Black and White Film and Artificial Lights

[IanBarber]

When I was doing low key still life with the digital setup it was fairly easy because you could see the results on the screen. Now I have moved to 4x5 everything appears to be heading south on me.

I use the following lights


Modelling lamp from a studio head (usually with a 10° grid)
Incandescent light


I have noticed that the majority of my exposures look awful, under-exposed, mushy low values.

I use the manufacturers (Fomapan) reciprocity times for exposures longer than 1 second but I have noticed that their data sheet does mention these times are for daylight.

Does black and white film react differently to this type of lighting in any way ?

[Bruce Watson]

I have noticed that the majority of my exposures look awful, under-exposed, mushy low values.

I use the manufacturers (Fomapan) reciprocity times for exposures longer than 1 second but I have noticed that their data sheet does mention these times are for daylight.

Does black and white film react differently to this type of lighting in any way?

Why yes, it does. Panchromatic films are basically orthochromatic films with added sensitization dyes to extend sensitivity down into the longer wave lengths. So to expose a B&W film to light that is lacking in blue light can push it into reciprocity failure sooner than you'd think.

Compounding this, the older cubic-grain emulsions (and Fomapan is a very old emulsion) are more problematic about this than modern t-grain emulsions. You probably would find your problem greatly diminished if you were using TMX, Delta, or Acros.

That said, the old saw: expose for the shadows and develop for the highlights" still holds true. If your shadows exhibit "under-exposed, mushy low values" then give them more exposure.

[IanBarber]

Thanks Bruce

I can see this really been trial and error especially if reciprocity kicks in sooner than you would expect

[Leigh]

Film emulsions are most sensitive to blue light.
That's just the nature of the chemistry and technology.

Sensitivity can be extended down through green to red and even infrared by adding "sensitizers".

Comparing the spectrum of an incandescent light to the spectrum of daylight shows a dramatic difference.
With daylight, the intensity peak is at blue, with green being lower and red being much lower.
An incandescent source has an intensity peak at red, with green being lower and blue being much lower.

http://www.atwaterkent.info/Images/Img_Light%20Spectrum%20by%20light_sun%20v%20incan.png

Depending on your meter, your readings may be quite a bit wrong when measuring incandescent.
Some experimentation is in order.

- Leigh

[IanBarber]

Depending on your meter, your readings may be quite a bit wrong when measuring incandescent.
Some experimentation is in order.

I use a Sekonic L758 Meter, usually taking incident light reading for this type of setup. So looking at those charts, with the blue been very low under incandescent and the fact that the light meter may be giving false readings, i feel a-lot of experimentation maybe required as you say

[Peter De Smidt]

I would do a bracketed series of shots of your scene, starting with your normal speed for outdoor use, moving on to a negative with 1 stop more exposure, and finishing with a negative with 2 stops more exposure. Develop normally and evaluate the negatives. You should be able to figure out the best EI for that film, developer, and lighting. When I tested HP5+ with tungsten lighting, my EI was only 100.

[IanBarber]

Just a thought although I maybe way off track, would adding a blue filter to the light source increase the amount of blue which is what the film like to receive

[John Olsen]

Does black and white film react differently to this type of lighting in any way ?

Normally you'd use a green #11 filter on the lens to get the tonal range of the image with tungsten light. This is consistent with the replies above concerning the redness of the hot lights. Of course, that costs two stops of exposure, pushing you further into reciprocity compensations. But you can get good images this way.

155643

[Harold_4074]

Ian,

For educational purposes, you might play with your digital camera: white-balance for daylight, and make your picture with incandescents. I expect that you will get images that look extremely warm, whereas the same picture with the camera white-balanced for the incandescents will look "normal". The human vision system has a pretty robust mechanism for adapting color perception to differing light sources, so the film may be reacting to the colors in the still life in a way that is difficult to visualize.

Your incident metering is of course immune to the colors in the subject, so you might consider doing a few exposure tests with a gray card to find out what the basic reciprocity correction should be in the mid-tones, and then work on contrast adjustment from there.

