C41 pushing not actually possible?

I got a very surprising reply from my local Fuji lab, when I asked

whether pushing my films one stop would cause any hassle. The lab

technician explained that all emulsions, regardless speed, are

processed the exactly same amount of time. Any over- or underexposure

of film is handled during the print process.

Is this correct; is the modern C41 process in a minilab working

always like this?

In a minilab this is correct. You needto send your film to a custom lab to extend the

development time.

Does this mean that if I take a roll of Reala 100 and a roll of Superia 1600 to the same minilab, both rolls are going to spend the same amount of time in the chemicals? If that's the case and it works fine, then why do pro labs offer pushing or pulling? What difference would it make?

<p>The difference between a 100 film and a 1600 film is not in the development; it's in the film itself. The 1600 film is more sensitive to light, so it takes less light striking the film to get an equivalent exposure. The C-41 development process is standardized, and any C-41 film, regardless of speed, is developed the same way (unless you're pushing or pulling it).</p>

"push processing' is jargon for lengthening the time in the developer. There are a

couple of reasons for this: the density of shadow and midrange detail is

(slightly) increased. The downsides are you run the risk of losing highlight detail,

"fog' in the shadow areas if the development is prolonged past a certain point, and a

general increase in contrast. there is also a color shift but usually when pushing this

isminimal.<P>I've been shooting twenty plus years and have never seen a need to

shorten the development time ("pull' process). The film gets flat, the color shift is bad

and the print looks ugly. I would only do it in an emergency.

Another insight on the film side of the equation: most color negative films for C-41 processing have a good amount of exposure latitude. This is especially true on the over-exposure side, some films up to 3 stops over in many cases. Under-exposure is generally OK 1 or 2 stops under, especially on the lower speed emulsions. This can be compensated for in the printing process.

 

If you have need to get more speed out of your film, then you can purposefully underexpose your negative film a couple stops, then have the professional lab push process your film accordingly. This will give you similar density in the negatives as if you had exposed them properly. This will come at expense of higher contrast and graininess.

I asked something similar when this forum was born: What are the effects, if any, or extending the developing time of C-41 from 3m15s to 6m30s?<p>

 

E6 is pretty straightforward because you have separate first- and color-developers. This isn't the case with C-41.

Ctein studied the effects of pushing 400+ films in Photo Techniques

writeups, Mar/Apr 2001 and again Jul/Aug 2002. Bottom line was that

some films (e.g. Portra 400NC and 400VC) didn't benefit much at all,

whereas other films (e.g. NPZ, NHG2, old NPH, and to a lesser extent Portra 800, although back then Kodak said Supra 800 pushed better)

gained about a stop of shadow density from 5 minute developing, i.e. push2.