Another Night of Deep Sky Photography

[wornish]

Well I learnt some lessons last night.

I had planned to take 60 x 1 min shots of the Horse head and Flame Nebula in Orion.

So what happened

1. My camera battery runs out after about 35 shots.
2. Forgot to re align on target after replacing battery.
3. Lenses get covered in DEW after about 40 mins when your out and the temperature is near zero.

Anyway here is my best effort using the initial 35 shots less three that had aeroplanes in them

[OM USer]

Re: Another Night of Deep Sky Photography

I am in awe of shots like these.

[Wee man]

Re: Another Night of Deep Sky Photography

Fantastic shot, what are you using to stack the shots? Which lens please. Are you realigning manually if so what do you recommend for length of shot before realignment?

[wornish]

Re: Another Night of Deep Sky Photography

Fantastic shot, what are you using to stack the shots? Which lens please. Are you realigning manually if so what do you recommend for length of shot before realignment?

Thanks.

I stack the shots using some free software call Deep Sky Stacker, and then process the stacked image in Photoshop ( thats the hard part).
The stacking is what removes a lot of the noise. Image stretching in PS pulls out the very fine differences in contrast.
DSS runs on Windows (It can also run on a Mac in a wineskin wrapper).

I used my Nikon 80 - 400mm zoom lens set at 300mm attached to my e-m5mk2 via an adapter.

Any lens from about 100 to max 300mm will works fine. The faster the lens the better but when my lens is zoomed I am at an aperture of around 6.3 and my ISO is set at 1600. Going beyond ISO 3200 will probably result in too much noise.

I do have a Skywatcher Star Adventurer mount which tracks the earths rotation so you can take longer shots and it sits on my normal tripod. But with a 300mm lens on the camera the slightest knock like when exchanging batteries means it will need manually realigning, which I didn't do.

If you are on a fixed tripped then I would limit the exposure time to say between 5 - 10secs otherwise the stars become elongated.

Some deep space objects are very bright like The Pleiades and can easily be captured with say 10 x 4 sec shots. Others like this one are very feint and can't be seen with the naked eye, these ideally need a total exposure time of over 60 mins or even longer so thats a lot of 5 second shots!

[Wally]

Re: Another Night of Deep Sky Photography

Overall, that's a great shot, especially with so few images. I particularly like the starred effect to the left of the horses head.

Thanks also for the 'howto' description and to the Wee Man for broaching the subject.

[Wee man]

Re: Another Night of Deep Sky Photography

Thanks very much will be just using a tripod so I think I might have a hard time. I will be removing a pane from the greenhouse and setting up in it using the 40 - 150 pro this will cut down movement caused by wind I hope.

[brian1208]

Re: Another Night of Deep Sky Photography

having tried this myself I'm full of admiration as I never got anything this satisfactory

[wornish]

Re: Another Night of Deep Sky Photography

Thanks very much will be just using a tripod so I think I might have a hard time. I will be removing a pane from the greenhouse and setting up in it using the 40 - 150 pro this will cut down movement caused by wind I hope.

That lens is on my wish list. At f/2.8 you will get a lot more light, so you can drop your iso to 800 to reduce noise. Good luck!

[Bikie John]

Re: Another Night of Deep Sky Photography

Vey impressive despite the operational problems. The horsehead nebula shows up really well.

Thanks for the general advice, I dabbled in this a few years back and it is a much more complicated subject than you might think. Is this the full frame from the 300mm view? I would have expected to need far more magnification than that.

Keep at it and keep sharing them .... John

[wornish]

Re: Another Night of Deep Sky Photography

Vey impressive despite the operational problems. The horsehead nebula shows up really well.

Thanks for the general advice, I dabbled in this a few years back and it is a much more complicated subject than you might think. Is this the full frame from the 300mm view? I would have expected to need far more magnification than that.

Keep at it and keep sharing them .... John

Thanks. Will keep trying.

Its about a 50% crop of the full frame. i.e around 2000 pixels long edge. The image was also rotated 90 degrees counter clockwise.

[Wee man]

Re: Another Night of Deep Sky Photography

Another question if I may how do I find the Horse head nebula the easy way?

[wornish]

Re: Another Night of Deep Sky Photography

Another question if I may how do I find the Horse head nebula the easy way?

One of the brightest things when looking South West for the next few days / weeks at between 20:00 and 21:00 is Orion's Belt they are three very bright stars in a row.

The Horsehead Nebula is just a little below the lowest left most star. As I said its invisible to the naked eye.

The really bright star in my shot is the leftmost star of Orion's Belt. Remember my shot is rotated 90 deg counter clockwise.

You can use a web based planetarium to help find them like this one:

https://in-the-sky.org/skymap.php

Or - I use free planetarium software like Stelarium, its brilliant.

Getting the right target manually is more of a challenge, especially with a telephoto lens as the field of view is very small.

If you raise the iso on your camera to 6400 or even higher you can see the stars on the lcd screen. its easier then to get proper infinite focus. especially if you use the electronic zoom, its very important to get this right or the pictures come out with blurred stars. Don't forget to put the iso back down before taking the actual picture though.

[Wee man]

Re: Another Night of Deep Sky Photography

Many thanks

[birdboy]

Re: Another Night of Deep Sky Photography

Great Images Dave did you use any darks or bias?. The Flame Nebular has come out well and did you have to do some processing to Ainitak to get it to sparkle. I've been there with your experiences, it then gets more expensive and wanting more equipment. Once dew forms on lens game over for the night. I've ended up getting tape heaters for the lens (HitecAstro four channel controller and 3 Astrozap heater tapes). Of course that then required a 12vdc battery pack and the camera is powered from the battery pack and inverter (300W Bestek) because there does not seem to be 12vdc device to power the camera OMD-EM1.

I am still sticking with star tools for the post processing

[Peter_Hartland]

Re: Another Night of Deep Sky Photography

a hell of a lot better than I could even attempt