[stevebrot]

The metering is fairly accurate. It's just about expanding creative choices.

Oh...well that is something different than "best practice". If you are shooting B&W negatives, there is a whole world of flexibility and approaches where matching film, developer, and processing technique will drive how you expose your subject. I suggest Ansel Adams, "The Negative" as a good introduction to that world. That book describes the basics of exposure and processing and opens the door on to how to leverage that for creative expression.

As for color negative...How strange do you want things to get? Exposure and color balance are closely related and while the film might have a forgiving shoulder (tolerates overexposure), it may come at a cost color-wise.

Transparency/reversal film. If you have very bright highlights (e.g. sunlit white clouds), you dare not expose for the shadows, though a gray card reading in the same light be safe. There is little that is more alarming that blocked out highlights on a transparency. If spot metering the cloud, add 2-3 stops exposure using M mode on the camera. Alternatively, use a graduated ND filter.


Steve

[DWS1]

Rule of thumb I was taught during the film era was negatives - expose for shadows - slides - expose for highlights.

That's what I learned as well.

[dms]

If you don't have a specific reason for adjusting the exposure/iso: typically because of the image you are taking (see below), or the past images you took were usually under or overexposed; then I think the company that made the film should know best.

As an example, if the scene you want to shoot has a very wide DR, you may want to decide if a part of the DR is more important to you. But basically instead of a blanket rule--develop your knowledge about film and make your own educated decisions.

Never the less, to answer your question, if the exposure reading is doubtful/tough it is commonly suggested (for negative film) to overexpose by about 1 stop (i.e., halve the iso value, or input a +1 adjustment to the automatic exposure). But this means:
-- a slower shutter speed and possibly motion blur
-- or possibly a higher iso film and more grain
-- or possibly a larger lens aperture and less DOF or more difficulty focusing
-- etc.
So there may be trade-offs with increasing exposure.

[leekil]

Jeez this is all very confusing. Does this sound right for color negs then?

- Over developing increases exposure by pushing highlights (contrast increases) whilst decreasing film grain
- Under developing decreases exposure by reducing highlights (decreases contrast) whilst increasing film grain

- underexpose has the effect of boosting saturation and contrast, crush shadows
- overexpose decreases saturation and contrast, lifts shadows

Combined the effect is:
"Pull" - over expose, under develop - allows detail capture of high DR scenes with least risk of highlight clipping, similar to HDR
"Push" - under expose, over develop - very punchy whilst maintaining overall exposure

So if you are pulling or pushing your film, then you would do it like you say above. But that is not how I interpreted your original question, I thought you just were referring to overexposing and developing normally. The main purpose of pushing your film would be to use it where there is not enough light to expose it regularly.

Mostly when people talk about overexposing their film these days, they do it because they think they can get more shadow detail, but they also do it for the decreased saturation and contrast. Like making Portra "more pastelly".

[fehknt]

When scanning (i.e., NOT wet printing) the overexposure with regular development leads to more density on the film and reduced contrast. This provides a negative that scans really well, with high flexability in post-processing, closer to what a digital RAW would (minus the inversion of highlight/shadow detail blocking that happens in extreme contrast).

If you're wet printing, you probably want to stick to box speed and normal development until you have a handle on how it effects things (if you're anything like me, mistakes will occasionally over/under expose and over/under develop); I tend to lean towards metering on shadows to place the bottom of my exposure with some density so I always get _something_ usable out but with the penalty that sometimes the negatives are only useful in a hybrid digital workflow due to overexposure.

[LesDMess]

Best practices for film exposure?

Know your films exposure characteristics
Expose what's important in the scene first and eveything else will fall into place.

I always shoot an exposure range fo a new to me film so that I will know what to expect from it in my own workflow. For instance Kodak Portra 400.



Then you also need to find out what you can do in your own workflow. If you scan, you may need to apply some scan settings adjustments and/or post work to get all the info out of one frame of Kodak Portra 400. In this single frame, there are deep shadows and what seem like blown out highlights.



However, by using SHADOWS and HIGHLIGHTS tool, you can see the film has captured details in those areas that you can recover if it is useful to you.

[someasiancameraguy]

If I buy a carton of film, will it be likely that all 5 rolls come from the same block then?

Should I also invest in a cooling/dehumidifying cabinet for storing film?

[leekil]

Yes, they all come from the same batch. The batch number is printed on the bottom of the box, usually.

