Low light and film grain

[anand_raghavan1]

A simple question for you folks. This matter sprung up after a

discussion with a friend who wanted some recommendation for a low

speed color negative film for night time photography. Now I rarely

ever use color negatives, so I couldn't suggest anything offhand.

 

In any case, my friend was under the impression that higher speed

films might show more grain under very low light situations. Of

course, higher speed films will show more grain, but does this have

anything to do with light levels? He came to this conclusion because a

few prints from an ISO 400 roll were very grainy and wondered if he

should have used ISO 100. My own thoughts were that the grain was

unusually high and must have been an abnormality in

processing/printing (done at a minilab). Especially so, considering

that only some of the prints were bad. ISO 400 should do very well

indeed for the print sizes in question and unless for some reason you

thought grain was more visible in shadow areas than highlight areas

(there being a lot of shadow area in night photos) there was no reason

to suspect film quality.

 

Any comments arising from your experience will help me clear this up.

Thanks.

[steve_levine]

First of all, you cannot judge anything from prints! Only negatives, or transparency films can be judged for grain.For example, a horrible grainy,out of focus print can easily be made from a good negative.

 

In my experience with night shooting.You are better off using higher speed film for time exposures, and general night time shots.Try a roll of 100 slide film, and a roll of 400.There will be much more detail in the scene with the 400.

[jordan_w.]

What you are seeing may be a result of the fact colour negative material tends to print "grainy" when underexposed. In-camera light meters can easily be fooled by point lights sources in a night scene and end up underexposing the whole thing. There is also reciprocity failure to contend with. My suggestion is to bracket, or at least deliberately overexpose (ie. use 400-speed film but set the meter to 200 or even 100) and see if that improves things.

[anand_raghavan1]

Yes, I understand that the negative may not be judged from the print. But I have not seen the negative and was trying to infer what I could. So long as you are not scanning into digital format for printing, and the print is not out of focus (which is readily visible), doesn't the presence of grain in the print mean the presence of a proportional amount/size of grain in the negative?

 

Let me make sure I understand your point about the detail on the higher speed film. Do you perhaps mean that the longer exposure required on the lower speed film (other things remaining constant) will entail flaring/washing out of highlights? I am not sure what the term is, but what I mean is that if you look at a night shot including say, a lit window, you will see the window periphery become increasingly hazy with longer exposure times. Is this one of the reasons for apparent loss of sharpness/detail?

[franka t.l.]

With any film of any speed, if the shadow area are exposed to extremem latitude, you will see grain and depending on the film, they can be objectionable.

 

Today's high speed film are generally OK with grain, by that I mean you have to accept grain being part of the image in a high speed film ( even with medium format ) and work with it, not working against it. The old habit of shooting for shadow and develop / print for highlight still applied ( sonewhat )

 

The issue with most minilab and in fact most of PRO lab today is their machine print is no longer analog/optical print, but Digitized print, and grain structure just pick up / magnified and manifested in not so sightly grain structure on the final print.

 

One final word, though, High speed and low light does not neccessary mean grainy neg. Underexposed frame do made grainy neg, and I suppose your friend run into this situation either because he/she handheld ( thus limiting the shutter speed ) or meter inapporopiately ( remember shoot for the shadow, not average out ).

[anand_raghavan1]

Thanks Jordan, I think I have seen underexposed negatives print somewhat grainy before. I can pass that along as a possible reason. I guess my belief that a 400 speed film would be good enough stands. I will still suggest continuing with ISO 400 to my friend (with a warning about underexposure).

[steve_dunn2]

<p>If both are exposed correctly, a slower film will show less grain than a faster film that's made with comparable technology. That's regardless of light levels, because "exposed correctly" accounts for the light levels. The slower film will require more exposure (a slower shutter speed and/or a wider aperture) to be exposed correctly than a faster film will.</p>

 

<p>If you underexpose colour negative film, your prints will look dull, muddy, drab, and very grainy. It is likely that this is what happened in his case.</p>

 

<p>If your friend picks a slower film, he will have to give the film more exposure; for instance, if he would shoot something at (say) 1/60s and f/4 with 400 film, he'd have to shoot at 1/15 and f/4, or 1/30 and f/2.8, or other equivalent exposures with 100 film. If he does this, then yes, he will get less grain with 100 film than with 400.</p>

 

<p>What camera is your friend using?</p>

[anand_raghavan1]

I'm sorry I don't know what camera was being used. It was probably an EOS Rebel or something. But yes, I understand the various points that were made. Thanks.

[bill_tuthill]

If your friend wants to take night shots with colored lights etc, a high-contrast film (e.g. slide film) will hold blacks in dark areas,

assuming that's what you want. Steve Dunn is correct: when 100 speed

print films are underexposed by the same number of stops as 400-800

speed, the slow film is almost always less grainy. One exception is

Kodak 400UC, which renders shadow detail with surprisingly low grain.

But note I said detail: if you want black, you need more contrast.

Superia 100 might actually have a use!