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Another exposure in the snow question

ymc226

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I am going to take my Mamiya 7II on a family ski trip. It has a built in refective exposure meter which has an exposure lock that you can aim at the skin to lock in the reading and then reframe the shot.

I've read that one needs to overexpose by 2 stops in the snow but does that only apply when an incident meter is used or do I need to overexpose as well using the built in meter? I would as stated above, meter on the face and then recompose using the initial reading.

If I do overexpose, for example, expose Neopan 400 at ASA 100, would I then develop using 400 or 100 times in the MDC?
 
If you meter the face up close, that reading should be fine. What I might do is take a reading of the snow, and put this on Zone 7-8, aka, overexpose 2-3 stops. I generally think of zone 7 as "white".

If you overexpose with 400 speed film, develop it as 400, because if you expose 400 two over (100) and develop at 100, then you haven't overexposed anymore.
 
The overexposure rule is when you are using centerweighted average type of metering of a snowy scene as the 18% grey assumption will be off by two stops with white snow. If you are spot metering or metering your hand then there is no need to compensate as you have already metered something other than snow. If you spot meter on the snow...
 
Reflective meters read the world as middle grey (18%) regardless of what it is pointed to snow, hand, black horse, whatever. If you want a value to be other than middle grey you must make a decision on how to adjust the exposure. Rule of thumb for years has been 1-2 stops for snow; depending on lighting conditions. 1/2 to 1 stop more for causian skin,etc.

It is best to test for these changes to see how your equipment is working.
 
I'd just add that if you shoot manually, you don't have to worry about the AE lock. Just meter off the face or hand, add a stop, and set that value. Because snow in the sunshine can be so reflective, you could also double-check by metering of the snow and add two stops.

If you use an incident meter, as you referenced in your post, you are measuring the light falling on the subject, and therefore don't need to make any adjustments.

-Laura
 
ok, i am confused, reflective or incident meter?
 
As in the light that is incident upon the scene. The reflections are all relative to that source intensity. That's the difference between an incident meter (the white bulb), and a reflection meter (looking at your subject).
 
I know the difference between the two, i got confused with what the OP was saying.
 
Thanks for all of your replies. I would be relying on the reflective meter in the camera. Subjects will be children who won't sit still long enough for me to get a reading close in so I guess my best option is to rate my 400 film at 100 and hope for the best.
 
This question is not so easy to answer. It depends what you want in the image.
Most of us imagine snow being white. If you want that - mostly white snow - and you believe in the measuring of a reflective meter - you get grey for snow. If give two extra stops than you get rather white snow.
But look at great snow images! I imagine one image of St. Ansel, where parts of the snow are dark-grey. And it looks naturally. An image with lots of snow: Perhaps you wish to structure these white areas. Then you need white grey and dark gray and somewhere black (not in the snow itself). It may be that in this case the settings of your reflecting meter are nearly correct.
We have snow here in Germany for many weeks now. I measured many scenes with a spot meter and decided which tone i want to have where. Then I compared the results with an simple wide angle reflective meter (the Selenium meter of my Rolleiflex 3,5F). The results were often identical und differed no more than half a stop.
 
I agree that this is not an easy question. There is no set guideline that will work. Using manual exposure settings is generally advisable, metering and tailoring each exposure for the situation. Snow leads to extreme contrast situations, with dark subjects against very light snow. Spot metering your main subject and setting it in the appropriate zone is generally a reasonable first step. But then also meter some other areas, including important snow areas, to get an idea of the contrast involved. Snow is terribly bright. For overall scenics, generally you need to add about 3 stops over what the meter for the overall scene says in order to render the non-snow subject correctly. This is even in overcast weather. In bright sun, things can really get difficult. Unfortunately, not all scenes will meter the same. If you have a lot of ordinary subject matter, they will be closer to correct, with the snow causing only slight problems (but still some). It there is important detail in the snow, you need to meter that detail and set it in Zone VII to capture it; then you have to make sure the other important things are not underexposed. Fortunately, snow is also a great reflector, and you can use it to compensate for some of the contrast issues when you have control of the scene.
 

Why not simply meter from your palm and open 1/2 - 1 stops? As long as you are receiving the same lighting with the children that should work fine ... and the snow will fall in the right tones

Make sure you underdevelop the film, so that the contrasty snow scene is contracted to printible densities. Box speed should be fine for mild underdevelopment.
 
Then there is always bracketing. Film is pretty cheap compared to the cost of getting the family back to that event.

John Powers
 
And then there's the 'Sunny 16' rule which pretty much covers it. Also, if you're outside on bright days with snow, I wouldn't use 400 film. I'd rather have 100 film in that case.
 
So most of these recommendations lead to similar options -
The sunny 16 rule is pretty much the same as an incident meter reading (which might be the easiest and most convenient for your situation). I places everything where it naturally falls, if it works for your visualization of the image.
Measuring a caucasian hand (I have a couple, so it's convenient for me) and adding a stop is based on the average reflection of caucasian skin being one stop brighter than 18% gray. This again gives a good reading for most scenes.
If you spot read several places and make a judgement about their intended values, as piu58 indicates, you need to be good at that kind of previsualization.
For a family trip, and for convenience, you might just want to use the sunny 16 rule, or the hand thing.
As Ann says, too, test whatever you choose before the trip. And you might consider slight under development (maybe 15 - 20%) just to hedge your bets (you did say B&W, right?). You can always pump up the contrast that much in printing if needed.
 
hpulley said:
I thought it was f/22 in sunny snow according to the "sunny 16" rule of thumb.
Click to expand...

It is because the snow reflects more light than the bare ground would (same for sand).

However if you're in an area which is often more like sunny f11 (the UK most of the year!) f16 may be more appropriate in snow.


Steve.
 

That sounds like it would be reasonably fast to work. One question, if metering off my palm, why would I need to open up an additional stop as wouldn't that overexpose the skin tones?
 
caucasian skin should be about a zone 6, a.k.a. 1 stop above middle gray (5)
 
holmburgers said:
caucasian skin should be about a zone 6, a.k.a. 1 stop above middle gray (5)
Click to expand...

The palm of any hand regardless of general skin colour reflects about one more stop of light than the standard 18% grey.

Weston light meters even have a mark to line up with the reading taken from a palm.

ymc226 said:
why would I need to open up an additional stop as wouldn't that overexpose the skin tones?
Click to expand...

The reading from the palm is twice the amount of light that you would get from an 18% grey card or general scene so the settings suggested by the meter let in half the amount of light that you actualy need. Therefore you need to double it either by opening the aperture by one stop or slowing down the shutter by one stop.


Steve.
 
Apart from the metering part of things (as described above I'd also suggest the metering off the hand idea - though it's not going to work off a ski-glove!), there is also the consideration of the contrast range. If you have a sunny day then you could rate your 400asa film at 200asa or less (ie. set 200asa on the camera meter) and then reduce the development slightly (test in advance). When the metering is good, that 'pull' can really help avoid, or reduce, blocked highlights or empty shadows. In grey and murky ski conditions though, you might find the contrast is not a problem - it all depends . . .
 
If you want snow shape and texture meter the snow. Otherwise open a stop or meter something similar like a ski parka.
 
MartinP said:
Apart from the metering part of things (as described above I'd also suggest the metering off the hand idea - though it's not going to work off a ski-glove!), [...]
Click to expand...

It is.
You have to see how much to compensate for the glove first, but there's no reason why it would not work.
 
When you're exposing for snow with texture you're not over exposing by 2 stops. Exposure meters always meter for middle gray, zone V or 18% grey. Since snow is NOT 18% grey, you lighten it by opening up 2 stops.
 
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