Canon Lens suitable for Astro Photography?

[Dennis G]

Can some kind member comment and advise on the Canon lens used for piggy back camera on the scope.
The lens in question is:
Canon EF 75-300 mm full frame auto /manual focus no image stablisation.
I'm using a 35/50mm lens with success but would like a higher mag. This then begs the question: is a zoom lens suitable for astro photography?
Dennis G

[bojan]

Try & see

[Octane (Humayun)]

Be prepared for loads of chromatic aberration (blue halos). It's not going to perform no matter how critical your focus or aperture.

H

[ZeroID (Brent)]

From what I hear Zoom lenses are less suitable than primes due to having more glass elements inside and therefore the possibility of more spurious reflections etc. All that being said Canon make some of the best glass around ( and I am a Minolta fan ) and modern lenses are pretty damn good.
When I get my EQ6 setup going I'll be trying with my Minolta 70-300 on the Dynax 7D to see if that works.
As bojan says, try it and see, what have you got to lose ?
So many options, so much fun .. !!

[graphworlok (James)]

I had the same issue myself recently - EOS40D, and i was not happy with the 18-55mm IS lense that came with the camera for assorted reasons (Hard to take flats, not optimal at any focal length, etc) - I ended up buying a second hand Pentax Takumar lense (135mm) from ebay for $70 - The sale also came with an SLR pentax (i didnt want, and didnt want to pay shipping for) as well as a broken 50mm lense, both prime. I bought an adaptor for quite cheap, and probably paid too much for the lense. Most APO/ED lenses will probably cost as much as a small APO/ED telescope. If you look down a few posts you should see my "new toys" post complete with some example images i shot with the Takumar, and also with a 2x teleconverter attached.

[Merlin66 (Ken)]

Old Zuiko telelenses with an adaptor (and a UV filter!) work well.
In the UK the 50mm f1.8 (Niffy Fifty) and the 85mm f1.8 EF seem to be very popular. I've seen some great wide angle spectroscope shots with the 85mm.

[Dennis G]

Thanks to all who replied to my question re Canon zoom for photography.
I got the message and will not purchase it. Might try for 50 to ? on ebay. It's great to have the support of knowledgeable folk via IIS.
Dennis G

[mswhin63 (Malcolm)]

All the image from the link to the end are done with the EF75 - 300mm but I used F8 in most cases

http://www.waelect.com.au/mswhin63/D..._02_02_LMC.png

Using the lower F-stop caused a lot of blue fringing. I am still using it though.

[mswhin63 (Malcolm)]

Somehow the link is not posting correctly, the link is correct but supposed to show 2 previous images first.

[midnight (Darrin)]

I quite like my EF50mm F1.4 lense. A cost effective lense, light and nice and sharp.

Downside, no zoom capability but I believe it is great for piggypack. I am rebuilding my old LXD55 and hope to get some wide fields in the next few weeks.

Cheers,
Darrin...

[ZeroID (Brent)]

I'm going to make an adapter to fit my NexImage to the back of the 70-300 KM lens and see how that works. I'll watch out for a 135 prime if the first experiment works ok. One way of building a cheap finder/ guide/imaging scope if the glass is good.