Free Shipping on ALL Products
camera reviewsbest cameraslens reviewsphotography tipscamera forumvideo toursphotography bookssupport me
It is currently Fri Dec 19, 2014 3:29 pm

All times are UTC




Post new topic Reply to topic  [ 12 posts ] 
Author Message
PostPosted: Sat Nov 01, 2008 5:22 pm 
Offline

Joined: Sat Oct 11, 2008 8:27 pm
Posts: 404
Location: Bristol, UK
Last night I broke out the camera again and was having a play with my fifty on it.

These shots are taken from almost overhead (don't know what constellation or part of its showing, sorry) And I have done two conversions. I don't really know what Im doing with these hence the differences.

Both shots are 145 x 5 sec exposures combined in Deep Sky Stacker, then tweaked in PS.

Can anyone comment on the 'ball' that has appeared on the first image? Is is a result of over-manipulation?


Number 1

Image

Number 2

Image

Any general comments always welcomed.

_________________
Lee Diggle
My Astronomy Blog | My Photography Gallery


Top
 Profile  
 
 Post subject:
PostPosted: Sat Nov 01, 2008 5:49 pm 
Hi
They're really good, could that light, have been from light, entering the viewfinder, on one of the shots? Also, am a newb to astrophotography, but would i be right in thinking you just take one image, or combine several, like a HDR?
Thanks


Top
  
 
 Post subject:
PostPosted: Sat Nov 01, 2008 5:58 pm 
Offline

Joined: Sat Oct 11, 2008 8:27 pm
Posts: 404
Location: Bristol, UK
Hi Ed,

These shots are made up from 145 frames each 5 seconds long. Each frame is then combined in Deep Sky Stacker to resolve more detail. DSS calculates star positions then uses these to stack the frames exactly on ontop of the other. The other option is to use something like startrails which just adds the frames together giving streaks across the frame.

You could be right about light entering from the viewfinder as I did not close this off.

_________________
Lee Diggle
My Astronomy Blog | My Photography Gallery


Top
 Profile  
 
 Post subject:
PostPosted: Sat Nov 01, 2008 6:03 pm 
Digz wrote:
145 frames each 5 seconds long.
:shock:

Ok thanks, i understand now, with my 40D, on the strap, there is a piece, of rubber which fits over the viewfinder, once you have taken the eyecup
off!


Top
  
 
 Post subject:
PostPosted: Sun Nov 02, 2008 10:49 am 
Offline

Joined: Sat Oct 11, 2008 8:27 pm
Posts: 404
Location: Bristol, UK
Now thats ingenius! With my camera there is a plastic slide that you can put over the eyepiece, which Ive put in a really safe place, if you know what I mean!!!

_________________
Lee Diggle
My Astronomy Blog | My Photography Gallery


Top
 Profile  
 
 Post subject:
PostPosted: Sun Nov 02, 2008 11:02 am 
Offline
User avatar

Joined: Fri Oct 24, 2008 8:08 pm
Posts: 1626
Location: New York, US
I guess that's why higher end cameras have the switch you can flip that moves a shade over the viewfinder.

_________________
Image


Top
 Profile  
 
 Post subject:
PostPosted: Sun Nov 02, 2008 11:50 am 
yeh, slthough it might get kinda annoying if you dont use the viewfinder curtain that often, and keep flicking it down. I have never actually had to use my rubber thing, which fit onto the viewfinder!


Top
  
 
 Post subject:
PostPosted: Sun Nov 02, 2008 12:05 pm 
Offline
Moderator
User avatar

Joined: Sat Sep 30, 2006 4:30 pm
Posts: 9833
Location: UK
Hi Digz,

So where was the Milky Way during this shot? I think you'll see a huge difference when you get that tracking mount or similar. You'll be able to use significantly longer exposure times and then your problem is more likely to be filtering out sky glow from the local street lighting rather than trying to pull in nebulosity from the sensor's own noise levels.

Bob.

_________________
Olympus OM-D E-M1 + M.Zuiko Digital ED 12-40mm f/2.8, Lumix 7-14mm f/4, Leica DG Summilux 15mm f/1.7 ASPH, M.Zuiko Digital 45mm 1:1.8, M.Zuiko Digital ED 75mm 1:1.8.
Leica D Vario-Elmar 14mm-150mm f/3.5 - f/5.6 ASPH.
OM-D E-M5, H-PS14042E, Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Nov 02, 2008 3:02 pm 
Offline

Joined: Sat Oct 11, 2008 8:27 pm
Posts: 404
Location: Bristol, UK
Hi Bob,

Thanks for the input. I think the Milky Way might have been out of shot on this, although I couldn't be 100% sure. I was pointing the camera NE and almost overhead. I think I need to learn my away around the stars a bit better so I can be more precise, sorry.

_________________
Lee Diggle
My Astronomy Blog | My Photography Gallery


Top
 Profile  
 
 Post subject:
PostPosted: Sun Nov 02, 2008 4:22 pm 
Offline

Joined: Sat Oct 11, 2008 8:27 pm
Posts: 404
Location: Bristol, UK
Ok here are two more images taken the same night but this time pointed roughly towards M31 (I hope I got this right.)

Again I did two conversions and the same ball of light became apparent which does lead me to believe it is light entering through the eyepiece.

Image

Image

These are 20 x 5sec images stacked in DSS. Can anyone tell me what the object is to the bottom right? It looks like the beginnings of another galaxy or is it distortion from the edge of my lens?

_________________
Lee Diggle
My Astronomy Blog | My Photography Gallery


Top
 Profile  
 
 Post subject:
PostPosted: Mon Nov 03, 2008 8:00 pm 
Offline
Site Admin
User avatar

Joined: Tue Nov 08, 2005 3:32 pm
Posts: 9975
Location: Queenstown, New Zealand
You'd need to tell us the focal lenght of your lens to give an idea of the field of view in your image (and if it's cropped), but yes, at first glance it looks like M31. It's a really bright Galaxy from our location, and can popup in lots of wide photos of the night sky - see the last two images in this gallery!

http://www.cameralabs.com/reviews/Canon5D/page5.shtml


Top
 Profile  
 
 Post subject:
PostPosted: Tue Nov 04, 2008 8:07 am 
Offline

Joined: Sat Oct 11, 2008 8:27 pm
Posts: 404
Location: Bristol, UK
Sorry Gordon, should have said that these were taken at 50mm and I was trying to aim at M31 and its uncropped :-)

_________________
Lee Diggle
My Astronomy Blog | My Photography Gallery


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  

All words, images, videos and layout, copyright 2005-2012 Gordon Laing. May not be used without permission.
/ How we test / Best Cameras / Advertising / Camera reviews / Supporting Camera Labs

Webdesign by Alphabase IT
Powered by phpBB® Forum Software © phpBB Group