In my own experience, I have found that pastel fabrics in pink, yellow and pale blue render in ways that are very difficult to predict (Caucasian skin, for example, on the negative just disappears against pale blue even though it is clearly separated visually). For reasons probably originating in dye technology, the darker earth tones seem to work well in both incandescent and strobe (nominally daylight-balanced) light. This is handy if, for example, you are photographing pomegranates (deep red and black) against natural burlap (medium tan) with leaves (yellow and green) and a flat black vase.

[IanG]

Check manufacturers data sheets B&W films have a different ISO for daylight and tngsten lighting. Some of this is no longer included on the most recent data sheets so look at ones from 15-20 years ago it's still the same.

Then add the filter factors if used, there's a guy in the UK with excellent misleading data (some for sale) about all this, he has a few websites & forums and never gets anything right :D

Ian

[Drew Wiley]

The specific tech sheets from major film mfg (Kodak, Fuji, Ilford) give you comparisons for daylight vs artificial light sources, along with recommended differences in filter factors. Most EU films don't. You can also balance artificial lighting the appropriate blue gels or lens filters, at expense to film speed. But there is simply no substitute for running your own tests until it's figured out. It can get complicated. For one thing, color response can shift at long exposures, and not just exposure
time compensation itself. A film that is quite consistent in this respect is Fuji ACROS, which also has reduced red sensitivity, much like a pan film with a no. 11
yellow-green filter on it. T-Max films are also relatively good for this kind of work, and have quite a bit of studio application testing behind them.

[Jerry Bodine]

Just a thought although I maybe way off track, would adding a blue filter to the light source increase the amount of blue which is what the film like to receive

Ian - have you considered using blue incandescent bulbs? I use them for indoor testing of my films for illuminating white mount boards;they're 500W and 4800K (fairly close to daylight color) in 12" reflectors. They may be a bit too hot for certain subjects, though. In the U.S. I get the best price from B&H: https://www.bhphotovideo.com/c/product/74523-REG/Wiko_EBW_Lamp_500.html
I also see them on Amazon for a bit more.

Don't know if they're available in UK.

[Bill Burk]

Since you are totally in control of the scene, are you considering your lighting ratio?

The first thing I thought when I read your dilemma is that maybe you created a low contrast scene and your film needs to be developed longer to boost the contrast in the negative.

[Peter De Smidt]

Development primarily effects higher densities, whereas exposure primarily effects low ones. Is the lighting ratio a normal one that can be captured easily on film? In other words, do the shadows fall on Zone III and the bright areas with detail fall on Zone VIII? If so, then given that he doesn't have enough shadow detail, then he needs to rate his film lower. Once he gets the proper density in the shadows, then he can figure out if he needs to develop more or less for Zone VIII. If the lighting ratio is leads to a greater contrast ratio than mentioned above, then fill light should be added.

[IanBarber]

Thanks everyone for all your comments. I shall be doing more testing over the next few days, I will start at the beginning again and concentrate on making sure the negative covers a good range and then look at tackling the colour issue.

I have alsi just ordered a box of Kodak TMAX to see if that gives any better results over the Fomapan

[IanBarber]

there's a guy in the UK with excellent misleading data (some for sale) about all this, he has a few websites & forums and never gets anything right :D

Any more information on URL's etc

[LabRat]

You are applying bellows compensation factors, correct??? If you are severely underexposed, you might be 1,2,3 or so stops under depending on the bellows extension... (My EI for the Foma 100 is about 50- (but usually) 80 depending on the batch)

The Fomapan 100 should be fine, as the reciprocity factors listed are correct on the tech sheets (+1 stop@1sec/+3 stops@10sec/+4 stops@100sec) and I have shot them many times under strobe/tungsten/CFL/LED lights and work fine... Foma 100 has a slight green sensitivity peak (in the middle of the spectrum) and most lights have plenty of green, so I think not the issue... I don't think filtering the lights is needed, and the issue is elsewhere...

