Given to Fly
Hi Sue,Thanks that's helpful. I haven't had chance yet to try your suggestion of moving the binoculars away from my face to see if that helps as it was dark when I read your message last night and I left for work this morning before it got light, but will try your suggestion when I get home this afternoon.
Interesting your comments about the Swarovski 8x30 possibly being more forgiving. I'm seeing a friend on Monday who has the Swarovski 10x30 but I'm not sure if it's the CL or a higher model but I thought I would ask her if I could give them a try. If all things were equal I think I would prefer the x10 magnification but I'm just aware of the risk people report of them being harder to keep stable. Do people ever find they buy a x8 and wished they'd gone for the x10 and vice versa?
It's very important to get the binoculars set up correctly for you - Inter-Pupillary Distance (IPD), Eye Relief (ER), and Diopter. Sometimes you do all that as well as possible, and the ease of view for you is still not great. ie. there doesn't seem to be much margin of error in alignment before things go a bit pear-shaped ..... black spots etc. It can be down to the way the binocular fits your face /glasses, or it's just a function of the optical design. GiGi certainly likes her Nikon MHG 8x30, so issues viewing through it sound a bit odd.
This 'Optical Box' thing is a term brought over by practitioners of other hobbies (that are verboten to mention here) who like to come on over and mine the vast knowledge of the enthusiasts and BB stackers here. It simply means a greater margin of error around the Exit Pupil (EP = Objective divided by Magnification) bundle and eye positioning (ER) - and indicates a better, more forgiving optical design. Swarovski with their latest models are quite well regarded for this welcome quality to their view (however some find this also has a bit of a drawback in more visible glare. It's an individual thing that needs to be tried for yourself).
As far as 8x vs 10x goes, there are a couple of important differences. As well as a bit more magnification (which is proportional to shake), the 10x has less Field of View (Fov), a smaller EP, often less ER (which can make things critical for glasses wearers), and less Depth of Field (Dof) - this is how much distance in front of and behind the focus point remains sharp. It can mean more focus wheel twiddling for the 10x.
In bad cases, where you are already having troubles with the ease of view, then this can exacerbate getting a good view. I once had a 10x which was so critical for setting up the binocular correctly, and had such a thin Dof, that there were times when I whacked them up to my face trying to get an id from a fleeting glimpse of a rapidly disappearing bird where I swear I could see virtually nothing - like literally nothing ! I ended up sending that one back, and haven't gone back to 10x since.
In general, the extra Fov, EP, and Dof of the 8x over the 10x makes them more forgiving to use (all things being equal - such as fit to eyes etc). Unless you are doing a lot of far away viewing of birds across wetland ponds, and/or distant Swifts /Raptors etc, the 8x is more versatile to use. However - let YOUR eyes be the final arbiters ' it is very important to try before you buy.
The Swarovski 8x30 CL B should be pretty forgiving to view through for it's EP size (3.75mm), and likewise the 100 gram heavier 8x32 SV (4mm EP). As you are lucky enough not to wear glasses birding, have a look at the Leica 8x32 UVHD+ as well (ER often rules that one out for glasses wearers unfortunately).
As Dennis said, the 8x42 Nikon Monarch HG has a 5.25mm EP and is only another ~80grams heavier again. The Meopta 8x32 B1.1 Plus also gets good value raps from those who have it.
Good luck with it all :t: