Making flat frames

[neil groves]

I have my dark frames which I made at the time of making my light frames, however I am going to make my flat frames using my laptop, what colour do I set my screen to for flat frames? Will 10 be enough?

Neil.

[joecoyle]

Hi Neil. Flats should be white, as evenly illuminated as possible. I use my iPad for now.

If using a DSLR, set it to Av mode to allow the camera to choose settings. Same iso.

I take about 30.

Have you moved the camera? Flats remove dust bunnies and correct for vignetting, so, the camera should ideally be unmoved from when you take lights.

HTH

Joe

[neil groves]

I was under the impression that it was dark frames that take out dust bunnies along with noise, I could be wrong though.

When you say about moving the camera, I take my light frames at night in the yard obviously, but surely I can bring the camera and scope indoors to do my flat frames instead of taking my laptop outside? Are you referring instead to not moving the camera settings?

Neil.

[geordie85]

I was under the impression that it was dark frames that take out dust bunnies along with noise, I could be wrong though.

When you say about moving the camera, I take my light frames at night in the yard obviously, but surely I can bring the camera and scope indoors to do my flat frames instead of taking my laptop outside? Are you referring instead to not moving the camera settings?

Neil.

It's best to leave your camera connected to the scope so the dust bunnies are in the exact same place as when you took your lights.

Just be very careful when moving your scope so it doesn't become slightly un-collimated

[goose35]

Thursday night i bought the tube and camera assembly indoors and without moving camera or focus i lay it on the table in front of laptop screen with notepad open.. put camera in AP mode and fired off 30 shots.

This seemed to work well, and i found it more comfy than holding it up to the tube outside.

Im thinking i might make up some supports to hold the tube in front of the laptop so i havent got to fumble around and risk knocking the camera/focus tube.

[s24man]

Hi Neil,

The proper way to take flat frames is to leave your scope/camera assembly exactly the same.  You want to shoot for an ADU that is about 45% of your max ADU (which with your 14 bit camera is about 7,000ish--if you scale it it will be about 35,000ish).  Take at least 30 individual frames.  

Stuart

[Stub Mandrel]

The other night, with the benefit of a full moon behind me, I fired off a short series of flats holding the back of a Philips Planisphere a foot in front of the scope. They definitely worked :-)