How many of you have done this to find your "personal film speed"?

Gerald C Koch said:

Film manufacturers spend a lot of time, energy and money on quality control. My question for the testanistas is what makes you think that you can really do a better job? They have all the necessary equipment to do it right. Additionally if you are getting an EI very different from box speed you need to look not at film testing but your equipment.

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Not just equipment, but methodology. Just because someone does testing and gets a result doesn't mean that the results are correct. Most popular methods don't account for all the variables, they tend to misinterpret theory, and are frequently based on antidotal and not empirical evidence. For instance, many popular methods instruct metering a gray card and stopping down four stops. The truth of the matter is that speed point is 3 1/3 stops from the metered exposure point. This alone will skew the results by two-thirds of a stop.

In 1960, there was a change in the color temperature of the sensitometric light source. It went from sunlight to daylight. This added more blue. An adjustment was need to factor this in as it tended to increase the apparent film speed by 1/3 stop. I've seen recommendations on the internet and in popular books that say to place the target gray card any where from direct sunlight to shade. This can make a difference and if 1/3 of a stop isn't something to worry about, why do the testing in the first place?

Then there is the calibration equipment argument. I shoot 4x5 which means every lens has its own shutter. So in order to factor in the shutter speed, I'd have to do a speed test for each speed setting on each lens. To test the speed of a film, all variables need to be limited and controlled. The film should be tested separately from the equipment. If the calibration of the lens is in question, have the lens tested.

The biggest factor in negative exposure is the personal taste and metering methodology of the photographer. If the resulting negatives come out thinner or denser than desired, change the EI. There is no such thing as perfect exposure in b&w photography. Good exposure is about providing the greatest potential for a quality print and as such it is a psychophysical phenomenon. Besides, the most crucial test in my book isn't for speed but for degree of development. My recommendation is to learn about that.

Craig75 said:

From kodak . "With black-and-white films there is a wide range of possible film and developer combinations. The choice of developers can be a significant factor in what film rating should be used. Accordingly, an EI is used to reflect the speed obtained with that developer"

Kodak's website explains the reasons why kodak itself often favours an EI over iso

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My interpretation is that they are not favoring either. They are just explaining EI.

Yes I did that after reading Barry Thorntons "No-Zone-System" (available online) and his Book "Elements". Found it to be an easy way of roughly determining personal film speed.

Gerald C Koch said:

Film manufacturers spend a lot of time, energy and money on quality control. My question for the testanistas is what makes you think that you can really do a better job? They have all the necessary equipment to do it right. Additionally if you are getting an EI very different from box speed you need to look not at film testing but your equipment.

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Certainly Kodak and other film manufacturers have served all of us well with testing and QC, but they haven't spent one second evaluating our individual preferences. To compensate for that, we can test, rely on the experiences of respected photographers, or evaluate our photos and make adjustments in our technique. Perhaps the success of Yousuf Karsh was almost as much due to his meticulous exposure and development as to his lighting, posing, and rapport with his subjects. Certainly few other major portraitists have achieved that dramatic balance between shadow and highlight contrast.

KidA said:

Anybody?

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No, Zones IX and X are for specular highlights. No one who understands anything about the Zone is going to place anything on Zones I, IX or X because there is no detail in those Zones, only tonality.

I know I'm a bit late to this thread but thought I'd put my 2 cents worth in.

Fred Picker, I read his manual years ago and later watched the war of words in the press when he started claiming cold light had mystical powers and that hypo was heavier than water. He was a salesman and made claims that made his products look like "must haves" I did like his proper proof chapter, good common sense but he lost me when he declared that photographers should "avoid backlit photos like the plague"

David Vestal, best photo technique writer on both technique and photography in general IMHO, his method of testing can actually be summed up by his own words, "make sure not to underexpose and be careful not to overdevelop" he also had a great quote about the absurdity of people worrying about 1/3 stops etc when our films can capture way more than our papers can handle in an unmanipulated print.

I knew a lot of pro photographers in the 70s and 80s and guess what, they all exposed 400TX at 250 and they all took off about 20% from the published Kodak times. In other words, experience all lead them to the same result which is roughly what Adams recommended in The Negative for Tri X.

Lately I've been printing a lot of my very old negs, from the 70s, I didn't really know what I was doing as far as film development went back then and there are lots of overdeveloped negs. When I printed them back then the prints were often pretty sad, now, with 40 years of darkroom experience behind me, the prints are generally pretty good even though the negs are pretty ordinary. Learning to print makes the difference, sadly many people are on eternal quest to find a magic film/developer combo and they think that when they find it they will produce nothing but masterpieces, sorry, but there is no magic film/developer combo, spend your time learning to print instead.

Never overlook the details, properly test your safelights, eliminate enlarger light leaks, keep print developers at 20 degrees and always time print development, these things alone can improve print quality way more than giving a neg half a stop more or less exposure.

markbau said:

... Learning to print makes the difference, sadly many people are on eternal quest to find a magic film/developer combo and they think that when they find it they will produce nothing but masterpieces, sorry, but there is no magic film/developer combo, spend your time learning to print instead.

Never overlook the details, properly test your safelights, eliminate enlarger light leaks, keep print developers at 20 degrees and always time print development, these things alone can improve print quality way more than giving a neg half a stop more or less exposure.

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Hear, hear.

I played around with the techniques linked in the first post last week. It appealed to me because results are based on paper, not a densitometer, and the methodology made sense. And I've been leaning away from my usual B&W films and towards some new emulsions, so - it's testing time regardless.

Overall, I think it would be a handy tool for someone wanting to dial in their technique. Pretty simple, makes sense, and the results are understandable. There are probably a lot of folks shooting film a little blindly who feel ready to up their game. I like how this system gives you some concrete ideas of shadow exposure and dev time - with 2 rolls and some notes on the conditions the still life was shot in (tonal range from the spotmeter) you can get a really good idea of what's going on with your developing time.

