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

Early Riser · Mar 12, 2016

As I use a custom processing scheme, an Xtol/D-76 split, I had to evaluate it's affect on film speed as well as it's toe to shoulder response. So densitometry was critical. I also tend to buy my film in bulk, all being the same emulsion so I test it's speed as well.

pentaxuser · Mar 12, 2016

Dali said:
On this matter, I listen to David Vestal... and his tests matched with the experience.

What does David Vestal have to say, Dali? Thanks

pentaxuser

MartinP · Mar 13, 2016

I don't think very often, but when I did I tried the following quick and simple check without any instrumentation required. It gives nicely printable negatives, confirms exposure and development choices and is easy to use to give beginners a grasp of what is going on with their film.

Dead Link Removed

Edit: I now see this was mentioned earlier. Call this a second vote.

removed account4 · Mar 13, 2016

hiOP

ISO is determined in a lab, under specific lab/exposure+development conditions.
i know my darkroom isn't a film manufacturer's lab, and my exposure techniques are anything
but scientific. not to mention, i probably dont' agitate my film like
the person or processing equipment the manufacturer might use, ...
and my shutter speeds might have drifted since i had my last cla ...
and from what i have read, the internet tells me the ISO, like film developement times are
"starting points"

whats the point of complicated ...
since you are shooting 35mm, how about bracketing 3 rolls
expose 1 exposure as the meter says"box speed", and the other 2 1 stop extra and 1 stop less.
develop each roll separately.
the first roll as the manufacturer recommends for the film you are using at "box speed"
the 2nd for 30% more, the 3rd 30% less.
when the film is dry, sleeve it and make 3 contact sheets and look at them.
see what exposures you like the best.
expose a whole roll and develop it as you decided worked for you and see if it is still the way you like it.
you can tweak it any way you want,

there really is no right or wrong way for anything, and a lot of people seem to forget this ...
you might decide you like over exposed and over developed by 1 stop and 50% for some things
and 30% less for others. do what you want, and as long as you like the results, keep doing it.
in the end it is just figuring out how the film, developer, camera and your photo paper are when they
play together. everyone's developement schemes are different &c ... why not figure out what works
best for what you have rather than taking some random stranger on the internet's word for it.
some internet strangers ( or 50 years old magazine article known quanitity )
might talk a good game, but their methods might not work well for you.

good luck
john

Richard S. (rich815) · Mar 13, 2016

Ken Nadvornick said:
You know, there are valid reasons to test for personalized parameters. Including film speeds.

Everyone here wants to just blindly accept the manufacturer's determinations. But that is only valid if each and every other contributing variable in your own overall system also exactly matches that manufacturer's testing regime. And that is virtually never the case.

Say, for example, that you have a camera whose shutter is old and slow. You love that camera, and want to continue using it. But you don't have the money to spend on an expensive CLA to bring the shutter back into factory spec.

What to do?

How about running an EI test for your favorite film to determine just what correction to the manufacturer's ISO rating you need to apply to get correctly exposed film for that particular camera system? Your film EIs will rise as your shutter slows.

The CLA might cost you a couple hundred dollars and six weeks. The film test might cost you a couple dollars and 60 minutes. And after the fact in both cases the film will be correctly exposed.

Ken

Except that a camera needing a CLA might be much more prone to inconsistency and if anything just gets worse....

Sirius Glass · Mar 13, 2016

This came from Samy's Camera. A longish video of wildlife photography that talks about shooting photographs of birds against a white sky. They yammer and yammer about photographing a white sky, looking the histogram, and then opening the aperture 10 clicks [3 1/3 stops] and then checking by taking another photograph of the sky, and then checking by taking a photograph of a bird. Each time chimpin'. Just take an incident reading and be done with it. There is no use for the endless testing.

http://www.bhphotovideo.com/explora/photography/tips-and-solutions/video-bird-photography-tips-serious-photographer?utm_medium=Email 88501b&utm_campaign=Content&utm_source=WeeklyContent 160312&utm_content=Explora&utm_term=bird-photography-tips

It does have some useful suggestions about the direction of the light and wind, bird behavior, ...

removed account4 · Mar 13, 2016

Richard S. (rich815) said:
Except that a camera needing a CLA might be much more prone to inconsistency and if anything just gets worse....

yeah, my off-shutter speeds are consistaently inconsistent

MattKing · Mar 13, 2016

A determination of personal film speed is probably most effective at compensating (or not) for personal metering preferences and technique.

