Orion Nebulae

[mickyjd]

I have taken this picture of the Orion Nebulae with a Celestron C8-NGT with a canon 350d set to bulb any tips on how to better this would be appreciated have i exposed the picture for to long. Any comments Good or bad would be welcome.

Thanks:icon_scratch:

[steppenwolf]

This is an excellent start but there are a couple of issues, the most important being the tracking which is off as shown by the elongated stars. Taking lots of images and stacking them will improve the quality of the finished image but you do need to try and improve the tracking.

There is a processing technique in PhotoShop that improves the star shapes but it is a bit (LOT!) of a kludge. If you make a duplicate of the finished image and change the blending mode to 'Darken' and then chose Filter - Other- Offset and adjust the position of the duplicate layer, you can tighten up the star shapes as per the following version of your image:-

[mickyjd]

Thanks for the feedback steve i will try the techniques you have suggested. I am just getting used to DSS and this was a single shot. I need to be more patient when setting up and calibrate more stars. The exposure time on this was 50 seconds so i may try more shots at 30 instead.

Cheers

[cloudbuster]

Hi mickyjd

Speaking as a beginner myself, thats not a bad first image. Ive only had one crack at the nebula myself (please see my photo album), but mine, although it is made up of some 15 stacked subs, still suffers from LP....and foolishly i shot it in jpeg would u believe!

cheers

bob

[sgazer]

Thanks for the feedback steve i will try the techniques you have suggested. I am just getting used to DSS and this was a single shot. I need to be more patient when setting up and calibrate more stars. The exposure time on this was 50 seconds so i may try more shots at 30 instead.

Cheers

hi,

that's a good start. Regarding the poor tracking, this is down to the polar aligment rather than how many stars it's aligned to, that just helps with the pointing accuracy. Accurate polar alignment is the key to good tracking. It will track just the same with 1 star alignment as with 5 stars because all it does is rotate the RA axis at a fixed (sidereal) rate. You should be able to get 2-3min from your CG mount.

hope this helps a bit.

[greenkat]

I had a quick go in photoshop adjusting the levels a few times

[dark knight]

What a wonderful start to astro photography. As Steve said the tracking needs improving, try reducing the exposure time by 10 secs each shot until you notice less tracking errors, this will give you darker images, but the data will capture the details. Take lots of images and stack them in Deep Sky Stacker (free software). The processing of the stacked image can then be done to bring out the details..Great start though....

Carl

[mickyjd]

Thanks to all of you on this one lots of advice and tips i can follow. Sgazer would i benefit from buying a pole finder for the mount? i get a good view of polaris and had this perfectly centred in the viewfinder or so i thought its nice to hear i can get 2 -3 minute exposures from this mount. Bob nice image seen as were just new starters.

Can anyone tell me what else i would be able to image with the 8" scope can i get the Horsehead nebulae or Andromeda Galaxy.

Thanks Again

Mick

[steppenwolf]

You will certainly get the Horsehead Nebula nicely in the frame but this is a really tricky object to try for as you will require quite long exposures to capture the red emission 'backdrop' that allows you to see the dark Horsehead.

[dark knight]

Galaxies, clusters, nebula's, there's no reason you can't have a go at any of them, it all depends on how accurate your polar alignment is...

[Tim]

Nice start to the hobby

As suggested, your best first stop would be to get really good polar alignment. You can do this with an eyepiece in. It involves adjusting the Altitude and Azimuth settngs on your mount.

This is the guide I use.

Classic Astrophotography - Photographing the Cosmos with ordinary film click to the drfit aligning guide

Remember that Polaris is not the same as the North Celestial Pole. Its close, but not close enough. When the mount is properly lined up with the NCP, You will see Polaris rotate around it.

When you are happy with that, take a few test shots at iso800 on the Bulb setting. See how long an exposure you can get before the stars start to look oval. As a matter of interest, what method are you using to fire the shutter? Ideally you want a method whereby you dont have to touch the camera/mount/scope at all, such as a remote control.

When you find out how long is practical, take at least 20 or so shots if you can. Then, as suggested, you can use DeepSkyStacker (free) to join them all together and bring out the detail a bit.

Looks like you'll have some fun

TJ

[mickyjd]

Thanks for the advice TJ you have got where i went wrong there. When i aligned Polaris i put it in the centre of the viewfinder and after a few minutes of doing something else when i looked again it had moved so i re-centred it. Should polaris rotate outside of the crosshairs? I do have a remote for the camera so that shouldnt be problem.

Thanks

[mickyjd]

The drift aligning guide is a great piece of kit as well TJ has helped me a lot.

Thanks again

[Pete Presland]

very nice!

[michael.h.f.wilkinson]

Thanks for the advice TJ you have got where i went wrong there. When i aligned Polaris i put it in the centre of the viewfinder and after a few minutes of doing something else when i looked again it had moved so i re-centred it. Should polaris rotate outside of the crosshairs? I do have a remote for the camera so that shouldnt be problem.

Thanks

Polaris is not exactly at the celestial pole. Good polar axis finders (my old Vixen GP mount has one) have a little circle offset from the crosshairs. After setting date, time and distance from nearest meridian correctly, setting Polaris in the centre of the little circle aligns very accurately. I got up to 15 min uncorrected photography at F6.3 (on 35mm film) with that in the past.