Nidelva river through Trondheim Norway

Nidelva river through Trondheim Norway
by Saaru Lindestokke                

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25

Likely culprits, in order of probability: Bad SD card (by far the most likely, especially with cheap cards). Bad cable or card reader (more common than you might think). Something wrong on your computer (many things can go wrong!). A bad connection inside the camera. Something horribly wrong with the camera's electronics. The "bad card" scenario is, ...


19

The lens correction software may be able to counter lens distortion and chromatic aberration distortion. Also perhaps it can counter poor contrast to some degree. But a good lens has more to offer: Sharper image. The lens correction cannot restore image detail lost due to an unsharp lens. Aperture. Good quality lenses typically have a larger aperture. You ...


17

I think it's more correct to say that Lightroom's lens profiles can make any lens "better." Bad lenses are still bad, good lenses are still good. The corrections Lightroom can make simply improve some aspects of image quality. Making the leap of taking a poor lens and making it good is far outside of what LR can do.


17

The terms are fisheye (circular distortion) and rectilinear (straight edges). Fisheye lenses are often unfairly branded as "special effect" lenses by some photographers, due to their near ubiquitous use in skateboarding magazines in the 90s, and the ease at which you can create unusual images when trained on nearly any subject. However fisheyes have sever ...


15

These are known as Chromatic Aberrations or Colour Fringing. These predominantly occur around areas with high contrast such as sharp edges in photographs or around the white water bottle and dark background in your case. A wider apeture can affect the lenses sensitivity to aberrations although certain lenses can see this "effect" vary depending on focal ...


14

The two types of lenses you refer to are: Rectilinear - lenses which produce straight horizontals and verticals across the image Fisheye - lenses with circular distortion Rectilinear lenses produce more 'natural' looking images but tend to stretch features towards the edges of the frame, so some subjects, e.g. faces, look odd. But they work well for ...


13

There are two major considerations that make lenses with less distortion, vignetting, or any other "correctable" aberrations more desirable for many photographers than correcting later in post. Time constraints. While it is true that you can use postprocessing applications to correct for distortion, vignetting, and other aberrations, doing so takes time. ...


12

It's not so much a defect as a property of wide-angle lenses: they distort things on the sides. This distortion is why they are not recommended for portraiture. Of course, the very same distortion is what gives wide-angle its power, making it great for photographing interiors (making them look larger) or when going for an "artsy" effect.


12

Unlike most other digital cameras, Panasonic micro four-thirds cameras record lens correction information (distortion and CA, iirc) into the EXIF information of their RAW files (and will bake in the correction if you shoot JPEG). Some applications recognize and apply this correction information, some don't. That's why you're seeing different results, ...


12

Those have completely different impact. Vignetting Vignetting is a darkening of the corners or edges which depends on aperture and focal-length. In order to correct this in software, pixels around the edge must be gradually lightened in proportion to the light fall off: Slight vignetting is hard to notice unless the background is known to be uniform. ...


11

Does anyone know if this software uses the Brown-Conrady model to achieve the lens correction? Yes they do use those very common camera calibration coefficients. I added some copyable text versions of the formulas to the following quote: Adobe Camera Model Geometric Distortion Model for Rectilinear Lenses xd = (1 + k1*r^2 + k2*r^4 + ...


10

You can correct lens distortion in post, but you do so at the expense of some of that higher resolution. Roger Cicala of LensRentals.com says in a blog post where he tests the uncorrected and post corrected resolution of an EF 24-105mm f/4 L lens at 24mm: But when someone wants to argue that they buy a lens with high distortion because it has higher ...


9

I think the distortion you are seeing is not caused by the lens, I think it's just perspective distortion. The Canon 50mm f/1.8 has a DXOmark distortion rating of 0.2% and if you look at the actual measurements, especially the grid you will see that the distortion is very low - too low to notice in a normal picture - I don't know about the other cameras you ...


8

No, it's not all that bad. On most shots, you won't be able to tell by eye if the curvilinear distortions have been corrected for or not - you'll need straight lines adjacently parallel to each other or to edge to tell. In nature, you won't have those lines. In portraiture, it will exaggerate some parts and diminish others, but perspective distortion and ...


