a camera with higher resolution. At the standard 300 ppi needed to produce high quality prints you need a camera with 5100 x 7200 pixels to produce a 17" x 24" print. Since most higher resolution digital cameras use a 3:2 aspect ratio, you really need 5100 X 7650 pixels. That comes to about 39 Megapixels.


3

There are more problems with comparing the resolution of film to that of a digital sensor. One problem is that the grain that you see is in fact not the image forming element but a form of noise. The actual elements are much smaller. Also, it matters if you look at B/W film or color film; the image in B/W film is composed of silver particles, while most ...


3

My iPhone 5S takes 8 megapixel images, specifically, 3264x2448 pixels. This is native size. This is speaking of still images, not the movie images which of course are 1920x1080 or 2 megapixels. However Apple likes to offer lots of opportunity to export them resampled much smaller, especially for sending with email or text messages, when a large image can ...


2

Generally I would say yes - if a component is going to fail due to manufacturing deficiencies, it will often do so in the first day/week/month if use (depending on usage of course) What you describe (depending on the number of defective pixels) sounds like it is degrading with use - if it is effecting image quality, I would call it a "DOA", so should be ...


2

Depending a lot on the developer used as well. 35 mm Adox CMS 20II dev. in Adotech IV gives you a resolution of about 500 MPix! http://www.adox.de/Photo/adox-films-2/cms-20-ii-adotech-ii/ With 510-Pyro I can blow up a 35mm Kentmere 100 @ ISO 50 in the range of several feet with high acutance and nearly zero grain.


2

There are a number of applications that can resize your image. In most of those you can set the size of the longest direction (vertical or horizontal) to 500 and have the program calculate the size of the other direction. One free such program is paint.net (Windows only).


2

Lightrooms' sliders are weighted distributions. It is not as simple as "Whites" are 127-255, "Blacks" are 0-127. The distributions are weighted, and different sets of sliders affect different ranges in different ways. Whites affects a broad range, but obviously affects brighter tones with more weight than darker tones. Same with blacks, only it's the inverse....


2

From casual observation it would appear that each slider affects all values, however each slider affects each value to a different degree. From slightly more detailed observation: The Exposure slider affects the whole range with great effect The Black and White sliders affect he entire range, with a larger effect as you move towards the end of the scale ...


2

Only if you still have the original data from the raw file. You cannot normally derive the original monochromatic luminance values from each sensel (pixel well) on the sensor from the demosaiced data because there are almost always more than one set of original data that could result in the same final RGB values, just as there are more than one set of RGB ...


2

These are irregular shapes and my guess is that they are not pixels, but drops of some purple liquid. If you set your camera to the cleaning mode, remove the lens and inspect your sensor with loupe and a flashlight. When you try to locate the spot on the sensor, don't forget that the image is recorded upside down.


2

With conventional CMOS sensors the issue isn't so much the spacing between photosites (pixels). It's all of the circuitry on top of them (usually on the edges of each photosite) that blocks light from getting through to the semiconductor layer. What microlenses do is redirect light that would otherwise fall on the edges of photosites where the circuitry ...


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