First widefield-How can I improve on this ?

[heavensabove]

Hello everyone ,

This is my first humble attempt to astrophotography , armed with my new camera canon 50D and kit lens 17-85mm , I shot 4 light frames and 1 dark at 17 mm , F4 , ISO800 for 30s each of Leo and surroundings .

I stacked in DSS ( that's a learning curve in itself) , and tweaked a bit in PSPX .

As you can see , on one of the frames a very bright satellite streaked through it , which I thought was quite cool .

I am not displeased with the result , I don't think I was too far from good focus , it did take several test frames before keeping those ones though .

I realise we all have to start somewhere but how can I improve on this .

By this I mean , is there a way to make this "pop" a little more , the image looks rather flat with very little colors in the stars .

The lower right and upper left suffer from rotation but I guess I was getting pretty low towards the horizon .

Any other tips and tricks would be greatly appreciated .

Cheers

Christophe

[Demonperformer]

1 dark on its own does not help, in fact, it adds noise to the finished result. You really want to aim at 20x darks (there is a thread somewhere on here that goes into the math), also more lights would help reduce the noise.

That said, it is a good start.

[Beyond_Vision]

A good start and as DP says more light frames and dark are required. You could also reduce the exposure time down to around 20s to lessen the rotation. After stacking you will need to boost the colour saturation. If you do this in DSS set it to around 18%.

Regards

Kevin

[Psychobilly]

Excellent start...

The "kit" 18-55 needs to be stopped down quite a lot to give better stars towards the edges.. this will mean longer and/or more subs for the same overall result...

I used to use mine beteen f5.6 and f8 but I am LP limited with EF-s lenses as I cant use the inbody filters...

Peter...

[Stargazer Jack]

Nice image with a satellite in What is the thing in the bottom right corner? Cluster or something?

[heavensabove]

Thanks DP , Peter & Kevin

I will get more light and dark frames the next time round , in fact I will try to play with DSS as well . So much to learn there .

I am also planning to get a piggy back bracket to get longer exposures , are longer exposures better than multiple short ones ?

Another question I have about the bracket is , would I need some sort of guiding for widefield imaging , I would love to take some close widefield if you know what I mean using a 300mm lens .

The tracking of the LXD55 is pretty good but is pretty good good enough ?

Peter the lens I used is the 17-85 mm , does stopping down still applies to that lens ?

Stargazer Jack , the cluster on the lower right is the M44 ( beehive cluster ) in Cancer .

Many thanks again

Christophe

[Psychobilly]

Sorry my mistake...

Stopping down applies to all lenses especially zooms...you can get some idea how much you neeed to stop it down using Zoomed liveview.

Focus on a bright star using liveview with it in the center of the frame then slew move the star 3/4 of the way out towards the edge adjust the Aperture value and see how it effects star shape...

if you can piggy back the camera it will make a big difference and at the short focal length you can expect to get decent results with exposures of several mins...

I manage 4-5 mins at fl up to 50mm unguided on an EQ3-pro so far with no lost frames at 200mm I tend to drop the exposure to around 2-3 mins depending on how the first few frames are looking...

200mm will need decent tracking and probably guiding as well if you aren't going to end up throwing away a fair proportion of your subs...

Peter...

[Demonperformer]

If you are piggybacking, and want to do guiding on the cheap, you could try doing it manually through a reticle eyepiece if you have the patience.

[heavensabove]

Sorry my mistake...

Stopping down applies to all lenses especially zooms...you can get some idea how much you neeed to stop it down using Zoomed liveview.

Focus on a bright star using liveview with it in the center of the frame then slew move the star 3/4 of the way out towards the edge adjust the Aperture value and see how it effects star shape...

if you can piggy back the camera it will make a big difference and at the short focal length you can expect to get decent results with exposures of several mins...

I manage 4-5 mins at fl up to 50mm unguided on an EQ3-pro so far with no lost frames at 200mm I tend to drop the exposure to around 2-3 mins depending on how the first few frames are looking...

200mm will need decent tracking and probably guiding as well if you aren't going to end up throwing away a fair proportion of your subs...

Peter...

Cheers Peter for that , I'll try the liveview .

2 or 3 minutes at 200mm unguided is quite respectable isn't it ?

it would be interesting to see what I could get away with on the lxd55 which I recently upgraded with a homemade wooden tripod , see here :http://stargazerslounge.com/diy-astronomer/139311-been-busy.html

It may be that for Astrophotography it is not quite god enough .

We shall see ...

In any case I will need a small refractor for guiding ,which would be great for visual as well as I sometimes really crave wider views .

Over the last couple of years , I have come to realise there's no such things as a do-it-all telescope and that there's no real point trying to turn one into another .

I also have a webcam I could put to good use for that too .

Christophe