Instantaneous exposures

[glen_h]

<p>Reading the instruction manual for the Brownie 2A, and I believe many cameras from that time frame:</p>

<p>"Never use the smallest stop opening for instantaneous exposures."</p>

<p>I suppose they never thought about ISO 400, or even higher, film. </p>

<p>The three stops on the 2A aren't marked, but might be about f/11, f/16, and f/22, or it could be even smaller than f/22. The shutter has 1/25, T, B, and 1/50 settings. </p>

<p>This was in the days of NC (non-curling) film. I don't know the ASA value for it, but I suspect it is pretty low.</p>

 

[Rick_van_Nooij]

<p>The numbered stops approximately match with 1 = f/11, 2 = f/16, 3 = f/22 and 4 = F/32 on most pre-World War 1 Folding Brownies. You'll find a lot of the Meniscus lenses on Kodak cameras have their maximum aperture choked off at f/11 (The math and measurments on the box brownie cameras makes the largest opening actually closer to f/16 as I recall).<br /><br />I'm pretty sure anything resembling ISO 400 did not appear on the market until after World War 2. So, yes, Kodak warned against using the smallest opening on the instantaneous speeds, as even with the lenient safety margin on those early films. I usually stick with ISO 100 for sunny outdoors photography with my early kodaks and ISO 200 when darker situations call for it.</p>

[JDMvW]

<p>To add a comment. One of the greatest difficulties in shooting many old cameras, especially pre-WWII ones, is that there are only a few films still sold that are slow enough to "fit" in the shutter and aperture ranges on even some once-considered-advanced cameras.<br>

Older film speed ratings were generally UNDER estimated as a "safety margin", and shooting of modern film may have to overexpose and compensate in processing.</p>

<p>Most "instant" speeds ("I") range from 1/25 to 1/60 second, depending on age, etc.</p>

[martin_jones1]

<p>This is where filters can come to the rescue. Yellow through red for BW films and ND for colour.<br>

Sometimes you have to be a bit creative in attaching the filters if you are not going to hold the filter in front of the lens,<br>

For box cameras I have used a blob of blu-tac on the filter rim and pressed the filter to the camera body. Use old filters as cleanup can be tricky.</p>