8

This effect is called fisheye effect You can either get this effect by using a fisheye lens or using photoshop. Try googling fisheye effect photoshop. I found there great tutorials there. http://www.marcofolio.net/photoshop/create_a_fish_eye_lens_effect_in_photoshop.html ...


8

Actually to avoid distortion the opposite of what you said holds true. Move faces or features you don't want to distort such as fingers away from the edge of the frame Keep the lens parallel to the subject if at all possible Step back and shoot, planning to crop to the desired framing later Consider using the distortion to your advantage for "fun" shots; ...


8

It's very difficult to correct by hand, but very very easy for a computer to correct, given a formula for how the distortion behaves. The reason the Photozone review states that this distortion is difficult to detect, is that most software only offers very simple correction based on radially symmetric distortions based on simple formulas. You can usually ...


8

Drone do not curve images. Camera lenses do. You can mount different types of cameras or lenses on a drone but many models now have their own built-in camera which usually incorporates a small fisheye lens. This allows them to have a huge field of view and so they do not need to fly very high to see an entire scene.


7

Your interpretation of distortion is correct. For an example of a lens that exhibits barrel distortion at the wide angle and pin cushion distortion at the telephoto end, have a look at the Canon 18-135mm Tools like PTLens and Hugin perform the corrections after the demosaicing of the Bayer data. I'm not sure why this would matter? If you're interested in ...


7

There are a limited set of defects that can be corrected in software, lateral chromatic aberration, yes, but not longitudinal chromatic aberration. Lateral CA results in the component colours of light being displaced radially across the sensor. This can be corrected by simply warping each colour channel slightly differently. Longitudinal CA causes out of ...


7

Lightroom does this for selected lenses, or you can create your own profile if your lens isn't listed. This blog post explains how this works, both with respect to the built-in profiles, adjusting manually, or creating your own with Adobe's software utility.


7

from http://wiki.panotools.org/Lens_correction_model The actual lens correction parameters a, b and c which are used to correct for barrel distortion, pincushion distortion and even wavy distortion. The a and c parameters control more complex forms of distortion. In most cases it will be enough to optimize for the b parameter only, which is good at ...


7

More generally, why is there even a drop-down for me to choose between rectilinear and fisheye, given that it's purely a function of focal length, which is already an input? I must be missing something. Your assumption is incorrect. Rectilinear and fisheye (or curvilinear) lenses are constructed differently, with different mixes of distortions. If ...


6

Not only is it possible, but it's becoming commonplace. The micro-four-thirds system makes extensive use of it, and some compact cameras now do too. (I imagine that if they don't yet, most super-zooms will within a few years.) Digital Photography Review has a good article on this at ...


6

You can use Hugin to do these types of corrections. They also have a nice guide for lens calibration, which allows you to calibrate for the distortion of your lens, then save those settings to apply later.


6

One possibility is operator error. Any one of these will do it: If you took out the card from the camera before it was finished writing. In this case your pictures are lost since they were never stored correctly. If you took out the memory from the reader before it was finished reading (If you use Windows, you should use the 'Disconnect Removable Device' ...


6

The first and third photos exhibit barrel distortion which is normally to be expected at 18mm when using an 18-55mm zoom lens. Software correction can help, but for best results you need software that includes a custom profile of that particular lens on that particular camera. There are also some perspective issues in shots #1 and 3, which are related to the ...


6

Two things common to Wide angle lenses can do this, barrel distortion and perspective distortion. For barrel distortion, when pulling in a very wide amount of information from off axis, light gets distorted based on how extreme of an angle it is coming in at because the lens can't completely correct for how far off the lens axis the light is. On the ...


6

There's nothing obviously wrong with the image. You've got a very narrow depth of field, so the grass in the foreground and background is out of focus, but that's not surprising if you were shooting something relatively close at a long focal length. There's some chromatic aberration (red and purple fringing) in the unfocused areas, which also isn't ...



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