[peggers]

I was wondering about the notion of "pushing" a film, ie shooting say a 400 film at 3200. I heard it was possible, provided it was developed according to the ASA you shot at. Does anyone have ideas on this?

[BigDave]

I was wondering about the notion of "pushing" a film, ie shooting say a 400 film at 3200. I heard it was possible, provided it was developed according to the ASA you shot at. Does anyone have ideas on this?

Pushing film in B&W is easy enough. You do need to experiment or use some data that others may have posted for that film. For color it is a different story. You are likely to get unwanted color shifts. See the post by LesDMess on the exposure series he did. You may need to do this with pushing/pulling at a given exposure with color films to know where your limits are.

[stevebrot]

I was wondering about the notion of "pushing" a film, ie shooting say a 400 film at 3200. I heard it was possible, provided it was developed according to the ASA you shot at. Does anyone have ideas on this?

B&W film is pushed by intentional over-development with fairly predictable results. The speed used while shooting is referred to as EI (exposure index), the term usually used in charts and instructions where other than box speed is meant. If you shoot at other than box speed, you can be cool in forum posts and say stuff like, "shot with Eastman XX at EI 150". For instructions, Google is helpful ("how to push tri-x to 1600"). Also helpful is the Massive Dev Chart at DigitalTruth:

Massive Dev Chart Film Development, Film Developing Database

Color negative film can also be pushed, but is less predictable.


Have fun!


Steve

[someasiancameraguy]

B&W film is pushed by intentional over-development with fairly predictable results. The speed used while shooting is referred to as EI (exposure index), the term usually used in charts and instructions where other than box speed is meant. If you shoot at other than box speed, you can be cool in forum posts and say stuff like, "shot with Eastman XX at EI 150". For instructions, Google is helpful ("how to push tri-x to 1600"). Also helpful is the Massive Dev Chart at DigitalTruth:

Massive Dev Chart Film Development, Film Developing Database

Color negative film can also be pushed, but is less predictable.

Have fun!

Steve

I've heard also that temperature and altitude affect development timings and such, is there any truth to this?

[stevebrot]

I've heard also that temperature and altitude affect development timings and such, is there any truth to this?

Temperature and time are fairly interchangeable (there are conversion charts). If altitude is a consideration, it is something I have not heard of.


Steve

[Viking42]

I've heard also that temperature and altitude affect development timings and such, is there any truth to this?

Every film's tech sheet will have a developing time adjustment chart for different temperatures. Basically the warmer the developer the more active it is, and the shorter your time needs to be; and vice-versa.

Getting back to your comment about all of this being confusing...that's understandable as you got quite a bit of conflicting advice here. Some of the advice was based on technical aspects (e.g. exposure latitude, metering for shadows, etc.), whereas others spoke of aesthetics like tonality, colour balance, contrast. Lots of good valid comments here. I think the best thing to do is just to start experimenting to try different things and find out what works for you and what "look" you like. The only thing I would caution about is not to try too many films, developers, etc. all at once. Keep it simple, pick one or two films and one developer (if b&w) and start shooting, changing only one variable at a time to see how it works. It won't take long and you'll soon learn a lot about how exposure, dev times, agitation regimes, etc. affect image quality. If shooting colour neg film, shoot a few subjects at the recommended EI at box speed, then shoot the same scene at, say +1 stop over and -1 stop under; then see which comes out best to your liking. If, for example, the overexposed ones consistently look best, then rate that film at 1/2 box speed going forward. Simple.

There is no single right way to do this...it's very personal, and is part of the creative process. Most of all, have fun in the journey!

[g026r]

B&W film is pushed by intentional over-development with fairly predictable results. The speed used while shooting is referred to as EI (exposure index), the term usually used in charts and instructions where other than box speed is meant. If you shoot at other than box speed, you can be cool in forum posts and say stuff like, "shot with Eastman XX at EI 150". For instructions, Google is helpful ("how to push tri-x to 1600"). Also helpful is the Massive Dev Chart at DigitalTruth:

Though it's worth noting that pushing & pulling doesn't affect all parts of the negative similarly. If pushing, you're going to get more of a lift in the upper end of the contrast curve than you will in the lower end. e.g. A push of one stop will move your highlights up the full stop but it may only move the darker shadows up 1/3 of a stop.

I found Minor White & Peter Lorenz's The New Zone System Manual to be quite useful in visualizing this.