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Originally Posted by chris lewis
Hi ! the question I would ask is why did you decided on the 9x63 mm variety ?The 9x63's have a 7mm exit pupil [similar to 7x50's] and with age the ability for the pupil to dilate decreases from about 7-8 mm at age 20 to about 4-5mm at age 50. [There are variarions to this]. If your pupil does not dilate in the dark to 6-7 mm then you are effectively loseing light - if your pupils dilate to say 'only' 5.5 mm it would be similar to to you using a 9x50mm binocular. [approx].The other issue with 9x63 mm binoculars is that they are best used under dark skies [mag 5.5 - 6 + ] - in moonlight or under semi suburban light polluted skies [mag 4.5-5.5] they will magnify the bright background skyglow and this can result in a 'washed out' appearance. Binos with large exit pupils are designed for maximum brightness and for use on faint extended objects like arms in galaxies, comet tails and nebulae etc. I have the Meade 9x63's - these are 'reasonable' binoculars - the main concern is that they are only 'Multi Coated' [the Orions are 'F.M.C'. which is desirable in Astro binos]. On axis stars are sharp with deterioration from about 80 % out. The Meades with 'only multi coatings' gives a moderate amount of noticable internal reflections / secondary 'ghostings' - esp. on brighter objects - this is also very noticable with lunar viewing. [Hence the need again for dark skies]. F.M.C. coatings improve light transmission, reduce internal reflections and also and give better color fidelity. The other concern with the Meades is that the quality control is variable - make sure they are well collimated and the build quality is sound. Make sure of your return policies with the company is good - Bintel is excellent. [Read the review on the Meades in Ice in space which I posted some time back]. One other point with 9x63 binos is that the Afov is not particularly wide - the Meades are 5.8* FOV which gives a 52.2 Afov - this is reasonably 'narrow'. The Orions have even less FOV at 5 degress - which results in a Afov of 45 degress which IS 'narrow' - it is important to know that these binos do not give 'wide view' images by any strech of the imagination. You may find this 'restrictive'. [A 65 * plus Afov - is considered 'wide' viewing]. I have not used the Orions so cannot comment on their performance - but by the various reviews they are do appear 'superior' to the Meades - esp. with the FMC lens and in the build quality. $150 worth of superior benefit ? - hard to say with out a side by side comparison. So in summary - if you are 'young' / and or have pupils that dilate to 6-7mm in the dark and you are viewing from a very dark situation - yes get the 9x63's. If you have light polluted skies or pupils that do not dilate sufficently then do not buy them - you are wasting aperture and you might as well buy some high quality 10x50's which will also give you a wider Afov ie. 70 * which will be more helpful if you are a novice. Hope this is helpful and not confusing !
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Thanks for the reply was very in-depth and thorough. I do understand what you mean with narrow fov and exit pupil. I'm 24 years old and most people have said at my age they'd dilate to 7mm, hence the reason why was looking for 9x63. Also i thought since the 9x63 have higher magnification and greater aperature than the 7x50's why not?
What would be then your advice? Which binoculars should I buy if not from those two which other? One with wider fov?
Sorry if I seem to be asking many questions but I'd rather listen to those who are experienced then to dive in myself. Thanks
