Getting Good Results!

[Herzy]

My setup:

Nexstar 90slt Computerized 

Nikon D320

Alright I understand that Alt/az mounts aren't good for astrophotography, but it's what I can afford so it'll have to do. I've been taking astrophotos for the past few months and the results are dissapointing. Although you can't see the streak of the Milky Way, our light pollution isn't too bad and the nights are always clear, so this isn't the issue. Unfortunately stacking softwares aren't an option either so I'm forced to do single exposure astrophotography with an unreliable mount!

I have tried imaging the Pleiades for about 40s exposures and I can't see any of the nebula, but I see pictures of single exposure pictures of it that are also 40s that you can see stunning detail. (I made sure we had exactly the same settings) 

I just want to be able to get some good deep sky images of things like the Andromeda Galaxy, double cluster, Whirlpool Galaxy, Pleiades, Orion Nebula, etc.

How should I go about getting decent results that would impress my friends/family with this setup (without purchasing anything expensive)!

[PeterCPC]

To be able to get good DSO results you will have to have some stacking software like DSS. Single exposures will never give you good results especially on an Alt/Az mount.

Good DSO imaging will involve an EQ mount but you should be able to image clusters and the Orion Nebula with multiple stacked images on an Alt/Az mount.

Peter

[SteveNickolls]

Hi Herzy, if you have some little money free might I suggest you buy a copy of, "Astro-photography on the Go: Using Short Exposures with Light Mounts" by Joseph Ashley ISBN-13:978-3319098302. You can do a lot with alt-az mounts and that's important to keep in mind particularly if you can't afford an equatorial mount and especially if it's the difference between being able to get out and do some imaging or having to sit indoors wishing. Hey, look at it another way you could have a heavy equatorial mount that you seldom use because it's an effort to move it outdoors or take to a dark site, or have an equatorial set up that gets beaten by the dreadful local light pollution!

Chin up and the very best of luck. The book is very good by the way :-)

 

Best Regards,
Steve

 

[Astrosurf]

If the problem with stacking is field rotation, I thought DSS had an option to account for that.

Alexxx

[happy-kat]

Look at each aspect what else could you do to make it easier, some suggestions.

The tripod is level

Just to start use only your camera and a short lens.

Watch videos on processing using GIMP as Gimp is free and there are astro tools for it.  It works on your MAC.

Work out how to manually stack images using GIMP.

Once you have mastered a manual way to stack you will be off to a great start. You need to use a lot more images to stack when the exspore time is short to pull out the detail.

[Herzy]

So I should take multiple short exposures and stack them via GIMP? I am very broke atm so it's just discouraging when people keep saying that I need this and that to get good results. I'll keep at it, thanks for all the help!!

[Davey-T]

As someone who started out in astro' imaging using an SLR and film a modern DSLR and any sort of mount would have seemed an impossible dream.
Imagine having to send your pic's off to be developed and getting nothing back because the person processing them decided they were "too dark".
The reason I had to start doing my own developing, another can of worms.

So persevere, astro' imaging aint easy but very worthwhile, plenty of vid's on Y'Tube using basic equipment.

Good luck

Dave

[hjw]

Hi Herzy,

I am afraid "good" results require long exposure times. I started about a year and a half ago and what I thought was a descent then is barely worth a mention now. Even with bright objects like M42  or eta Carina I consider now about 3 hours worth of 5min exposures to be the minimum (ISO800). when I started a total exposure time of 60 minutes was "plenty". I am planning to go to 1o min subs but I know my camera will be struggling. It is a evolution and that's where a good EQ mount comes into the picture. EQ and guiding and eventually a cooled CCD camera are the key to "good" results. Having said this, trying to maximize the outcome of your current setup will certainly help in the future.

Clear skies and good luck!

HJ

[happy-kat]

3 hours ago, Herzy said:

So I should take multiple short exposures and stack them via GIMP? I am very broke atm so it's just discouraging when people keep saying that I need this and that to get good results. I'll keep at it, thanks for all the help!!

Hi

GIMP is free and installs on MAC which I think is why you cannot use Deep Space Stacker as that is only for Windows.

You can work with what you already have you have just got to keep trying.

You just need to be methodical and work out what will work with your setup. When you look at some of the images on that no eq challenge thread where members use altaz mounts the key commonality is that they took lots of images and combined them. Do any of your friends/family have a windows pc. You could put all your images on a sd card (probably already are on the camera card) and use their PC to use DSS or keep searching to find a suitable free MAC solution. Don't give up just get resourcefull.

[dph1nm]

3 hours ago, Herzy said:

So I should take multiple short exposures and stack them via GIMP? I am very broke atm so it's just discouraging when people keep saying that I need this and that to get good results. I'll keep at it, thanks for all the help!!

Yes, I started off this way and GIMP is fine, if a little tedious if you want to stack 50 images by hand!  Calibration is trickier as you should really do this with unprocessed raw files. The  GIMP mainstream 2.8 release only works in 8-bit colour space, which can causes problems if you start dividing by flat fields, but there is a trial version 2.9 32-bit release. There are some limited astro tools for GIMP 2.8:  http://registry.gimp.org/node/2352

NigelM

[wornish]

Deep Sky Stacker is free but it only runs on windows.

But......

You can run it on a MAC if you use Wineskin as a wrapper.  Wineskin is also free.

Here is a great link that fixed it for me.

http://blog.tom-goetz.org/2013/01/running-deepskystacker-for-windows-on.html