Hello guys. I sold my astrophotography equipment as i simply don't have enough free time in recent years but decided to buy good binocular for occasional look at the night sky. The new ED series from Celestron caught my attention and i bought the 15x70 Pro ED. Binocular arrived yesterday and i managed to perform some tests when i got back home from work. I only had time to take two quick pictures of the binocular itself to send to friend but tonight i will take some more and will add these to the album. I will also try to take picture with my phone through the binocular so that you can judge yourself the quality of the optics but i am not sure if this will work as i don't have phone adapter and will have to hold my phone with hand.
All comparisons of image quality are with my old Nikon Action 12x50 (non EX version) as i don't have any other binocular and also haven't looked through any in the recent years (my focus for years was astrophotography).
Pictures - https://photos.app.g...RRdfgfWMLs8QqF6
First impressons:
1. Build quality
Definitely binocular looks good. Nice rubber cover which makes it pleasant to touch and easy to get good grip. Eyepiece cups are smooth as well as the dioptric adjustment of the right eyepiece. Dioptric adjustment is separated well from the eyecup adjustment so that it is hard to accidentally move it while observing. The only thing that is not top notch according to me is the focuser. It has a little more resistance than i would like and it is more pronounced in one direction than the other. I am not sure if it is design choice or slight quality control issue but in any case it doesn't prevent accurate and stable focus in any way.
2. Design
There are some design choices which may not be good for everybody. First are the eyepieces. They are quite big due to the 1.25" filter threads and big eyecups. I definitely like the abilty to easily use filters and the AFOV of the eyepieces is bigger than the one on my old Nikon which i also appreciate. What i don't like is that due to the big eyepieces there is quite small place to put your nose between them which in turn makes the correct positioning of your eyes more difficult. And my nose is quite normal in size. My interpupil distance is 67, 68mm which is also average. Eye relief is listed as 16mm so considering that i don't wear glasses means that i expected to be able to use the eyecups fully extended. For some reason though i need to almost fully retract the eyecups to be able to see whole FOV properly. Good news is that even in such configuration adding astronomik uhc-e 1.25" filters on both eyepieces i still manage to see the whole FOV.
3. Optics quality
I am really happy with the optics quality. Coatings on the lenses are the classic Celestron violet XLT ones. I tested with the flashlight of my phone directly pointed on the lens in dark room and there are almost no reflections. Internally baffles also are very well made and i don't see any shiny parts. Exit pupil is perfectly circular and prisms are definitely BAK-4 as per specifications. Exit pupil size is 4.4mm (as per specifications) and effective aperture is 66mm (measured the circle exiting the lens when flashlight is pointed in the eyepiece).
For the daylight tests i was looking for case causing extreme purple fringing (for example white directly sunlit surface with blue sky for background). In such cases you can see slight purple chromatic aberration but is definitely much much better than my nikon action 12x50. On non extreme cases i couldn't see chromatic aberration in the center. Field of view is very good till around 70% and between 70% and 85% it is also usable as the field curvature is main problem there (slight refocusing helps). The extreme 15% of the FOV are affected by other aberrations (most probably coma but a proper night time test will need to be performed for this to be confirmed). Generally situation is much improved compared with my old Nikon. On the Nikon 50% of the FOV are good with good sharpness but after that image degrades quite quickly and refocusing doesn't help. Generally i really like the sharpness, color and correction of most of the FOV.
Proper night time testing was not possible yesterday as i had both thin clouds and almost full moon. Look of the moon through some gaps in the clouds (and in some cases through the thin clouds themselves) was good and i am eager to see what the binocular can do under clear and dark sky.
