Pentax 1/21 Spotmeter lens cap

[Noah B]

I recently picked one of these up for next to nothing and I thought I'd give it a try. Unfortunately it doesn't have a lens cap, and since this model is always on I need to get one before I put fresh batteries in. I've did some searching but haven't found out what lens cap diameter this one takes. Any help is appreciated, thanks!

[Doremus Scudder]

Why do you need a lens cap? A meter is not a camera; the lens will work fine enough for metering purposes even if it has a scratch or two. Plus, when you have a cap on, you have to take it off to use the meter. Why not just keep it "ready to rumble" all the time and save yourself a few seconds when metering. If the lens gets dusty, just clean it with one of those microfiber cloths used for cleaning eyeglasses.

I have three Pentax meters; none of them go into the field with a lens cap on them.

Best,

Doremus

[Noah B]

This particular meter doesn't have an off switch, so if there's no lens cap on it will be reading light and draining the battery. I need to know what diameter lens cap this takes so I can save on battery life.

[Regular Rod]

This particular meter doesn't have an off switch, so if there's no lens cap on it will be reading light and draining the battery. I need to know what diameter lens cap this takes so I can save on battery life.

Yes it will go flat quite quickly!

48mm

I made my own out of cardboard, black gaffer tape over a lining of black self adhesive light seal cut into a strip.




RR

[Jac@stafford.net]

Every serious photographer should have at least a metric ruler, or better - a dial caliper; an inexpensive one will suffice. A non-dial caliper can be had for as little as $3.

[wombat2go]

I just restored the early model Honeywell Pentax 3/21. I re-did the electronics to allow it to use a single common 9V battery.
This model had/has a 2 stage switch, and battery is isolated when not pressed

[Noah B]

Wombat,

That's a cool upgrade, do you think it could work with the 1/21? I'm going to have to fix up the meter I got, the terminals are corroded which won't be too difficult. I recently repaired a Mamiya RB67 metered prism that had corroded terminals and now it's working perfectly.

[Noah B]

Hi Rod, thanks for the info! Is that 48mm for a push on or snap in?

Yes it will go flat quite quickly!

48mm

I made my own out of cardboard, black gaffer tape over a lining of black self adhesive light seal cut into a strip.




RR

[Regular Rod]

Hi Rod, thanks for the info! Is that 48mm for a push on or snap in?

Push on.

RR

[wombat2go]

Hi Noah,
I put a thread on apug > Repairs and Mods, with the details of the 3/21 refurbishment