Alley in Pisa, Italy

by Lars Kotthoff

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7,363 reputation
1835
bio website bitdepth.thomasrutter.com
location Australia
age 33
visits member for 3 years, 6 months
seen 12 hours ago

Mar
13
comment Why does raising ISO make image quality appear lower even though my measurements suggest it shouldn't?
Thanks for the link rfusca, that test illustrates the same issue I think that Jon found in his testing - that raising ISO without changing exposure to compensate will appear to reduce noise - but ONLY because in the lower ISO test was severely underexposed and required a lot of boosting in post/raw processing to bring it to similar exposure as the correctly exposed high ISO case. Throwing more light on the subject (either with more light, longer shutter or wider aperture) when going to lower ISO will always result in better results.
Mar
12
answered Why does raising ISO make image quality appear lower even though my measurements suggest it shouldn't?
Mar
12
comment Why does raising ISO make image quality appear lower even though my measurements suggest it shouldn't?
It's difficult to figure out what your question is and you may want to re-write it - I think what you're asking is "Why does raising ISO make image quality appear lower even though your measurements suggest it shouldn't?"
Feb
26
revised Why don't more people use fisheye lenses as a cheap wide angle lens?
deleted 20 characters in body
Feb
24
comment Why don't more people use fisheye lenses as a cheap wide angle lens?
@mattdm to follow up on your question almost 3 years later ;) I think I understand you better now - the horizontal angle of view of that yellow rectangle is the same as the horizontal angle of view of the fisheye it's from, since the old picture area meets the yellow rectangle at the horizontal (and vertical) points. It's in from the corners of the image where all the discarded image comes from. It's how this would translate to focal length that I wouldn't know how to calculate.
Feb
24
revised Why don't more people use fisheye lenses as a cheap wide angle lens?
deleted 43 characters in body
Feb
24
comment Why don't more people use fisheye lenses as a cheap wide angle lens?
Updated because the link to the second image broke so I've found a new example, and made other slight modifications.
Feb
24
revised Why don't more people use fisheye lenses as a cheap wide angle lens?
deleted 43 characters in body
Feb
12
comment Why and how do “bigger pixels” make a better picture?
I've modified my answer more to emphasize that the amount by which they've enlarged the sensor - about 6% - is so small that the difference is going to be insignificant.
Feb
12
revised Why and how do “bigger pixels” make a better picture?
deleted 141 characters in body
Jan
25
awarded  Necromancer
Jan
24
awarded  Yearling
Jan
16
comment What is RAW, technically?
Some cameras do apply lens correction in-camera. On all the cameras I've used that have done this, the RAW file does not have the lens correction pre-applied so the camera has done it after that step.
Jan
15
revised How can I make short people look taller in photographs?
added 34 characters in body
Jan
8
awarded  Nice Answer
Dec
27
revised Is there a DSLR fixed lens camera?
deleted 114 characters in body
Nov
6
revised Is GPU or CPU more important for Photoshop and Lightroom?
deleted 131 characters in body
Oct
28
comment How do old lenses get dented just on the filter ring?
"Tin foil" is made of aluminium these days. Both aluminium and tin are quite a bit softer than brass. The reason it's easy to bend tin foil is mainly how thin it is. Brass is harder than most metals, including copper and gold, and only a little softer than platinum and iron. As far as materials for camera construction go, any metal will be soft enough to dent easily, especially at its thinnest point. Steel or cast iron are the only metals that are somewhat hard, and that's only because they are an alloy of iron and carbon, carbon being a non-metal and the hardest material there is.
Oct
18
comment What is the math behind white-balance, and how to choose it?
Cameras and software can't determine correct white balance, they can only take a guess. To determine correct white balance you need to have measured a white or grey reference under the same light source.
Oct
17
awarded  Nice Answer