To a smaller extent, it is a determination of personal printing preferences.

The best types of these sorts of determinations include a choice between various prints.

Sirius Glass · Mar 13, 2016

MattKing said:
A determination of personal film speed is probably most effective at compensating (or not) for personal metering preferences and technique.

To a smaller extent, it is a determination of personal printing preferences.

The best types of these sorts of determinations include a choice between various prints.

Y*E*S

Learn to take reflectance light meter readings without including large portions of the sky and them re-aim the camera. Then you can throw out all the personal film speed and endless testing.

Ken Nadvornick · Mar 13, 2016

Richard S. (rich815) said:
Except that a camera needing a CLA might be much more prone to inconsistency and if anything just gets worse....

True, that...

But then such error would also manifest when that same camera was loaded with film rated at the standard manufacturer's recommendation. Meaning, a personalized film speed test would not be an appropriate compensation tool for that camera, or at least for that shutter, in the first place.

But for those camera shutters where the normal effects of age lead to relatively consistent slowness across all speeds, an EI compensation can be a welcome short term workaround.

I once routinely rated my HP5+ at 800 to compensate for an overall slow shutter in a Yashica Mat-124G. Each speed was, of course, off by a slightly different amount. But all were on the slow side due to age, so I just averaged the correction factor for the three speeds I used most frequently.

When using transparency films, I also do similarly for the two highest speeds on most of my leaf shutters. The 1/250 an 1/500 settings are almost never that, due to unavoidable blade physics. The former is usually about a third to a half a stop slow, and the latter occasionally up to a full stop, especially in older or antique shutters.

But rather than compensate at the EI level, when using those speeds I make the compensation at the meter level, where for convenience I just add in a measured compensation exposure factor. A half or third to a full stop is a lot when exposing color slides, so the effort is worth it.

Ken

benjiboy · Mar 13, 2016

My "personal film speed" is the one printed on the box unless I'm getting very poor results and I have a very good reason, because I think that Kodak and Fuji know more about their film than I do.

benjiboy · Mar 13, 2016

Sirius Glass said:
Keep life simple:

Shoot at box speed

Do not include the sky in the reflective light meter reading

If the composition is either all white [very light] or all black [very dark] use and incidence meter

Tell the testinestas to shove it

My sentiments entirely Steve, except if you use an incidental meter and the composition is either all white (very light) give it half a stop more or all black (very dark) half a stop less than the meter reading.

Dali · Mar 13, 2016

pentaxuser said:
What does David Vestal have to say, Dali? Thanks

pentaxuser

More or less what jnanian detailed.

David Allen · Mar 13, 2016

Sirius Glass said:
Y*E*S

Learn to take reflectance light meter readings without including large portions of the sky and them re-aim the camera. Then you can throw out all the personal film speed and endless testing.

Oh really? - have you actually found this to be true over multiple cameras, multiple films and multiple developers? - how many films, cameras and developers have you actually tested?

Do not give beginners bad advice - in my opinion, that is absolutely not the idea of such a website as this.

A couple of simple tests can, once and forever, pin down the principal variables for a beginner and get them on to the most important road which is making pictures that mean something to them. If you want to propagate bad advice as a way of feeling superior then please enjoy yourself but this is not how newcomers to the medium will be helped. All this 'learn to do what I do blah, blah' as a way to make you feel like you are a genius will be great for your ego but it is no help to a beginner.

Bests,

David.
www.dsallen.de

Sirius Glass · Mar 13, 2016

David Allen said:
Oh really? - have you actually found this to be true over multiple cameras, multiple films and multiple developers? - how many films, cameras and developers have you actually tested?

