Do you shoot film at box speed?

Asha

Asha

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Asha
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As title really.

Ignoring any innacurate meters, O.O.D film etc which may require a little manipulation of camera iso setting, do you always shoot your film at box speed or have better results come from overexposing a little?
 
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I have taken to rating my 100 asa slide at 80 as it seems do the job.
 
Depends on the film! C41 any value I fancy below box speed and a stop over at a real push, B&W at box or pushed a stop or 2, Adox CMS anywhere between 80 and 200 rather than 20!
 
Generally, though for convenience FP4+ is rated at 100 as is Portra. I'll some times give an indvidual frame a half stop if i'm shooting on a manual camera but its another one of those guidlines I forget half the time.
 
Nah...all my life have relied on Kodak grey readings...for example in sunny Ibiza just take an exposure reading of a dark grey pavement or equivalent of Kodak grey like deep blue sky or dark green shrubs etc...and you can use that reading for hours on general shots that are in sunshine.
 
I shoot Portra 160 at 100 and Velvia 50 about 1/3 stop over. Provia I tend to shoot at box speed and likewise with astia.

B&W films I tend to shoot at box speed also. Adox CHS 25 I shot at 25 as it was quite intolerant of over exposure and I don't tend to grad B&W.
 
When getting into the realm of fine adjustments like this it is also worth taking into account how your meter behaves. I have a few Nikon bodies and the meters in the F2, F3 and F4 are consistent with each other and generally very accurate. By comparison, my FE2 for some reason consistently overexposes by about 1/3 to 1/2 a stop. That's neither here nor there for most uses with print film, but I try to remember to up the ISO by a notch if I'm using slide film in the FE2.

Other than that, the only time I play with the ISO is when I'm using Portra 400 and exploiting its amazing exposure latitude. If I'm indoors and without flash, I'll often knock it up to 800 or even 1600, without any need to adjust development.
 
An interesting mix of responses....Seems that b&w neg film is pretty much left alone or only maybe a third (ish) of a stop under box speed unless of course it's being pushed.

Alan Clogwyn said:
C41 any value I fancy below box speed
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Woodsy said:
I shoot Portra 160 at 100 .
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These two responses appear to suggest that C41 colour film is much more tolerant of being overexposed?



Steve Smith said:
Over expose by one stop, reduce development by 25%.


Steve.
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Steve, what advantages does that offer?
Does the reduction in development simply not cancel out the stop of extra light?
 
Asha said:
Steve, what advantages does that offer?
Does the reduction in development simply not cancel out the stop of extra light?
Click to expand...

In terms of getting the exposure "right" in total, yes, it does cancel out, but normally it tends to give a smoother grain IIRC
 
Asha said:
An interesting mix of responses....Seems that b&w neg film is pretty much left alone or only maybe a third (ish) of a stop under box speed unless of course it's being pushed.

These two responses appear to suggest that C41 colour film is much more tolerant of being overexposed?
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Neg film generally can be thoroughly abused exposure wise, god knows, even Ive not managed to hit the limits yet.
1/2 or 1/3 of a stop either way with most neg film will be nigh on indistinguishable from correct exposure. Once you're into slide film however then it makes a world of difference.
 
robhooley167 said:
Neg film generally can be thoroughly abused exposure wise, god knows, even Ive not managed to hit the limits yet.
1/2 or 1/3 of a stop either way with most neg film will be nigh on indistinguishable from correct exposure. Once you're into slide film however then it makes a world of difference.
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I managed to under expose some K100 (?) by about 5 stops when the battery in the OM30 started to die unnoticed. Very dark but still got an image.
 
An interesting read indeed, if not a little worrying for me. I've got 5 rolls of slide to put through an old 6x6 folder whilst on holiday next week. I've just finished a test roll in it but its HP5 (?) so going from what you guys are saying it'll be a lot more tolerant to my sketchy exposures with a handheld light meter, :lol: Perhaps i'm best leaving the light meter and using the D300 that will also be in attendence for more accurate metering?
 
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robhooley167 said:
Neg film generally can be thoroughly abused exposure wise, god knows, even Ive not managed to hit the limits yet.
1/2 or 1/3 of a stop either way with most neg film will be nigh on indistinguishable from correct exposure. Once you're into slide film however then it makes a world of difference.
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Sectionate said:
Slide film can be a world of hurt if you under expose by 0.00000000000000001 of a stop.

Bloody Slide.
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My intention this year was to push and pull and experiment a lot more with film latitude...how ever it hasn't come off except for the play I had at pushing Agfa Vista ( cross processed in b&w chems) and a mess at pushing Tri X with mixed resuts.