I've really been wanting to master Rollei's IR 400 with a deep red (not opaque) filter for a while now, and it's tough since shadows and highlights can get a little wacky. I'll run a few rolls through.

BTW - to test 35mm, you don't really need to do all the ISOs suggested if you have a rough idea. I cut some tiny tabs of blue painter's tape and fold 'em in half to make little "tabs", and when I shoot a series of test frames, I open the camera in the darkroom and stick one on the film at the current frame. very easy to find these when you're loading reels, snip the film and store parts of it to process later.

Sirius Glass said:

And if you follow this advice and are not satisfied double your money back.

Haven't we had enough of these threads???

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For those of us who have been here awhile maybe, but as "elders" it's our job to be patient and extend as much help as possible to those that are just starting out.

My two cents on the subject. Doing a bunch of testing may, and I stress may, yield some useful results for sheet film, but is of little use for roll film. It's rather hard to develop a 36 exp roll of 35mm with multiple N pluses and minuses with any bias to one or the other. Best to just develop the film down the middle and do what you can in the darkroom. For roll films I find that box ISO (or ASA for us old guys) is fine for films like Delta 100 or 400 and 1/2 ISO for films like HP5 or Tri-X. Development times are very close to posted suggested times. Do a little tweaking to account for your personal water source. Using the Zone System is useful for shadow or highlight placement. Multi contrast paper is your friend.

Sheet film is another story. Personally I use a regime where I measure the Scene Brightness Ratio (subject luminescence range to be more correct), determine the ISO to use from that and then develop that sheet accordingly. My film of choice is an old style emulsion, box rated at 100 ISO. If the scene brightness ratio is 12, I rate the film for that shot at 20 ISO and develop it for 15 minutes semi-stand. Say the brightness ratio is 9, film speed would be set at 50 ISO and development would be 23 minutes, semi-stand. For an SBR of 5 that sheet is rated at 125 ISO and it gets 47 minutes in the developer, again semi-stand. A buddy of mine came up with the numbers using a densitometer and I confirmed his findings in the darkroom. Essentially what we are doing is following the old under expose, over develop or over expose and under develop rules to adjust contrast. In this case the ISO's and development times have been tailored to a particular film. However I have found they work for other 100 ISO films as well. I have a densitometer but quite frankly have never used it. The above methodology is derived from Phil Davis's Beyond The Zone System or BTZS for short. Here is a link http://www.btzs.org/

If I'm in a rush then I just measure whatever part of the scene is most important to me, maybe shadows, maybe highlights, place it on whatever zone that corresponds to, and then make my exposure at one half box rated ISO. There is enough fudge factor built in to yield a printable negative.

Two more things to consider. The two biggest contrast killers are not using a proper lens shade and not testing your safelight if wet printing. I use different papers depending on what I am after and have found I have to use different safe lights for my main two.

As far as contact sheets are concerned I always print mine with very low contrast. This allows me to judge the nuisances in the negatives tonality better.

The wonderful book "Way Beyond Monochrome" by our esteemed APUG member Ralph Lambrecht and his co-author Chris Woodhouse goes into detail on what SBR is and isn't. Check out this link: https://goo.gl/Ezr2ey

If you don't have a copy of this book, either edition, get one! IMHO it's the monochrome bible.

Naturally there will be those that don't agree with my methods. All I can say is it works for me.

Eric

ic-racer said:

Keep it simple. Expose negatives 1/2 box speed. Develop negatives so prints look good on #2 and use multicontrast paper.

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+1

Some thoughts:

1) Determining a "personal" speed is crucial only if you are shooting FP100 peel apart film, because with that stuff, exposure is the only control you have.

2) My "personal" speed is box speed, other than for FP100c45, of which I have an ever dwindling supply. I spot meter and place tones where I want them. If the film or shutter or aperture or meter or sunspots are off, they won't be off by much, and anyway it all gets corrected under the enlarger when I print. My prints are always a swarm of exposures where I choose what ends up on the paper.

3) I don't strive for "perfect" negatives. I strive for negatives that have all the information I intended to capture. "Perfection" comes under the enlarger.

Doing a large set of tests to determine my "personal" film speed would waste my film, waste my time, and waste my chemistry. I shoot 4 different film types, using a large format camera with five different lenses. That alone is 20 combinations, just for my LF camera. Plus, I use a variety of chemistries based on my mood. I've found that Sirius Glass is right - keep it simple. Shoot box speed, meter for the detail you want to retain either in the highlight or shadow area (depends on your vision for the image). Develop (if you're using sheets) based on the exposure range. Get on with making art, stop worrying about the numbers.

With large format, I spot meter. With medium format (Mamiya 6MF), I follow Sirius and use my hand to block the sky from the built in light meter. With 35mm, I trust Nikon's matrix metering.

And to those that keep linking to Barry Thornton: please find yourself a guru that understands the concept of paragraphs. Thank you.

I was out shooting Kodak T-Max 400 in 4x5 sheets this week... I practiced Zone System exposure metering and notation, with an un-modified analog Pentax Spotmeter V.

In my exposure notes, along with everything else, I included the EI. Sometimes I noted EI 250 and sometimes I noted EI 400.

I treated EI as a factor used to determine the f/stop and shutter speed combination I will use for a shot.

When done with each shot, if I changed EI, I set the meter back at EI 250 because that's the speed I consider most appropriate for Zone System for this film. But EI 400 is also a correct speed to use with this film.

After I develop the film and try to print, I can look back over my notes to see how good the decision was... to choose that f/stop and shutter speed (and development time).