Line noise in images - DPChallenge Forums

Samsung Galaxy S21, S21+, S21 Ultra

09/26/2006 12:48:39 AM · #1

There seems to be horizontal lines that appear in the noise in my images when taken with iso 400 or higher. I have the upgraded firmware for my 20d, anyone else experienced this?

Bear_Music

Sony 24-70mm F4 Vario-Tessar T* FE OSS

09/26/2006 12:52:02 AM · #2

Show us an example?

R.

jmsetzler

Sony Alpha a6000

Sony 16-50mm f/3.5-5.6 E-mount

09/26/2006 12:53:25 AM · #3

I have seen that sort of problem when using the 50mm f/1.8 and f/1.4 lenses in very low light situations.

Canon EF 85mm f/1.2L II USM

09/26/2006 01:57:54 AM · #4

May be hard to see here, but there are horizontal lines running across the center of the image,
btw this is a 30 sec exposure.

Ragga2000

Canon EOS-5D Mark IV

09/26/2006 07:08:15 AM · #5

I am rather curious about these lines also, so.... bumping :o)

Matthew

Canon EOS-5D Mark II

Peleng 8mm f/3.5 Fisheye MC In M42 Mount

09/26/2006 07:13:07 AM · #6

Was the image originally underexposed? Banding happens in underexposed areas on the 20d (plus others, but quite noticeable on the 20d).

They are hard to get rid of - I sometimes use a huge dose of noise reduction in a new layer, reduce opacity to 20% or so, then erase parts of the noise reduction layer where detail is more critical than smooth tones.

Peleng 8mm f/3.5 Fisheye MC In M42 Mount

09/26/2006 11:14:46 AM · #7

Yes, the areas where the lines are most visible are areas that were underexposed. When processing the raw photo, if the exposure is increased the lines get much worse.

Matthew

Canon EOS-5D Mark II

09/26/2006 12:04:39 PM · #8

The best way of avoiding banding is to expose to the right of the histogram: that means getting the right hand side of the histogram as close to the right hand side of the chart, without hitting it (which results in over exposure).

In your case, you needed a higher ISO, wider aperture or longer exposure to avoid unnecessary underexposure.

The banding is pretty common to all digital cameras, but as I say, it has always been picked up on as being particularly noticeable in the 20D.

Edit to add that higher ISO increases the amount of grain and therefore the banding - you should probably aim to use as low an ISO as possible to minimise banding while maintaining proper exposure.

Message edited by author 2006-09-26 12:06:20.