Hi Paul,
I have yet to tackle M42, but will, if you guys ever send some fine weather across.
If I might suggest focus, with the stars "blobby" or tracking (although this tends to elongate the star images).
It would be one of my biggest headaches as well.
What ISO rating?
Keep at it,
Gary
Good shot Paul, it looks like you need a wider field there though, you're missing 1/4 of the nebula
Have you figured out how to use PixInSight LE yet? It looks like a great program, but from my initial attempts trying to learn it, there's a steep learning curve to get past before it becomes of really good value.
Gary Iso was 1000, and the focus was a little off. It looked focused in the view finder when I used the mask on Rigel
Ice, I bought a focal reducer but cannot gain focus with the field derotator and the focal reducer. Will need to speak to the shop and get some advice. As for Pixinsight, I have given it a try a couple of times but find that photoshop works best for me. I agree it is really hard to learn.
Hi Paul,
don't take my comments as critisism, please. It ios a great shot.
Do you really need the field derotator, with such short exposures, keep them short, shoot more, and stack them.
I can normally find a very bright star, focus on that by eye, and then switch to the target, and keep focus. (with a 1250mm newt anyway, and your focal reduced SCT should be similar??).
Try a trial with the reducer, and no derotator.
Gary
Gary, I will try without the field rotator and just track with the off axis guider. That way I might be able to get a wider field and possibly encompass the whole nebula.
Paul
Last edited by rumples riot; 17-11-2004 at 04:35 PM.
Paul,
good idea, let us know how you get on.
I recall my first shot with the new digital SLR. It was of Omega Cent, and through an MN66. Flopped it into the focuser, shot about 3 minutes, no guiding, not nothing. It was perfect, but was alsao a fluke, as I haven't been able to duplicate it, not since.
Now I have an ST80 (Nextstar 80) as a guidescope, with a ToUcam (not modded) and use IRIS to guide. When everything goes OK I get good results, but the frustration levels are up there, and I sometimes wonder "why". Sometimes it is just nice to actually look through an eyepiece, and reflect.
Gary
Paul, i've been reading that on M42, the pros usually take some shorter exposures to get the trapezium stars, and some longer exposures for the nebula, and join them together later in PS.
Have you tried something like that? You've got good detail in the nebula in your shot, but the trap stars are burnt out a bit.
Have been doing something like this, but I need to apply a mask to stop the trap stars from being over written by the longer exposures. Must learn how to do this mask properly.
ie: have both images (short exposure and long exposures) as different layers, and select the burnt out core of the long-exposure and cut it out, so when you flatten the layers you'll get the less-exposed core from the shorter images?
Both images will have to match exactly in every other way I spose, but with your tracking mount that shouldn't be too much of a problem I'm guessing.
