Questions tagged [contrast-detection]

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3 votes
2 answers
1k views

Remove color range (to black) in Darktable

I'm quite new to DarkTable, I'm trying to learn but I can't spot how to do what I want and can't find it in the tutorials. I have taken some light painting photos, there is an overcast night sky in ...
2 votes
1 answer
345 views

Does near infrared AF assist light work with sensor based autofocus?

Some flashes, cameras and wireless flash triggers (like Canon ST-E2) have a near infrared AF assist light that is invisible to the human eye. My understanding is that his AF assist light works at ...
1 vote
3 answers
290 views

Are larger aperture lenses at a disadvantage with contrast-detection autofocus?

I already read that the autofocus of non-STM lenses is rather slow on the M models, but I noticed that my Canon EF 50mm/1.4 is noticeable slower in autofocus than my EF 28mm/1.8. Also a EF 100mm/2.8 ...
3 votes
2 answers
351 views

Why does contrast detection usually work?

Based on a quick perusal of contrast detection descriptions on the internet, I understand that the camera computer measures the gradient of the intensity in that region and then changes the focus, in ...
3 votes
2 answers
926 views

Is contrast-based autofocus really better than phase-based, or is it just me?

I feel like I quite consistently get: Blurrier autofocus Lower exposure when shooting with my T5i's viewfinder than its LCD (i.e., in phase-based vs. contrast-based mode). But whenever I search ...
1 vote
1 answer
1k views

What is the Autofocus type in Nikon D3300?

What is the autofocus type in Nikon D3300, Is it phase detection or contrast detection ? Or both ? If both then when is phase detection used and when is contrast detection used ? I was looking in the ...
4 votes
1 answer
3k views

What is "hybrid AF", and how does it compare to other autofocus technologies?

I've heard of some new cameras — particularly mirrorless cameras — with a feature called "hybrid autofocus". What does this mean, and how does it relate to the traditional approaches of contrast and ...
3 votes
2 answers
600 views

How advanced is phase detect AF for bird photography compared to contrast detect AF?

My first and only camera is a panasonic Lumix G5 with a panasonic 45-200mm. I wanted to have a first hand experience and decide if I want to switch to aps-c dslrs, but I never had an opportunity to ...
0 votes
2 answers
3k views

Which image processing algorithm does the contrast auto focus use to check the sharpens?

My read is that the contrast auto focus is using edge detection algorithms like laplace or sobel.
4 votes
1 answer
1k views

Do mirrorless cameras focus less or more accurately than SLRs under low light?

How do the following compare in terms of autofocus accuracy for night photography: Mirrorless cameras like the Sony NEX-5R, in hybrid autofocus mode. The NEX-5R, in contrast-only autofocus mode. A ...
23 votes
6 answers
41k views

What is the practical difference between phase-detect and contrast-based autofocus?

What are the main differences in field use between phase detect AF and contrast based AF? I understand the technical differences, but I am not sure what the implications from a photographer ...