LP - lower ISO longer Subs

[adamsp123]

Will a combination of lowering the ISO setting on a DSLR and taking longer subs in light polluted conditons (orange muck) help significantly with the final results?

[Catanonia]

Don't really think it would do much other than possibly reduce noise, but that depends on the length of subs you go to.

All the ISO is doing is increasing the sensitiviy of the the CMOS / CCD cells and so LP would be equally effected compared to DSO.

LP filter is the way I combated the problem, the EOS Clip or CCD equivalent worked best for me and orange glow.

[brianb]

Fiddling with ISO / exposure length will not change the signal to pollution ratio. Increasing the exposure time & reducing ISO to get the same image density will improve signal to noise.

To improve signal to pollution, you need to find a darker sky or use a filter which will selectively remove pollution.

[adamsp123]

Well thanks, you have confirmed my line of thinking - cheers