Quote:
Originally Posted by Startrek
Thanks Craig,
Great information
I use the Optolong L Extreme duel band to image emission Nebula and the 2600MC has a UV/ IR protective window so I can expect longer exposures using this arrangement.
Your 533MC has a 14bit ADU ie: max ADU of 32,768 so applying 50% would be around 16,400 ADU. Choosing higher at 20,000 ADU at the same illumination level would take a longer exposure , right ??
Cheers
Martin
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I use the L-extreme too, although my OTA is f7 and your newt's should be faster - unsure if OTA f/ratio impacts flats exposure time but I assume it would, so my 8s is partly because of the relative slowness of the Esprit 120 I suppose.
You're right about the ADU target, perhaps a target of 20,000 is too high for the sensor, although it does not appear to cause any issues. I often shoot flats but have never once actually needed to use them, it's more of a "just in case"
I'll try 16,400 next time and see how it goes. Cheers I use an iPad with a white tshirt over the dew shield by the way, although with the standard 10.5" iPad it doesn't actually cover the entire dew shield (about 2-3mm of uncovered dew shield on the short side) but does not appear to have caused issues either.