My First Nebula: M42 Orion

[EzyStyles]

Hey Guys,

tonight i decided to give the DSI a good try. After many frustrating shots (1500+) and sore back I took this frame without any tracking besides turning the slow-mo knobs.

At 5.7 sec long exposure and auto exposure set at 0.15 in AutoStar Suite. No stacking, no processing besides photoshop cs2.

Many thanks to Hitchicker (adam) for helping me on this.

If anyone can give me some advise as to what settings i should have, stacking in AutoStar Suite etc that would be great.

Thanks.

[davidpretorius]

hey ezystyles, haven't used the dsi or software, but it looks like you are on the right track. for a 5.7s exposure, the stars look pretty good.

with this nebula, can you drop back a bit in the magnification, it is a big nebula and i reckon the image would benefit from being further out so to speak. ideally you want 10 or more exposures to stack to start clearing out any noise

[Hitchhiker]

Hi EzyStyles, as the saying goes "A journey of a thousand miles begins with a single step..." You've made your first step. Congratulations.

Can you remind me what scope you have and the status of your tracking.

What do you mean by "auto exposure set at 0.15"? Also, what format did you save your file in - I would like to see your original file (before processing in Photoshop).

Adam

[2020BC]

The big things with prime-focus CCD is to get i) good polar alignment and ii) good focus. Even with stacking short exposures you'll find that the quality of the image will improve if polar alignment and tracking is good. This is because the image isn't 'smudged' across the exposure. Ideally you want the image not to move on the chip for the duration of your exposure. Judging by the look of the core in your pic I think 5 secs is a good place for you to get started. If you can setup your mount, with tracking on, so that you get no visible drift measured over 5 seconds then you're in business. To get Polar alignment use the Drift Method. For focus use a Hartmann mask. (http://www.zodiaclight.com/equipment/HartmannMask.htm) Hope this helps in some way.

[h0ughy]

well done mate, only up from here

[[1ponders]]

Way to go Ezy. I think everyone has hit on the important first issues, polar aligning, exposure length, (eventually you will lean to take many shots at different exposure lengths and then layer mask them in PS to capture the trapezium but still get good nebulosity.) and focus (always the hardest I found using the DSI)

Unless he's using a barlow atm in his image train, Ezy would find this difficult to do Dave. With the dimensions of his chip (not much bigger than a ToUcam) he's pretty well stuck at that field of view. Which is a bit of a pain , I found the same problem. :( Unless of course we can come up with a focal reducer for him ;) Something to work on.

[EzyStyles]

thanks guys.

Hey dave, i've got some not as magnified as that but couldnt see any details at all. I'll try again and this time doing stacking/processing.

Thanks adam. I had auto exp set to 0.25 secs and in the long exp box next to the preview button, i had it set to 5.7 secs? thats what the meade videos said unless im doing something wrong?

2020BC, i don't have tracking whatsoever. That pic was done manually tracking with the slow-mo knobs in my EQ3.

Thanks h0ughy :) your DSI works :D

focusing i judged by looking at the laptop screen. not accurate enough i must admit. since my is a F/4, wouldnt i get good field of view?

thanks all.

[EzyStyles]

here's a better pic

[EzyStyles]

and this

[Hitchhiker]

Hi EzyStyles,

The last image you posted looks really good!

Understand what you mean by "auto exposure" now, thanks. I think everyone has hit on the important issues.

It is possible to get some results in astrophotography by manual tracking. There have been posts on IIS of the Orion nebula taken with webcams. With no tracking you can let the object drift through your field of view, take lots of pics and combine them in Registax. The DSI is not as suited to this kind of imaging, however, as it has a very slow 'frame rate' compared to the ToUCam, for example. Also, by manually operating the slow-mo knob you tend to jiggle the tube and cause funny star trails - I'll bet you have a few of those among your 1500+ shots!

With tracking, you can expose for longer without the stars trailing. Have you been able to get an RA drive motor for your mount?

Congratulations, again, on your image. For the conditions you are working under it is a great result.

[ving]

your getting there :)
congrats :)

[[1ponders]]

Second shot definately looks better. focusing practice now :)

[atalas]

Congrats on your first shots easy !

[EzyStyles]

thanks guys. im surprised that you guys think it is nice because im quite disappointed with it. maybe ive seen too many other people's pic of M42 and there is no comparison to mine one :P