Carmencita - How Exposure Affects Film

shapeshifter said:
First both photos look to expose exactly the same to me and second it is utterly impossible for the second photo to appear like it does with those settings.The first quote of f11 at 500th for iso 400 is about right for full sun.But f2.8 at 125th for iso 400 is wrong.The second photo is nearly exposed the same asthe first!
Click to expand...

It's wrong, huh?

You either have never shot colour negative film or haven't shot colour negative film for a long time. With print film, you can adjust for differences in exposure at the printing or scanning stages, that's why they look similar.

The second shot was definitely shot at f/2.8, as you can see the out-of-focus foreground. Even if I were wrong about the shutter speed (which I'm not), my camera's maximum shutter speed is only 1/500, so that photo would still have to be at least 5 stops overexposed.
 
Well we will have to agree to disagree.To the OP I would give that article very little credence.
 
shapeshifter said:
First both photos look to expose exactly the same to me and second it is utterly impossible for the second photo to appear like it does with those settings.The first quote of f11 at 500th for iso 400 is about right for full sun.But f2.8 at 125th for iso 400 is wrong.The second photo is nearly exposed the same asthe first!
Click to expand...

Here are more examples of colour negative film's tolerance for overexposure:

UK-Film-Lab-Exposure-and-Film-Stock-tests_0001.jpg


Now, don't get me wrong, I'm not saying you should go and overexpose the hell out of film all the time, but it's just simply not going to blow out the way that you're suggesting and you will still get useable images. The times I've gone very far over are usually mistakes.
 
Last edited:
skysh4rk said:
Have I at least convinced you that I know what a stop is?
Click to expand...

Nope! :D

We all know that you have contacts at fuji and kodak who fabricate 400 ISO film with 12 ISO émulsion especially for you........either that or your aperture blades are stuck at F/16 :p:D:D
 
shapeshifter said:
Well we will have to agree to disagree.To the OP I would give that article very little credence.
Click to expand...
So are you saying that if I underexpose a black and white film by 6 stops that I can't then recover enough detail in the darkroom to obtain a usable print?

Seems a lot of evidence saying that you can.....I can feel a test coming on :)
 
Steve said:
So are you saying that if I underexpose a black and white film by 6 stops that I can't then recover enough detail in the darkroom to obtain a usable print?

Seems a lot of evidence saying that you can.....I can feel a test coming on :)
Click to expand...

H'mm under expose by 6 stops :eek: now that would be interesting.
 
Has the collective wisdom of F&C put the troll back under his bridge?

"agree to disagree" aka I know not of what I speak....
 
steveo_mcg said:
Has the collective wisdom of F&C put the troll back under his bridge?
Click to expand...

Let's not resort to name-calling guys, instead lets concentrate on what we've already done - given examples, from differing sources - including our own work which prove that the person with the alternate viewpoint would be best served to go away and do some testing of modern emulsions himself before making any more posts in here...
 
TheBigYin said:
Let's not resort to name-calling guys, instead lets concentrate on what we've already done - given examples, from differing sources - including our own work which prove that the person with the alternate viewpoint would be best served to go away and do some testing of modern emulsions himself before making any more posts in here...
Click to expand...

Fair enough, though if it looks like a trolling and smells like a trolling.... maybe I'm being to sensitive. More coffee please Roberts.
 
skysh4rk said:
I think @shapeshifter actually meant to say that we can 'agree to disregard' his comments.
Click to expand...

There's a useful forum function that allows people to be "disregarded wholesale"... it's not something I recommend often - but there are people for which it can be a helpful solution.
 
TheBigYin said:
There's a useful forum function that allows people to be "disregarded wholesale"... it's not something I recommend often - but there are people for which it can be a helpful solution.
Click to expand...

Yeah, I've considered using it a couple of times in the past, but it's never quite reached that point. Things are generally very friendly in the areas of the forum that I visit.
 
skysh4rk said:
Here you go in plain English with settings included.

Right, so Fuji recommends f/16, 1/500sec. for bright sunlight at ISO 400 with Fuji 400H (http://www.fujifilm.com/products/professional_films/pdf/pro_400h_datasheet.pdf). These two photographs are from bright and sunny Hong Kong, so would definitely qualify for those bright conditions.

This photo was shot at f/8, 1/500 with ISO 400 film.

roll-145-5-of-12-jpg.20482



This photo was shot at f/2.8, 1/125 with ISO 400 film.

roll-145-6-of-12-jpg.20483


I'll let you count the stops.
Click to expand...

Interesting...I've well over exposed a neg a few times by accident but never accurately counted the stops......maybe a challenge is to waste a few shots of your film in going up to say nine stops over exposed....there must be limit for over as well as under.
 
On underexposure: I can't quote actual exposure values because I don't note them down, but I have a couple of large format negatives that I was certain were unexposed (no "der", just a "doh!") until I just caught site of a very faint image on one when held at a particular angle to the light. Based on that, I scanned both (and the second I've never seen any image on with my eyes). Both produced a scanned image. Poor, yes. Big gaps in the histogram, yes. But a poor but recognisable image that coiuld have been used if the image were priceless.

The main practical problem as I understand it with the latitude of black and white film is the fitting of the negative's very great tonal range onto the limited range of printing paper. I think that that's why the characteristic curves are now cut at a density of 3.0 rather than going on to show the shoulder - you can't make use of it in the darkroom.

