New answers tagged noise
No. The same amount of light goes to the part of the sensor you are using with a DX lens on your FX body, so ISO is not impacted. When you use the DX lens you use less of the sensor, keeping the ISO / Shutter Speed / Aperture relationship unchanged.
Well, sort of. If you use only part of the sensor — as you do in DX crop mode — you are inherently gathering less light. (The light per area is the same — so your exposure settings are the same — but you have less area.) That means that if you print at the same size as you would an image from an FX lens, your print inherently has less light per area — or, to ...
ISO is all to do with your camera the ISO proformance will be the same nomater what lens is on your camera. I will say that quality of light has a big impact on noise. ISO 1600 in a dark room will be more noiser (I think that's a word) that 1600 outside in the sun.
I agree with @mattdm 's link to "What is noise..." as fairly comprehensive, but not complete today. It would be conventional to say that the glass and metal of a lens does not add noise to the image. A simple definition of noise might be the random disturbance of an image. In other words, if you took the same picture again and again, what might change ...
I would have said "no" a week ago, however I have change my opinion. Yes, a cheap lens can cause noise, at least in video. I was shooting with a RED in the mountains, and my good mid range lens was destroyed. I used the 18-55mm as back up. I was switching between the kit 18-55mm to my 70-200mm f/4 L-series. Same ISO, same settings and there is a huge noise ...
Noise reduction is generally effective in dark areas because there is little detail to retain. Most noise will be chroma (color) noise so it is easy to remove in your RAW processor or with third party noise reduction. Remember that there is no "correct" sunset exposure. I always bracket widely and choose the best result.
An alternative to "exposing to the right" proposed by @mattdm could be noise reduction through image stacking: align images (all images taken with "as identical as possible" intrinsic and extrinsic parameters (view point, focal length, etc.)) stack aligned images as layers in a single image blend layers using median/average/...
This is a perfect example of "expose to the right" — that is, even though you want the final result to be low key (largely dark), take the initial exposure as bright as you can (without blowing out the brighter part of the sky, reflections, or any more subtle brighter areas). When you expose so that dark areas are really dark — either because you are ...
The short answer is both, but it requires some explanation. Megapixels. Yes, but only if we're talking about 12MP vs 24MP for a given sensor size. The issue is not the absolute number of megapixels per se, but the size of each individual pixel. Buckets in the rain is the common analogy used. Essentially, if you have two buckets out in the rain, the bigger ...
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