Need Some "Steering"

I was just wondering if some of you super photobugs can steer a novice that just bought a Canon EOS 20D on what exposure settings to try 1st? LX200 GPS 10" (Fork Mounted)

Say I wanted to shoot M42... What camera settings would I start at?

Thanks, folks.

Jeff

Start at ISO 400 or 800, 1600 will blow out stars, F10? if you have it set to bulb mode and go 3 min or so given your sky noise. if unguided go 1.5 min at ISO 800, take at least 5 darks and sigma clip combine them, for lights go to town. But without more detail on sky conditions, autoguiding etc I cant give more advice than that. Remember in astro world ISO doesnt buy much if anything. And set the camera to not long exposure compensate / noise redue - or watever that is, you want to do that ( dark frame subtraction ) outside of the camera with an average combine of sampled dark frames.

M42 is difficult in that the bright core will brun out first. It really is a multiple exposure shot.

ISO 1600 is good for a rapid imaging and I know some advocate lower ISOs but not sure about the benefits and this has been the topic of some discussion on various groups. I think tracking weakness will utlimately be the determining factor where maximum ISO gets you "out of jail from tracking errors". Even ISO 3200. 3200 will give you a lovely bright image in 2 minutes that will bring out a lot fo detail but will burn out the core. Tak a series of 10 second exposures for that. Then you need photo shop skills to layer in the shorter exposure to replace the burnt out core.

If that is too much for starters then stick to the ISO800/1600 and 90 seconds. I would think ISO400 would be way too dim.

Greg.

five minutes at ISO 800 is my standard at a dark sky site. Then I collect as many of those as I reasonably can. At least twelve of them.

However, M42 presents a peculiar challenge. You need to have some short exposures (as short as thirty seconds) to get good exposure on the core. But thirty seconds will get you little on the outer fringes. So, you layer that short exposure in with the longer exposures to get the whole thing.

In general, take a picture at whatever setting. Then look at the histogram in the back of the camera. Unless you are trying to get lots of color in the stars, make sure that the long extension of the histogram gets to the right edge of the graph. Try also to have the big hump at the bottom at about one quarter of the way up (from the left) the graph, with just a little gap at the bottom (left) of the graph.

Alex