On the other side, I have a negative from Holy Trinity Church in York. The pews are too dark to register on the Sekonic spotmeter bit I still have detail in them and in the stained glass window (FP4).

Extra exposure should give increased grain (take a look at skies in landscapes) and resuced sharpness (light scatter in the emulsion).

Kodak originally set film speeds based on practical trials to determine the minimum exposure that wouldn't give a noticeably inferior print to a print made from a negative with more exposure. The researchers made umpteen exposures and the best possible print from each.

N.B. I'm on holiday with a slow internet connection, so all from memory,
 
excalibur2 said:
and what part of the world is sunny 16 based on, well at a guess would suggest midway in North America.
Click to expand...

Rochester, New York.

Ruffmeister said:
I may be wrong here but some film stocks seem to fair better with +1 to +3 stops over, especially the likes of Portra and Pro400H. The lab does seem to make a big difference too however in how it's delivered - quote me if I am wrong here.
Click to expand...
For black and white film, it is very common to over expose and under develop to increase shadow detail. I will regularly give an extra stop of exposure and reduce development time by about 20%


Steve.
 
Last edited:
excalibur2 said:
Interesting...I've well over exposed a neg a few times by accident but never accurately counted the stops......maybe a challenge is to waste a few shots of your film in going up to say nine stops over exposed....there must be limit for over as well as under.
Click to expand...

My examples of extreme overexposure in this thread were simply mistakes and not something I'd necessarily advocate doing. I keep a record of all of my exposures though, so that's why I was able to dig these out and had the exposure information handy.
 
Hard core bracketing. I've not got any Protra in 135 and I'm not sure I'm willing to waste a roll of 120 even for science, but if any one wants to have a go and report back I'd be interested.
 
steveo_mcg said:
Hard core bracketing. I've not got any Protra in 135 and I'm not sure I'm willing to waste a roll of 120 even for science, but if any one wants to have a go and report back I'd be interested.
Click to expand...

...Well for 35mm guys no problem when wanting to use the film up....but it also depends on what film that is used (well I don't know the best film for over\under exposure) ...but I have many rolls of bootie film and Agfa Vista I could use, but I'm not sure if it would prove much as the Vista (Fuji C200) would be the only film that is fresh and could have poor latitude anyway.
 
Early neg colour film also had wide exposure latitude. But it suffered from crossed colour curves at both over and under exposure.
The most recent films hardly suffer from this at all. But it does cause colour shifts that are difficult to correct.
Like trannies, Neg colour can suffer from out of Gamut colour saturation. (Typically a flower might have no detail in the petals just a strong saturated colour.
In the 50's this was euphemistically called "subject Failure" by labs.

The best possible tonal quality is obtained at "Correct exposures"
This is true of all Photography.
The Tranny film and digital have very little "safety net" compared to either Black and white or Colour negative.
Safety nets are for emergencies. They are not what you should aim at using.

Those brought up on hand held reflected light meters, for the most part used up some of this "Latitude" by taking readings off the subject. or by taking a shadow reading. Tranny film responded far better by using an Incident meter.
 
Terrywoodenpic said:
Early neg colour film also had wide exposure latitude. But it suffered from crossed colour curves at both over and under exposure.
The most recent films hardly suffer from this at all. But it does cause colour shifts that are difficult to correct.
Like trannies, Neg colour can suffer from out of Gamut colour saturation. (Typically a flower might have no detail in the petals just a strong saturated colour.
In the 50's this was euphemistically called "subject Failure" by labs.

The best possible tonal quality is obtained at "Correct exposures"
This is true of all Photography.
The Tranny film and digital have very little "safety net" compared to either Black and white or Colour negative.
Safety nets are for emergencies. They are not what you should aim at using.

Those brought up on hand held reflected light meters, for the most part used up some of this "Latitude" by taking readings off the subject. or by taking a shadow reading. Tranny film responded far better by using an Incident meter.
Click to expand...

Do you know what are early colour negs i.e are you referring the say 1960s colour film. When I pick up film from the bootie going for peanuts I have chosen an arbitrary cut off point of nothing older than 2006, although have posted shots of 120 film expired in 2001 of course with some colour shifts I had to correct, but some esp pro films (to be used fresh) defeated me getting a balance of the right colours. And I've found using all these films at box speed give a good neg, which is against the advice usually given i.e. 1 stop for so many years of aging.
 
excalibur2 said:
Do you know what are early colour negs i.e are you referring the say 1960s colour film. When I pick up film from the bootie going for peanuts I have chosen an arbitrary cut off point of nothing older than 2006, although have posted shots of 120 film expired in 2001 of course with some colour shifts I had to correct, but some esp pro films (to be used fresh) defeated me getting a balance of the right colours. And I've found using all these films at box speed give a good neg, which is against the advice usually given i.e. 1 stop for so many years of aging.
Click to expand...

The first colour film I used was Dufay colour in the late 40's This was in reality a B/W film shot though a dye riseau and processed as a direct positive. Giving a Additive colour process. I bought my first Kodacolor negative films in the early 50's, As far as I can remember they were imported from Eastman Kodak in the USA (Though they had been available since about 1942.)

When I mean old mean just that. Not that I use outdated film.
Though I do have a few unused out dated films in my film draw, including a pack of Kodak royal 400 dated 3/2003 which I never got round to using.
 
You must log in or register to reply here.
Back
Top