The light meter. It's only a lithium battery, and I've never had to change it, so it's not really something that needs thinking about. A good point though, since the light meter I passed you doesn't use batteries.
Without knowing too precisely how light meters work, the old one must be using a photocell to directly drive the needle, which can then overload. Presumably photocells don't respond linearly? augeas's comment makes me think that it could change performance due to age as well.
Presumably on my SLR, the photocell is just used as the input to a battery powered amplifier. Or some such excuse.
Then again, maybe it will just use it as a self defense mechanism against errant users.
![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
timeasmymeasure
Re: Or...
Date: 2003-06-03 07:22 am (UTC)Without knowing too precisely how light meters work, the old one must be using a photocell to directly drive the needle, which can then overload. Presumably photocells don't respond linearly?
Presumably on my SLR, the photocell is just used as the input to a battery powered amplifier. Or some such excuse.
Then again, maybe it will just use it as a self defense mechanism against errant users.