Shooting and metering high iso (>6400)

[Vautrin]

Hi,

So I went out and bought a bunch of ilford delta 3200

I'm fascinated with the idea of being able to shoot handheld, no flash, outside at night or inside.

What do I need to know for shooting films at high isos (pushprocesing to 6400 or greater)?

How do I meter for ISO > 6400? If my meter gives an exposure value of 10 for ISO 800, do I just add the number of stops away my iso is?

So if ISO 800 is a 10, is ISO 1600 an 11, ISO 3200 a 12, and ISO 6400 a 13?

Does this hold up to really high ISOs? (>50,000)


I did some googling and I saw some nifty pictures but most advice seems to be "bracket and use test exposures to figure out best results"

I'd rather know how to shoot correctly, anyone have any tips?

Thanks,

Dan

 

[compur]

I did some googling and I saw some nifty pictures but most advice seems to be "bracket and use test exposures to figure out best results"

I'd rather know how to shoot correctly, anyone have any tips?

Thanks,

Dan

That advice is shooting correctly under the circumstances you've given.

Film has a characteristic called reciprocity which means that opening your
aperture one stop while increasing shutter speed one stop doesn't change
the effective exposure on film. One stop more exposure from opening your
aperture combined with one stop less exposure from increasing your
shutter speed results in no change in effective exposure. But, that only
works within a certain range of exposure values. Above or below that
range you get what's called reciprocity failure. The equal trade-off
between aperture and shutter speed is no longer equal and things start to
get unpredictable. That's why it's good advice to bracket exposures when
you're shooting at extremes -- either on the high or low sides.

Delta 3200 is already being pushed beyond its actual ISO when you shoot
it at box speed. Same for any ISO 1000+ B&W film. If you go even further
beyond that you're in unpredictable territory so bracketing is best.

 

[maris]

Basically, film does not go to ISO 6400. Quantum efficiency limits and storage stability concerns mean that the fastest films in existence go to ISO values of 800 to 1000. ISO film speed is the result of a specific testing procedure and is a fixed and unchangeable value for each type of film. EI, alias Exposure Index, is a number you can set on a meter to calculate exposures that are not based on a film's ISO speed.

Ilford Delta 3200 has an actual ISO speed of about 1000 but it is a low contrast film that can be under-exposed and then over-developed to give useable negatives. That's what Ilford say (correctly) you can do even at an EI of 3200. The negatives you get don't look like the ones you see from fully exposed film, the dark areas of your subject are missing completely, but mid tones and highlights are there and the resulting pictures offer an interesting if somewhat stylised rendition. And they are better than no pictures at all!

In the past I've tried hand-held shooting at night with a Leica and Noctilux f1.0 lens. I used Tri-X rated at 3200 and the results were disappointing. What's dark in the scene stays dark and empty in the picture. Much of what can be seen with a dark adapted eye doesn't register on film at all. Brightly lit things come out fine but for those I don't need 3200 film and a f1.0 lens.

Now when I do night photography I use a tripod and Tmax 100 or Fuji Acros 100 film. By giving a long enough exposure I can get things on film that I can't even see.

 

[djacobox372]

Hi,

So I went out and bought a bunch of ilford delta 3200

I'm fascinated with the idea of being able to shoot handheld, no flash, outside at night or inside.

What do I need to know for shooting films at high isos (pushprocesing to 6400 or greater)?

How do I meter for ISO > 6400? If my meter gives an exposure value of 10 for ISO 800, do I just add the number of stops away my iso is?

So if ISO 800 is a 10, is ISO 1600 an 11, ISO 3200 a 12, and ISO 6400 a 13?

Does this hold up to really high ISOs? (>50,000)


I did some googling and I saw some nifty pictures but most advice seems to be "bracket and use test exposures to figure out best results"

I'd rather know how to shoot correctly, anyone have any tips?

Thanks,

Dan

Just meter for 800 and then add three stops. Simple as that.