I only have over fifty years experience with many different slide and print films in cameras ranging from single frame 35mm to 4"x5" including processing and printing. I also have over four decades of designing optical systems, telescopes, remote sensing instruments and focal plane arrays. That includes working for a little yellow box company in upstate New York. You probably never heard of the company. It was Eastman Kodak.

Gerald C Koch · Mar 13, 2016

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.

removed account4 · Mar 13, 2016

edited the next day:

gerald:

while i understand where you are coming from, that if film is consistantly under or over exposed
it might be due to equipment failure rather than the iso caluculated at the manufacturer, but a simple exposure test,
allows the user to just be certain his camera, optic, shutter, development + printing ( or skkann) technique are all harmonizing. i have and use lots of different things, and if i did a cla on every thing i own
to assure the flaw wasn't with my gear, it would cost over $1000. a quick and dirty expose film/process the film/contact print-evaluate negatives/ print -scan negatives costs nothing in comparison,AND
it allows someone new to the process of making exposures, processing film, contact printing and printing/scanning
to get practice.
while i understand film makers know their films and do a fantastic job of manufacturing them and providing
us with consistent materials ... i don't live in a perfect world ( like the lab used to determine iso ). my technique is less than perfect, my exposure technique is less than perfect, my processing technique is less than perfect too. maybe if i was rich and could have all my gear CLA'd every few months i'd live in a more perfect world ...
but for now i will bracket and proceed.
( as the first guy i assisted for said: you have to be insane not to bracket your exposures, you want to make sure you get at least 1 good one )

YMMV

Sirius Glass · Mar 13, 2016

jnanian said:
hi gerald

it would cost me 1000$ to cla every shutter i have
vs. a few rolls or sheets to determine what looks +prints good to me
the manufacturers are in a "perfect world" mine is far from a perfect one.

"great" negatives are subjective anyways.

John, maybe you have too many dirty lenses? Carol Flutot charges a lot less than most others.

Sirius Glass · Mar 13, 2016

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.

Gerald understands.

Ken Nadvornick · Mar 13, 2016

Sirius Glass said:
John, maybe you have too many dirty lenses? Carol Flutot charges a lot less than most others.

Carol Miller? Charles Edward Flutot's lovely daughter? At Flutot's Camera Repair? * She is one of the nicest and easiest people to work with that I've ever encountered.

She just finished two Mamiya TLR lenses for me. Has another two in-shop right now. And there are three more waiting in the wings. I've never had anything but perfect results from her over the years. And delivered with a genuine smile.

:w00t: (still hoping this guy makes a comeback some day...)

Ken

* Shameless off-topic plug on my part.

removed account4 · Mar 13, 2016

Michael R 1974 said:
You can just skip the test, know that a Zone System EI will nearly always end up around 2/3 stop below ISO by definition, round that to 1 stop, and you're done.

i remember reading that michael.
just the same i'd rather make sure
with a simple and effortless test roll/test sheet.

I'm always amazed at the pushback about burning a roll or sheets to test
developer, time, camera paper .. and the funny thing is
it's a roll or a couple of rolls of film. it's the same concept as
use a new to you camera /lens or exotic development, new developers
technique before doing important things using them.
wouldn't catch me dead using a new lens/camera body with a shutter
or a new film or developer &c in a job or something "important"
just accepting box speed and a suggested development starting point
found on the massive chart is about the same thing.

Alan Klein · Mar 14, 2016

rpavich said:
1.) When scanning negs the scanner optimizes the density of each so that it appears that I've been super consistent in my exposures.

Switch to scanning "flat" so the scanner doesn't auto correct the exposure during the scan. Then you will see the difference in the histograms among the various bracketed shots.

Sirius Glass · Mar 14, 2016

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.

Michael R 1974 said:
We should understand the tests we run, otherwise we can't interpret the results and can't come to meaningful conclusions. When you say you need to "make sure", I assume you mean make sure you use the right EI. What are the criteria for determining your EI? What are these criteria based on? How do you know your test gives you the right EI? Are we making the negatives we think we are making? Etc.

