air photography

[jorisbens]

If i want to make a photo of (mostly) the sky, with a lot of blue air and some white clouds, and I use centerweighted metering. How many stops should I approximately adjust the reading for good exposure. And how many stops for a sky with very big clouds varying from white to very dark gray?

I can understand that this might be a difficult question, but some rules of thumb would be very useful.

 

[back alley]

i would stop at least 2 but really i think it best to vary the exposure (bracket) and then see what looks best after.

 

[FrankS]

If it is a blue sky with some white clouds, then set the exposure using the sunny sixteen rule. A heavy cloudy day with very big clouds varying from white to very dark gray, I would go with the suggested reflected light meter reading. If you are using colour or B+W negative film, it doesn't hurt to give an extra stop of exposure.

 

[bmattock]

Hate to disagree with everyone, but Sunny 16 does not apply to taking a photo of the sky, only taking a photo when the sky is sunny with open clouds - very different!

Meters are designed to give proper exposure when measuring something that is called 'middle grey'. That's an 18% grey card, available at camera stores. If you meter off very white fluffy clouds, you get underexposure - the clouds will come out grey and the blue sky will be dark. If you meter off of the blue sky, I have no idea what you will get - depends on the shade of blue - it might meter as a good 'middle tone grey'.

I agree that bracketing would be a good idea. I would also not shoot with color-print film, it usually renders blue sky with a lot of gunk in it. I've never liked skies with color print film of any kind - marginally better with color-print film and a polarizer. B&W does a fine job, and so does most slide film. But both have less exposure latitude than color-print film.

I would take a meter reading of several different points in the sky - from darkest cloud to blue sky to fluffy white cloud and average them - add all the f-stops together and divide by the number of readings you took, using the same shutter speed. And then bracket like crazy too.

Best Regards,

Bill Mattocks

 

[Wayne R. Scott]

Here in the Midwest between 10 am and 2 pm a clear blue NORTH sky will give a reading similar to an 18% gray card. For predominatly white clouds you would want to give about 1 1/2 to 2 stops MORE exposure than what your averaging meter is reading. For dark stormy black clouds 1 1/2 to 2 stops LESS exposure than your averaging meter reading. Avoid having the sun in your frame when taking your meter reading as it will give you grossly underexposed results.

Just my 2 cents.

Wayne

P.S. For Black & white film a yellow no. 8 or 15 filter will increase your contrast for the clouds to show up. A no.25 red or 29 red filter will dramatically increase contrast.

 

[FrankS]

I'm pretty certain about this:

Sunny 16 setting with render blue skies medium grey, and fluffy white clouds white. Set the camera manually referencing the film speed in use, ignore the built-in reflected light meter (which may be fooled by the white clouds.)

An overcast day containing a range of white to very dark clouds (info from original post) would average out to medium grey, so go with the built-in reflected light meter, or open up a stop from that reading.

 

[jorisbens]

Thanx for the advice, I think i will study the "art" of air-photography by shooting different skies with a lot of bracketing and I will post the results on RFF when I'm finished. 🙂 (This might take a few weeks because of my recent project and my exams) And i will post the best shots in the gallery so everyone can enjoy them 😛

Joris