The Keyhole

2020BC (Bill Christie) · #1 18-04-2008, 07:10 PM

LXD-75 mount and Meade SN-8 scope. Guided.
Canon 350D unmod 59x1 mins ISO 1600.

jase (Jason) · #2 18-04-2008, 08:10 PM

Nice work Bill. Stars look heavily saturated. You may want to try taking shorter subs to manage them better (just re-layer them). You've collected some impressive detail. Well done.

peter_4059 (Peter) · #3 18-04-2008, 08:16 PM

Jase - would it be better to turn the ISO down a bit or reduce the exposure time? I thought higher ISO lead to more noise and that 1 min was not an excessive exposure time?

jase (Jason) · #4 18-04-2008, 08:28 PM

Peter, indeed reducing the ISO will assist, but at the same time has the potential to increase the exposure time. The most rewarding results typically come from variations of ISO and or exposure times in subs. Take high ISO or long exposure subs for nebulosity and low ISO or short exposures for stars. Layer them in PS using the lighten function works well (sometimes). Depends on what Bill wants to convey to the audience.

You are correct, 1min is not an excessive exposure time (certainly not for DSOs). However at ISO 1600, it doesn't do much for star aesthetics.

Ric · #5 18-04-2008, 10:10 PM

A very nice rendition of the keyhole Bill, well done

cheers

Chippy (Nick) · #6 18-04-2008, 11:48 PM

I don't know much (anything) about imaging - but looks like a very nice pic to me. Excellent!!!