Steve K

[IanBarber]

Thanks Steve

Am I right in assuming that when you worked out the EI for the fomapan, this was based on Darkroom printing. I currently only scan the negatives and wasn't that sure as to whether a personal EI was something I should be looking at

[LabRat]

Thanks Steve

Am I right in assuming that when you worked out the EI for the fomapan, this was based on Darkroom printing. I currently only scan the negatives and wasn't that sure as to whether a personal EI was something I should be looking at

Yes, the corrected EI will produce good shadow density, and balanced highlights to the Dmax (the film takes a little overexposure pretty well), that wet prints well, and is nicely balanced for scanning... At the box speed, the shadow detail is a little thin, and the lower values are a little depressed, so a little tweak there helps... Slightly cutting development (try about a minute less) prevents the highlights from blocking up, so that is a starting point...

Nice film,but it's that reciprocity thing to watch for during longer exposures, but the tables do work well... And double check your bellows factors...

Good luck testing!!!

Steve K

[SergeiR]

When I was doing low key still life with the digital setup it was fairly easy because you could see the results on the screen. Now I have moved to 4x5 everything appears to be heading south on me.

I use the following lights


Modelling lamp from a studio head (usually with a 10° grid)
Incandescent light


I have noticed that the majority of my exposures look awful, under-exposed, mushy low values.

I use the manufacturers (Fomapan) reciprocity times for exposures longer than 1 second but I have noticed that their data sheet does mention these times are for daylight.

Does black and white film react differently to this type of lighting in any way ?

so instead of doing some esoteric calculations, have you ever tried to just calculate values using scale or scale target? I think best thing i ever did for my still life stuff is to by visual target scale that takes all the guess work away - you just stick it to your object, focus, measure compensation on ground glass and move on ;)

[IanBarber]

I think best thing i ever did for my still life stuff is to by visual target scale that takes all the guess work away - you just stick it to your object, focus, measure compensation on ground glass and move on

Do you have any information where these can be obtained from

[chris_4622]

Try this:
http://www.salzgeber.at/disc/

[IanBarber]

Thanks, that looks interesting, I will try that

[IanG]

It's actually all quite simple. The OP is I think is using Foma film but has no idea of the true EI, that needs tests but for Daylight most use half the bos soeed and reduced development, the with tungsten light ut will bewill be less, Then there's reciprocity Foma films are supposedly bad, my tests and use show that's not qnyware bad as the manufatcturers nfigures, as long as you've tested and haniled the true EI ansd development time.

The other factor is the OP probably hasn't allowed for the bellows extension for close up work.

So we have three issues, no idea of the true film speed with tungsten light, no allowance or more importantly testing for reciprocity , all made worse by no allowance for bellows extension, a recipe for disaster :D

Ian

[Leigh]

So we have three issues, no idea of the true film speed with tungsten light, no allowance or more importantly testing for reciprocity , all made worse by no allowance for bellows extension, a recipe for disaster :D
While that's certainly true, I'll add a fourth issue.

Random tungsten lighting is a recipe for frosting on the disaster cake because the spectrum isn't predictable.

The illumination level varies with AC line voltage, and the spectrum varies as the intensity varies.
This creates problems with filtration and correlating light meter readings with true exposure.

- Leigh

[John Olsen]

While that's certainly true, I'll add a fourth issue.

Random tungsten lighting is a recipe for frosting on the disaster cake because the spectrum isn't predictable.

The illumination level varies with AC line voltage, and the spectrum varies as the intensity varies.

- Leigh

Yes, random lighting is unpredictable, but if you use real tungsten bulbs of 3200 degrees the spectrum is certain. Buy good stuff and it works well, or buy cheap crap and have problems. Really, you're making this much more mysterious than you need. Hot lights have been a reliable part of photography for a long time. I think there's some reinventing of the wheel going on here. Please go back and look at the classic photo manuals. Then notice out how cost-effective tungsten is compared to flash for still lifes and architectural work.

[Leigh]

Yes, random lighting is unpredictable, but if you use real tungsten bulbs of 3200 degrees the spectrum is certain.
Yes it is certain, but for perhaps a very short period of time.

Bulbs with color temperature ratings can have service lives as short as 4 hours, but typically 40 to 100.

Halogen bulbs last longer, but still not nearly as long as similar lamps used for general illumination.


