Flats before Lights?

[bendiddley]

Can anyone tell me if it's OK to take flats before lights? Cheers.

[ChrisEll]

Yes, as along as you don't change the focus later.

[bendiddley]

Great cheers.

[daz]

Or the camera orientation!

[bendiddley]

1 minute ago, daz said:

Or the camera orientation!

Cool cheers

[bendiddley]

I assume with flats it's ok to tilt the scope to horizontal to take them?

[ChrisEll]

1 hour ago, bendiddley said:

I assume with flats it's ok to tilt the scope to horizontal to take them?

Yes, I do that, much easier.

[Demonperformer]

Curious.  I always find them much easier if I point the scope vertically and that keeps the light panel in place while they are being taken and I am packing other stuff away. But whatever suits. 

[bendiddley]

1 hour ago, Demonperformer said:

Curious.  I always find them much easier if I point the scope vertically and that keeps the light panel in place while they are being taken and I am packing other stuff away. But whatever suits. 

So do you just lay the light panel over the top of the scope? I thought you had to place it some distance away?

[carastro]

Quote

So do you just lay the light panel over the top of the scope? I thought you had to place it some distance away?

 

When I had a light panel I always put it over the end of the scope.  I only stopped using it when it went wrong, and I had to temporarily use sky flats, and just continued doing that. 

Carole 

[ChrisEll]

The camera determines the exposure length of flats so I guess you can never have it too bright. I use my laptop with a white image, turn the brightness to max and hold it about an inch from the end of the scope.

[Demonperformer]

10 hours ago, bendiddley said:

So do you just lay the light panel over the top of the scope? I thought you had to place it some distance away?

Actually over the end of the dew shield, so that means it is 20-30cm from the end of the scope.

As long as it is providing an even light source, I'm not sure that distance matters that much, but more experienced APers may know better.

[ste7e]

I like to do it upside down...

I put an external monitor on a crate on the floor (the crate that I use for all my cables and junk) and use Second Monitor Lightbox to automatically control the brightness of the external monitor to match my filters (extra useful for NB filters).

There's a thread discussing SML here: