Sensitive exposure situations

[richard_baumer]

I shoot a variety of nature scenes (have for some time) and I always bracket. Usually I get one shot that is under-exposed, one that is over exposed, and one that is just right. Occasionally - about 10% of the time at least two of the images are so close that, if I did not know better, I would say they were taken at a half stop apart or less. Less often - but recently - I get results where no picture seems right (one will be under exposed and the next over exposed.) My question is: Are there situations where the exposure is more sensitive that one stop, where you must bracket at half-stop intervals, (e.g. 32@1 sec, 32@ 3/4 sec, 32@1/2 sec, etc.) I am imagining that perhaps strong light or high contrast might make this necessary. I shoot Velvia and this last experience with this occured shooting a bright, contrasty scene. I took the shoot with both medium format and large format cameras and the phenomina seemed to occure in both. (I showed the large format transparancy to two other people and both of them agreed that one appeared a little over exposed and the other, underexposed.)

[bobatkins]

This really isn't a NATURE question, but I'll leave it here for a

short while.

 

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For Velvia, which has little exposure latitude, a 1 stop bracket would

be way too much. In fact for most slide film a 1 stop bracket is a lot and a 1/2 stop bracket is recommended. Clearly situations in which the exposure latitude of the film is being taxed (i.e. bright highlights and deep shadows) need more careful bracketing.

 

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If the exposures are long, reciprocity failure must be taken into

account when bracketing. Typically this would be with exposures of

several seconds, depending strongly on the film type. When reciprocity effects are present (and not taken into account), the results would

tend to make the exposures much closer than otherwise expected.

[ron_shaw]

I agree with Bob. With reversal film, 1/2 stop is the most I would go, and many use 1/3. A full stop is probably fine for negative film.

[jeff_hallett]

Depending on the situation, it is often hard to see 1/2 stop differences in an image. A half stop one way or the other in low contrast scenes are this way sometimes. You may like them both but an editor

who looks at thousands may prefer one over the other very strongly.

I do agree with the above comments.

[matthew_plunkett]

I almost always bracket using 1/2 stop intervals. My experience has

shown me that I can get within 1/2 stop of proper exposure about 90%

of the time so I don't go to 1 stop bracketing very often.

 

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With that said, 1/2 stop difference on Velvia screams out at me. 1/2

stop on Sensia II, I can't even tell the difference sometimes.

 

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Velvia is tough. If the scene is high-contrast, I don't use it.

Prefer instead E100 series or (better still) Sensia II / Astia.

 

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[larry_korhank]

For a "bright contrasty scene" where you need detail in the highlights

and shadows, bracketing often won't help with velvia. You may get

better results by waiting for a cloud to dim the highlights or using a

flash to light the shadows.