Megaloblatta
Active member
I have a pair of Maven B1.2 binoculars which I rate very highly. However, when I used them in the field for the first time on a recent month long trip to Indonesia, I was annoyed to find that I kept getting the kidney bean effect, no matter how carefully I adjusted them. I worked out that I had to hold them a few mm beyond my eyebrows to stop the blacking-out, and this wasn't satisfactory as I wanted them to rest just under my eyebrows so I could better steady them. After I got back to the UK I read up about how to extend the eyecups slightly, but the solutions were not that neat. I therefore decided to buy a sheet of 5mm adhesive-backed neoprene foam and cut 'washers' to fit on the front of the eyecups. When searching for this on eBay, I found a company called T&P Supplies, UK (tpsupplies2013 on eBay) which sold pre-cut contact adhesive-backed neoprene washers in a range of sizes and thicknesses. I bought a selection of 42mm outside diameter/32mm inside diameter hard neoprene and neoprene foam washers and used one hard 2mm rubber washer with a 3mm foam washer stuck on top of it, to extend my eyepieces. The contact adhesive feels firmly stuck, but time will tell. The eyecups are now a perfect length when I rest them below my eyebrows, and there is no more kidney beaning. What's more, they are more comfortable than they were originally thanks to the upper layer of neoprene foam (the eyecups are very firm rubber). Problem solved I hope...
