Exposure settings for night photography

[milan_moudgill]

Hi,

 

this may have been answered in a general way on this site...

 

My questions... If I am using 100ASA (Provea over Velvia), and am shooting

on landscapes on a dark night in the middle of no where (no city lights)...

1. What exposure combination should I use (I believe 5.6 at 30 is good)

2. What are the comparative differences (advantages/disadvantages)

between using, for example, 5.6, 8 and 11

3. Should I be using a filter to colour correct the shifts

 

Any other tips (beyond cable release, rigid tripod etc.) will be greatly

appreciated

 

Thanks in advance,

 

Milan

[doug grosjean]

Hi Milan,

 

The URL below should answer your exposure questions:

http://www.fredparker.com/ultexp1.htm

 

I've used it quite a bit, and found it to be accurate.

 

As far as color shifts, night photography is unpredicable there. If nobody else has shot exactly the same thing with exactly the same film and close to the same exposure times, you'll have to experiment.

 

Doug Grosjean

[bueh]

Check the reciprocity factor for the films you are going to use and adjust your exposure accordingly. This is important and should not be disregarded.

 

Get an up-to-date electronic light meter for correct exposure in any given situation.

 

That Ultimate Exposure Computer link is useful if you don't have one.

 

Bracket.

 

Different aperture settings will affect your depth-of-field.

[milan_moudgill]

Thanks guys. the link was quite a find.

 

Obviously compensation is an important consideration. The Fuji website does

give reciprocity failure data for their films (and the compensation required),

but stops at 8mins. I am looking at 30 min and 1 hour shots. Are there charts

for this?

 

my 5.6, 8, 11 f-stop question was not about the obvious DOP. I was wondering

what would be a 'better' aperture to shoot at night. The corelation could be

with the length of the star trails? Obviously f-11 would mean longer

exposures, which would record the entire star trail... then again this would

depend upon the amount of sky showing in the composition?

 

Re filters for colour correction: There is no standard advice - eg. Provea 100,

30 min exposure of a starlit landscape I would need a particular filter to

correct colour shift?

 

thanks for your responses,

 

Milan

[sndr]

The correction factor for reciprocity failure for slide films is apparently quadratically increasing with the exposure time (past the point of exposure reciprocity). That means that, every time you double the exposure, you must quadruple the compensation.

 

See http://home.earthlink.net/~kitathome/LunarLight/moonlight_gallery/technique/reciprocity.htm

for data on Provia 100F.

 

As you might be aware, anything increasing quadratically goes up quickly: suppose we use the example given above, and the reciprocity failure starts at 128 seconds and that exposure compensation for reciprocity is 1 stop at 1000 seconds (rougly, from the Provia 100F data). Then it will be 4 stops at 2000 seconds, 16 stops at 4000 seconds of indicated exposure: a one hour indicated exposure will be practically impossible to actually achieve.

 

This is really why you should experiment: of course there will be an image on film after an exposure of several hours, but the darker areas will just be way darker than they were and you'll just get star trails; in practice, however, a light level of -4 EV (and that's very dark indeed), just requires an 8 minute indicated exposure at f/5.6. This needs a 9 minute actual exposure according to the website above.

 

The color correction you need really depends on what you're trying to achieve (moonlight btw., is daylight balanced, because the moon is lit by the sun), and you'll probably just end up color-correcting after you get the film back from the lab. Try without filters first and see whether you like it.

[doug grosjean]

I've only shot star trails accidentally couple times, when doing a 20 minute exposure on a snowy landscape of my sister's farmhouse, lit by the full moon bouncing off the snow.

 

Star trails you can calculate out. They'd be 180 degrees in 12 hours, so 15 degrees each hour, 5 degrees each 20 minutes. So only 7.5 degrees in 30 minutes.

 

The trails get fainter with smaller aperture, brighter with bigger aperture. But you have to expose for the main subject.

 

And it's also going to depend on which direction you're shooting. North, and the North Star is the center, and 7.5 degrees of arc isn't much. But facing south, and that radius is much further from the North center, and 7.5 degrees of rotation should be quite a bit more arc when facing south than when facing north. But they might only be straigh lines when facing south, instead of arcs.

[ranong]

i can not answer many of your questions exactly, but here are my experiences. i am shooting with a pinhole 4x5. i mostly shoot b&w but i have shot a bit of color C41. i shoot in the day and for up to 30 min and i have noticed more of a mis-coloring more than a "shift" but maybe they are one and the same. i have shot some E6 but mostly ant fairly short shutter speeds and i had no problems. sometimes the color shifting actually makes the image. as you already know you will have to test. please post me your finding as i would love the information but probably will never test them....but i would use em to shoot with.

 

checkout f295 http://f295.tompersinger.com/cgi-bin/Blah/Blah.pl? they are a pinhole group and they are very familiar with long exposures

 

eddie