M42 (Orion Nebula)

STM

Senior Member
I went out last night and started playing around doing some test shots of the Orion Nebula (M42). I set up the D850 on a tripod and mounted my 200mm f/2 ED IF AIS Nikkor. I set the ISO to 3200 and pointed the camera at the northern skies at Orion or more specifically, Orion's "belt". I stopped down to f/2.8, focused very carefully in live view (magnified) and tried a 1 sec exposure using a wireless remote cable release to eliminate any camera shake. I was astounded by the number of stars that showed up that were not visible to the naked eye. The D850 handles ISO 3200 like a champ, the noise levels are amazingly low. I was really not surprised at this as I shot an image of a rattlesnake in a zoo at ISO 4000 and saw essentially no noise.

This was just a warm-up, however. It is supposed to rain this evening but clear around midnight. I shot the stuff last night around 2am, at that time tonight it is supposed to be clear again. If tonight does not work, skies are supposed to be clear all day and all night on Sunday. When I go out next, conveniently only as far as the end of the driveway, I will have the 400mm f/2.8 mounted on the D850 and will take a considerable number of images using an intervalometer. I will probably take about 100 images of the nebula itself, 50 frames at the same exposure with the lens cap on, 50 frames at 1/8000 with the lens cap on and 50 frames of my labtop screen showing a bright white screen and the exposure set to middle gray. I will insert all the images into a program called "DeepSkyStacker" and let it work its magic. Once done, I will take the final .tif image and post process it in PS.

As always, I really cannot be bothered in the least with changing all of the "Non-CPU" settings in the camera each time I change lenses so the EXIF is not going to be correct. I was using a 200mm lens and the f/ was 2.8. The shutter speed is correct.


This is what the sky kind of looked like to the naked eye..............

Orions belt naked eye.jpg

But this is what the D850 sensor saw with an exposure of 1 sec @f/2.8 @ISO 3200

M42.jpg

I really did very little post processing on this image. I will "stretch" it in levels in all colors of the RGB once I have gotten the stacked image. Using a longer lens will enable me to get a larger image of the nebula as well.

This stuff is REALLY fun!

In the Infantry we always used to say that the Army never sleeps, I guess the same holds true for Astrophotography! I can't wait until my telescope finally arrives!
 
Last edited:

Bikerbrent

Senior Member
This photo is spectacular, especially for just a camera shot. You get a decent telescope and continue with your telephotography, you may have a new career!
 

STM

Senior Member
This photo is spectacular, especially for just a camera shot. You get a decent telescope and continue with your telephotography, you may have a new career!

I have ordered a Celestron Nexstar 8SE but unfortunately it is backordered until March sometime! It has a focal length of just over 2000mm and a aperture of 8" which works out to f/10. It comes very highly reviewed so I am super psyched to get it!

celestron 8SE.jpg
 
Last edited:

Bikerbrent

Senior Member
I have ordered a Celestron Nexstar 8SE but unfortunately it is backordered until March sometime! It has a focal length of just over 2000mm and a aperture of 8" which works out to f/10. It comes very highly reviewed so I am super psyched to get it!

Yup, that should do the job.
 

BF Hammer

Senior Member
Good scouting mission. I have had a project planned for Orion for a month now and just do not get clear enough skies (without moon) to do it. Been cloudy/overcast in my part of the world since Christmas. My plan involves D750 with Sigma 20mm f/1.4 on tripod for a night-landscape with Orion. At the same time my D7000 with Tamron 90mm f/2.8 on star tracker shooting Orion with a wider field to catch the nebulosity all around Orion. Have a light-pollution filter to try with that also. If all goes right, I want over 60 minutes of total exposure time each.
 

STM

Senior Member
Good scouting mission. I have had a project planned for Orion for a month now and just do not get clear enough skies (without moon) to do it. Been cloudy/overcast in my part of the world since Christmas. My plan involves D750 with Sigma 20mm f/1.4 on tripod for a night-landscape with Orion. At the same time my D7000 with Tamron 90mm f/2.8 on star tracker shooting Orion with a wider field to catch the nebulosity all around Orion. Have a light-pollution filter to try with that also. If all goes right, I want over 60 minutes of total exposure time each.

We have a waxing crescent right now but it is not significant enough (12%) to have a major impact on Orion right now. Plus it sets at 9:13 tonight so it will be below the horizon before it really becomes a factor. It is supposed to be clear tonight so I am going go out and re-shoot it. This image was a one off; just one shot, no dark, bias or flat frames. I got my flats and darks shot last night but when I went out last night around midnight and was setting up for the bias and light frames it all clouded up. CRAP!! :mad: I already have the flats and darks taken now, so tonight I all I have to shoot are the bias (once the camera cools to ambient temp), and the light files. I will probably shoot 120-150 light files and stack everything in DeepSkyStacker. This one was also shot at ISO 3200, which in hindsight was excessive; it added a lot of noise and skewed the histogram to the right. I had to try to minimize the noise by "stretching" the shadow index marker in levels in Photoshop. I am going to shoot at ISO 800 tonight and expose for 1.3 sec @ f/2.8 using the 300mm f/2.8 ED IF AIS. I think that will make for a significantly better image. 1.3sec is about my limit in the advanced MFN calc to prevent star trails.

If you have not checked it out, go to Société Astronomique du Havre - Règle NPF : temps de pose pour éviter le filé d'étoiles (archive.org) and use the calculator there. It is awesome! It does the rule of 500, which is pretty outdated, a simplified and an advanced MFN calc. I use the advanced one as it is more conservative. It will be in the box on the left side of the screen, divided into 9 squares. Pick the average, but stay on the low side, of all of the 9 squares for the best exposure length.
 
Last edited:

STM

Senior Member
Yup, that should do the job.

I am certainly hoping so! I also got a Celestron wedge, since this is only an alt-az mount and the wedge is really needed so you can do longer exposures and counter field rotation. I also got a 60mm guide scope and 1.2MP camera which will allow me to take even longer exposures.
 

STM

Senior Member
I stacked 240 frames of M42 in DeepSkyStacker with the D850 and 300mm f/2.8 ED IF AIS Nikkor. 1 sec @f/2.8 ISO 800

M42.jpg
 
Top