A quick trawl of the internet reveals many opinions on the subject of lens cleaning. There are lots of products too...
I wonder what recommendations people have for keeping bins in tip-top condition?
Thanks in advance
Hi Blues,
First advice is don't touch! Imo, more binocs are wrecked by loving care than by neglect.
Binoculars have spectacularly complex coatings, some close to 100 layers, so they are sensitive and even the most dedicated manufacturer cannot create a miracle coating able to withstand assiduous polishing.
So easy does it, turn them upside down and use a photographer bulb and brush to help any loose bits to drop off.
Even if there are sufficient residues on the lenses to be a bother, careful washing with a bit of soap under cool running water works for waterproof glasses is my limit. Some swear by Residual Oil Remover for non waterproof optics, but in all cases use clean, not recycled, lens tissue or cloth to dry. Do not polish unless you want to leave swirls on the surfaces.
That said, there are many rugged birders who simply breathe on their lens surfaces and polish with their shirt tail without obvious distress. Other threads on this site showed some of the optics used by professional birders that looked to have been used to drive fence posts. So clearly a good glass will take a lot of abuse, but why not treat it with respect.
Hi Blues,
etudiant has a lot of good point and I can only agree with his statement "more binocs are wrecked by loving care than by neglect"
but on the other hand, dirty lenses can easily reduce the transmission by 20% and have a strong negative influence on image quality. We tend to suggest people remove the eyecups and hold the lenses under plentiful gently running water. After a few seconds, you can use your finger to gently sweep away residual dirt on the lenses. Wash the eyecups out under the faucet. Dry the lenses with a clean microfibre cloth.
Most of the top binocular manufaturers have external coatings that make cleaning your lenses much easier. Underneath this, Swaro bins have Swarodur - a very tough antireflexion coating highly resistant to scratching. While the Swarodur might hold up, rubbing sand in to your lenses is definitely not going to do good things to the Swaroclean (sorry for the brand-ness, but because of my affiliation if I am to talk of specifics then I can only say something useful about Swarovski).
The other cleaning trick I use in the field is to simply lick the dirt off the lenses. The enzymes in the saliva are really good at getting even the most stubbornly stuck stuff off the lenses. Dry off with a clean microfibre cloth. Sometimes the lenses taste like crisps. Bonus.
Kind regards,
Dale