Go Back   IceInSpace > Equipment > Astrophotography and Imaging Equipment and Discussions

Reply
 
Thread Tools Rate Thread
  #1  
Old 20-03-2012, 06:35 AM
cybereye's Avatar
cybereye (Mario)
Mozzies love me!

cybereye is offline
 
Join Date: Aug 2009
Location: Brisbane
Posts: 1,277
A question on eyepiece projection & resolution

Good morning!

I have a question on just how much resolution I can expect from my current planetary imaging setup. To set up the question, I'll firstly go through how I understand some of the basics.

I have an 8" reflector with a focal length of 1200mm. As I understand it, the maximum useful magnification I will get from my scope is 400x. Now using a 10mm eyepiece I have a magnification of 120x and if I add my 2x Barlow into the mix my magnification is now 240x which is still well below the theoretical 400x that I spoke about before.

However when I take an image using eyepiece projection onto the chip of my QHY5V, I calculate from my plate scale that I'm working my scope as though it has a focal length of about 6400mm. So my question is:

Does that mean my magnification is 640x and I've gone way past my theoretical limit of magnification for my scope? Or am I OK and I can use a 3x Barlow to give me more detail (this being 360x magnification)?

Obviously I haven't taken seeing into consideration but I'll keep that out of the equations for the time-being!!

Thanks in advance for any help people might be able to give me on this,

Cheers,
Mario
Reply With Quote
  #2  
Old 20-03-2012, 09:45 AM
bojan's Avatar
bojan
amateur

bojan is offline
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 6,932
Magnification is meaningful only when you observe something visually.
Than the magnification (this is a number without dimension) indicates how larger the viewing angle is - for example, Moon has apparent diameter of 0.5° on the sky .
If your telescope has magnification 100x, the Moon will be seen through the eyepiece with apparent diameter of 50°.

When taking photographs, we are dealing with the scale: arcsec/pixel for example.
Your estimate of FL (6400mm) and you pixel size will give you the scale of your camera system.
Assuming pixel size is 5.7u, you have 0.36 arcsec/pixel

Last edited by bojan; 20-03-2012 at 10:34 AM.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 06:10 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement