Jump to content

Canada's top-tier Telescopes & Accessories
Be as specific as possible when reporting issues and *ALWAYS* include the full version number of the application you are using and your exact *CAMERA MODEL*
  • 0

Lens suggestions for Canon 40D - multiple choices



Hi Guys,

Many years ago I spent much time with modded Canon 40Ds with BYE on SCTs and Refractors, then I switched to ZWO cameras.  Recently I thought my mount has plenty of carrying capacity so I decided to re-mount my 40D on top of my main SCT with a 30 - 70mm Canon lens (first time I will have ever used it not connected to an OTA)!  I have decent a range of Canon lens I  can attach to the camera, of varying focal length - I simply wondered if any folk could offer a suggestion as which to use.  I am not really sure what I expect it to do as I often image dim targets from my astro-lab .  But I guess I wanted to see what a wider field shot actually looks like thru a Canon camera lens.

Any advice on what lens / targets / image durations make for good choices would be much appreciated - as its strange to find after a decade I am trying something with astro-imaging!

Many thanks,



Link to comment
Share on other sites

  • Answers 2
  • Created
  • Last Reply

Top Posters For This Question

Top Posters For This Question

2 answers to this question

Recommended Posts

  • 0

Well, the Milky Way likes really wide angles, such as 11 - 14mm. The Orion molecular cloud complex (HorseHead, Flame, etc) wants a little narrower. Your 70mm might be good for that. I've gotten some nice shots of M51 and M101 with a 400L.


Link to comment
Share on other sites

  • 0

If you are AutoGuiding, you should have all the time in the world for your exposures.  If not, the 70mm will likely show minor Star Trailing after about 45-60 seconds piggybacked on your SCT.  That should be decent Exposure Time for any Target...

If you have a Choice, try one of your Prime Lens - they are usually easier to set and maintain Focus AND likely to have fewer Aberrations (that last depends on Price Category of Lens of course).

For a pleasant surprise, try your 50mm f/1.8 (if you have one).  They don't call them "Nifty Fifty" for nothing...


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

This site uses cookies to offer your a better browsing experience. You can adjust your cookie settings. By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to the use of cookies, our Privacy Policy, and our Terms of Use