Given that it's now well into October, i guess it could become next years project! :D

Anyway, talking of slide film, I recently had a roll of OOD Velvia ( I think it was) devd at local lab.

Was first time I've ever shot slide film ( last winter throuh the RZ67), though did understand it has very little latitude and found myself being very careful not to blow the highlights. In doing so most of what i shot cme out underexposed although recovarable in PP.

A few results directly off the scanner with no pp:

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I rather like the look of colour and black and white negative film over exposed by a stop or so then corrected in scanning. Seems to give a light, smooth, low contrast sort of a look which i very much enjoy. My local lab can push process but not pull. I have pushed a couple of rolls of 400 to 1600 but not experimented further.
 
I never shoot negative film at box speed unless there's just simply not enough light to maintain appropriate shutter speeds.

For Kodak Portra (160 and 400), I will usually meter for the shadows and shoot between 2/3 to one stop over.

For Fuji Pro films (160NS and 400H), I meter for the shadows and usually go between 1 and 3 stops over depending on light.

I find there's good shadow detail this way and I've never had a problem with highlights.
 
What a wide open question, and replies show it.

Three reasons for shooting film at a different ASA setting than stated on box.

1/ To Push/Pull process.
Ie; dont have fast film to hand; shoot 400 rated at 1600 and Push-Process' give it longer in the tank to compensate. Comes out grainy and contrasty, but you get shots. Alternatively; don't have slow film to hand, bung in 400 and expose at 100, and shorten the dev-time.
Sometimes done for convenience, sometimes for effect, some-times for cost.
Some films also designed for push/pull processing and may come with dev compensation times.

Used to do this a lot with bulk-loaded Croatian Agfa copy stock in B&W and Slide. Got a 30m roll of ASA400; roll into cans, and attach masking tape lable, stating 'B&W' or 'SLIDE' then when I shot it, would mark what ASA I rated it at before putting it in the camera. Would use it as either 200, 400, 800 or 1600, to save buying lots of different rated films.

2/ Frame By Frame Exposure Compensation
My old Olympus XA2 compact has no exposure compensation dial. Want to add 2/3 of a stop over exposure to compensate for back-light? Do it on the ASA dial. Same with the OM10, and my Konica C35, which are all meter-coupled AE exposure. Its the only way to get any 'manual' over-ride to meter suggested settings.

3/ Base-line adjustment
Film or circumstance dependent; 'correction' to metering.
Eg: If you know your meter has tendancy to over-expose, compensate by upping the ASA setting, to 're-calibrate' without taking it to bits.
Shooting slide film; was always advised to under-expose by aprox 1/3 stop, to avoid blown highlights and saturate the transparency for projection. So if I rated a slide film at 400 'box-speed' I'd then compensate one click under.. no idea what that would be, Olympus just have two inter divisions between major ASA settings!
Other-wise; shooting a set; rather than adjusting frame by frame, as all are going to need much the same adjustment; say when skiing, and everything's white & meter will tend to under-expose, presuming 18% grey; or at a Rock-Gig in dingy student gym, where dark, and meter will presume black stage is lighter and try and over-expose.

So basically; for various reasons, one way or another, very seldom set box ASA speed and been a slave to the meter and its couples exposure settings.
 
andy1868 said:
An interesting read indeed, if not a little worrying for me. I've got 5 rolls of slide to put through an old 6x6 folder whilst on holiday next week. I've just finished a test roll in it but its HP5 (?) so going from what you guys are saying it'll be a lot more tolerant to my sketchy exposures with a handheld light meter, :lol: Perhaps i'm best leaving the light meter and using the D300 that will also be in attendence for more accurate metering?
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i think id be more concerned that the shutter speeds were off ,,,
 
Asha said:
These two responses appear to suggest that C41 colour film is much more tolerant of being overexposed?
Click to expand...

Very much so.



Asha said:
Steve, what advantages does that offer?
Does the reduction in development simply not cancel out the stop of extra light?
Click to expand...

The extra exposure increases the shadow detail and the reduction in development tames down the highlights. As the low amount of exposure doesn't give the developer much to work with, development time variations affect the highlights (darker parts of the negative) more than the shadows. This means that development time/strength/temperature can be used to alter contrast.

This is my idiots' guide type of explanation:

http://www.freewebs.com/stevesmithphoto/personal.html

And this:

http://www.freewebs.com/stevesmithphoto/contrast.html

But I'm no expert, I really wrote those pages as a guide for myself.


Steve.
 
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Donutagain, with everything else going on that thought hadn't even entered my mind :( looks like I'll have to see what comes out from the test roll!

