steve1000
Posts: 9
Joined: Thu May 14, 2020 10:48 am

HQ-cam noisy DNGs

Tue Feb 23, 2021 10:53 am

Hi,

I am still experimenting with the hq cam and raw images via PyDNG.

JPGs look fine - which I guess is the result of internal noise reduction.

The images are taken with in a dark room with a roughly synchronised strobe light via a subprocess call of raspistill.

Does anyone have a tip how to minimise image noise?

User avatar
topguy
Posts: 6995
Joined: Tue Oct 09, 2012 11:46 am
Location: Trondheim, Norway

Re: HQ-cam noisy DNGs

Tue Feb 23, 2021 11:17 am

The point of using RAW images is so you can have better options when processing the images in programs like RawTherapee etc.. ? You are supposed to postprocess them which include finetuning the noise-suppression.

Other tip:
Don't take pictures in a dark room ;-)

steve1000
Posts: 9
Joined: Thu May 14, 2020 10:48 am

Re: HQ-cam noisy DNGs

Tue Feb 23, 2021 12:38 pm

Thanks for the reply!
I’m aware how raw works, but thought there might be a calibration or filter option that could be used.

Jack Hogan
Posts: 105
Joined: Wed May 13, 2020 2:08 pm
Contact: Website

Re: HQ-cam noisy DNGs

Tue Feb 23, 2021 5:03 pm

steve1000 wrote:
Tue Feb 23, 2021 10:53 am
Does anyone have a tip how to minimise image noise?
If you can, increase strobe power :)

steve1000
Posts: 9
Joined: Thu May 14, 2020 10:48 am

Re: HQ-cam noisy DNGs

Tue Feb 23, 2021 6:08 pm

Thanks!

I’m already minimaxing focus, exposure and strobe intensity... what have you.

My “fixed” measurements so far:

Optimal aperture is roughly between f5.6 an f8

The shortest capture time I can reliably manage over all 12 cams used is 1/4s
(Trigger, delay x, flash)
I can indeed reduce noise via adobe raw, and all the images are - given they come out of a raspberry- very good.

I was just wondering, if I could spare myself some time and calibrate the raw profile or apply a filter at the pi level

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