Another Dumb Question

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No, by following the film recommendations, and opening the equivalent of 4 stops, you are actually shooting the film at rated speed. (ASA, ISO, whatever) To push process, you need to reduce the light (underexpose) getting to the film by rating it at higher than the stated speed... 1.6 X 2 = 3.2, 1 stop underexposure, 1.6 X 4= 6.4... 2 stops...etc., etc. Then increase your developing time to compensate. for the lowered light ("increased sensitivity")of the film.
Better yet, IMNHO, buy a quality film with a more usable speed, then, if it is slide film, underexpose by 1/3-1/2 stop for more saturated colors, or, if color film, overexpose 1/2-1 stop for better negatives and color.
 

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I don't think he ever wanted to push the film (i.e. treat it as a film with a higher ISO than 1.6).
This was just a confusion that arose when trying to explain how to calculate exposure for such a low ISO.
It would be far easier to use a faster film than push this one.
 
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Nearly right ...

OK, let's try the Sunny 16 rule:
The basic rule is, "On a sunny day set aperture to f/16 and shutter speed to the [reciprocal of the] ISO film speed [or ISO setting] for a subject in direct sunlight."

So let's start by pretending you have ISO 25 film. So the correct setting for direct sunlight is ISO 25, f/16, shutter 1/25.
But you need four more stops than that to get to ISO 1.6.
Let's start by just changing the aperture, so we count 16, 11, 8, 5.6, 4 - so now we have ISO 1.6, f/4, 1/25. Now we have the right exposure.

But you want a faster shutter speed, so let's go two stops faster, and compensate by adding two stops more aperture.
So the final result is:
ISO 1.6, f/2, 1/100.

The film will now be correctly exposed. You process it normally. The bit about "pushing development" was a red herring.
Got it! Thanks for the correction.
 
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I'm glad you understand the exposure side of this, one of the hard parts is done.
Are you doing your own development? Our process to push 5 stops was quite complex, and actually involved Kodak chemists and about 200hours of my time to get down. My memory of our exact process is fuzzy, but I know we used two different developing chemicals at different temperatures, the first was a cooler development to minimize and lock grain size before we really pushed it. If you are sending it to a lab, make sure they understand what you want. I personally have never had a lab push that much, but I guess they can. Take lots of notes as you shoot, so two weeks later when you get the negatives back you know what you did. Sounds like a fun project. Please keep us posted.
Gary
Hey there!
Not doing my own developing. We have a really good lab in town so I use their developing services.
 
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I don't think he ever wanted to push the film (i.e. treat it as a film with a higher ISO than 1.6).
This was just a confusion that arose when trying to explain how to calculate exposure for such a low ISO.
It would be far easier to use a faster film than push this one.
Yes true.
I just like using non-traditional film.:D

For example, the shot below is with "Dubblefilm Apollo (ASA 200)". I shot it on my Olympus Trip 35 and had it developed at our local lab.
 

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Any time you are using a camera's manual exposure mode, you could put that information to use by understanding the relationships between a stop of light controlled by shutter speed, by aperture value and by ISO value. As an example, when using a particular ISO value, you might decide that the other ideal settings are f/5.6 and 1/30 second. If you then decide that you need 1/60 second shutter speed to be able to eliminate the effect of camera shake when handholding the camera, you would then need to know that you would compensate by changing the aperture and/or ISO setting. Or you might decide that you want a smaller depth of field than f/5.6 provides. If you change the aperture to f/2.8 to make that happen, you would need to compensate by changing the shutter speed and/or the ISO value. Lots of other examples when using manual exposure mode would require you to put the knowledge about incremental stops to good use, especially if you don't rely on the camera's exposure display.

Photographers using multiple strobe lights and flash units will often set up a scene in which the look of the final image relies on the lighting ratios of the various light sources. As an example, a key light will provide more light than a fill light. They will use a manual setting in one light source that, as an example, might be 1/32 of the source's maximum output. If they want another light to provide half that amount (one stop less light), they would use a manual setting of 1/64 of the source's maximum output.
In other words, in order to get the balance of the light right the incidental light hitting the camera might be so low that the photographer would have to open the aperture wider than he would like to get the correct DOF, so the only alternative in film is very slow film. Am I getting that right?
 
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In other words, in order to get the balance of the light right the incidental light hitting the camera might be so low that the photographer would have to open the aperture wider than he would like to get the correct DOF, so the only alternative in film is very slow film. Am I getting that right?
The only time a camera's built-in meter is metering incidental light is when it is directly metering the light source; otherwise, which is in almost all situations, it is metering reflected light. That explains why the technology of meters built into cameras are reflected light meters rather than incidental light meters.

In the situation you described, I think you're suggesting that the film photographer would prefer to use a smaller aperture to obtain the ideal depth of field. If a different film is to be used to help make that happen, it would be faster, not slower. The film photographer in that situation would have a few alternatives:
  • Use a slower shutter speed, in which case a tripod or similarly stable support may be required;
  • Set an ISO value in the camera that is higher than the film's rated ISO, set the aperture and shutter as if the film's ISO really was the ISO set in the camera, and compensate for all of that during development (called push processing);
  • Use a faster film (one that is rated at a higher ISO); or
  • Use a combination of some or all of the above.
 
