Canon lens

[kirkster501]

Hi all,

Been playing with wide field on top of my main rig.  Using Canon 50mm nifty-fifty but looking at maybe a better telephoto to get the likes of the whole of Orion on frame.  What should I be looking at pale to go onto a Canon 450D?  Or maybe a canon fit Samyang or soemthing like that?

[RichM63]

There are a lot of lens choices, but it depends mostly on budget for the project.

[Dr_Ju_ju]

Have a look for Asahi Pentax Super Takumar lenses on eBay etc...  They are older, but excellent value for money, you'll just need to factor in an adaptor, which also means they are manual only, i.e. no auto focus, aperture etc...

[RichLD]

Do you want the whole constellation in the frame or just M42 etc? The 50mm should be about perfect for the constellation, if you want a good un look at Samyang, as they have aspherical elements with very good coma control and sharpness wide open.

Also, as a general rule try to use a lens with flourite or ed elements to avoid CA. Something like an old manual Nikkor ED180 (with adapter) would be an excellent choice for the whole of Orion's sword, for example. They come up on fleabay every now and again for £200ish.

Finally, I recommend using an aperture mask rather than stopping the lens down to avoid diffraction artefacts on bright stars - step down rings are a very effective and cheap way of achieving this.

HTH

Rich

[SteveNickolls]

Hi,

This is a fine reference source when considering good potential lenses-http://www.astropix.com/html/i_astrop/lenses.html

And https://www.lenstip.com/lenses_reviews.html do a number of lens reviews to help you in the decision making before you buy new or second hand. I've found mpb a good source of pre-loved lenses- https://www.mpb.com/en-uk/used-equipment/used-photo-and-video/used-lenses/used-canon-fit-lenses/.

Cheers,
Steve

[michael.h.f.wilkinson]

I use a 200mm F/2.8 on my EOS 550D to good effect on a fairly wide view of Orion, capturing the region from Horse Head to M42. I plan to use my 50 mm and an old 85mm F/1.4 Zeiss  lens for wider shots.

 

[Alien 13]

As said without knowing a few more details its hard to be specific, I would start by using the FOV simulator on this site under Resources > Astronomy tools to give an idea of the focal length you are interested in.

The Samyang range has some excellent widefield lenses and of course the impressive 135 mm f/2, there is also the Canon L range like the 200 mm f/2.8 and even the 70-200 mm f/4 which is good even wide open and relatively "cheap" if buying used.

Alan

[kirkster501]

Thanks for your thoughts on this guys!