• Welcome to Orpington Astronomical Society.
 

News:

New version SMF 2.1.4 installed. You may need to clear cookies and login again...

Main Menu

First attempt at starfields

Started by Kenny, Dec 26, 2014, 17:36:42

Previous topic - Next topic

0 Members and 2 Guests are viewing this topic.

Kenny

A couple more shots from Christmas day's astrophotography experiment at Otford. Canon 450D again. Sigma DC 18-200mm lens. These were quick trial shots so I didn't play around with the settings much.

Cygnus and Lyra (25/12/2014 18:19, Otford. 18mm, f/5.6, 30 sec, ISO-1600)


Taurus and M45 Pleiades (25/12/2014 17:57, Otford. 48mm, f/5, 10 sec, ISO-1600)

MarkH

They're pretty good Kenny, shows the light pollution of London when looking west. How did you trigger the shutter ?

Kenny

Quote from: MarkH on Dec 26, 2014, 18:15:50
They're pretty good Kenny, shows the light pollution of London when looking west. How did you trigger the shutter ?

Capture details above the pics.

Kenny

Cygnus and Lyra were descending towards the western horizon but even the North Downs to the northwest of Otford hiding London couldn't shield the glow.

MarkH

Duncan showed me a good trick with the canon ... in settings you can lock the mirror in the up position between exposures which cuts down on vibration.

Kenny

Ooh, thanks. That's useful to know. Where in the menu is that?

I was manually pressing the shutter release with 2 second delay to give me time to let go of the camera and for it to stop moving. About to invest in a remote control. But keeping the shutter open will help more.

MarkH

Oh bugger the battery on my camera has gone dead. I think it was under settings, exposure, also the use of an intervalometer is useful as you can pre programe your exposures.

The Thing

Nice photos, even a hint of the Milky Way!

Mirror lockup is on the Custom Function menu. An intervalometer is a tenner on ebay, also doubles as a remote release. Both help avoid camera shake.

Kenny

Another go last night. Still single frames (stacking is another story / challenge).

Orion and Canis Major from Otford. Canon EOS 450D. 18mm, f/3.5, 15 seconds. 28th Dec 2014, around 1am!

Original is here

p.s. I found the mirror lock setting. Plus the Long Exposure and High ISO Noise Reduction settings.

Fay

Getting a lot better Kenny!

Do you go down to Otford specially? I thought you lived around the corner to me

Fay
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

julian


MarkS

Very nice hunter and dog!

The full size version even shows colour in the Orion Nebula.  However it also shows the stars to be distorted across the whole field, even in the centre of the frame.  It looks to me like coma.  It might indicate a problem with the lens itself or the way it is mounted on your camera. 

Mark

Kenny

Quote from: Fay on Dec 28, 2014, 14:51:05
Do you go down to Otford specially? I thought you lived around the corner to me

Yes and yes. It's not dark enough in my back garden and the house, trees, streetlights block the southern horizon.

Quote from: MarkS on Dec 28, 2014, 15:04:48
The full size version even shows colour in the Orion Nebula.  However it also shows the stars to be distorted across the whole field, even in the centre of the frame.  It looks to me like coma.  It might indicate a problem with the lens itself or the way it is mounted on your camera. 

Noted. I've seen that as well. Will add to my list of things to look into. Worth comparing the Nikon with the Canon kit lens.
p.s. could it be a focus problem?


MarkS

Quote from: Kenny
Noted. I've seen that as well. Will add to my list of things to look into. Worth comparing the Nikon with the Canon kit lens.
p.s. could it be a focus problem?

Focusing might or might not improve things slightly.  Defocused stars in the centre of the field should look "blobby" but not distorted.

Mark

Kenny

I've just read that inceasing the aperture a couple of stops from its lowest value can help reduce coma. Is that something you've seen?