Then notice out how cost-effective tungsten is compared to flash for still lifes and architectural work.
Tungsten for architecture?

You must have a huge lighting budget, and a very large generator mounted on a truck.

- Leigh

[IanBarber]

So we have three issues, no idea of the true film speed with tungsten light, no allowance or more importantly testing for reciprocity , all made worse by no allowance for bellows extension, a recipe for disaster

Ok so lets go back to the beginning and look at Personal EI.

I have read how people consider to be very useful and I fully appreciate the reasons for finding out this information about a particular film.

For someone like myself who does not use, own or have access to a darkroom and darkroom equipment and solely relies on scanning the negatives prior to digital printing, can anyone explain or at least point me in the right direction to how I can find out the EI of my films.

[IanG]

Foma films are in a league of their own, the published ISo and ndevelopment times seem way off to most people but once you've nailed the effective EI and development times they are excellent. I didn't use a darkroom when I did my own EI tests on Fomapan 100 & 200, rather than using sheet film I used 120, in the past I've used 36mm. The first test film is to determine the effective ISO many in the US would use a densitometer to do this, however it's easy to do visually and is described in Ansel Adams The Negative , or Minor White's books on the Zone Systen, it's well described online.

Then having detemined what you think is the effective EI you need to test to find the optimal development time usually to print at a specific grade on a chosen paper,, this is done by processing sections of the film (or different sheets) all given the same exposure of a test subject the for differing times. If the optimal development time is significantly different to the time used in the first test you may need to adjust the effective EI slightly. It's far easier to do than describe, I did my tests while living in Turkey with no access to a darkroom and my Foma films all printed easily with excellent results when I was next back in the UK.

As a guideline most users of Fomapan 100 & 200 shoot at half the box speed and development times are about 75% less than other films as Foma films build up density and contrast very quickly during development and you need to tame the contrast.

As your scanning I'd suggest that you need to adjust the development times to match the best negative you have made on other films, I matched my Foma films to Tmax 100 negatives that I knew were good.

Ian

[LabRat]

As a guideline most users of Fomapan 100 & 200 shoot at half the box speed and development times are about 75% less than other films as Foma films build up density and contrast very quickly during development and you need to tame the contrast.



Ian

Correction needed that the dev time is about 75% less than other films... (Now that's a short development!!!) :-)

The times match up fairly close to Agfa APX100 also as a starting point...

Steve K

[IanG]

75% of the more typical times, so a correction 25% less :D

Ian

[Bill Burk]

Ok so lets go back to the beginning and look at Personal EI.

Have you ever figured out what went wrong in the first place? Was it bellows extension? If so, then it's not a personal EI problem.

My personal EI is two-thirds stops below the box speed, because I want to be able to use Zone System scene evaluation with my meter. I set the clipping points on my Sekonic L-758DR at whole stops instead of the factory default (my points are at Zone I and II, then Zone VIII and IX). I mention that because you pointed out that's like the meter you use.

Even though I use 2/3 less than rated speed, I am counting on the fact that I know and trust that fresh film developed for a normal time in a normal developer, will get the rated speed. And that the relationship between Zone System evaluation and standards is 2/3 stop.

My adjustment is my personal EI because of the way I want to meter and the results I want to get.

Classic Zone System tests are aimed to paper and include a lot of variables that guarantee that different people will get different results... That's a "different" definition of personal EI than I am offering... But it might be what you are hearing a lot about.

You can design your own tests any way you like, there are so many ideas out there I don't want to put one above the other (A sensitometer or other step-wedge based exposure device is the absolute best and a step wedge costs less than the film you would waste in any other test. But I didn't come here to preach).

Here's a stupidly simple test:

If you know how "Sunny 16" works... If your shutter is any good, you might go outside on a nice clear sunny day and take a bunch of pictures of a subject you are interested in photographing... at different shutter speeds at f/16.

Then develop all the film.

As you work with the resulting negatives, pick one that gives you the best results with the least trouble... its corresponding shutter speed could be your personal EI.

The problem with this test is that it builds in your shutter error. But the idea shows how simple a test could be...