acceptable storage conditions

[sulla]

Dear all!

What are acceptable storage conditions for lenses in terms of temperature / humidity?
Is it safe to store equipment, lenses in particular, at 20-25°C and 60-68% relative humidity without having to fear fungus in the long term?

Canon usually do not specify storage conditions, just operating conditions (http://cpn.canon-europe.com/content/education/infobank/care_and_maintenance/camera_and_lens_care.do), and recommendations in certain websites indicate "half maximum operating humidity", which seems not well substantiated. For Canon gear, maximum operating humidity is quoted at 85%, and this simple recommendation leads to very dry storage conditions of maximally 42% relative humidity, which is unrealistically dry for a common house (at least in continental Europe).

Thanks,
Sulla

 

[GammyKnee]

I researched this in the past given that I live in an area (west coast of Scotland) that frequently has high relative humidity.

The guide that most people seem to trust and reference comes from Zeiss. Here's a link to their UK page on fungus prevention: https://www.zeiss.co.uk/camera-lenses/service/content/fungus-on-lenses.html

FWIW my cheapskate solution is this: large air-tight tupperware boxes with self-indicating silica gel in perforated nylon drawstring bags. From what I've read, the silica gel (while in a fresh state and in sufficient quantity) will keep the humidity down below 60%, but should never be able to do better than 50%, which puts it in the Zeiss "safe" range. The silica gel I use (bought cheaply in quantity from eBay) is orange when dry and turns green when saturated.

Any time I'm changing lenses and I notice the orange color fading, I just unpack the gel, give it 3-4 minutes in the microwave at 50% power and it's good to go again once cool. I've been doing this for eight years and haven't had a problem so far. (Damn, I shouldn't have said that, probably put a hex on my lenses now )

Note: I also use the same silica gel bags in my camera bags, recharging them as necessary so even lenses that are in regular use don't experience long periods of fungus-friendly conditions.

 

[sulla]

Thanks. That looks great!