I do have 2 rolls of 400 neopan too to take if that's going to be more forgiving. If the worse comes to worst I'll leave it behind. I don't fancy ruining £30 of film and then spending the same again if not more developing and scanning if it's not right!
 
I generally expose PanF at the rated speed, and FP4 at 80. The results suit me. The adverse effects of overexposure (increased grain size, reduced sharpness) if I am overposing don't affect me with the larger than 35mm negatives I produce for the print size I produce.

As well as inaccurate shutter speeds (and people using between lens shutters might get a surprise if they look into the question of shutter efficiency) there are also inaccurate aperture markings. Ansel Adams recounted calibrating the smaller apertures on at least some of his lenses. This won't matter for anyone using TTL metering of course - if the readings are taken at the working aperture.
 
StephenM said:
The adverse effects of overexposure (increased grain size, reduced sharpness)
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It's under exposure which can increase grain, not over exposure.

This from my most trusted source, Ron Mowrey, ex Kodak research chemist:

Generally, a single emulsion is not capable of getting a smooth linear H&D curve over the range required. Therefore, most films that I know of are blends of 3 emulsions or are comprised of 3 emulsion layers.

These emulsions are denoted fast, medium, and slow. You can see representative cross sections of these on the EK and Fuji web sites.

The fast emulsion records the toe in negative films and the shoulder in reversal films. Either way, this emulsion has the coarsest grain and is seen in high density areas in the final viewable print.

Due to the relationship between density and grain, you see a bell shaped curve in RMSG plots (grain vs speed). High grain is in the highest speed region with grain rising with density until the curve begins dropping again.

This is obscured in reversal films due to the two development stages, and in B&W processes due to the solvent effects of some developers.

It is generally best to overexpose slightly to achieve better grain. If you overexpose too much, you may have too much flare which will reduce sharpness.

Ron Mowrey
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Steve.
 
Perhaps Ilford and Kodak films are different. Jack Coote in Monochrome Darkroom Practice, p41, states the reverse; and goes on to describe the behaviour of XP2 in terms of not suffering from increased grainess on overexpose as a "surprising fact".

I have seen the same reported elsewhere - Ansel Adams explicitly describes increased grain being caused by over exposure.

My own negatives certainly seem to be grainier in the bright whites of the print (the dark parts of the negative) compared to the thinner shadow areas.

Apologies to all for a second post on this.
 
There's only one way to settle it. Deliberately over and under expose same scene and see which is grainiest...
 
StephenM said:
Perhaps Ilford and Kodak films are different. Jack Coote in Monochrome Darkroom Practice, p41, states the reverse; and goes on to describe the behaviour of XP2 in terms of not suffering from increased grainess on overexpose as a "surprising fact".

I have seen the same reported elsewhere - Ansel Adams explicitly describes increased grain being caused by over exposure.

My own negatives certainly seem to be grainier in the bright whites of the print (the dark parts of the negative) compared to the thinner shadow areas.

Apologies to all for a second post on this.
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That could result from whether you describe under/overexposure based on the actual negative, or on the resulting positive.

Increased grain is definitely from underexposure of negative films, just try underexposing most negative films by a couple of stops, to pull the detail back to get it 'correctly exposed' you'll get an increase in grain where the subsequent print/scan has had to effectively be 'pushed'.
 
Sorry to return to this - I promise I won't again - but surely grain is something that exists in the negative rather than the print, so scans (where noise in the shadow areas can resemble grain) and prints won't really help. Only examining the negatives themselves.

Since the effect (whether you assume Coote, Adams, Hicks and sundry others are correct, or Paul Mowrey and s162216 doesn't matter) depends on the amount of exposure (and why should negative film users go for "minimum exposure" if they're going to be hit with increaed grain?) then surely any negative that contains areas with a full exposure (e.g. the sky) and a mimimum one (e.g. heavy shadows) can be examined for grain without having to make side by side exposures?
 
StephenM said:
Sorry to return to this - I promise I won't again - but surely grain is something that exists in the negative rather than the print, so scans (where noise in the shadow areas can resemble grain) and prints won't really help. Only examining the negatives themselves.

Since the effect (whether you assume Coote, Adams, Hicks and sundry others are correct, or Paul Mowrey and s162216 doesn't matter) depends on the amount of exposure (and why should negative film users go for "minimum exposure" if they're going to be hit with increaed grain?) then surely any negative that contains areas with a full exposure (e.g. the sky) and a mimimum one (e.g. heavy shadows) can be examined for grain without having to make side by side exposures?
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All true and AAMOI on the Kodak site, Kodak say:- best results on film is when it is correctly exposed and that would mean to THEIR Kodak grey card.
 
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