Dark Frame Library

[I Albert]

Hi, guys

I need a library of darks for my master degree in arts project. It doesn't matter the type of camera or any other details as I am doing a project on noise. Could anyone share with me his darks? Thanks a lot that would be awesome.

[vlaiv]

Hi and welcome to SGL.

Since you are doing degree in arts, I'm wondering what sort of noise do you need (do you need to be very scientific about it and what qualities are you looking in the noise).

It would be far easier to use software that can generate different types of noise for you. Most obvious difference between real data and "synthetic" data would be that one is true random number generator, while other is pseudo random number generator (good enough for solid scientific work, so I presume not poor for arts project as well)?

[Skipper Billy]

You can download a full set of lights, darks, bias and flats from here - scroll down to the bottom of the page to mono imaging. https://www.easypixinsight.com/?fbclid=IwAR3kZB6yzmDCAQsH0RPQG0jIaA18XH0Cy4r2dd3FrVMvedpeJ7scyCZy5-M

If for some reason you cant do that then PM me and I will stick  slew of darks in a dropbox folder and email you the link - it will be a big download !

[I Albert]

Hello everybody,

And thanks a lot for your help. @Billy Skipper I really appreciate sharing all the material with me! @Vlaiv I am actually working on a visual 'phenomenon' called Eigengrau that takes place in the retina while no photons are present, which is exactly the type of dark noise temperature related you can experience on a camera sensor. That's why working on darks seems quite appropriate.

[vlaiv]

12 minutes ago, I Albert said:

Hello everybody,

And thanks a lot for your help. @Billy Skipper I really appreciate sharing all the material with me! @Vlaiv I am actually working on a visual 'phenomenon' called Eigengrau that takes place in the retina while no photons are present, which is exactly the type of dark noise temperature related you can experience on a camera sensor. That's why working on darks seems quite appropriate.

Ok, still not sure what you are after, although I do understand what your work is about (just don't see relation to darks yet).

Dark subs are meant to correct for dark current but also other phenomena on sensor - like amp glow and hot/warm pixels. In principle it is Poisson type noise from thermal source, but there are other things with sensors that happen as well.

Now if you are after just Poisson type noise (or any other type of noise - Gaussian, uniform distribution, ....), then you can generate it quite easily with different parameters (something you might need). For example, here is small image 256x256 with Poisson noise and signal of "1" (let's say 1 photon/pixel/s and exposure 1s):

I'm not sure if you are doing "stills" or something like "video" in your research, but just for fun, here is "simulation", or rather animated gif made out of 16 such frames:

If above is something that you will find useful - just let me know and I'll explain here what software to get (ImageJ - it is free, java based and therefore OS agnostic) and what plugin for it to get (RandomJ) and how to generate such things.

[Stub Mandrel]

9 hours ago, vlaiv said:

Ok, still not sure what you are after, although I do understand what your work is about (just don't see relation to darks yet).

Dark subs are meant to correct for dark current but also other phenomena on sensor - like amp glow and hot/warm pixels. In principle it is Poisson type noise from thermal source, but there are other things with sensors that happen as well.

Now if you are after just Poisson type noise (or any other type of noise - Gaussian, uniform distribution, ....), then you can generate it quite easily with different parameters (something you might need). For example, here is small image 256x256 with Poisson noise and signal of "1" (let's say 1 photon/pixel/s and exposure 1s):

I'm not sure if you are doing "stills" or something like "video" in your research, but just for fun, here is "simulation", or rather animated gif made out of 16 such frames:

If above is something that you will find useful - just let me know and I'll explain here what software to get (ImageJ - it is free, java based and therefore OS agnostic) and what plugin for it to get (RandomJ) and how to generate such things.

This reminds me of a conversation I had with a friend many years ago.

We were sat in a room with a black and white TV that wasn't tuned properly. those of us of a certain age will remember the appearance of a screen of 'static', which is a pretty balanced random image as the automatic gain control averages it out to a mid grey.

We noted that it was possible to stare at the screen form much longer than, say, a plain painted wall or a blank sheet of paper. We surmised this was because the ever changing, but essentially information less image didn't 'bore' the retina or the brain as the nerve cells were receiving constantly changing input.

You can try this experiment with @vlaiv's two simulations. It's a pain to stare at the static one for more than a few seconds but the moving one has a wierd fascination. Obviously something with a longer cycle would be better as this short animation has some detectable repeating patterns.