Help with Canon IS Binoculars

I am interested in the Canon IS system to use in LP skies while observing from my home.

I had a look thru Canon 18x50 IS and was impressed but found them quite heavy.

The 15x50 IS version does not appear much lighter.

What about the 12x36 or 10x30 IS or any suggestions?
Should I just get the 18x50 IS (used pair) since better magnification and smaller exit pupil.

thanks in advance for any insight/advice.

howard

I have the IS 10x30's. They cannot be compared with similarly-sized non-IS binoculars; since the image shake is eliminated, they will show you fainter stars than you would ordinarily be able to see with traditional hand-helds. They are quite small and lightweight, the images are razor-sharp, and make a wonderful "quick look" pair of binoculars. I always pack them when I travel, and I recommend them highly.

I have used the 10x30s and own the 12x36 IIs. They are quite light, and the IS system works very well. The 15x50s or 18x50s would certainly show you more, at the expense of field of view and extra weight. Since I use mine also for birding, I did not want the weight. You will also find the larger sizes are considerably more expensive.

You can compare bincoular performance on the night sky by simply multiplying the magnification by the aperture, giving Bishop's "Visibility Factor." Adler thinks magnification should be given more weight, and multiplies magnification by the square root of the aperture. In either case, increasing aperture or increasing magnification increases what you can see in the night sky.

In some cases, you might want to give some weight to true field of view. A 7 or 8 degree field is not something you can get with a telescope.

Clear skies, Alan

I have both the 10x30 and 15x50. I think the
10x30 is alot more fun -- much lighter and
easier to hold. The 15x50 is more work to
use -- even with the IS running you still have
to hold them relatively still for optimal
viewing, and this gets more difficult after a
couple minutes when your arms start to shake
from the weight. (Maybe other people have
different experience....)
There is probably a reason why the 15x50
has a tripod socket but the 10x30 does not.

thanks for all the great advice ... still can't decide ... probably need at least two pairs after reading this thread!

howard

I have a pair of 18x50IS...love them..the weight and slightly reduced FOV is an insignificant tradoff for me given the additional magification and potentency in such a compact package (this is where the IS technology really struts its stuff).....initially tried the 15x50's but after giving the 18x50s a go, the smaller amplification is a disappointment...