I'm not trying to change the way people do things, or argue against whatever EI people like. It's just a matter of understanding what one is doing and/or why. Perhaps counter intuitively, it can even simplify things.

The whole reason for the Exposure Index testing regimen is to commit testanistas do endless, useless, and senseless testing rather then going out in the real world and actually taking interesting, well composed photographs. The positive side effect is that it improves the sales of film, chemistry, photographic paper and darkroom supplies; thus enabling photographic supply manufacturers, middlemen and photographic supply stores stay in business.

removed account4 · Mar 14, 2016

Michael R 1974 said:
When you say you need to "make sure", I assume you mean make sure you use the right EI. What are the criteria for determining your EI? What are these criteria based on? How do you know your test gives you the right EI? .

michael, at this point, I bracket a roll of film and make a print. not sure how that is counter intuitive.
it's not endless testing. if it is sheet film, it is a sheet. as I said I'd rather make sure I have enough exposure or development
especially if I am using materials I am not used to. i hate to admit this, but i don't even know what EI
numbers are or what they mean, it has never been an interest of mine to delve into that, or log-charts, or
senso-denso-readings, i'd rather be exposing film to be honest.

when i was processing and printing all the sheet film of a busy portrait studio what i did was -
put the heat wand in the developer and get it to temperature. i looked at the chart that i made that said for
every second between 50-somethingºF and 70-somethingºF what time i processed the film at.
i put 2 sheets in hangers and processed for the calculated time. once out of the fixer and rinsed, i'd turn on
the adams retouching desk and examine the film in-hanger to see if it was dense enough, had enough
contrast &c.
then i would develop between 50 and 100 sheets of 5x7 film ( somedays more ),
extract developer, replenish and mark the card with how many films went through the tank. my eye got to
be OK looking at the film at the adams desk, and none of the film was processed wrong during the time i was
there. that was case after case of tri x, and tank after tank of DK-50, and sheet after sheet of consistently
perfectly exposed film. day after day ... and every day it was the same routine.
that was at a professional lab.

not really sure how this is unreasonable, or could be thought of by some as excessive.
it wasn't unreasonable for a lab that had been running for 60 years before i got there,
and it seems to be a simple, and reliable practice for someone new to analog photography as well.

as always YMMV

David Allen · Mar 14, 2016

Sirius Glass said:
The whole reason for the Exposure Index testing regimen is to commit testanistas do endless, useless, and senseless testing rather then going out in the real world and actually taking interesting, well composed photographs. The positive side effect is that it improves the sales of film, chemistry, photographic paper and darkroom supplies; thus enabling photographic supply manufacturers, middlemen and photographic supply stores stay in business.

The point of doing a simple test is to equip the beginner with the knowledge to go out and concentrate on making images. There is no need for endless testing - indeed, as someone who uses one camera, one lens, one film and one developer my last test for my equipment was made some 15 years ago.

The OP's question was about correcting the inconsistent results achieved so far. If you look at my post #20 in this thread on Saturday at 10:04am you will see that I made two points regarding the value of testing being to fix variables and use this information to enable the student to have a very easy to remember and apply method of exposing to achieve consistently high quality results. These are based on teaching a lot of students - all of whom made rapid progress in achieving consistently well exposed negatives that delivered good quality prints / scans. This, in my opinion, was what the OP's was seeking to achieve. The OP had been using box speed and standard development and was not achieving the desired results.

Now it may be that the OP has poor metering technique or not the very many years of experience of some of the people posting on APUG. So does telling the OP that they have poor technique or lack of experience actually help them? Does telling the OP that all tests are senseless help? In my experience, the test and subsequent exposure methodology that I suggested will deliver consistently well exposed and developed negatives - which, presumably, is what the OP is seeking to achieve and was the reason the OP started the thread in the first place.

Bests,

David.
www.dsallen.de

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

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