Flats Panel

[JSeaman]

I don't know why I didn't do this before - I have never bothered with flats often and when I have it has been with a T shirt over the scope during the day and I usually end up moving it and generally doing a rubbish job. Today I took delivery of a 40x40cm 36W LED panel (eBay 124209366763) and attached it to the observatory. I managed to make the scope pirouette to it with the roof in place and stored that as an unpark position in EQMod and tested it tonight - perfect. I shoudl have done this long ago! £11 and 10 minutes is all it took

[michael8554]

36 Watts !

How did you attenuate that enough to get good Flats ?

Michael

[JSeaman]

? It's not brighter than pointing at the sky, just adjust the duration for a mean value of ~30k and away it goes. Worked perfectly

[michael8554]

What exposure was that ?

Michael

[JSeaman]

0.06 on the panel, 0.01 last time I used the sky

[michael8554]

So no mechanical shutter on the camera ?

Michael

[JSeaman]

I don't understand what you're getting at?

[michael8554]

I was concerned about your extremely fast exposures.

Cameras with mechanical rolling shutters such as the ASI 1600MM will often have a shutter artefact in the Flat with exposures faster than about 1 second.

Michael

[bottletopburly]

11 minutes ago, michael8554 said:

So no mechanical shutter on the camera ?

Michael

Looks like a zwo camera in photo so global shutter 

[JSeaman]

No there are no artefacts

[wimvb]

2 hours ago, bottletopburly said:

Looks like a zwo camera in photo so global shutter 

Actually, no. Many zwo cameras have rolling shutters. Just not mechanical. Still, there can be problems with short exposure times. But there’s only one way to find out: examine the images.

[michael8554]

6 hours ago, JSeaman said:

No there are no artefacts

Good to hear

Michael