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We look forward to seeing your progress. In my experience you can successfully chemically push print film 1 to 2 stops in the darkroom. After that the wheels come off. If you are setting your camera at iso 25 I would at least overexpose the film 2 stops in camera, then you only have to have the lab push it 2 more.
We have not even started on the other film variables that come to life as we push film, like reciprocity failure. Lots of variables, but hopefully there will be light at the end of the tunnel. It will be a challenging venture.
Gary
 
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We look forward to seeing your progress. In my experience you can successfully chemically push print film 1 to 2 stops in the darkroom. After that the wheels come off. If you are setting your camera at iso 25 I would at least overexpose the film 2 stops in camera, then you only have to have the lab push it 2 more.
We have not even started on the other film variables that come to life as we push film, like reciprocity failure. Lots of variables, but hopefully there will be light at the end of the tunnel. It will be a challenging venture.
Gary
The OP is NOT desiring to push process the film. Instead, he is required to set the ISO value in his camera faster than the film's rated ISO. That's because the film is rated ISO 1.6 and the camera has no such ISO setting. So, assuming the lowest ISO setting available on his camera is 25, he is using that setting, which is four stops faster than the film's rated ISO. He is then compensating by setting the aperture and shutter speed so that, between them, those two exposure settings combined are four stops slower. The lab would then develop the film at its rated ISO value.
 
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The only time a camera's built-in meter is metering incidental light is when it is directly metering the light source; otherwise, which is in almost all situations, it is metering reflected light. That explains why the technology of meters built into cameras are reflected light meters rather than incidental light meters.

In the situation you described, I think you're suggesting that the film photographer would prefer to use a smaller aperture to obtain the ideal depth of field. If a different film is to be used to help make that happen, it would be faster, not slower. The film photographer in that situation would have a few alternatives:
  • Use a slower shutter speed, in which case a tripod or similarly stable support may be required;
  • Set an ISO value in the camera that is higher than the film's rated ISO, set the aperture and shutter as if the film's ISO really was the ISO set in the camera, and compensate for all of that during development (called push processing);
  • Use a faster film (one that is rated at a higher ISO); or
  • Use a combination of some or all of the above.
Right, reflected light.

Okay, that is clear about the relationships between shutter speed, aperture and ISO. Slower shutter speeds, larger aperture, higher ISO film all are ways of opening up more stops. Ignoring push processing, very slow film would mean longer shutter speeds and/or larger apertures.

Would very slow film be for getting the least DOF and/or for longer exposures? I'm not sure of the use of film that slow. If I remember correctly my D70 only went to ISO 200, and I never missed not having ISO 100. The faster the better seemed to be the rule, except, of course, for the extra noise.

It'll be interesting to see what the OP comes up with.
 
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Would very slow film be for getting the least DOF and/or for longer exposures?
You can produce small depth of field on any film. Even if the film was so fast that you couldn't use the largest aperture on a particular camera (because it doesn't have shutter speeds fast enough to compensate), you could mount a neutral density filter on the lens to solve that issue without changing film. The same could be done for achieving longer exposures.

In the days when film was a mass-market product, the lower the ISO rating, the less grain, which was a desirable trait unless the photographer wanted grain as an artistic effect. So, manufacturers made film with relatively low ISO ratings for that purpose. I've never heard of film with such low ISO as being discussed here, so I don't know what the typical benefits might be.

Every film produces its own look though the differences between them might be difficult for many eyes to detect. That leads to...

I just got it because I like the way it looks!
What are the characteristics of the look that you like?
 
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You can produce small depth of field on any film. Even if the film was so fast that you couldn't use the largest aperture on a particular camera (because it doesn't have shutter speeds fast enough to compensate), you could mount a neutral density filter on the lens to solve that issue without changing film. The same could be done for achieving longer exposures.

In the days when film was a mass-market product, the lower the ISO rating, the less grain, which was a desirable trait unless the photographer wanted grain as an artistic effect. So, manufacturers made film with relatively low ISO ratings for that purpose. I've never heard of film with such low ISO as being discussed here, so I don't know what the typical benefits might be.

Every film produces its own look though the differences between them might be difficult for many eyes to detect. That leads to...



What are the characteristics of the look that you like?
That works for me. I was looking at some of the results of the very low ISO films. Very cool!
 
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What are the characteristics of the look that you like?
Tough to describe it...but the blueish tone I'd say without much in depth thought....

That being said, I've been REALLY gravitating to non-traditional film.
For example, I shot this one (Olympus Trip 35) with Lomochrome's "Metropolis" Film (ASA 100-400)
 

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Since you will be taking this to your film developer, have you spoken with them about how to expose it and how they think is the best way to process it?
 
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Since you will be taking this to your film developer, have you spoken with them about how to expose it and how they think is the best way to process it?
Not yet - but I will.
They seem to be pretty good with the non-traditional color films so we'll see.

Right now, I'm waiting for them to develop my roll of Cinestill 800t - Tungsten balanced film. Assuming that the photographer didn't screw things up, :wideyed: :smuggrin:, I'm looking forward to them!
 
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