Comparison 15 x 70mm 20 x 80mm

[mdstuart]

Good evening

After enjoying my Celestron 15 by 70mm for many months I now have some Revelation 20 by 80mm to compare with.

The 80mm are much larger and heavier. You might think an extra 10mm will not make much difference..well let me tell you the 15 by 70mm feel like toys compared to the 20 by 80mm...

Certainly the 15 by 70mm are the largest you could hold by hand for any length of time as has been said on many of the reviews..

The coating on the 80mm which is green seems much better than the purple 70mm coatign as it reflects much less light when held up in a room.

I expected a much smaller FOV..It is smaller but the view is about four moon widths so it still feels reasonable when compared to low power on the 10 inch dob!

I did have a fiddle with the collimation to get it spot on. This was pretty easy using the hidden screws after reading a collimation explanation on cloudy nights.

Great so far..

More to follow after the next clear night!

Mark

[lunator]

Mark

look forward to hearing about the comparison

Cheers

Ian

[kidlands]

Thanks Mark

I was thinking of upgrading to 20x80's and that has helped, looking foreward to your report.

steve

[southernman]

I have a set of 20 x 80 (konus) that I have been using for some time. Compared to my other binoculars (9x 63 Meade and 10x50 nikon ) they are much harder to use hand held. The views though when mounted securely are simply staggering. Good luck with your observing

[mdstuart]

Update...

Full moon but I thought I would give the two sets of binos a work out.

The extra 5x magnification does make a noticable difference so Jupiters moons are further apart, the moon is noticably bigger, Star cluster look more resoved etc. M57 for example is much more noticable as a non stellar object. Double stars are a little further apart. Albeiro looks fab in both sets of binos! It allows more detail to be picked out but its not a huge step up.

The 80mm along with the higher mag pulls in more light. I would say about 0.5 magnitude tonight. To be fair the moon was washing everything out tonight but M31 was fine in both binos but M32 was more prominent in the 80mm.

Both sets produce stars as nice points (as long as your eyes are central to the eyepieces). Both show coma in the last 25% or so of the FOV but not too much to make an issue.

The double cluster is awaesome in the 80mm with its extra mag and light drawing power...

So the 80mm win, they are a step up but not a huge difference...

On a dark night I think I will be able to pick out those slightly fainter galaxies such as NGC 7331, 2903 278 etc...

So who wants my 15 by 70's ....£35 delivered??

Or swap for a manfrotto 222 joystick tripod head!

Regards

Mark

[matt c]

Hmmm maybe 20 + 80 bins with a good tripod are a better upgrade from 10 + 50s instead of 15 + 70s

[Mark at Beaufort]

Interesting review Mark - I knew you were going to enjoy these larger binos.

My main problem is that you got me thinking - perhaps I should upgrade my Celestron 15x70!!

See you soon.

Mark