Basic exposure question

[acharrier]

My apology in advance if this question is too easy. 🙂 I'm still trying to figure out a few things.

I have an Electro that takes wonderful photos. But, the auto metering system is sketchy and unpredictable. I've found that the most reliable solution to be taking out the battery, sticking to the 1/500th default exposure, and living by the Sunny 16 rule using 400 speed film. Thanks to a little trial and error I've got a pretty good handle on what f-stop to use for various situations.

But I'd like shoot with slower flim like Kodachrome 64. So, assuming a shutter speed of 1/500th would an f-stop of 5.6 or 4 be about the same as a f-stop 16 or 11 when using 400 speed film?

Thanks very much.

 

[OldNick]

Based on the scales on my hand-held meter, it appears that f/5.6 would be about right.

Jim N.

 

[Nh3]

Get a light meter.

 

[btgc]

You are right, as I assume.

Why not get Lynx for manual control? 🙂

 

[Al Kaplan]

ISO 400 at f/11 = ISO 200 at f/8 = ISO 100 at f/5.6 = ISO 50 at f/4

ISO 64 would thus be between 5.6 and 4. You figured correctly.

 

[gb hill]

I wouldn't shoot Kodachrome in that camera if you are playing a guessing game with exposure. Exposure has to be spot on. Too risky IMO because of monitary factors.

 

[bmattock]

Your math is correct, I think.

http://en.wikipedia.org/wiki/Film_speed#ISO_film_speed_scales

Measured in ISO, each doubling equals a doubling of light sensitivity. So, ISO 400 is twice as sensitive as ISO 200, which is twice as sensitive as ISO 100, and so on.

Shutter speeds and f-stops are divided by stops, which correspond to ISO ratings.

http://en.wikipedia.org/wiki/F-stops

So, 1/500 of a second at f/8 is the same exposure as 1/1000 of a second at f/5.6.

Using this ruler, if you are locked at 1/500 (the default shutter speed of the Electro in non-powered mode), then dropping film speed from ISO 400 to ISO 64 is the same as losing 2.5 stops. What was f/16 would be f/5.6 or f/4 with ISO 64 film.

I might suggest you consider getting a camera that has operable shutter speeds - the Electro is nice, but there are others out there, and 1/500 is not always going to give you the range you might otherwise find useful.

 

[acharrier]

Thanks everybody. I'll shoot a roll and if I have a couple worth sharing, I'll scan and post.

Happy new year!

 

[b1bmsgt]

I have an Electro that takes wonderful photos. But, the auto metering system is sketchy and unpredictable.

How so?

Russ

 

[acharrier]

Seems to have two problems:

1. It's like their is a short or contacts are dirty. The over and under lights flicker, etc.

2. When I dial down the ISO to a slower speed, the shutter speed does not change. If I shoot a roll of 100 speed film and follow the metering lights, such as they are, the photos are vastly underexposed.

 

[btgc]

My 35G underexposed until I adjusted release shaft from bottom. Symptoms were - when release were kept depressed until shutter closed, it were OK. If I just pressed and removed finger from release, it didn't keep shutter open for proper time.

Though flickering lights speak for themselves. That camera needs some attention and you will be rewarded.